Patent Publication Number: US-11032200-B2

Title: Apparatus for transmitting broadcast signal, apparatus for receiving broadcast signal, method for transmitting broadcast signal and method for receiving broadcast signal

Description:
This application is a Continuation of U.S. patent application Ser. No. 16/185,704, filed on Nov. 9, 2018 (now issued as U.S. Pat. No. 10,778,580 B2 on Sep. 15, 20201, which is a Divisional of U.S. patent application Ser. No. 15/100,875, filed on Jun. 1, 2016 (now U.S. Pat. No. 10,142,233, issued on Nov. 27, 2018), which was filed as the National Phase of PCT International Application No. PCT/KR2016/000648, filed on Jan. 21, 2016, which claims priority under 35 U.S.C. 119(e) to U.S. Provisional Application No. 62/105,749, filed on Jan. 21, 2015 and to U.S. Provisional Application No. 62/114,022, filed on Feb. 9, 2015, all of these applications are hereby expressly incorporated by reference into the present application. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to an apparatus for transmitting a broadcast signal, an apparatus for receiving a broadcast signal and methods for transmitting and receiving a broadcast signal. 
     Discussion of the Related Art 
     As analog broadcast signal transmission comes to an end, various technologies for transmitting/receiving digital broadcast signals are being developed. A digital broadcast signal may include a larger amount of video/audio data than an analog broadcast signal and further include various types of additional data in addition to the video/audio data. 
     That is, a digital broadcast system can provide HD (high definition) images, multichannel audio and various additional services. However, data transmission efficiency for transmission of large amounts of data, robustness of transmission/reception networks and network flexibility in consideration of mobile reception equipment need to be improved for digital broadcast. 
     SUMMARY OF THE INVENTION 
     The present invention provides a system capable of effectively supporting future broadcast services in an environment supporting future hybrid broadcasting using terrestrial broadcast networks and the Internet and related signaling methods. 
     The present invention can control quality of service (QoS) with respect to services or service components by processing data on the basis of service characteristics, thereby providing various broadcast services. 
     The present invention can achieve transmission flexibility by transmitting various broadcast services through the same radio frequency (RF) signal bandwidth. 
     The present invention can provide methods and apparatuses for transmitting and receiving broadcast signals, which enable digital broadcast signals to be received without error even when a mobile reception device is used or even in an indoor environment. 
     The present invention can effectively support future broadcast services in an environment supporting future hybrid broadcasting using terrestrial broadcast networks and the Internet. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings: 
         FIG. 1  illustrates a receiver protocol stack according to an embodiment of the present invention; 
         FIG. 2  illustrates a relation between an SLT and service layer signaling (SLS) according to an embodiment of the present invention; 
         FIG. 3  illustrates an SLT according to an embodiment of the present invention; 
         FIG. 4  illustrates SLS bootstrapping and a service discovery process according to an embodiment of the present invention; 
         FIG. 5  illustrates a USBD fragment for ROUTE/DASH according to an embodiment of the present invention; 
         FIG. 6  illustrates an S-TSID fragment for ROUTE/DASH according to an embodiment of the present invention; 
         FIG. 7  illustrates a USBD/USD fragment for MMT according to an embodiment of the present invention; 
         FIG. 8  illustrates a link layer protocol architecture according to an embodiment of the present invention; 
         FIG. 9  illustrates a structure of a base header of a link layer packet according to an embodiment of the present invention; 
         FIG. 10  illustrates a structure of an additional header of a link layer packet according to an embodiment of the present invention; 
         FIG. 11  illustrates a structure of an additional header of a link layer packet according to another embodiment of the present invention; 
         FIG. 12  illustrates a header structure of a link layer packet for an MPEG-2 TS packet and an encapsulation process thereof according to an embodiment of the present invention; 
         FIG. 13  illustrates an example of adaptation modes in IP header compression according to an embodiment of the present invention (transmitting side); 
         FIG. 14  illustrates a link mapping table (LMT) and an RoHC-U description table according to an embodiment of the present invention; 
         FIG. 15  illustrates a structure of a link layer on a transmitter side according to an embodiment of the present invention; 
         FIG. 16  illustrates a structure of a link layer on a receiver side according to an embodiment of the present invention; 
         FIG. 17  illustrates a configuration of signaling transmission through a link layer according to an embodiment of the present invention (transmitting/receiving sides); 
         FIG. 18  is a block diagram illustrating a configuration of a broadcast signal transmission apparatus for future broadcast services according to an embodiment of the present invention; 
         FIG. 19  is a block diagram illustrating a bit interleaved coding &amp; modulation (BICM) block according to an embodiment of the present invention; 
         FIG. 20  is a block diagram illustrating a bit interleaved coding &amp; modulation (BICM) block according to another embodiment of the present invention; 
         FIG. 21  illustrates a bit interleaving process of physical layer signaling (PLS) according to an embodiment of the present invention; 
         FIG. 22  is a block diagram illustrating a configuration of a broadcast signal reception apparatus for future broadcast services according to an embodiment of the present invention; 
         FIG. 23  illustrates a signaling hierarchy structure of a frame according to an embodiment of the present invention; 
         FIG. 24  is a table illustrating PLS1 data according to an embodiment of the present invention; 
         FIG. 25  is a table illustrating PLS2 data according to an embodiment of the present invention; 
         FIG. 26  is a table illustrating PLS2 data according to another embodiment of the present invention; 
         FIG. 27  illustrates a logical structure of a frame according to an embodiment of the present invention; 
         FIG. 28  illustrates PLS mapping according to an embodiment of the present invention; 
         FIG. 29  illustrates time interleaving according to an embodiment of the present invention; 
         FIG. 30  illustrates a basic operation of a twisted row-column block interleaver according to an embodiment of the present invention; 
         FIG. 31  illustrates an operation of a twisted row-column block interleaver according to another embodiment of the present invention; 
         FIG. 32  is a block diagram illustrating an interleaving address generator including a main pseudo-random binary sequence (PRBS) generator and a sub-PRBS generator according to each FFT mode according to an embodiment of the present invention; 
         FIG. 33  illustrates a main PRBS used for all FFT modes according to an embodiment of the present invention; 
         FIG. 34  illustrates a sub-PRBS used for FFT modes and an interleaving address for frequency interleaving according to an embodiment of the present invention; 
         FIG. 35  illustrates a write operation of a time interleaver according to an embodiment of the present invention; 
         FIG. 36  is a table illustrating an interleaving type applied according to the number of PLPs; 
         FIG. 37  is a block diagram including a first example of a structure of a hybrid time interleaver; 
         FIG. 38  is a block diagram including a second example of the structure of the hybrid time interleaver; 
         FIG. 39  is a block diagram including a first example of a structure of a hybrid time deinterleaver; 
         FIG. 40  is a block diagram including a second example of the structure of the hybrid time deinterleaver; 
         FIG. 41  is a block diagram illustrating a hybrid broadcast reception apparatus according to an embodiment of the present invention; 
         FIG. 42  is a block diagram illustrating a hybrid broadcast receiver according to an embodiment of the present invention; 
         FIG. 43  illustrates a protocol stack of a future hybrid broadcast system according to an embodiment of the present invention; 
         FIG. 44  illustrates a structure of a transport frame delivered to a physical layer of a future broadcast transmission system according to an embodiment of the present invention; 
         FIG. 45  illustrates a transport packet of an application layer transport protocol according to an embodiment of the present invention; 
         FIG. 46  illustrates a method for transmitting signaling data by a future broadcast system according to an embodiment of the present invention; 
         FIG. 47  illustrates signaling data transmitted, for fast broadcast service scan of a receiver, by the future broadcast system according to an embodiment of the present invention; 
         FIG. 48  illustrates signaling data transmitted, for fast broadcast service scan of the receiver, by the future broadcast system according to an embodiment of the present invention; 
         FIG. 49  illustrates a method for transmitting FIC based signaling according to an embodiment of the present invention; 
         FIG. 50  illustrates signaling data transmitted, for fast broadcast service scan of the receiver, by the future broadcast system according to an embodiment of the present invention; 
         FIG. 51  illustrates a method for transmitting FIC based signaling according to another embodiment of the present invention; 
         FIG. 52  illustrates a service signaling message format of the future broadcast system according to an embodiment of the present invention; 
         FIG. 53  shows service signaling tables used in the future broadcast system according to an embodiment of the present invention; 
         FIG. 54  shows a service mapping table used in the future broadcast system according to an embodiment of the present invention; 
         FIG. 55  shows a service signaling table used in the future broadcast system according to an embodiment of the present invention; 
         FIG. 56  shows a component mapping table used in the future broadcast system according to an embodiment of the present invention; 
         FIG. 57  illustrates component mapping table description according to an embodiment of the present invention; 
         FIG. 58  illustrates a syntax of the component mapping table of the future broadcast system according to an embodiment of the present invention; 
         FIG. 59  illustrates a method for delivering signaling related to each service through a broadband network in the future broadcast system according to an embodiment of the present invention; 
         FIG. 60  illustrates a method for signaling an MPD in the future broadcast system according to an embodiment of the present invention; 
         FIG. 61  illustrates a syntax of an MPD delivery table used in the future broadcast system according to an embodiment of the present invention; 
         FIG. 62  illustrates transport session instance description of the future broadcast system according to an embodiment of the present invention; 
         FIG. 63  illustrates a SourceFlow element of the future broadcast system according to an embodiment of the present invention; 
         FIG. 64  illustrates an EFDT of the future broadcast system according to an embodiment of the present invention; 
         FIG. 65  illustrates a method for transmitting an ISDT used by the future broadcast system according to an embodiment of the present invention; 
         FIG. 66  illustrates a signaling message delivery structure of the future broadcast system according to an embodiment of the present invention; 
         FIG. 67  illustrates signaling data transmitted, for fast broadcast service scan of the receiver, by the future broadcast system according to an embodiment of the present invention; 
         FIG. 68  illustrates signaling data transmitted, for fast broadcast service scan of the receiver, by the future broadcast system according to an embodiment of the present invention; 
         FIG. 69  illustrates component mapping table description according to an embodiment of the present invention; 
         FIG. 70  illustrates a component mapping table description according to an embodiment of the present invention; 
         FIGS. 71 and 72  illustrate component mapping table description according to an embodiment of the present invention; 
         FIG. 73  illustrates component mapping table description according to an embodiment of the present invention; 
         FIG. 74  illustrates common attributes and elements of an MPD according to an embodiment of the present invention; 
         FIG. 75  illustrates transport session instance description according to an embodiment of the present invention; 
         FIG. 76  illustrates a SourceFlow element of the future broadcast system according to an embodiment of the present invention; 
         FIG. 77  illustrates signaling data transmitted, for fast broadcast service scan of a receiver, by a future broadcast system according to another embodiment of the present invention; 
         FIG. 78  illustrates signaling data transmitted, for fast broadcast service scan of the receiver, by a future broadcast system according to another embodiment of the present invention; 
         FIG. 79  illustrates a method for acquiring service layer signaling in the future broadcast system according to an embodiment of the present invention; 
         FIG. 80  illustrates a method for acquiring service layer signaling and link layer signaling in the future broadcast system according to an embodiment of the present invention; 
         FIG. 81  illustrates a method for acquiring service layer signaling in the future broadcast system according to an embodiment of the present invention; 
         FIG. 82  illustrates a method for acquiring service layer signaling and link layer signaling in the future broadcast system according to an embodiment of the present invention; 
         FIG. 83  illustrates a method for delivering service layer signaling in the future broadcast system according to an embodiment of the present invention; 
         FIG. 84  illustrates a method for delivering service layer signaling and link layer signaling in the future broadcast system according to an embodiment of the present invention; 
         FIG. 85  illustrates a method for delivering service layer signaling in the future broadcast system according to an embodiment of the present invention; 
         FIG. 86  illustrates a method for delivering service layer signaling and link layer signaling in the future broadcast system according to an embodiment of the present invention; 
         FIG. 87  illustrates a method for transmitting service layer signaling in the future broadcast system according to an embodiment of the present invention; 
         FIG. 88  illustrates a method for delivering service layer signaling in the future broadcast system according to an embodiment of the present invention; 
         FIG. 89  illustrates a syntax of a header of a signaling message according to another embodiment of the present invention; 
         FIG. 90  illustrates a protocol stack which processes a DASH initialization segment according to an embodiment of the present invention; 
         FIG. 91  illustrates part of layered coding transport (LCT) session instance description (LSID) according to an embodiment of the present invention; 
         FIG. 92  illustrates signaling object description (SOD) providing information for filtering a service signaling message according to an embodiment of the present invention; 
         FIG. 93  illustrates an object including a signaling message according to an embodiment of the present invention; 
         FIG. 94  illustrates TOI configuration description (TCD) according to an embodiment of the present invention; 
         FIG. 95  illustrates a payload format element of a transport packet according to an embodiment of the present invention; 
         FIG. 96  illustrates TOI configuration instance description (TCID) according to an embodiment of the present invention; 
         FIG. 97  illustrates a syntax of a payload of a fast information channel (FIC) according to an embodiment of the present invention; 
         FIG. 98  illustrates a syntax of a payload of an FIC according to another embodiment of the present invention; 
         FIG. 99  illustrates a syntax of serving level signaling according to another embodiment of the present invention; 
         FIG. 100  illustrates component mapping description according to another embodiment of the present invention; 
         FIG. 101  illustrates a syntax of URL signaling description according to another embodiment of the present invention; 
         FIG. 102  illustrates a SourceFlow element according to another embodiment of the present invention; 
         FIG. 103  illustrates a process of acquiring signaling information through a broadcast network according to another embodiment of the present invention; 
         FIG. 104  illustrates a process of acquiring signaling information through a broadcast network and a broadband network according to another embodiment of the present invention; 
         FIG. 105  illustrates a process of acquiring signaling information through a broadband network according to another embodiment of the present invention; 
         FIG. 106  illustrates a process of acquiring an electronic service guide (ESG) through a broadcast network according to another embodiment of the present invention; 
         FIG. 107  illustrates a process of acquiring video segments and audio segments of broadcast services through a broadcast network according to another embodiment of the present invention; 
         FIG. 108  illustrates a process of acquiring video segments through a broadcast network and acquiring audio segments through a broadband network according to another embodiment of the present invention; 
         FIG. 109  illustrates a configuration of a clock_reference_bootstrap_descriptor according to an embodiment of the present invention; 
         FIG. 110  illustrates a configuration of a clock_reference_value_descriptor according to an embodiment of the present invention; 
         FIG. 111  illustrates a configuration of a fast information channel (FIC) according to an embodiment of the present invention; 
         FIG. 112  illustrates a configuration of an FIC according to another embodiment of the present invention; 
         FIG. 113  illustrates a configuration of service description according to an embodiment of the present invention; 
         FIG. 114  illustrates a configuration of component mapping description according to an embodiment of the present invention; 
         FIG. 115  illustrates a method for transmitting a broadcast signal according to an embodiment of the present invention; 
         FIG. 116  illustrates a method for receiving a broadcast signal according to an embodiment of the present invention; 
         FIG. 117  illustrates a configuration of an apparatus for transmitting a broadcast signal according to an embodiment of the present invention; 
         FIG. 118  illustrates a configuration of an apparatus for receiving a broadcast signal according to an embodiment of the present invention; 
         FIG. 119  illustrates service description information when session description information is included in the service description information and transmitted according to an embodiment of the present invention; 
         FIG. 120  illustrates message formats for delivering session description information when the session description information is delivered through a service signaling channel according to an embodiment of the present invention; 
         FIG. 121  illustrates a method for transmitting session description information through a path outside of a session according to an embodiment of the present invention; 
         FIG. 122  illustrates a method for transmitting session description information through a path outside of a session according to another embodiment of the present invention; 
         FIG. 123  illustrates a method for transmitting session description information through a path outside of a session according to another embodiment of the present invention; 
         FIG. 124  illustrates a signaling message extended for initialization information delivery according to an embodiment of the present invention; 
         FIG. 125  illustrates message formats for initialization information delivery according to an embodiment of the present invention; 
         FIG. 126  illustrates message formats for session description information delivery when the session description information is delivered through a serving signaling channel according to another embodiment of the present invention; 
         FIG. 127  illustrates a method for processing service data according to an embodiment of the present invention; 
         FIG. 128  illustrates an apparatus for processing service data according to an embodiment of the present invention; 
         FIG. 129  illustrates ESG bootstrap information according to an embodiment of the present invention; 
         FIG. 130  illustrates ESG bootstrap information transmission type according to an embodiment of the present invention; 
         FIG. 131  illustrates ESG bootstrap information signaling according to a first embodiment of the present invention; 
         FIG. 132  illustrates ESG bootstrap information signaling according to a second embodiment of the present invention; 
         FIG. 133  illustrates ESG bootstrap information signaling according to a third embodiment of the present invention; 
         FIG. 134  illustrates ESG bootstrap information signaling according to a fourth embodiment of the present invention; 
         FIG. 135  illustrates ESG bootstrap information signaling according to a fifth embodiment of the present invention; 
         FIG. 136  illustrates a GAT according to the fifth embodiment of the present invention; 
         FIG. 137  illustrates effects of the first to fifth embodiments of the present invention; 
         FIG. 138  is a flowchart illustrating operation of a broadcast reception apparatus according to an embodiment of the present invention; 
         FIG. 139  illustrates a channel map configuration method according to an embodiment of the present invention; 
         FIG. 140  illustrates a channel map configuration method according to an embodiment of the present invention; 
         FIG. 141  illustrates an FIC according to an embodiment of the present invention; 
         FIG. 142  illustrates an FIC according to an embodiment of the present invention; 
         FIG. 143  illustrates an FIC according to an embodiment of the present invention; 
         FIG. 144  illustrates an FIC according to an embodiment of the present invention; 
         FIG. 145  illustrates an FIC according to an embodiment of the present invention; 
         FIG. 146  illustrates an FIC according to an embodiment of the present invention; 
         FIG. 147  illustrates an SSC according to an embodiment of the present invention; 
         FIG. 148  is a flowchart illustrating a broadcast transmission method according to an embodiment of the present invention; 
         FIG. 149  is a flowchart illustrating a broadcast reception method according to an embodiment of the present invention; 
         FIG. 150  illustrates a handover situation to another frequency while a receiver moves, according to an embodiment of the present invention; 
         FIG. 151  illustrates an information transmission method for seamless handover according to an embodiment of the present invention; 
         FIG. 152  illustrates an information transmission method for seamless handover according to another embodiment of the present invention; 
         FIG. 153  illustrates information for seamless handover according to an embodiment of the present invention; 
         FIG. 154  illustrates low level signaling information according to an embodiment of the present invention; 
         FIG. 155  illustrates a procedure of presenting a service in a receiver, using an FIC, according to an embodiment of the present invention; 
         FIG. 156  illustrates low level signaling information according to another embodiment of the present invention; 
         FIG. 157  illustrates low level signaling information according to another embodiment of the present invention; 
         FIG. 158  illustrates low level signaling information according to another embodiment of the present invention; 
         FIG. 159  illustrates a procedure of presenting a service in a receiver, using an FIC, according to another embodiment of the present invention; 
         FIG. 160  is a flowchart illustrating a method for generating and processing a broadcast signal according to an embodiment of the present invention; 
         FIG. 161  illustrates a broadcast system according to an embodiment of the present invention; 
         FIG. 162  illustrates a protocol stack of a broadcast system according to another embodiment of the present invention; 
         FIG. 163  illustrates an SLT according to another embodiment of the present invention; 
         FIG. 164  illustrates an SLT according to another embodiment of the present invention; 
         FIG. 165  illustrates an SLT according to another embodiment of the present invention; 
         FIG. 166  illustrates LSID according to another embodiment of the present invention; 
         FIG. 167  illustrates description of a source flow/repair flow according to another embodiment of the present invention; 
         FIG. 168  is a signaling flow diagram according to another embodiment of the present invention; 
         FIG. 169  is a flowchart illustrating a method for transmitting a broadcast signal according to an embodiment of the present invention; and 
         FIG. 170  is a block diagram of an apparatus for transmitting a broadcast signal according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The detailed description, which will be given below with reference to the accompanying drawings, is intended to explain exemplary embodiments of the present invention, rather than to show the only embodiments that can be implemented according to the present invention. The following detailed description includes specific details in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without such specific details. 
     Although the terms used in the present invention are selected from generally known and used terms, some of the terms mentioned in the description of the present invention have been selected by the applicant at his or her discretion, the detailed meanings of which are described in relevant parts of the description herein. Furthermore, it is required that the present invention is understood, not simply by the actual terms used but by the meanings of each term lying within. 
     The present invention provides apparatuses and methods for transmitting and receiving broadcast signals for future broadcast services. Future broadcast services according to an embodiment of the present invention include a terrestrial broadcast service, a mobile broadcast service, an ultra high definition television (UHDTV) service, etc. The present invention may process broadcast signals for the future broadcast services through non-MIMO (Multiple Input Multiple Output) or MIMO according to one embodiment. A non-MIMO scheme according to an embodiment of the present invention may include a MISO (Multiple Input Single Output) scheme, a SISO (Single Input Single Output) scheme, etc. 
       FIG. 1  illustrates a receiver protocol stack according to an embodiment of the present invention. 
     Two schemes may be used in broadcast service delivery through a broadcast network. 
     In a first scheme, media processing units (MPUs) are transmitted using an MMT protocol (MMTP) based on MPEG media transport (MMT). In a second scheme, dynamic adaptive streaming over HTTP (DASH) segments may be transmitted using real time object delivery over unidirectional transport (ROUTE) based on MPEG DASH. 
     Non-timed content including NRT media, EPG data, and other files is delivered with ROUTE. Signaling may be delivered over MMTP and/or ROUTE, while bootstrap signaling information is provided by the means of the Service List Table (SLT). 
     In hybrid service delivery, MPEG DASH over HTTP/TCP/IP is used on the broadband side. Media files in ISO Base Media File Format (BMFF) are used as the delivery, media encapsulation and synchronization format for both broadcast and broadband delivery. Here, hybrid service delivery may refer to a case in which one or more program elements are delivered through a broadband path. 
     Services are delivered using three functional layers. These are the physical layer, the delivery layer and the service management layer. The physical layer provides the mechanism by which signaling, service announcement and IP packet streams are transported over the broadcast physical layer and/or broadband physical layer. The delivery layer provides object and object flow transport functionality. It is enabled by the MMTP or the ROUTE protocol, operating on a UDP/IP multicast over the broadcast physical layer, and enabled by the HTTP protocol on a TCP/IP unicast over the broadband physical layer. The service management layer enables any type of service, such as linear TV or HTML5 application service, to be carried by the underlying delivery and physical layers. 
     In this figure, a protocol stack part on a broadcast side may be divided into a part transmitted through the SLT and the MMTP, and a part transmitted through ROUTE. 
     The SLT may be encapsulated through UDP and IP layers. Here, the SLT will be described below. The MMTP may transmit data formatted in an MPU format defined in MMT, and signaling information according to the MMTP. The data may be encapsulated through the UDP and IP layers. ROUTE may transmit data formatted in a DASH segment form, signaling information, and non-timed data such as NRT data, etc. The data may be encapsulated through the UDP and IP layers. According to a given embodiment, some or all processing according to the UDP and IP layers may be omitted. Here, the illustrated signaling information may be signaling information related to a service. 
     The part transmitted through the SLT and the MMTP and the part transmitted through ROUTE may be processed in the UDP and IP layers, and then encapsulated again in a data link layer. The link layer will be described below. Broadcast data processed in the link layer may be multicast as a broadcast signal through processes such as encoding/interleaving, etc. in the physical layer. 
     In this figure, a protocol stack part on a broadband side may be transmitted through HTTP as described above. Data formatted in a DASH segment form, signaling information, NRT information, etc. may be transmitted through HTTP. Here, the illustrated signaling information may be signaling information related to a service. The data may be processed through the TCP layer and the IP layer, and then encapsulated into the link layer. According to a given embodiment, some or all of the TCP, the IP, and the link layer may be omitted. Broadband data processed thereafter may be transmitted by unicast in the broadband through a process for transmission in the physical layer. 
     Service can be a collection of media components presented to the user in aggregate; components can be of multiple media types; a Service can be either continuous or intermittent; a Service can be Real Time or Non-Real Time; Real Time Service can consist of a sequence of TV programs. 
       FIG. 2  illustrates a relation between the SLT and SLS according to an embodiment of the present invention. 
     Service signaling provides service discovery and description information, and comprises two functional components: Bootstrap signaling via the Service List Table (SLT) and the Service Layer Signaling (SLS). These represent the information which is necessary to discover and acquire user services. The SLT enables the receiver to build a basic service list, and bootstrap the discovery of the SLS for each service. 
     The SLT can enable very rapid acquisition of basic service information. The SLS enables the receiver to discover and access services and their content components. Details of the SLT and SLS will be described below. 
     As described in the foregoing, the SLT may be transmitted through UDP/IP. In this instance, according to a given embodiment, data corresponding to the SLT may be delivered through the most robust scheme in this transmission. 
     The SLT may have access information for accessing SLS delivered by the ROUTE protocol. In other words, the SLT may be bootstrapped into SLS according to the ROUTE protocol. The SLS is signaling information positioned in an upper layer of ROUTE in the above-described protocol stack, and may be delivered through ROUTE/UDP/IP. The SLS may be transmitted through one of LCT sessions included in a ROUTE session. It is possible to access a service component corresponding to a desired service using the SLS. 
     In addition, the SLT may have access information for accessing an MMT signaling component delivered by MMTP. In other words, the SLT may be bootstrapped into SLS according to the MMTP. The SLS may be delivered by an MMTP signaling message defined in MMT. It is possible to access a streaming service component (MPU) corresponding to a desired service using the SLS. As described in the foregoing, in the present invention, an NRT service component is delivered through the ROUTE protocol, and the SLS according to the MMTP may include information for accessing the ROUTE protocol. In broadband delivery, the SLS is carried over HTTP(S)/TCP/IP. 
       FIG. 3  illustrates an SLT according to an embodiment of the present invention. 
     First, a description will be given of a relation among respective logical entities of service management, delivery, and a physical layer. 
     Services may be signaled as being one of two basic types. First type is a linear audio/video or audio-only service that may have an app-based enhancement. Second type is a service whose presentation and composition is controlled by a downloaded application that is executed upon acquisition of the service. The latter can be called an “app-based” service. 
     The rules regarding presence of ROUTE/LCT sessions and/or MMTP sessions for carrying the content components of a service may be as follows. 
     For broadcast delivery of a linear service without app-based enhancement, the service&#39;s content components can be carried by either (but not both): (1) one or more ROUTE/LCT sessions, or (2) one or more MMTP sessions. 
     For broadcast delivery of a linear service with app-based enhancement, the service&#39;s content components can be carried by: (1) one or more ROUTE/LCT sessions, and (2) zero or more MMTP sessions. 
     In certain embodiments, use of both MMTP and ROUTE for streaming media components in the same service may not be allowed. 
     For broadcast delivery of an app-based service, the service&#39;s content components can be carried by one or more ROUTE/LCT sessions. 
     Each ROUTE session comprises one or more LCT sessions which carry as a whole, or in part, the content components that make up the service. In streaming services delivery, an LCT session may carry an individual component of a user service such as an audio, video or closed caption stream. Streaming media is formatted as DASH Segments. 
     Each MMTP session comprises one or more MMTP packet flows which carry MMT signaling messages or as a whole, or in part, the content component. An MMTP packet flow may carry MMT signaling messages or components formatted as MPUs. 
     For the delivery of NRT User Services or system metadata, an LCT session carries file-based content items. These content files may consist of continuous (time-based) or discrete (non-time-based) media components of an NRT service, or metadata such as Service Signaling or ESG fragments. Delivery of system metadata such as service signaling or ESG fragments may also be achieved through the signaling message mode of MMTP. 
     A broadcast stream is the abstraction for an RF channel, which is defined in terms of a carrier frequency centered within a specified bandwidth. It is identified by the pair [geographic area, frequency]. A physical layer pipe (PLP) corresponds to a portion of the RF channel. Each PLP has certain modulation and coding parameters. It is identified by a PLP identifier (PLPID), which is unique within the broadcast stream it belongs to. Here, PLP can be referred to as DP (data pipe). 
     Each service is identified by two forms of service identifier: a compact form that is used in the SLT and is unique only within the broadcast area; and a globally unique form that is used in the SLS and the ESG. A ROUTE session is identified by a source IP address, destination IP address and destination port number. An LCT session (associated with the service component(s) it carries) is identified by a transport session identifier (TSI) which is unique within the scope of the parent ROUTE session. Properties common to the LCT sessions, and certain properties unique to individual LCT sessions, are given in a ROUTE signaling structure called a service-based transport session instance description (S-TSID), which is part of the service layer signaling. Each LCT session is carried over a single physical layer pipe. According to a given embodiment, one LCT session may be transmitted through a plurality of PLPs. Different LCT sessions of a ROUTE session may or may not be contained in different physical layer pipes. Here, the ROUTE session may be delivered through a plurality of PLPs. The properties described in the S-TSID include the TSI value and PLPID for each LCT session, descriptors for the delivery objects/files, and application layer FEC parameters. 
     A MMTP session is identified by destination IP address and destination port number. An MMTP packet flow (associated with the service component(s) it carries) is identified by a packet id which is unique within the scope of the parent MMTP session. Properties common to each MMTP packet flow, and certain properties of MMTP packet flows, are given in the SLT. Properties for each MMTP session are given by MMT signaling messages, which may be carried within the MMTP session. Different MMTP packet flows of a MMTP session may or may not be contained in different physical layer pipes. Here, the MMTP session may be delivered through a plurality of PLPs. The properties described in the MMT signaling messages include the packet id value and PLPID for each MMTP packet flow. Here, the MMT signaling messages may have a form defined in MMT, or have a deformed form according to embodiments to be described below. 
     Hereinafter, a description will be given of low level signaling (LLS). 
     Signaling information which is carried in the payload of IP packets with a well-known address/port dedicated to this function is referred to as low level signaling (LLS). The IP address and the port number may be differently configured depending on embodiments. In one embodiment, LLS can be transported in IP packets with address 224.0.23.60 and destination port 4937/udp. LLS may be positioned in a portion expressed by “SLT” on the above-described protocol stack. However, according to a given embodiment, the LLS may be transmitted through a separate physical channel (dedicated channel) in a signal frame without being subjected to processing of the UDP/IP layer. 
     UDP/IP packets that deliver LLS data may be formatted in a form referred to as an LLS table. A first byte of each UDP/IP packet that delivers the LLS data may correspond to a start of the LLS table. The maximum length of any LLS table is limited by the largest IP packet that can be delivered from the PHY layer, 65,507 bytes. 
     The LLS table may include an LLS table ID field that identifies a type of the LLS table, and an LLS table version field that identifies a version of the LLS table. According to a value indicated by the LLS table ID field, the LLS table may include the above-described SLT or a rating region table (RRT). The RRT may have information about content advisory rating. 
     Hereinafter, the SLT will be described. LLS can be signaling information which supports rapid channel scans and bootstrapping of service acquisition by the receiver, and SLT can be a table of signaling information which is used to build a basic service listing and provide bootstrap discovery of SLS. 
     The function of the SLT is similar to that of the program association table (PAT) in MPEG-2 Systems, and the fast information channel (FIC) found in ATSC Systems. For a receiver first encountering the broadcast emission, this is the place to start. SLT supports a rapid channel scan which allows a receiver to build a list of all the services it can receive, with their channel name, channel number, etc., and SLT provides bootstrap information that allows a receiver to discover the SLS for each service. For ROUTE/DASH-delivered services, the bootstrap information includes the destination IP address and destination port of the LCT session that carries the SLS. For MMT/MPU-delivered services, the bootstrap information includes the destination IP address and destination port of the MMTP session carrying the SLS. 
     The SLT supports rapid channel scans and service acquisition by including the following information about each service in the broadcast stream. First, the SLT can include information necessary to allow the presentation of a service list that is meaningful to viewers and that can support initial service selection via channel number or up/down selection. Second, the SLT can include information necessary to locate the service layer signaling for each service listed. That is, the SLT may include access information related to a location at which the SLS is delivered. 
     The illustrated SLT according to the present embodiment is expressed as an XML document having an SLT root element. According to a given embodiment, the SLT may be expressed in a binary format or an XML document. 
     The SLT root element of the SLT illustrated in the figure may include @bsid, @sltSectionVersion, @sltSectionNumber, @total SltSectionNumbers, @language, @capabilities, InetSigLoc and/or Service. According to a given embodiment, the SLT root element may further include @providerId. According to a given embodiment, the SLT root element may not include @language. 
     The service element may include @serviceId, @SLTserviceSeqNumber, @protected, @majorChannelNo, @minorChannelNo, @serviceCategory, @shortServiceName, @hidden, @slsProtocolType, BroadcastSignaling, @slsPlpId, @slsDestinationIpAddress, @slsDestinationUdpPort, @slsSourceIpAddress, @slsMajorProtocolVersion, @SlsMinorProtocolVersion, @serviceLanguage, @broadbandAccessRequired, @capabilities and/or InetSigLoc. 
     According to a given embodiment, an attribute or an element of the SLT may be added/changed/deleted. Each element included in the SLT may additionally have a separate attribute or element, and some attribute or elements according to the present embodiment may be omitted. Here, a field which is marked with @ may correspond to an attribute, and a field which is not marked with @ may correspond to an element. 
     @bsid is an identifier of the whole broadcast stream. The value of BSID may be unique on a regional level. 
     @providerId can be an index of broadcaster that is using part or all of this broadcast stream. This is an optional attribute. When it&#39;s not present, it means that this broadcast stream is being used by one broadcaster. @providerId is not illustrated in the figure. 
     @sltSectionVersion can be a version number of the SLT section. The sltSectionVersion can be incremented by 1 when a change in the information carried within the slt occurs. When it reaches maximum value, it wraps around to 0. 
     @sltSectionNumber can be the number, counting from 1, of this section of the SLT. In other words, @sltSectionNumber may correspond to a section number of the SLT section. When this field is not used, @sltSectionNumber may be set to a default value of 1. 
     @totalSltSectionNumbers can be the total number of sections (that is, the section with the highest sltSectionNumber) of the SLT of which this section is part. sltSectionNumber and totalSltSectionNumbers together can be considered to indicate “Part M of N” of one portion of the SLT when it is sent in fragments. In other words, when the SLT is transmitted, transmission through fragmentation may be supported. When this field is not used, @totalSltSectionNumbers may be set to a default value of 1. A case in which this field is not used may correspond to a case in which the SLT is not transmitted by being fragmented. 
     @language can indicate primary language of the services included in this slt instance. According to a given embodiment, a value of this field may have a three-character language code defined in the ISO. This field may be omitted. 
     @capabilities can indicate required capabilities for decoding and meaningfully presenting the content for all the services in this slt instance. 
     InetSigLoc can provide a URL telling the receiver where it can acquire any requested type of data from external server(s) via broadband. This element may include @urlType as a lower field. According to a value of the @urlType field, a type of a URL provided by InetSigLoc may be indicated. According to a given embodiment, when the @urlType field has a value of 0, InetSigLoc may provide a URL of a signaling server. When the @urlType field has a value of 1, InetSigLoc may provide a URL of an ESG server. When the @urlType field has other values, the field may be reserved for future use. 
     The service field is an element having information about each service, and may correspond to a service entry. Service element fields corresponding to the number of services indicated by the SLT may be present. Hereinafter, a description will be given of a lower attribute/element of the service field. 
     @serviceId can be an integer number that uniquely identify this service within the scope of this broadcast area. According to a given embodiment, a scope of @serviceId may be changed. @SLTserviceSeqNumber can be an integer number that indicates the sequence number of the SLT service information with service ID equal to the serviceId attribute above. SLTserviceSeqNumber value can start at  0  for each service and can be incremented by 1 every time any attribute in this service element is changed. If no attribute values are changed compared to the previous Service element with a particular value of ServiceID then SLTserviceSeqNumber would not be incremented. The SLTserviceSeqNumber field wraps back to 0 after reaching the maximum value. 
     @protected is flag information which may indicate whether one or more components for significant reproduction of the service are in a protected state. When set to “1” (true), that one or more components necessary for meaningful presentation is protected. When set to “0” (false), this flag indicates that no components necessary for meaningful presentation of the service are protected. Default value is false. 
     @majorChannelNo is an integer number representing the “major” channel number of the service. An example of the field may have a range of 1 to 999. 
     @minorChannelNo is an integer number representing the “minor” channel number of the service. An example of the field may have a range of 1 to 999. 
     @serviceCategory can indicate the category of this service. This field may indicate a type that varies depending on embodiments. According to a given embodiment, when this field has values of 1, 2, and 3, the values may correspond to a linear A/V service, a linear audio only service, and an app-based service, respectively. When this field has a value of 0, the value may correspond to a service of an undefined category. When this field has other values except for 1, 2, and 3, the field may be reserved for future use. @shortServiceName can be a short string name of the Service. 
     @hidden can be Boolean value that when present and set to “true” indicates that the service is intended for testing or proprietary use, and is not to be selected by ordinary TV receivers. The default value is “false” when not present. 
     @slsProtocolType can be an attribute indicating the type of protocol of Service Layer Signaling used by this service. This field may indicate a type that varies depending on embodiments. According to a given embodiment, when this field has values of 1 and 2, protocols of SLS used by respective corresponding services may be ROUTE and MMTP, respectively. When this field has other values except for 0, the field may be reserved for future use. This field may be referred to as @slsProtocol. 
     BroadcastSignaling and lower attributes/elements thereof may provide information related to broadcast signaling. When the BroadcastSignaling element is not present, the child element InetSigLoc of the parent service element can be present and its attribute urlType includes URL_type 0x00 (URL to signaling server). In this case attribute url supports the query parameter svc=&lt;service_id&gt; where service_id corresponds to the serviceId attribute for the parent service element. 
     Alternatively when the BroadcastSignaling element is not present, the element InetSigLoc can be present as a child element of the slt root element and the attribute urlType of that InetSigLoc element includes URL_type 0x00 (URL to signaling server). In this case, attribute url for URL_type 0x00 supports the query parameter svc=&lt;service_id&gt; where service_id corresponds to the serviceId attribute for the parent Service element. 
     @slsPlpId can be a string representing an integer number indicating the PLP ID of the physical layer pipe carrying the SLS for this service. 
     @slsDestinationIpAddress can be a string containing the dotted-IPv4 destination address of the packets carrying SLS data for this service. 
     @slsDestinationUdpPort can be a string containing the port number of the packets carrying SLS data for this service. As described in the foregoing, SLS bootstrapping may be performed by destination IP/UDP information. 
     @slsSourceIpAddress can be a string containing the dotted-IPv4 source address of the packets carrying SLS data for this service. 
     @slsMajorProtocolVersion can be major version number of the protocol used to deliver the service layer signaling for this service. Default value is 1. 
     @SlsMinorProtocolVersion can be minor version number of the protocol used to deliver the service layer signaling for this service. Default value is 0. 
     @serviceLanguage can be a three-character language code indicating the primary language of the service. A value of this field may have a form that varies depending on embodiments. 
     @broadbandAccessRequired can be a Boolean indicating that broadband access is required for a receiver to make a meaningful presentation of the service. Default value is false. When this field has a value of True, the receiver needs to access a broadband for significant service reproduction, which may correspond to a case of hybrid service delivery. 
     @capabilities can represent required capabilities for decoding and meaningfully presenting the content for the service with service ID equal to the service Id attribute above. 
     InetSigLoc can provide a URL for access to signaling or announcement information via broadband, if available. Its data type can be an extension of the any URL data type, adding an @urlType attribute that indicates what the URL gives access to. An @urlType field of this field may indicate the same meaning as that of the @urlType field of InetSigLoc described above. When an InetSigLoc element of attribute URL_type 0x00 is present as an element of the SLT, it can be used to make HTTP requests for signaling metadata. The HTTP POST message body may include a service term. When the InetSigLoc element appears at the section level, the service term is used to indicate the service to which the requested signaling metadata objects apply. If the service term is not present, then the signaling metadata objects for all services in the section are requested. When the InetSigLoc appears at the service level, then no service term is needed to designate the desired service. When an InetSigLoc element of attribute URL_type 0x01 is provided, it can be used to retrieve ESG data via broadband. If the element appears as a child element of the service element, then the URL can be used to retrieve ESG data for that service. If the element appears as a child element of the SLT element, then the URL can be used to retrieve ESG data for all services in that section. 
     In another example of the SLT, @sltSectionVersion, @sltSectionNumber, @totalSltSectionNumbers and/or @language fields of the SLT may be omitted 
     In addition, the above-described InetSigLoc field may be replaced by @sltInetSigUri and/or @sltInetEsgUri field. The two fields may include the URI of the signaling server and URI information of the ESG server, respectively. The InetSigLoc field corresponding to a lower field of the SLT and the InetSigLoc field corresponding to a lower field of the service field may be replaced in a similar manner. 
     The suggested default values may vary depending on embodiments. An illustrated “use” column relates to the respective fields. Here, “1” may indicate that a corresponding field is an essential field, and “0 . . . 1” may indicate that a corresponding field is an optional field. 
       FIG. 4  illustrates SLS bootstrapping and a service discovery process according to an embodiment of the present invention. 
     Hereinafter, SLS will be described. 
     SLS can be signaling which provides information for discovery and acquisition of services and their content components. 
     For ROUTE/DASH, the SLS for each service describes characteristics of the service, such as a list of its components and where to acquire them, and the receiver capabilities required to make a meaningful presentation of the service. In the ROUTE/DASH system, the SLS includes the user service bundle description (USBD), the S-TSID and the DASH media presentation description (MPD). Here, USBD or user service description (USD) is one of SLS XML fragments, and may function as a signaling herb that describes specific descriptive information. USBD/USD may be extended beyond 3GPP MBMS. Details of USBD/USD will be described below. 
     The service signaling focuses on basic attributes of the service itself, especially those attributes needed to acquire the service. Properties of the service and programming that are intended for viewers appear as service announcement, or ESG data. 
     Having separate Service Signaling for each service permits a receiver to acquire the appropriate SLS for a service of interest without the need to parse the entire SLS carried within a broadcast stream. 
     For optional broadband delivery of Service Signaling, the SLT can include HTTP URLs where the Service Signaling files can be obtained, as described above. 
     LLS is used for bootstrapping SLS acquisition, and subsequently, the SLS is used to acquire service components delivered on either ROUTE sessions or MMTP sessions. The described figure illustrates the following signaling sequences. Receiver starts acquiring the SLT described above. Each service identified by service_id delivered over ROUTE sessions provides SLS bootstrapping information: PLPID(#1), source IP address (sIP1), destination IP address (diP1), and destination port number (dPort1). Each service identified by service_id delivered over MMTP sessions provides SLS bootstrapping information: PLPID(#2), destination IP address (diP2), and destination port number (dPort2). 
     For streaming services delivery using ROUTE, the receiver can acquire SLS fragments carried over the IP/UDP/LCT session and PLP; whereas for streaming services delivery using MMTP, the receiver can acquire SLS fragments carried over an MMTP session and PLP. For service delivery using ROUTE, these SLS fragments include USBD/USD fragments, S-TSID fragments, and MPD fragments. They are relevant to one service. USBD/USD fragments describe service layer properties and provide URI references to S-TSID fragments and URI references to MPD fragments. In other words, the USBD/USD may refer to S-TSID and MPD. For service delivery using MMTP, the USBD references the MMT signaling&#39;s MPT message, the MP Table of which provides identification of package ID and location information for assets belonging to the service. Here, an asset is a multimedia data entity, and may refer to a data entity which is combined into one unique ID and is used to generate one multimedia presentation. The asset may correspond to a service component included in one service. The MPT message is a message having the MP table of MMT. Here, the MP table may be an MMT package table having information about content and an MMT asset. Details may be similar to a definition in MMT. Here, media presentation may correspond to a collection of data that establishes bounded/unbounded presentation of media content. 
     The S-TSID fragment provides component acquisition information associated with one service and mapping between DASH Representations found in the MPD and in the TSI corresponding to the component of the service. The S-TSID can provide component acquisition information in the form of a TSI and the associated DASH representation identifier, and PLPID carrying DASH segments associated with the DASH representation. By the PLPID and TSI values, the receiver collects the audio/video components from the service and begins buffering DASH media segments then applies the appropriate decoding processes. 
     For USBD listing service components delivered on MMTP sessions, as illustrated by “Service #2” in the described figure, the receiver also acquires an MPT message with matching MMT_package_id to complete the SLS. An MPT message provides the full list of service components comprising a service and the acquisition information for each component. Component acquisition information includes MMTP session information, the PLPID carrying the session and the packet id within that session. 
     According to a given embodiment, for example, in ROUTE, two or more S-TSID fragments may be used. Each fragment may provide access information related to LCT sessions delivering content of each service. 
     In ROUTE, S-TSID, USBD/USD, MPD, or an LCT session delivering S-TSID, USBD/USD or MPD may be referred to as a service signaling channel. In MMTP, USBD/UD, an MMT signaling message, or a packet flow delivering the MMTP or USBD/UD may be referred to as a service signaling channel. 
     Unlike the illustrated example, one ROUTE or MMTP session may be delivered through a plurality of PLPs. In other words, one service may be delivered through one or more PLPs. As described in the foregoing, one LCT session may be delivered through one PLP. Unlike the figure, according to a given embodiment, components included in one service may be delivered through different ROUTE sessions. In addition, according to a given embodiment, components included in one service may be delivered through different MMTP sessions. According to a given embodiment, components included in one service may be delivered separately through a ROUTE session and an MMTP session. Although not illustrated, components included in one service may be delivered via broadband (hybrid delivery). 
       FIG. 5  illustrates a USBD fragment for ROUTE/DASH according to an embodiment of the present invention. 
     Hereinafter, a description will be given of SLS in delivery based on ROUTE. 
     SLS provides detailed technical information to the receiver to enable the discovery and access of services and their content components. It can include a set of XML-encoded metadata fragments carried over a dedicated LCT session. That LCT session can be acquired using the bootstrap information contained in the SLT as described above. The SLS is defined on a per-service level, and it describes the characteristics and access information of the service, such as a list of its content components and how to acquire them, and the receiver capabilities required to make a meaningful presentation of the service. In the ROUTE/DASH system, for linear services delivery, the SLS consists of the following metadata fragments: USBD, S-TSID and the DASH MPD. The SLS fragments can be delivered on a dedicated LCT transport session with TSI=0. According to a given embodiment, a TSI of a particular LCT session (dedicated LCT session) in which an SLS fragment is delivered may have a different value. According to a given embodiment, an LCT session in which an SLS fragment is delivered may be signaled using the SLT or another scheme. 
     ROUTE/DASH SLS can include the user service bundle description (USBD) and service-based transport session instance description (S-TSID) metadata fragments. These service signaling fragments are applicable to both linear and application-based services. The USBD fragment contains service identification, device capabilities information, references to other SLS fragments required to access the service and constituent media components, and metadata to enable the receiver to determine the transport mode (broadcast and/or broadband) of service components. The S-TSID fragment, referenced by the USBD, provides transport session descriptions for the one or more ROUTE/LCT sessions in which the media content components of a service are delivered, and descriptions of the delivery objects carried in those LCT sessions. The USBD and S-TSID will be described below. 
     In streaming content signaling in ROUTE-based delivery, a streaming content signaling component of SLS corresponds to an MPD fragment. The MPD is typically associated with linear services for the delivery of DASH Segments as streaming content. The MPD provides the resource identifiers for individual media components of the linear/streaming service in the form of Segment URLs, and the context of the identified resources within the Media Presentation. Details of the MPD will be described below. 
     In app-based enhancement signaling in ROUTE-based delivery, app-based enhancement signaling pertains to the delivery of app-based enhancement components, such as an application logic file, locally-cached media files, network content items, or a notification stream. An application can also retrieve locally-cached data over a broadband connection when available. 
     Hereinafter, a description will be given of details of USBD/USD illustrated in the figure. 
     The top level or entry point SLS fragment is the USBD fragment. An illustrated USBD fragment is an example of the present invention, basic fields of the USBD fragment not illustrated in the figure may be additionally provided according to a given embodiment. As described in the foregoing, the illustrated USBD fragment has an extended form, and may have fields added to a basic configuration. 
     The illustrated USBD may have a bundleDescription root element. The bundleDescription root element may have a userServiceDescription element. The userServiceDescription element may correspond to an instance for one service. 
     The userServiceDescription element may include @serviceId, @atsc:serviceId, @atsc: serviceStatus, @atsc:fullMPDUri, @atsc:sTSIDUri, name, serviceLanguage, atsc:capabilityCode and/or deliveryMethod. 
     @serviceId can be a globally unique URI that identifies a service, unique within the scope of the BSID. This parameter can be used to link to ESG data (Service@globalServiceID). 
     @atsc:serviceId is a reference to corresponding service entry in LLS(SLT). The value of this attribute is the same value of serviceId assigned to the entry. 
     @atsc:serviceStatus can specify the status of this service. The value indicates whether this service is active or inactive. When set to “1” (true), that indicates service is active. When this field is not used, @atsc:serviceStatus may be set to a default value of 1. 
     @atsc:fullMPDUri can reference an MPD fragment which contains descriptions for contents components of the service delivered over broadcast and optionally, also over broadband. 
     @atsc:sTSIDUri can reference the S-TSID fragment which provides access related parameters to the Transport sessions carrying contents of this service. 
     name can indicate name of the service as given by the lang attribute. name element can include lang attribute, which indicating language of the service name. The language can be specified according to XML data types. 
     serviceLanguage can represent available languages of the service. The language can be specified according to XML data types. 
     atsc:capabilityCode can specify the capabilities required in the receiver to be able to create a meaningful presentation of the content of this service. According to a given embodiment, this field may specify a predefined capability group. Here, the capability group may be a group of capability attribute values for significant presentation. This field may be omitted according to a given embodiment. 
     deliveryMethod can be a container of transport related information pertaining to the contents of the service over broadcast and (optionally) broadband modes of access. Referring to data included in the service, when the number of the data is N, delivery schemes for respective data may be described by this element. The deliveryMethod may include an r12:broadcastAppService element and an r12:unicastAppService element. Each lower element may include a basePattern element as a lower element. 
     r12:broadcastAppService can be a DASH Representation delivered over broadcast, in multiplexed or non-multiplexed form, containing the corresponding media component(s) belonging to the service, across all Periods of the affiliated media presentation. In other words, each of the fields may indicate DASH representation delivered through the broadcast network. 
     r12:unicastAppService can be a DASH Representation delivered over broadband, in multiplexed or non-multiplexed form, containing the constituent media content component(s) belonging to the service, across all periods of the affiliated media presentation. In other words, each of the fields may indicate DASH representation delivered via broadband. 
     basePattern can be a character pattern for use by the receiver to match against any portion of the segment URL used by the DASH client to request media segments of a parent representation under its containing period. A match implies that the corresponding requested media segment is carried over broadcast transport. In a URL address for receiving DASH representation expressed by each of the r12:broadcastAppService element and the r12:unicastAppService element, a part of the URL, etc. may have a particular pattern. The pattern may be described by this field. Some data may be distinguished using this information. The proposed default values may vary depending on embodiments. The “use” column illustrated in the figure relates to each field. Here, M may denote an essential field, O may denote an optional field, OD may denote an optional field having a default value, and CM may denote a conditional essential field. 0 . . . 1 to 0 . . . N may indicate the number of available fields. 
       FIG. 6  illustrates an S-TSID fragment for ROUTE/DASH according to an embodiment of the present invention. 
     Hereinafter, a description will be given of the S-TSID illustrated in the figure in detail. 
     S-TSID can be an SLS XML fragment which provides the overall session description information for transport session(s) which carry the content components of a service. The S-TSID is the SLS metadata fragment that contains the overall transport session description information for the zero or more ROUTE sessions and constituent LCT sessions in which the media content components of a service are delivered. The S-TSID also includes file metadata for the delivery object or object flow carried in the LCT sessions of the service, as well as additional information on the payload formats and content components carried in those LCT sessions. 
     Each instance of the S-TSID fragment is referenced in the USBD fragment by the @atsc:sTSIDUri attribute of the userServiceDescription element. The illustrated S-TSID according to the present embodiment is expressed as an XML document. According to a given embodiment, the S-TSID may be expressed in a binary format or as an XML document. 
     The illustrated S-TSID may have an S-TSID root element. The S-TSID root element may include @serviceId and/or RS. 
     @serviceID can be a reference corresponding service element in the USD. The value of this attribute can reference a service with a corresponding value of service_id. 
     The RS element may have information about a ROUTE session for delivering the service data. Service data or service components may be delivered through a plurality of ROUTE sessions, and thus the number of RS elements may be 1 to N. 
     The RS element may include @bsid, @sIpAddr, @dIpAddr, @dport, @PLPID and/or LS. 
     @bsid can be an identifier of the broadcast stream within which the content component(s) of the broadcastAppService are carried. When this attribute is absent, the default broadcast stream is the one whose PLPs carry SLS fragments for this service. Its value can be identical to that of the broadcast stream id in the SLT. 
     @sIpAddr can indicate source IP address. Here, the source IP address may be a source IP address of a ROUTE session for delivering a service component included in the service. As described in the foregoing, service components of one service may be delivered through a plurality of ROUTE sessions. Thus, the service components may be transmitted using another ROUTE session other than the ROUTE session for delivering the S-TSID. Therefore, this field may be used to indicate the source IP address of the ROUTE session. A default value of this field may be a source IP address of a current ROUTE session. When a service component is delivered through another ROUTE session, and thus the ROUTE session needs to be indicated, a value of this field may be a value of a source IP address of the ROUTE session. In this case, this field may correspond to M, that is, an essential field. 
     @dIpAddr can indicate destination IP address. Here, a destination IP address may be a destination IP address of a ROUTE session that delivers a service component included in a service. For a similar case to the above description of @sIpAddr, this field may indicate a destination IP address of a ROUTE session that delivers a service component. A default value of this field may be a destination IP address of a current ROUTE session. When a service component is delivered through another ROUTE session, and thus the ROUTE session needs to be indicated, a value of this field may be a value of a destination IP address of the ROUTE session. In this case, this field may correspond to M, that is, an essential field. 
     @dport can indicate destination port. Here, a destination port may be a destination port of a ROUTE session that delivers a service component included in a service. For a similar case to the above description of @sIpAddr, this field may indicate a destination port of a ROUTE session that delivers a service component. A default value of this field may be a destination port number of a current ROUTE session. When a service component is delivered through another ROUTE session, and thus the ROUTE session needs to be indicated, a value of this field may be a destination port number value of the ROUTE session. In this case, this field may correspond to M, that is, an essential field. 
     @PLPID may be an ID of a PLP for a ROUTE session expressed by an RS. A default value may be an ID of a PLP of an LCT session including a current S-TSID. According to a given embodiment, this field may have an ID value of a PLP for an LCT session for delivering an S-TSID in the ROUTE session, and may have ID values of all PLPs for the ROUTE session. 
     An LS element may have information about an LCT session for delivering a service data. Service data or service components may be delivered through a plurality of LCT sessions, and thus the number of LS elements may be 1 to N. 
     The LS element may include @tsi, @PLPID, @bw, @startTime, @endTime, SrcFlow and/or RprFlow. 
     @tsi may indicate a TSI value of an LCT session for delivering a service component of a service. 
     @PLPID may have ID information of a PLP for the LCT session. This value may be overwritten on a basic ROUTE session value. 
     @bw may indicate a maximum bandwidth value. @startTime may indicate a start time of the LCT session. @endTime may indicate an end time of the LCT session. A SrcFlow element may describe a source flow of ROUTE. An RprFlow element may describe a repair flow of ROUTE. 
     The proposed default values may be varied according to an embodiment. The “use” column illustrated in the figure relates to each field. Here, M may denote an essential field, O may denote an optional field, OD may denote an optional field having a default value, and CM may denote a conditional essential field. 0 . . . 1 to 0 . . . N may indicate the number of available fields. 
     Hereinafter, a description will be given of MPD for ROUTE/DASH. 
     The MPD is an SLS metadata fragment which contains a formalized description of a DASH Media Presentation, corresponding to a linear service of a given duration defined by the broadcaster (for example a single TV program, or the set of contiguous linear TV programs over a period of time). The contents of the MPD provide the resource identifiers for Segments and the context for the identified resources within the Media Presentation. The data structure and semantics of the MPD fragment can be according to the MPD defined by MPEG DASH. 
     One or more of the DASH Representations conveyed in the MPD can be carried over broadcast. The MPD may describe additional Representations delivered over broadband, e.g. in the case of a hybrid service, or to support service continuity in handoff from broadcast to broadcast due to broadcast signal degradation (e.g. driving through a tunnel). 
       FIG. 7  illustrates a USBD/USD fragment for MMT according to an embodiment of the present invention. 
     MMT SLS for linear services comprises the USBD fragment and the MMT Package (MP) table. The MP table is as described above. The USBD fragment contains service identification, device capabilities information, references to other SLS information required to access the service and constituent media components, and the metadata to enable the receiver to determine the transport mode (broadcast and/or broadband) of the service components. The MP table for MPU components, referenced by the USBD, provides transport session descriptions for the MMTP sessions in which the media content components of a service are delivered and the descriptions of the Assets carried in those MMTP sessions. 
     The streaming content signaling component of the SLS for MPU components corresponds to the MP table defined in MMT. The MP table provides a list of MMT assets where each asset corresponds to a single service component and the description of the location information for this component. 
     USBD fragments may also contain references to the S-TSID and the MPD as described above, for service components delivered by the ROUTE protocol and the broadband, respectively. According to a given embodiment, in delivery through MMT, a service component delivered through the ROUTE protocol is NRT data, etc. Thus, in this case, MPD may be unnecessary. In addition, in delivery through MMT, information about an LCT session for delivering a service component, which is delivered via broadband, is unnecessary, and thus an S-TSID may be unnecessary. Here, an MMT package may be a logical collection of media data delivered using MMT. Here, an MMTP packet may refer to a formatted unit of media data delivered using MMT. An MPU may refer to a generic container of independently decodable timed/non-timed data. Here, data in the MPU is media codec agnostic. 
     Hereinafter, a description will be given of details of the USBD/USD illustrated in the figure. 
     The illustrated USBD fragment is an example of the present invention, and basic fields of the USBD fragment may be additionally provided according to an embodiment. As described in the foregoing, the illustrated USBD fragment has an extended form, and may have fields added to a basic structure. 
     The illustrated USBD according to an embodiment of the present invention is expressed as an XML document. According to a given embodiment, the USBD may be expressed in a binary format or as an XML document. 
     The illustrated USBD may have a bundleDescription root element. The bundleDescription root element may have a userServiceDescription element. The userServiceDescription element may be an instance for one service. 
     The userServiceDescription element may include @serviceId, @atsc:serviceId, name, serviceLanguage, atsc:capabilityCode, atsc:Channel, atsc:mpuComponent, atsc:routeComponent, atsc:broadbandComponent and/or atsc:ComponentInfo. 
     Here, @serviceId, @atsc:serviceId, name, serviceLanguage, and atsc:capabilityCode may be as described above. The lang field below the name field may be as described above. atsc:capabilityCode may be omitted according to a given embodiment. 
     The userServiceDescription element may further include an atsc:contentAdvisoryRating element according to an embodiment. This element may be an optional element. atsc:contentAdvisoryRating can specify the content advisory rating. This field is not illustrated in the figure. 
     atsc:Channel may have information about a channel of a service. The atsc:Channel element may include @atsc:majorChannelNo, @atsc:minorChannelNo, @atsc:serviceLang, @atsc:serviceGenre, @atsc:serviceIcon and/or atsc:ServiceDescription. @atsc:majorChannelNo, @atsc:minorChannelNo, and @atsc:serviceLang may be omitted according to a given embodiment. 
     @atsc:majorChannelNo is an attribute that indicates the major channel number of the service. 
     @atsc:minorChannelNo is an attribute that indicates the minor channel number of the service. 
     @atsc:serviceLang is an attribute that indicates the primary language used in the service. 
     @atsc:serviceGenre is an attribute that indicates primary genre of the service. 
     @atsc:serviceIcon is an attribute that indicates the Uniform Resource Locator (URL) for the icon used to represent this service. 
     atsc:ServiceDescription includes service description, possibly in multiple languages. atsc:ServiceDescription includes can include @atsc:serviceIDescrText and/or @atsc: serviceIDescrLang. 
     @atsc:serviceIDescrText is an attribute that indicates description of the service. 
     @atsc:serviceIDescrLang is an attribute that indicates the language of the serviceIDescrText attribute above. 
     atsc:mpuComponent may have information about a content component of a service delivered in a form of an MPU. atsc:mpuComponent may include @atsc:mmtPackageId and/or @atsc:nextMmtPackageId. 
     @atsc:mmtPackageId can reference a MMT Package for content components of the service delivered as MPUs. 
     @atsc:nextMmtPackageId can reference a MMT Package to be used after the one referenced by @atsc:mmtPackageId in time for content components of the service delivered as MPUs. 
     atsc:routeComponent may have information about a content component of a service delivered through ROUTE. atsc:routeComponent may include @atsc:sTSIDUri, @sTSIDPlpId, @sT SIDDestinationIpAddress, @sTSIDDestinationUdpPort, @sTSIDSourceIpAddress, @sTSIDMajorProtocol Version and/or @sTSIDMinorProtocolVersion. 
     @atsc:sTSIDUri can be a reference to the S-TSID fragment which provides access related parameters to the Transport sessions carrying contents of this service. This field may be the same as a URI for referring to an S-TSID in USBD for ROUTE described above. As described in the foregoing, in service delivery by the MMTP, service components, which are delivered through NRT, etc., may be delivered by ROUTE. This field may be used to refer to the S-TSID therefor. 
     @sTSIDPlpId can be a string representing an integer number indicating the PLP ID of the physical layer pipe carrying the S-TSID for this service. (default: current physical layer pipe). 
     @sTSIDDestinationIpAddress can be a string containing the dotted-IPv4 destination address of the packets carrying S-TSID for this service. (default: current MMTP session&#39;s source IP address) 
     @sTSIDDestinationUdpPort can be a string containing the port number of the packets carrying S-TSID for this service. 
     @sTSIDSourceIpAddress can be a string containing the dotted-IPv4 source address of the packets carrying S-TSID for this service. 
     @sTSIDMajorProtocolVersion can indicate major version number of the protocol used to deliver the S-TSID for this service. Default value is 1. 
     @sTSIDMinorProtocolVersion can indicate minor version number of the protocol used to deliver the S-TSID for this service. Default value is 0. 
     atsc:broadbandComponent may have information about a content component of a service delivered via broadband. In other words, atsc:broadbandComponent may be a field on the assumption of hybrid delivery. atsc:broadbandComponent may further include @atsc:fullfMPDUri. 
     @atsc:fullfMPDUri can be a reference to an MPD fragment which contains descriptions for contents components of the service delivered over broadband. 
     An atsc:ComponentInfo field may have information about an available component of a service. The atsc:ComponentInfo field may have information about a type, a role, a name, etc. of each component. The number of atsc:ComponentInfo fields may correspond to the number (N) of respective components. The atsc:ComponentInfo field may include @atsc:componentType, @atsc:componentRole, @atsc:componentProtectedFlag, @atsc:componentId and/or @atsc:componentName. 
     @atsc:componentType is an attribute that indicates the type of this component. Value of 0 indicates an audio component. Value of 1 indicates a video component. Value of 2 indicated a closed caption component. Value of 3 indicates an application component. Values 4 to 7 are reserved. A meaning of a value of this field may be differently set depending on embodiments. 
     @atsc:componentRole is an attribute that indicates the role or kind of this component. 
     For audio (when componentType attribute above is equal to 0): values of componentRole attribute are as follows: 0=Complete main, 1=Music and Effects, 2=Dialog, 3=Commentary, 4=Visually Impaired, 5=Hearing Impaired, 6=Voice-Over, 7-254=reserved, 255=unknown. 
     For video (when componentType attribute above is equal to 1) values of componentRole attribute are as follows: 0=Primary video, 1=Alternative camera view, 2=Other alternative video component, 3=Sign language inset, 4=Follow subject video, 5=3D video left view, 6=3D video right view, 7=3D video depth information, 8=Part of video array &lt;x,y&gt; of &lt;n,m&gt;, 9=Follow-Subject metadata, 10-254=reserved, 255=unknown. 
     For Closed Caption component (when componentType attribute above is equal to 2) values of componentRole attribute are as follows: 0=Normal, 1=Easy reader, 2-254=reserved, 255=unknown. 
     When componentType attribute above is between 3 to 7, inclusive, the componentRole can be equal to 255. A meaning of a value of this field may be differently set depending on embodiments. 
     @atsc:componentProtectedFlag is an attribute that indicates if this component is protected (e.g. encrypted). When this flag is set to a value of 1 this component is protected (e.g. encrypted). When this flag is set to a value of 0 this component is not protected (e.g. encrypted). When not present the value of componentProtectedFlag attribute is inferred to be equal to 0. A meaning of a value of this field may be differently set depending on embodiments. 
     @atsc:componentId is an attribute that indicates the identifier of this component. The value of this attribute can be the same as the asset_id in the MP table corresponding to this component. 
     @atsc:componentName is an attribute that indicates the human readable name of this component. 
     The proposed default values may vary depending on embodiments. The “use” column illustrated in the figure relates to each field. Here, M may denote an essential field, O may denote an optional field, OD may denote an optional field having a default value, and CM may denote a conditional essential field. 0 . . . 1 to 0 . . . N may indicate the number of available fields. 
     Hereinafter, a description will be given of MPD for MMT. 
     The Media Presentation Description is an SLS metadata fragment corresponding to a linear service of a given duration defined by the broadcaster (for example a single TV program, or the set of contiguous linear TV programs over a period of time). The contents of the MPD provide the resource identifiers for segments and the context for the identified resources within the media presentation. The data structure and semantics of the MPD can be according to the MPD defined by MPEG DASH. 
     In the present embodiment, an MPD delivered by an MMTP session describes Representations delivered over broadband, e.g. in the case of a hybrid service, or to support service continuity in handoff from broadcast to broadband due to broadcast signal degradation (e.g. driving under a mountain or through a tunnel). 
     Hereinafter, a description will be given of an MMT signaling message for MMT. 
     When MMTP sessions are used to carry a streaming service, MMT signaling messages defined by MMT are delivered by MMTP packets according to signaling message mode defined by MMT. The value of the packet_id field of MMTP packets carrying service layer signaling is set to ‘00’ except for MMTP packets carrying MMT signaling messages specific to an asset, which can be set to the same packet id value as the MMTP packets carrying the asset. Identifiers referencing the appropriate package for each service are signaled by the USBD fragment as described above. MMT Package Table (MPT) messages with matching MMT_package_id can be delivered on the MMTP session signaled in the SLT. Each MMTP session carries MMT signaling messages specific to its session or each asset delivered by the MMTP session. 
     In other words, it is possible to access USBD of the MMTP session by specifying an IP destination address/port number, etc. of a packet having the SLS for a particular service in the SLT. As described in the foregoing, a packet ID of an MMTP packet carrying the SLS may be designated as a particular value such as 00, etc. It is possible to access an MPT message having a matched packet ID using the above-described package IP information of USBD. As described below, the MPT message may be used to access each service component/asset. 
     The following MMTP messages can be delivered by the MMTP session signaled in the SLT. 
     MMT Package Table (MPT) message: This message carries an MP (MMT Package) table which contains the list of all Assets and their location information as defined by MMT. If an Asset is delivered by a PLP different from the current PLP delivering the MP table, the identifier of the PLP carrying the asset can be provided in the MP table using physical layer pipe identifier descriptor. The physical layer pipe identifier descriptor will be described below. 
     MMT ATSC3 (MA3) message mmt_atsc3_message( ): This message carries system metadata specific for services including service layer signaling as described above. mmt_atsc3_message( ) will be described below. 
     The following MMTP messages can be delivered by the MMTP session signaled in the SLT, if required. 
     Media Presentation Information (MPI) message: This message carries an MPI table which contains the whole document or a subset of a document of presentation information. An MP table associated with the MPI table also can be delivered by this message. 
     Clock Relation Information (CRI) message: This message carries a CRI table which contains clock related information for the mapping between the NTP timestamp and the MPEG-2 STC. According to a given embodiment, the CRI message may not be delivered through the MMTP session. 
     The following MMTP messages can be delivered by each MMTP session carrying streaming content. 
     Hypothetical Receiver Buffer Model message: This message carries information required by the receiver to manage its buffer. 
     Hypothetical Receiver Buffer Model Removal message: This message carries information required by the receiver to manage its MMT de-capsulation buffer. 
     Hereinafter, a description will be given of mmt_atsc3_message( ) corresponding to one of MMT signaling messages. An MMT Signaling message mmt_atsc3_message( ) is defined to deliver information specific to services according to the present invention described above. The signaling message may include message ID, version, and/or length fields corresponding to basic fields of the MMT signaling message. A payload of the signaling message may include service ID information, content type information, content version information, content compression information and/or URI information. The content type information may indicate a type of data included in the payload of the signaling message. The content version information may indicate a version of data included in the payload, and the content compression information may indicate a type of compression applied to the data. The URI information may have URI information related to content delivered by the message. 
     Hereinafter, a description will be given of the physical layer pipe identifier descriptor. 
     The physical layer pipe identifier descriptor is a descriptor that can be used as one of descriptors of the MP table described above. The physical layer pipe identifier descriptor provides information about the PLP carrying an asset. If an asset is delivered by a PLP different from the current PLP delivering the MP table, the physical layer pipe identifier descriptor can be used as an asset descriptor in the associated MP table to identify the PLP carrying the asset. The physical layer pipe identifier descriptor may further include BSID information in addition to PLP ID information. The BSID may be an ID of a broadcast stream that delivers an MMTP packet for an asset described by the descriptor. 
       FIG. 8  illustrates a link layer protocol architecture according to an embodiment of the present invention. 
     Hereinafter, a link layer will be described. 
     The link layer is the layer between the physical layer and the network layer, and transports the data from the network layer to the physical layer at the sending side and transports the data from the physical layer to the network layer at the receiving side. The purpose of the link layer includes abstracting all input packet types into a single format for processing by the physical layer, ensuring flexibility and future extensibility for as yet undefined input types. In addition, processing within the link layer ensures that the input data can be transmitted in an efficient manner, for example by providing options to compress redundant information in the headers of input packets. The operations of encapsulation, compression and so on are referred to as the link layer protocol and packets created using this protocol are called link layer packets. The link layer may perform functions such as packet encapsulation, overhead reduction and/or signaling transmission, etc. 
     Hereinafter, packet encapsulation will be described. Link layer protocol allows encapsulation of any type of packet, including ones such as IP packets and MPEG-2 TS. Using link layer protocol, the physical layer need only process one single packet format, independent of the network layer protocol type (here we consider MPEG-2 TS packet as a kind of network layer packet.) Each network layer packet or input packet is transformed into the payload of a generic link layer packet. Additionally, concatenation and segmentation can be performed in order to use the physical layer resources efficiently when the input packet sizes are particularly small or large. 
     As described in the foregoing, segmentation may be used in packet encapsulation. When the network layer packet is too large to process easily in the physical layer, the network layer packet is divided into two or more segments. The link layer packet header includes protocol fields to perform segmentation on the sending side and reassembly on the receiving side. When the network layer packet is segmented, each segment can be encapsulated to link layer packet in the same order as original position in the network layer packet. Also each link layer packet which includes a segment of network layer packet can be transported to PHY layer consequently. 
     As described in the foregoing, concatenation may be used in packet encapsulation. When the network layer packet is small enough for the payload of a link layer packet to include several network layer packets, the link layer packet header includes protocol fields to perform concatenation. The concatenation is combining of multiple small sized network layer packets into one payload. When the network layer packets are concatenated, each network layer packet can be concatenated to payload of link layer packet in the same order as original input order. Also each packet which constructs a payload of link layer packet can be whole packet, not a segment of packet. 
     Hereinafter, overhead reduction will be described. Use of the link layer protocol can result in significant reduction in overhead for transport of data on the physical layer. The link layer protocol according to the present invention may provide IP overhead reduction and/or MPEG-2 TS overhead reduction. In IP overhead reduction, IP packets have a fixed header format, however some of the information which is needed in a communication environment may be redundant in a broadcast environment. Link layer protocol provides mechanisms to reduce the broadcast overhead by compressing headers of IP packets. In MPEG-2 TS overhead reduction, link layer protocol provides sync byte removal, null packet deletion and/or common header removal (compression). First, sync byte removal provides an overhead reduction of one byte per TS packet, secondly a null packet deletion mechanism removes the 188 byte null TS packets in a manner that they can be re-inserted at the receiver and finally a common header removal mechanism. 
     For signaling transmission, in the link layer protocol, a particular format for the signaling packet may be provided for link layer signaling, which will be described below. 
     In the illustrated link layer protocol architecture according to an embodiment of the present invention, link layer protocol takes as input network layer packets such as IPv4, MPEG-2 TS and so on as input packets. Future extension indicates other packet types and protocol which is also possible to be input in link layer. Link layer protocol also specifies the format and signaling for any link layer signaling, including information about mapping to specific channel to the physical layer. Figure also shows how ALP incorporates mechanisms to improve the efficiency of transmission, via various header compression and deletion algorithms. In addition, the link layer protocol may basically encapsulate input packets. 
       FIG. 9  illustrates a structure of a base header of a link layer packet according to an embodiment of the present invention. Hereinafter, the structure of the header will be described. 
     A link layer packet can include a header followed by the data payload. The header of a link layer packet can include a base header, and may include an additional header depending on the control fields of the base header. The presence of an optional header is indicated from flag fields of the additional header. According to a given embodiment, a field indicating the presence of an additional header and an optional header may be positioned in the base header. 
     Hereinafter, the structure of the base header will be described. The base header for link layer packet encapsulation has a hierarchical structure. The base header can be two bytes in length and is the minimum length of the link layer packet header. 
     The illustrated base header according to the present embodiment may include a Packet_Type field, a PC field and/or a length field. According to a given embodiment, the base header may further include an HM field or an S/C field. 
     Packet_Type field can be a 3-bit field that indicates the original protocol or packet type of the input data before encapsulation into a link layer packet. An IPv4 packet, a compressed IP packet, a link layer signaling packet, and other types of packets may have the base header structure and may be encapsulated. However, according to a given embodiment, the MPEG-2 TS packet may have a different particular structure, and may be encapsulated. When the value of Packet_Type is “000”, “001” “100” or “111”, that is the original data type of an ALP packet is one of an IPv4 packet, a compressed IP packet, link layer signaling or extension packet. When the MPEG-2 TS packet is encapsulated, the value of Packet_Type can be “010”. Other values of the Packet_Type field may be reserved for future use. 
     Payload_Configuration (PC) field can be a 1-bit field that indicates the configuration of the payload. A value of 0 can indicate that the link layer packet carries a single, whole input packet and the following field is the Header_Mode field. A value of 1 can indicate that the link layer packet carries more than one input packet (concatenation) or a part of a large input packet (segmentation) and the following field is the Segmentation_Concatenation field. 
     Header_Mode (HM) field can be a 1-bit field, when set to 0, that can indicate there is no additional header, and that the length of the payload of the link layer packet is less than 2048 bytes. This value may be varied depending on embodiments. A value of 1 can indicate that an additional header for single packet defined below is present following the Length field. In this case, the length of the payload is larger than 2047 bytes and/or optional features can be used (sub stream identification, header extension, etc.). This value may be varied depending on embodiments. This field can be present only when Payload_Configuration field of the link layer packet has a value of 0. 
     Segmentation_Concatenation (S/C) field can be a 1-bit field, when set to 0, that can indicate that the payload carries a segment of an input packet and an additional header for segmentation defined below is present following the Length field. A value of 1 can indicate that the payload carries more than one complete input packet and an additional header for concatenation defined below is present following the Length field. This field can be present only when the value of Payload_Configuration field of the ALP packet is 1. 
     Length field can be an 11-bit field that indicates the 11 least significant bits (LSBs) of the length in bytes of payload carried by the link layer packet. When there is a Length_MSB field in the following additional header, the length field is concatenated with the Length_MSB field, and is the LSB to provide the actual total length of the payload. The number of bits of the length field may be changed to another value rather than 11 bits. 
     Following types of packet configuration are thus possible: a single packet without any additional header, a single packet with an additional header, a segmented packet and a concatenated packet. According to a given embodiment, more packet configurations may be made through a combination of each additional header, an optional header, an additional header for signaling information to be described below, and an additional header for time extension. 
       FIG. 10  illustrates a structure of an additional header of a link layer packet according to an embodiment of the present invention. 
     Various types of additional headers may be present. Hereinafter, a description will be given of an additional header for a single packet. 
     This additional header for single packet can be present when Header_Mode (HM)=“1”. The Header_Mode (HM) can be set to 1 when the length of the payload of the link layer packet is larger than 2047 bytes or when the optional fields are used. The additional header for single packet is shown in Figure (tsib 10010 ). 
     Length_MSB field can be a 5-bit field that can indicate the most significant bits (MSBs) of the total payload length in bytes in the current link layer packet, and is concatenated with the Length field containing the 11 least significant bits (LSBs) to obtain the total payload length. The maximum length of the payload that can be signaled is therefore 65535 bytes. The number of bits of the length field may be changed to another value rather than 11 bits. In addition, the number of bits of the Length MSB field may be changed, and thus a maximum expressible payload length may be changed. According to a given embodiment, each length field may indicate a length of a whole link layer packet rather than a payload. 
     SIF (Sub stream Identifier Flag) field can be a 1-bit field that can indicate whether the sub stream ID (SID) is present after the HEF field or not. When there is no SID in this link layer packet, SIF field can be set to 0. When there is a SID after HEF field in the link layer packet, SIF can be set to 1. The detail of SID is described below. 
     HEF (Header Extension Flag) field can be a 1-bit field that can indicate, when set to 1, presence of an additional header for future extension. A value of 0 can indicate that this extension header is not present. 
     Hereinafter, a description will be given of an additional header when segmentation is used. 
     This additional header (tsib 10020 ) can be present when Segmentation_Concatenation (S/C)=“0”. Segment_Sequence Number can be a 5-bit unsigned integer that can indicate the order of the corresponding segment carried by the link layer packet. For the link layer packet which carries the first segment of an input packet, the value of this field can be set to 0x0. This field can be incremented by one with each additional segment belonging to the segmented input packet. 
     Last_Segment Indicator (LSI) can be a 1-bit field that can indicate, when set to 1, that the segment in this payload is the last one of input packet. A value of 0, can indicate that it is not last segment. 
     SIF (Sub stream Identifier Flag) can be a 1-bit field that can indicate whether the SID is present after the HEF field or not. When there is no SID in the link layer packet, SIF field can be set to 0. When there is a SID after the HEF field in the link layer packet, SIF can be set to 1. 
     HEF (Header Extension Flag) can be a This 1-bit field that can indicate, when set to 1, that the optional header extension is present after the additional header for future extensions of the link layer header. A value of 0 can indicate that optional header extension is not present. 
     According to a given embodiment, a packet ID field may be additionally provided to indicate that each segment is generated from the same input packet. This field may be unnecessary and thus be omitted when segments are transmitted in order. 
     Hereinafter, a description will be given of an additional header when concatenation is used. 
     This additional header (tsib 10030 ) can be present when Segmentation_Concatenation (S/C)=“1”. 
     Length_MSB can be a 4-bit field that can indicate MSB bits of the payload length in bytes in this link layer packet. The maximum length of the payload is 32767 bytes for concatenation. As described in the foregoing, a specific numeric value may be changed. 
     Count can be a field that can indicate the number of the packets included in the link layer packet. The number of the packets included in the link layer packet, 2 can be set to this field. So, its maximum value of concatenated packets in a link layer packet is 9. A scheme in which the count field indicates the number may be varied depending on embodiments. That is, the numbers from 1 to 8 may be indicated. 
     HEF (Header Extension Flag) can be a 1-bit field that can indicate, when set to 1 the optional header extension is present after the additional header for future extensions of the link layer header. A value of 0, can indicate extension header is not present. 
     Component_Length can be a 12-bit length field that can indicate the length in byte of each packet. Component Length fields are included in the same order as the packets present in the payload except last component packet. The number of length field can be indicated by (Count+1). According to a given embodiment, length fields, the number of which is the same as a value of the count field, may be present. When a link layer header consists of an odd number of Component Length, four stuffing bits can follow after the last Component Length field. These bits can be set to 0. According to a given embodiment, a Component length field indicating a length of a last concatenated input packet may not be present. In this case, the length of the last concatenated input packet may correspond to a length obtained by subtracting a sum of values indicated by respective Component length fields from a whole payload length. 
     Hereinafter, the optional header will be described. 
     As described in the foregoing, the optional header may be added to a rear of the additional header. The optional header field can contain SID and/or header extension. The SID is used to filter out specific packet stream in the link layer level. One example of SID is the role of service identifier in a link layer stream carrying multiple services. The mapping information between a service and the SID value corresponding to the service can be provided in the SLT, if applicable. The header extension contains extended field for future use. Receivers can ignore any header extensions which they do not understand. 
     SID (Sub stream Identifier) can be a 8-bit field that can indicate the sub stream identifier for the link layer packet. If there is optional header extension, SID present between additional header and optional header extension. 
     Header_Extension ( ) can include the fields defined below. 
     Extension_Type can be an 8-bit field that can indicate the type of the Header_Extension ( ). 
     Extension_Length can be an 8-bit field that can indicate the length of the Header Extension ( ) in bytes counting from the next byte to the last byte of the Header_Extension ( ). 
     Extension Byte can be a byte representing the value of the Header_Extension 0. 
       FIG. 11  illustrates a structure of an additional header of a link layer packet according to another embodiment of the present invention. 
     Hereinafter, a description will be given of an additional header for signaling information. 
     How link layer signaling is incorporated into link layer packets are as follows. Signaling packets are identified by when the Packet_Type field of the base header is equal to 100. 
     Figure (tsib 11010 ) shows the structure of the link layer packets containing additional header for signaling information. In addition to the link layer header, the link layer packet can consist of two additional parts, additional header for signaling information and the actual signaling data itself. The total length of the link layer signaling packet is shown in the link layer packet header. 
     The additional header for signaling information can include following fields. According to a given embodiment, some fields may be omitted. 
     Signaling_Type can be an 8-bit field that can indicate the type of signaling. 
     Signaling_Type_Extension can be a 16-bit filed that can indicate the attribute of the signaling. Detail of this field can be defined in signaling specification. 
     Signaling_Version can be an 8-bit field that can indicate the version of signaling. 
     Signaling Format can be a 2-bit field that can indicate the data format of the signaling data. Here, a signaling format may refer to a data format such as a binary format, an XML format, etc. 
     Signaling_Encoding can be a 2-bit field that can specify the encoding/compression format. This field may indicate whether compression is not performed and which type of compression is performed. 
     Hereinafter, a description will be given of an additional header for packet type extension. 
     In order to provide a mechanism to allow an almost unlimited number of additional protocol and packet types to be carried by link layer in the future, the additional header is defined. Packet type extension can be used when Packet type is 111 in the base header as described above. Figure (tsib 11020 ) shows the structure of the link layer packets containing additional header for type extension. 
     The additional header for type extension can include following fields. According to a given embodiment, some fields may be omitted. 
     extended type can be a 16-bit field that can indicate the protocol or packet type of the input encapsulated in the link layer packet as payload. This field cannot be used for any protocol or packet type already defined by Packet_Type field. 
       FIG. 12  illustrates a header structure of a link layer packet for an MPEG-2 TS packet and an encapsulation process thereof according to an embodiment of the present invention. 
     Hereinafter, a description will be given of a format of the link layer packet when the MPEG-2 TS packet is input as an input packet. 
     In this case, the Packet_Type field of the base header is equal to 010. Multiple TS packets can be encapsulated within each link layer packet. The number of TS packets is signaled via the NUMTS field. In this case, as described in the foregoing, a particular link layer packet header format may be used. 
     Link layer provides overhead reduction mechanisms for MPEG-2 TS to enhance the transmission efficiency. The sync byte (0x47) of each TS packet can be deleted. The option to delete NULL packets and similar TS headers is also provided. 
     In order to avoid unnecessary transmission overhead, TS null packets (PID=OxlFFF) may be removed. Deleted null packets can be recovered in receiver side using DNP field. The DNP field indicates the count of deleted null packets. Null packet deletion mechanism using DNP field is described below. 
     In order to achieve more transmission efficiency, similar header of MPEG-2 TS packets can be removed. When two or more successive TS packets have sequentially increased continuity counter fields and other header fields are the same, the header is sent once at the first packet and the other headers are deleted. HDM field can indicate whether the header deletion is performed or not. Detailed procedure of common TS header deletion is described below. 
     When all three overhead reduction mechanisms are performed, overhead reduction can be performed in sequence of sync removal, null packet deletion, and common header deletion. According to a given embodiment, a performance order of respective mechanisms may be changed. In addition, some mechanisms may be omitted according to a given embodiment. 
     The overall structure of the link layer packet header when using MPEG-2 TS packet encapsulation is depicted in Figure (tsib 12010 ). 
     Hereinafter, a description will be given of each illustrated field. Packet_Type can be a 3-bit field that can indicate the protocol type of input packet as describe above. For MPEG-2 TS packet encapsulation, this field can always be set to 010. 
     NUMTS (Number of TS packets) can be a 4-bit field that can indicate the number of TS packets in the payload of this link layer packet. A maximum of 16 TS packets can be supported in one link layer packet. The value of NUMTS=0 can indicate that 16 TS packets are carried by the payload of the link layer packet. For all other values of NUMTS, the same number of TS packets are recognized, e.g. NUMTS=0001 means one TS packet is carried. 
     AHF (Additional Header Flag) can be a field that can indicate whether the additional header is present of not. A value of 0 indicates that there is no additional header. A value of 1 indicates that an additional header of length 1-byte is present following the base header. If null TS packets are deleted or TS header compression is applied this field can be set to 1. The additional header for TS packet encapsulation consists of the following two fields and is present only when the value of AHF in this link layer packet is set to 1. 
     HDM (Header Deletion Mode) can be a 1-bit field that indicates whether TS header deletion can be applied to this link layer packet. A value of 1 indicates that TS header deletion can be applied. A value of “O” indicates that the TS header deletion method is not applied to this link layer packet. 
     DNP (Deleted Null Packets) can be a 7-bit field that indicates the number of deleted null TS packets prior to this link layer packet. A maximum of 128 null TS packets can be deleted. When HDM=0 the value of DNP=0 can indicate that 128 null packets are deleted. When HDM=1 the value of DNP=0 can indicate that no null packets are deleted. For all other values of DNP, the same number of null packets are recognized, e.g. DNP=5 means 5 null packets are deleted. 
     The number of bits of each field described above may be changed. According to the changed number of bits, a minimum/maximum value of a value indicated by the field may be changed. These numbers may be changed by a designer. 
     Hereinafter, SYNC byte removal will be described. 
     When encapsulating TS packets into the payload of a link layer packet, the SYNC byte (0x47) from the start of each TS packet can be deleted. Hence the length of the MPEG2-TS packet encapsulated in the payload of the link layer packet is always of length 187 bytes (instead of 188 bytes originally). 
     Hereinafter, null packet deletion will be described. 
     Transport Stream rules require that bit rates at the output of a transmitter&#39;s multiplexer and at the input of the receiver&#39;s de-multiplexer are constant in time and the end-to-end delay is also constant. For some Transport Stream input signals, null packets may be present in order to accommodate variable bitrate services in a constant bitrate stream. In this case, in order to avoid unnecessary transmission overhead, TS null packets (that is TS packets with PID=OxlFFF) may be removed. The process is carried-out in a way that the removed null packets can be re-inserted in the receiver in the exact place where they were originally, thus guaranteeing constant bitrate and avoiding the need for PCR time stamp updating. 
     Before generation of a link layer packet, a counter called DNP (Deleted Null-Packets) can first be reset to zero and then incremented for each deleted null packet preceding the first non-null TS packet to be encapsulated into the payload of the current link layer packet. Then a group of consecutive useful TS packets is encapsulated into the payload of the current link layer packet and the value of each field in its header can be determined. After the generated link layer packet is injected to the physical layer, the DNP is reset to zero. When DNP reaches its maximum allowed value, if the next packet is also a null packet, this null packet is kept as a useful packet and encapsulated into the payload of the next link layer packet. Each link layer packet can contain at least one useful TS packet in its payload. 
     Hereinafter, TS packet header deletion will be described. TS packet header deletion may be referred to as TS packet header compression. 
     When two or more successive TS packets have sequentially increased continuity counter fields and other header fields are the same, the header is sent once at the first packet and the other headers are deleted. When the duplicated MPEG-2 TS packets are included in two or more successive TS packets, header deletion cannot be applied in transmitter side. HDM field can indicate whether the header deletion is performed or not. When TS header deletion is performed, HDM can be set to 1. In the receiver side, using the first packet header, the deleted packet headers are recovered, and the continuity counter is restored by increasing it in order from that of the first header. 
     An example tsib 12020  illustrated in the figure is an example of a process in which an input stream of a TS packet is encapsulated into a link layer packet. First, a TS stream including TS packets having SYNC byte (0x47) may be input. First, sync bytes may be deleted through a sync byte deletion process. In this example, it is presumed that null packet deletion is not performed. 
     Here, it is presumed that packet headers of eight TS packets have the same field values except for CC, that is, a continuity counter field value. In this case, TS packet deletion/compression may be performed. Seven remaining TS packet headers are deleted except for a first TS packet header corresponding to CC=1. The processed TS packets may be encapsulated into a payload of the link layer packet. 
     In a completed link layer packet, a Packet_Type field corresponds to a case in which TS packets are input, and thus may have a value of 010. A NUMTS field may indicate the number of encapsulated TS packets. An AHF field may be set to 1 to indicate the presence of an additional header since packet header deletion is performed. An HDM field may be set to 1 since header deletion is performed. DNP may be set to 0 since null packet deletion is not performed. 
       FIG. 13  illustrates an example of adaptation modes in IP header compression according to an embodiment of the present invention (transmitting side). 
     Hereinafter, IP header compression will be described. 
     In the link layer, IP header compression/decompression scheme can be provided. IP header compression can include two parts: header compressor/decompressor and adaptation module. The header compression scheme can be based on the Robust Header Compression (RoHC). In addition, for broadcasting usage, adaptation function is added. 
     In the transmitter side, ROHC compressor reduces the size of header for each packet. Then, adaptation module extracts context information and builds signaling information from each packet stream. In the receiver side, adaptation module parses the signaling information associated with the received packet stream and attaches context information to the received packet stream. ROHC decompressor reconstructs the original IP packet by recovering the packet header. 
     The header compression scheme can be based on the RoHC as described above. In particular, in the present system, an RoHC framework can operate in a unidirctional mode (U mode) of the RoHC. In addition, in the present system, it is possible to use an RoHC UDP header compression profile which is identified by a profile identifier of 0x0002. 
     Hereinafter, adaptation will be described. 
     In case of transmission through the unidirectional link, if a receiver has no information of context, decompressor cannot recover the received packet header until receiving full context. This may cause channel change delay and turn on delay. For this reason, context information and configuration parameters between compressor and decompressor can be always sent with packet flow. 
     The Adaptation function provides out-of-band transmission of the configuration parameters and context information. Out-of-band transmission can be done through the link layer signaling. Therefore, the adaptation function is used to reduce the channel change delay and decompression error due to loss of context information. 
     Hereinafter, extraction of context information will be described. 
     Context information may be extracted using various schemes according to adaptation mode. In the present invention, three examples will be described below. The scope of the present invention is not restricted to the examples of the adaptation mode to be described below. Here, the adaptation mode may be referred to as a context extraction mode. 
     Adaptation Mode 1 (not illustrated) may be a mode in which no additional operation is applied to a basic RoHC packet stream. In other words, the adaptation module may operate as a buffer in this mode. Therefore, in this mode, context information may not be included in link layer signaling 
     In Adaptation Mode 2 (tsib 13010 ), the adaptation module can detect the IR packet from ROHC packet flow and extract the context information (static chain). After extracting the context information, each IR packet can be converted to an IR-DYN packet. The converted IR-DYN packet can be included and transmitted inside the ROHC packet flow in the same order as IR packet, replacing the original packet. 
     In Adaptation Mode 3 (tsib 13020 ), the adaptation module can detect the IR and IR-DYN packet from ROHC packet flow and extract the context information. The static chain and dynamic chain can be extracted from IR packet and dynamic chain can be extracted from IR-DYN packet. After extracting the context information, each IR and IR-DYN packet can be converted to a compressed packet. The compressed packet format can be the same with the next packet of IR or IR-DYN packet. The converted compressed packet can be included and transmitted inside the ROHC packet flow in the same order as IR or IR-DYN packet, replacing the original packet. 
     Signaling (context) information can be encapsulated based on transmission structure. For example, context information can be encapsulated to the link layer signaling. In this case, the packet type value can be set to “100”. 
     In the above-described Adaptation Modes 2 and 3, a link layer packet for context information may have a packet type field value of 100. In addition, a link layer packet for compressed IP packets may have a packet type field value of 001. The values indicate that each of the signaling information and the compressed IP packets are included in the link layer packet as described above. 
     Hereinafter, a description will be given of a method of transmitting the extracted context information. 
     The extracted context information can be transmitted separately from ROHC packet flow, with signaling data through specific physical data path. The transmission of context depends on the configuration of the physical layer path. The context information can be sent with other link layer signaling through the signaling data pipe. 
     In other words, the link layer packet having the context information may be transmitted through a signaling PLP together with link layer packets having other link layer signaling information (Packet_Type=100). Compressed IP packets from which context information is extracted may be transmitted through a general PLP (Packet_Type=001). Here, depending on embodiments, the signaling PLP may refer to an L1 signaling path. In addition, depending on embodiments, the signaling PLP may not be separated from the general PLP, and may refer to a particular and general PLP through which the signaling information is transmitted. 
     At a receiving side, prior to reception of a packet stream, a receiver may need to acquire signaling information. When receiver decodes initial PLP to acquire the signaling information, the context signaling can be also received. After the signaling acquisition is done, the PLP to receive packet stream can be selected. In other words, the receiver may acquire the signaling information including the context information by selecting the initial PLP. Here, the initial PLP may be the above-described signaling PLP. Thereafter, the receiver may select a PLP for acquiring a packet stream. In this way, the context information may be acquired prior to reception of the packet stream. 
     After the PLP for acquiring the packet stream is selected, the adaptation module can detect IR-DYN packet form received packet flow. Then, the adaptation module parses the static chain from the context information in the signaling data. This is similar to receiving the IR packet. For the same context identifier, IR-DYN packet can be recovered to IR packet. Recovered ROHC packet flow can be sent to ROHC decompressor. Thereafter, decompression may be started. 
       FIG. 14  illustrates a link mapping table (LMT) and an RoHC-U description table according to an embodiment of the present invention. 
     Hereinafter, link layer signaling will be described. 
     Generally, link layer signaling is operates under IP level. At the receiver side, link layer signaling can be obtained earlier than IP level signaling such as Service List Table (SLT) and Service Layer Signaling (SLS). Therefore, link layer signaling can be obtained before session establishment. 
     For link layer signaling, there can be two kinds of signaling according input path: internal link layer signaling and external link layer signaling. The internal link layer signaling is generated in link layer at transmitter side. And the link layer takes the signaling from external module or protocol. This kind of signaling information is considered as external link layer signaling. If some signaling need to be obtained prior to IP level signaling, external signaling is transmitted in format of link layer packet. 
     The link layer signaling can be encapsulated into link layer packet as described above. The link layer packets can carry any format of link layer signaling, including binary and XML. The same signaling information may not be transmitted in different formats for the link layer signaling. 
     Internal link layer signaling may include signaling information for link mapping. The Link Mapping Table (LMT) provides a list of upper layer sessions carried in a PLP. The LMT also provides addition information for processing the link layer packets carrying the upper layer sessions in the link layer. 
     An example of the LMT (tsib 14010 ) according to the present invention is illustrated. 
     signaling_type can be an 8-bit unsigned integer field that indicates the type of signaling carried by this table. The value of signaling_type field for Link Mapping Table (LMT) can be set to 0x01. 
     PLP_ID can be an 8-bit field that indicates the PLP corresponding to this table. 
     num_session can be an 8-bit unsigned integer field that provides the number of upper layer sessions carried in the PLP identified by the above PLP_ID field. When the value of signaling_type field is 0x01, this field can indicate the number of UDP/IP sessions in the PLP. 
     src_IP_add can be a 32-bit unsigned integer field that contains the source IP address of an upper layer session carried in the PLP identified by the PLP_ID field. 
     dst_IP_add can be a 32-bit unsigned integer field that contains the destination IP address of an upper layer session carried in the PLP identified by the PLP_ID field. 
     src_UDP_port can be a 16-bit unsigned integer field that represents the source UDP port number of an upper layer session carried in the PLP identified by the PLP_ID field. 
     dst_UDP_port can be a 16-bit unsigned integer field that represents the destination UDP port number of an upper layer session carried in the PLP identified by the PLP_ID field. 
     SID_flag can be a 1-bit Boolean field that indicates whether the link layer packet carrying the upper layer session identified by above 4 fields, Src_IP_add, Dst IP_add, Src_UDP_Port and Dst_UDP_Port, has an SID field in its optional header. When the value of this field is set to 0, the link layer packet carrying the upper layer session may not have an SID field in its optional header. When the value of this field is set to 1, the link layer packet carrying the upper layer session can have an SID field in its optional header and the value the SID field can be same as the following SID field in this table. 
     compressed_flag can be a 1-bit Boolean field that indicates whether the header compression is applied the link layer packets carrying the upper layer session identified by above 4 fields, Src IP add, Dst IP add, Src_UDP_Port and Dst_UDP_Port. When the value of this field is set to 0, the link layer packet carrying the upper layer session may have a value of 0x00 of Packet_Type field in its base header. When the value of this field is set to 1, the link layer packet carrying the upper layer session may have a value of 0x01 of Packet_Type field in its base header and the Context_ID field can be present. 
     SID can be an 8-bit unsigned integer field that indicates sub stream identifier for the link layer packets carrying the upper layer session identified by above 4 fields, Src_IP_add, Dst_IP_add, Src_UDP_Port and Dst_UDP_Port. This field can be present when the value of SID_flag is equal to 1. 
     context_id can be an 8-bit field that provides a reference for the context id (CID) provided in the ROHC-U description table. This field can be present when the value of compressed_flag is equal to 1. 
     An example of the RoHC-U description table (tsib 14020 ) according to the present invention is illustrated. As described in the foregoing, the RoHC-U adaptation module may generate information related to header compression. 
     signaling_type can be an 8-bit field that indicates the type of signaling carried by this table. The value of signaling_type field for ROHC-U description table (RDT) can be set to “0x02”. 
     PLP_ID can be an 8-bit field that indicates the PLP corresponding to this table. 
     context_id can be an 8-bit field that indicates the context id (CID) of the compressed IP stream. In this system, 8-bit CID can be used for large CID. 
     context_profile can be an 8-bit field that indicates the range of protocols used to compress the stream. This field can be omitted. 
     adaptation_mode can be a 2-bit field that indicates the mode of adaptation module in this PLP. Adaptation modes have been described above. 
     context_config can be a 2-bit field that indicates the combination of the context information. If there is no context information in this table, this field may be set to “OxO”. If the static_chain( ) or dynamic_chain( ) byte is included in this table, this field may be set to “0x01” or “0x02” respectively. If both of the static_chain( ) and dynamic_chain( ) byte are included in this table, this field may be set to “0x03”. 
     context_length can be an 8-bit field that indicates the length of the static chain byte sequence. This field can be omitted. 
     static_chain_byte ( ) can be a field that conveys the static information used to initialize the ROHC-U decompressor. The size and structure of this field depend on the context profile. 
     dynamic_chain_byte ( ) can be a field that conveys the dynamic information used to initialize the ROHC-U decompressor. The size and structure of this field depend on the context profile. 
     The static_chain_byte can be defined as sub-header information of IR packet. The dynamic_chain_byte can be defined as sub-header information of IR packet and IR-DYN packet. 
       FIG. 15  illustrates a structure of a link layer on a transmitter side according to an embodiment of the present invention. 
     The present embodiment presumes that an IP packet is processed. From a functional point of view, the link layer on the transmitter side may broadly include a link layer signaling part in which signaling information is processed, an overhead reduction part, and/or an encapsulation part. In addition, the link layer on the transmitter side may include a scheduler for controlling and scheduling an overall operation of the link layer and/or input and output parts of the link layer. 
     First, signaling information of an upper layer and/or a system parameter tsib 15010  may be delivered to the link layer. In addition, an IP stream including IP packets may be delivered to the link layer from an IP layer tsib 15110 . 
     As described above, the scheduler tsib 15020  may determine and control operations of several modules included in the link layer. The delivered signaling information and/or system parameter tsib 15010  may be filterer or used by the scheduler tsib 15020 . Information, which corresponds to a part of the delivered signaling information and/or system parameter tsib 15010 , necessary for a receiver may be delivered to the link layer signaling part. In addition, information, which corresponds to a part of the signaling information, necessary for an operation of the link layer may be delivered to an overhead reduction controller tsib 15120  or an encapsulation controller tsib 15180 . 
     The link layer signaling part may collect information to be transmitted as a signal in a physical layer, and convert/configure the information in a form suitable for transmission. The link layer signaling part may include a signaling manager tsib 15030 , a signaling formatter tsib 15040 , and/or a buffer for channels tsib 15050 . 
     The signaling manager tsib 15030  may receive signaling information delivered from the scheduler tsib 15020  and/or signaling (and/or context) information delivered from the overhead reduction part. The signaling manager tsib 15030  may determine a path for transmission of the signaling information for delivered data. The signaling information may be delivered through the path determined by the signaling manager tsib 15030 . As described in the foregoing, signaling information to be transmitted through a divided channel such as the FIC, the EAS, etc. may be delivered to the signaling formatter tsib 15040 , and other signaling information may be delivered to an encapsulation buffer tsib 15070 . 
     The signaling formatter tsib 15040  may format related signaling information in a form suitable for each divided channel such that signaling information may be transmitted through a separately divided channel. As described in the foregoing, the physical layer may include separate physically/logically divided channels. The divided channels may be used to transmit FIC signaling information or EAS-related information. The FIC or EAS-related information may be sorted by the signaling manager tsib 15030 , and input to the signaling formatter tsib 15040 . The signaling formatter tsib 15040  may format the information based on each separate channel. When the physical layer is designed to transmit particular signaling information through a separately divided channel other than the FIC and the EAS, a signaling formatter for the particular signaling information may be additionally provided. Through this scheme, the link layer may be compatible with various physical layers. 
     The buffer for channels tsib 15050  may deliver the signaling information received from the signaling formatter tsib 15040  to separate dedicated channels tsib 15060 . The number and content of the separate channels may vary depending on embodiments. 
     As described in the foregoing, the signaling manager tsib 15030  may deliver signaling information, which is not delivered to a particular channel, to the encapsulation buffer tsib 15070 . The encapsulation buffer tsib 15070  may function as a buffer that receives the signaling information which is not delivered to the particular channel. 
     An encapsulation block for signaling information tsib 15080  may encapsulate the signaling information which is not delivered to the particular channel. A transmission buffer tsib 15090  may function as a buffer that delivers the encapsulated signaling information to a DP for signaling information tsib 15100 . Here, the DP for signaling information tsib 15100  may refer to the above-described PLS region. 
     The overhead reduction part may allow efficient transmission by removing overhead of packets delivered to the link layer. It is possible to configure overhead reduction parts corresponding to the number of IP streams input to the link layer. 
     An overhead reduction buffer tsib 15130  may receive an IP packet delivered from an upper layer. The received IP packet may be input to the overhead reduction part through the overhead reduction buffer tsib 15130 . 
     An overhead reduction controller tsib 15120  may determine whether to perform overhead reduction on a packet stream input to the overhead reduction buffer tsib 15130 . The overhead reduction controller tsib 15120  may determine whether to perform overhead reduction for each packet stream. When overhead reduction is performed on a packet stream, packets may be delivered to a robust header compression (RoHC) compressor tsib 15140  to perform overhead reduction. When overhead reduction is not performed on a packet stream, packets may be delivered to the encapsulation part to perform encapsulation without overhead reduction. Whether to perform overhead reduction of packets may be determined based on the signaling information tsib 15010  delivered to the link layer. The signaling information may be delivered to the encapsulation controller tsib 15180  by the scheduler tsib 15020 . 
     The RoHC compressor tsib 15140  may perform overhead reduction on a packet stream. The RoHC compressor tsib 15140  may perform an operation of compressing a header of a packet. Various schemes may be used for overhead reduction. Overhead reduction may be performed using a scheme proposed by the present invention. The present invention presumes an IP stream, and thus an expression “RoHC compressor” is used. However, the name may be changed depending on embodiments. The operation is not restricted to compression of the IP stream, and overhead reduction of all types of packets may be performed by the RoHC compressor tsib 15140 . 
     A packet stream configuration block tsib 15150  may separate information to be transmitted to a signaling region and information to be transmitted to a packet stream from IP packets having compressed headers. The information to be transmitted to the packet stream may refer to information to be transmitted to a DP region. The information to be transmitted to the signaling region may be delivered to a signaling and/or context controller tsib 15160 . The information to be transmitted to the packet stream may be transmitted to the encapsulation part. 
     The signaling and/or context controller tsib 15160  may collect signaling and/or context information and deliver the signaling and/or context information to the signaling manager in order to transmit the signaling and/or context information to the signaling region. 
     The encapsulation part may perform an operation of encapsulating packets in a form suitable for a delivery to the physical layer. It is possible to configure encapsulation parts corresponding to the number of IP streams. 
     An encapsulation buffer tsib 15170  may receive a packet stream for encapsulation. Packets subjected to overhead reduction may be received when overhead reduction is performed, and an input IP packet may be received without change when overhead reduction is not performed. 
     An encapsulation controller tsib 15180  may determine whether to encapsulate an input packet stream. When encapsulation is performed, the packet stream may be delivered to a segmentation/concatenation block tsib 15190 . When encapsulation is not performed, the packet stream may be delivered to a transmission buffer tsib 15230 . Whether to encapsulate packets may be determined based on the signaling information tsib 15010  delivered to the link layer. The signaling information may be delivered to the encapsulation controller tsib 15180  by the scheduler tsib 15020 . 
     In the segmentation/concatenation block tsib 15190 , the above-described segmentation or concatenation operation may be performed on packets. In other words, when an input IP packet is longer than a link layer packet corresponding to an output of the link layer, one IP packet may be segmented into several segments to configure a plurality of link layer packet payloads. On the other hand, when an input IP packet is shorter than a link layer packet corresponding to an output of the link layer, several IP packets may be concatenated to configure one link layer packet payload. 
     A packet configuration table tsib 15200  may have configuration information of a segmented and/or concatenated link layer packet. A transmitter and a receiver may have the same information in the packet configuration table tsib 15200 . The transmitter and the receiver may refer to the information of the packet configuration table tsib 15200 . An index value of the information of the packet configuration table tsib 15200  may be included in a header of the link layer packet. 
     A link layer header information block tsib 15210  may collect header information generated in an encapsulation process. In addition, the link layer header information block tsib 15210  may collect header information included in the packet configuration table tsib 15200 . The link layer header information block tsib 15210  may configure header information according to a header structure of the link layer packet. 
     A header attachment block tsib 15220  may add a header to a payload of a segmented and/or concatenated link layer packet. The transmission buffer tsib 15230  may function as a buffer to deliver the link layer packet to a DP tsib 15240  of the physical layer. 
     The respective blocks, modules, or parts may be configured as one module/protocol or a plurality of modules/protocols in the link layer. 
       FIG. 16  illustrates a structure of a link layer on a receiver side according to an embodiment of the present invention. 
     The present embodiment presumes that an IP packet is processed. From a functional point of view, the link layer on the receiver side may broadly include a link layer signaling part in which signaling information is processed, an overhead processing part, and/or a decapsulation part. In addition, the link layer on the receiver side may include a scheduler for controlling and scheduling overall operation of the link layer and/or input and output parts of the link layer. 
     First, information received through a physical layer may be delivered to the link layer. The link layer may process the information, restore an original state before being processed at a transmitter side, and then deliver the information to an upper layer. In the present embodiment, the upper layer may be an IP layer. 
     Information, which is separated in the physical layer and delivered through a particular channel tsib 16030 , may be delivered to a link layer signaling part. The link layer signaling part may determine signaling information received from the physical layer, and deliver the determined signaling information to each part of the link layer. 
     A buffer for channels tsib 16040  may function as a buffer that receives signaling information transmitted through particular channels. As described in the foregoing, when physically/logically divided separate channels are present in the physical layer, it is possible to receive signaling information transmitted through the channels. When the information received from the separate channels is segmented, the segmented information may be stored until complete information is configured. 
     A signaling decoder/parser tsib 16050  may verify a format of the signaling information received through the particular channel, and extract information to be used in the link layer. When the signaling information received through the particular channel is encoded, decoding may be performed. In addition, according to a given embodiment, it is possible to verify integrity, etc. of the signaling information. 
     A signaling manager tsib 16060  may integrate signaling information received through several paths. Signaling information received through a DP for signaling tsib 16070  to be described below may be integrated in the signaling manager tsib 16060 . The signaling manager tsib 16060  may deliver signaling information necessary for each part in the link layer. For example, the signaling manager tsib 16060  may deliver context information, etc. for recovery of a packet to the overhead processing part. In addition, the signaling manager tsib 16060  may deliver signaling information for control to a scheduler tsib 16020 . 
     General signaling information, which is not received through a separate particular channel, may be received through the DP for signaling tsib 16070 . Here, the DP for signaling may refer to PLS, L1, etc. Here, the DP may be referred to as a PLP. A reception buffer tsib 16080  may function as a buffer that receives signaling information delivered from the DP for signaling. In a decapsulation block for signaling information tsib 16090 , the received signaling information may be decapsulated. The decapsulated signaling information may be delivered to the signaling manager tsib 16060  through a decapsulation buffer tsib 16100 . As described in the foregoing, the signaling manager tsib 16060  may collate signaling information, and deliver the collated signaling information to a necessary part in the link layer. 
     The scheduler tsib 16020  may determine and control operations of several modules included in the link layer. The scheduler tsib 16020  may control each part of the link layer using receiver information tsib 16010  and/or information delivered from the signaling manager tsib 16060 . In addition, the scheduler tsib 16020  may determine an operation mode, etc. of each part. Here, the receiver information tsib 16010  may refer to information previously stored in the receiver. The scheduler tsib 16020  may use information changed by a user such as channel switching, etc. to perform a control operation. 
     The decapsulation part may filter a packet received from a DP tsib 16110  of the physical layer, and separate a packet according to a type of the packet. It is possible to configure decapsulation parts corresponding to the number of DPs that can be simultaneously decoded in the physical layer. 
     The decapsulation buffer tsib 16100  may function as a buffer that receives a packet stream from the physical layer to perform decapsulation. A decapsulation controller tsib 16130  may determine whether to decapsulate an input packet stream. When decapsulation is performed, the packet stream may be delivered to a link layer header parser tsib 16140 . When decapsulation is not performed, the packet stream may be delivered to an output buffer tsib 16220 . The signaling information received from the scheduler tsib 16020  may be used to determine whether to perform decapsulation. 
     The link layer header parser tsib 16140  may identify a header of the delivered link layer packet. It is possible to identify a configuration of an IP packet included in a payload of the link layer packet by identifying the header. For example, the IP packet may be segmented or concatenated. 
     A packet configuration table tsib 16150  may include payload information of segmented and/or concatenated link layer packets. The transmitter and the receiver may have the same information in the packet configuration table tsib 16150 . The transmitter and the receiver may refer to the information of the packet configuration table tsib 16150 . It is possible to find a value necessary for reassembly based on index information included in the link layer packet. 
     A reassembly block tsib 16160  may configure payloads of the segmented and/or concatenated link layer packets as packets of an original IP stream. Segments may be collected and reconfigured as one IP packet, or concatenated packets may be separated and reconfigured as a plurality of IP packet streams. Recombined IP packets may be delivered to the overhead processing part. 
     The overhead processing part may perform an operation of restoring a packet subjected to overhead reduction to an original packet as a reverse operation of overhead reduction performed in the transmitter. This operation may be referred to as overhead processing. It is possible to configure overhead processing parts corresponding to the number of DPs that can be simultaneously decoded in the physical layer. 
     A packet recovery buffer tsib 16170  may function as a buffer that receives a decapsulated RoHC packet or IP packet to perform overhead processing. 
     An overhead controller tsib 16180  may determine whether to recover and/or decompress the decapsulated packet. When recovery and/or decompression are performed, the packet may be delivered to a packet stream recovery block tsib 16190 . When recovery and/or decompression are not performed, the packet may be delivered to the output buffer tsib 16220 . Whether to perform recovery and/or decompression may be determined based on the signaling information delivered by the scheduler tsib 16020 . 
     The packet stream recovery block tsib 16190  may perform an operation of integrating a packet stream separated from the transmitter with context information of the packet stream. This operation may be a process of restoring a packet stream such that an RoHC decompressor tsib 16210  can perform processing. In this process, it is possible to receive signaling information and/or context information from a signaling and/or context controller tsib 16200 . The signaling and/or context controller tsib 16200  may determine signaling information delivered from the transmitter, and deliver the signaling information to the packet stream recovery block tsib 16190  such that the signaling information may be mapped to a stream corresponding to a context ID. 
     The RoHC decompressor tsib 16210  may restore headers of packets of the packet stream. The packets of the packet stream may be restored to forms of original IP packets through restoration of the headers. In other words, the RoHC decompressor tsib 16210  may perform overhead processing. 
     The output buffer tsib 16220  may function as a buffer before an output stream is delivered to an IP layer tsib 16230 . 
     The link layers of the transmitter and the receiver proposed in the present invention may include the blocks or modules described above. In this way, the link layer may independently operate irrespective of an upper layer and a lower layer, overhead reduction may be efficiently performed, and a supportable function according to an upper/lower layer may be easily defined/added/deleted. 
       FIG. 17  illustrates a configuration of signaling transmission through a link layer according to an embodiment of the present invention (transmitting/receiving sides). 
     In the present invention, a plurality of service providers (broadcasters) may provide services within one frequency band. In addition, a service provider may provide a plurality of services, and one service may include one or more components. It can be considered that the user receives content using a service as a unit. 
     The present invention presumes that a transmission protocol based on a plurality of sessions is used to support an IP hybrid broadcast. Signaling information delivered through a signaling path may be determined based on a transmission configuration of each protocol. Various names may be applied to respective protocols according to a given embodiment. 
     In the illustrated data configuration tsib 17010  on the transmitting side, service providers (broadcasters) may provide a plurality of services (Service #1, #2, . . . ). In general, a signal for a service may be transmitted through a general transmission session (signaling C). However, the signal may be transmitted through a particular session (dedicated session) according to a given embodiment (signaling B). 
     Service data and service signaling information may be encapsulated according to a transmission protocol. According to a given embodiment, an IP/UDP layer may be used. According to a given embodiment, a signal in the IP/UDP layer (signaling A) may be additionally provided. This signaling may be omitted. 
     Data processed using the IP/UDP may be input to the link layer. As described in the foregoing, overhead reduction and/or encapsulation may be performed in the link layer. Here, link layer signaling may be additionally provided. Link layer signaling may include a system parameter, etc. Link layer signaling has been described above. 
     The service data and the signaling information subjected to the above process may be processed through PLPs in a physical layer. Here, a PLP may be referred to as a DP. The example illustrated in the figure presumes a case in which a base DP/PLP is used. However, depending on embodiments, transmission may be performed using only a general DP/PLP without the base DP/PLP. 
     In the example illustrated in the figure, a particular channel (dedicated channel) such as an FIC, an EAC, etc. is used. A signal delivered through the FIC may be referred to as a fast information table (FIT), and a signal delivered through the EAC may be referred to as an emergency alert table (EAT). The FIT may be identical to the above-described SLT. The particular channels may not be used depending on embodiments. When the particular channel (dedicated channel) is not configured, the FIT and the EAT may be transmitted using a general link layer signaling transmission scheme, or transmitted using a PLP via the IP/UDP as other service data. 
     According to a given embodiment, system parameters may include a transmitter-related parameter, a service provider-related parameter, etc. Link layer signaling may include IP header compression-related context information and/or identification information of data to which the context is applied. Signaling of an upper layer may include an IP address, a UDP number, service/component information, emergency alert-related information, an IP/UDP address for service signaling, a session ID, etc. Detailed examples thereof have been described above. 
     In the illustrated data configuration tsib 17020  on the receiving side, the receiver may decode only a PLP for a corresponding service using signaling information without having to decode all PLPs. 
     First, when the user selects or changes a service desired to be received, the receiver may be tuned to a corresponding frequency and may read receiver information related to a corresponding channel stored in a DB, etc. The information stored in the DB, etc. of the receiver may be configured by reading an SLT at the time of initial channel scan. 
     After receiving the SLT and the information about the corresponding channel, information previously stored in the DB is updated, and information about a transmission path of the service selected by the user and information about a path, through which component information is acquired or a signal necessary to acquire the information is transmitted, are acquired. When the information is not determined to be changed using version information of the SLT, decoding or parsing may be omitted. 
     The receiver may verify whether SLT information is included in a PLP by parsing physical signaling of the PLP in a corresponding broadcast stream (not illustrated), which may be indicated through a particular field of physical signaling. It is possible to access a position at which a service layer signal of a particular service is transmitted by accessing the SLT information. The service layer signal may be encapsulated into the IP/UDP and delivered through a transmission session. It is possible to acquire information about a component included in the service using this service layer signaling. A specific SLT-SLS configuration is as described above. 
     In other words, it is possible to acquire transmission path information, for receiving upper layer signaling information (service signaling information) necessary to receive the service, corresponding to one of several packet streams and PLPs currently transmitted on a channel using the SLT. The transmission path information may include an IP address, a UDP port number, a session ID, a PLP ID, etc. Here, depending on embodiments, a value previously designated by the IANA or a system may be used as an IP/UDP address. The information may be acquired using a scheme of accessing a DB or a shared memory, etc. 
     When the link layer signal and service data are transmitted through the same PLP, or only one PLP is operated, service data delivered through the PLP may be temporarily stored in a device such as a buffer, etc. while the link layer signal is decoded. 
     It is possible to acquire information about a path through which the service is actually transmitted using service signaling information of a service to be received. In addition, a received packet stream may be subjected to decapsulation and header recovery using information such as overhead reduction for a PLP to be received, etc. 
     In the illustrated example (tsib 17020 ), the FIC and the EAC are used, and a concept of the base DP/PLP is presumed. As described in the foregoing, concepts of the FIC, the EAC, and the base DP/PLP may not be used. 
     While MISO or MIMO uses two antennas in the following for convenience of description, the present invention is applicable to systems using two or more antennas. The present invention proposes a physical profile (or system) optimized to minimize receiver complexity while attaining the performance required for a particular use case. Physical (PHY) profiles (base, handheld and advanced profiles) according to an embodiment of the present invention are subsets of all configurations that a corresponding receiver should implement. The PHY profiles share most of the functional blocks but differ slightly in specific blocks and/or parameters. For the system evolution, future profiles may also be multiplexed with existing profiles in a single radio frequency (RF) channel through a future extension frame (FEF). The base profile and the handheld profile according to the embodiment of the present invention refer to profiles to which MIMO is not applied, and the advanced profile refers to a profile to which MIMO is applied. The base profile may be used as a profile for both the terrestrial broadcast service and the mobile broadcast service. That is, the base profile may be used to define a concept of a profile which includes the mobile profile. In addition, the advanced profile may be divided into an advanced profile for a base profile with MIMO and an advanced profile for a handheld profile with MIMO. Moreover, the profiles may be changed according to intention of the designer. 
     The following terms and definitions may be applied to the present invention. The following terms and definitions may be changed according to design. 
     Auxiliary stream: sequence of cells carrying data of as yet undefined modulation and coding, which may be used for future extensions or as required by broadcasters or network operators 
     Base data pipe: data pipe that carries service signaling data 
     Baseband frame (or BBFRAME): set of Kbch bits which form the input to one FEC encoding process (BCH and LDPC encoding) 
     Cell: modulation value that is carried by one carrier of orthogonal frequency division multiplexing (OFDM) transmission 
     Coded block: LDPC-encoded block of PLS1 data or one of the LDPC-encoded blocks of PLS2 data 
     Data pipe: logical channel in the physical layer that carries service data or related metadata, which may carry one or a plurality of service(s) or service component(s). 
     Data pipe unit (DPU): a basic unit for allocating data cells to a DP in a frame. 
     Data symbol: OFDM symbol in a frame which is not a preamble symbol (the data symbol encompasses the frame signaling symbol and frame edge symbol) 
     DP_ID: this 8-bit field identifies uniquely a DP within the system identified by the SYSTEM_ID 
     Dummy cell: cell carrying a pseudo-random value used to fill the remaining capacity not used for PLS signaling, DPs or auxiliary streams 
     Emergency alert channel (EAC): part of a frame that carries EAS information data 
     Frame: physical layer time slot that starts with a preamble and ends with a frame edge symbol 
     Frame repetition unit: a set of frames belonging to the same or different physical layer profiles including an FEF, which is repeated eight times in a superframe 
     Fast information channel (FIC): a logical channel in a frame that carries mapping information between a service and the corresponding base DP 
     FECBLOCK: set of LDPC-encoded bits of DP data 
     FFT size: nominal FFT size used for a particular mode, equal to the active symbol period Ts expressed in cycles of an elementary period T 
     Frame signaling symbol: OFDM symbol with higher pilot density used at the start of a frame in certain combinations of FFT size, guard interval and scattered pilot pattern, which carries a part of the PLS data 
     Frame edge symbol: OFDM symbol with higher pilot density used at the end of a frame in certain combinations of FFT size, guard interval and scattered pilot pattern 
     Frame group: the set of all frames having the same PHY profile type in a superframe 
     Future extension frame: physical layer time slot within the superframe that may be used for future extension, which starts with a preamble 
     Futurecast UTB system: proposed physical layer broadcast system, the input of which is one or more MPEG2-TS, IP or general stream(s) and the output of which is an RF signal 
     Input stream: a stream of data for an ensemble of services delivered to the end users by the system 
     Normal data symbol: data symbol excluding the frame signaling symbol and the frame edge symbol 
     PHY profile: subset of all configurations that a corresponding receiver should implement 
     PLS: physical layer signaling data including PLS1 and PLS2 
     PLS1: a first set of PLS data carried in a frame signaling symbol (FSS) having a fixed size, coding and modulation, which carries basic information about a system as well as parameters needed to decode PLS2 
     NOTE: PLS1 data remains constant for the duration of a frame group 
     PLS2: a second set of PLS data transmitted in the FSS, which carries more detailed PLS data about the system and the DPs 
     PLS2 dynamic data: PLS2 data that dynamically changes frame-by-frame 
     PLS2 static data: PLS2 data that remains static for the duration of a frame group 
     Preamble signaling data: signaling data carried by the preamble symbol and used to identify the basic mode of the system 
     Preamble symbol: fixed-length pilot symbol that carries basic PLS data and is located at the beginning of a frame 
     The preamble symbol is mainly used for fast initial band scan to detect the system signal, timing thereof, frequency offset, and FFT size. 
     Reserved for future use: not defined by the present document but may be defined in future 
     Superframe: set of eight frame repetition units 
     Time interleaving block (TI block): set of cells within which time interleaving is carried out, corresponding to one use of a time interleaver memory 
     TI group: unit over which dynamic capacity allocation for a particular DP is carried out, made up of an integer, dynamically varying number of XFECBLOCKs 
     NOTE: The TI group may be mapped directly to one frame or may be mapped to a plurality of frames. The TI group may contain one or more TI blocks. 
     Type 1 DP: DP of a frame where all DPs are mapped to the frame in time division multiplexing (TDM) scheme 
     Type 2 DP: DP of a frame where all DPs are mapped to the frame in frequency division multiplexing (FDM) scheme 
     XFECBLOCK: set of Nceiis cells carrying all the bits of one LDPC FECBLOCK 
       FIG. 18  illustrates a configuration of a broadcast signal transmission apparatus for future broadcast services according to an embodiment of the present invention. 
     The broadcast signal transmission apparatus for future broadcast services according to the present embodiment may include an input formatting block  1000 , a bit interleaved coding &amp; modulation (BICM) block  1010 , a frame building block  1020 , an OFDM generation block  1030  and a signaling generation block  1040 . Description will be given of an operation of each block of the broadcast signal transmission apparatus. 
     In input data according to an embodiment of the present invention, IP stream/packets and MPEG2-TS may be main input formats, and other stream types are handled as general streams. In addition to these data inputs, management information is input to control scheduling and allocation of the corresponding bandwidth for each input stream. In addition, the present invention allows simultaneous input of one or a plurality of TS streams, IP stream(s) and/or a general stream(s). 
     The input formatting block  1000  may demultiplex each input stream into one or a plurality of data pipes, to each of which independent coding and modulation are applied. A DP is the basic unit for robustness control, which affects QoS. One or a plurality of services or service components may be carried by one DP. The DP is a logical channel in a physical layer for delivering service data or related metadata capable of carrying one or a plurality of services or service components. 
     In addition, a DPU is a basic unit for allocating data cells to a DP in one frame. 
     An input to the physical layer may include one or a plurality of data streams. Each of the data streams is delivered by one DP. The input formatting block  1000  may covert a data stream input through one or more physical paths (or DPs) into a baseband frame (BBF). In this case, the input formatting block  1000  may perform null packet deletion or header compression on input data (a TS or IP input stream) in order to enhance transmission efficiency. A receiver may have a priori information for a particular part of a header, and thus this known information may be deleted from a transmitter. A null packet deletion block  3030  may be used only for a TS input stream. 
     In the BICM block  1010 , parity data is added for error correction and encoded bit streams are mapped to complex-value constellation symbols. The symbols are interleaved across a specific interleaving depth that is used for the corresponding DP. For the advanced profile, MIMO encoding is performed in the BICM block  1010  and an additional data path is added at the output for MIMO transmission. 
     The frame building block  1020  may map the data cells of the input DPs into the OFDM symbols within a frame, and perform frequency interleaving for frequency-domain diversity, especially to combat frequency-selective fading channels. The frame building block  1020  may include a delay compensation block, a cell mapper and a frequency interleaver. 
     The delay compensation block may adjust timing between DPs and corresponding PLS data to ensure that the DPs and the corresponding PLS data are co-timed at a transmitter side. The PLS data is delayed by the same amount as the data pipes by addressing the delays of data pipes caused by the input formatting block and BICM block. The delay of the BICM block is mainly due to the time interleaver. In-band signaling data carries information of the next TI group so that the information is carried one frame ahead of the DPs to be signaled. The delay compensation block delays in-band signaling data accordingly. 
     The cell mapper may map PLS, DPs, auxiliary streams, dummy cells, etc. to active carriers of the OFDM symbols in the frame. The basic function of the cell mapper  7010  is to map data cells produced by the TIs for each of the DPs, PLS cells, and EAC/FIC cells, if any, into arrays of active OFDM cells corresponding to each of the OFDM symbols within a frame. A basic function of the cell mapper is to map a data cell generated by time interleaving for each DP and PLS cell to an array of active OFDM cells (if present) corresponding to respective OFDM symbols in one frame. Service signaling data (such as program specific information (PSI)/SI) may be separately gathered and sent by a DP. The cell mapper operates according to dynamic information produced by a scheduler and the configuration of a frame structure. The frequency interleaver may randomly interleave data cells received from the cell mapper to provide frequency diversity. In addition, the frequency interleaver may operate on an OFDM symbol pair including two sequential OFDM symbols using a different interleaving-seed order to obtain maximum interleaving gain in a single frame. 
     The OFDM generation block  1030  modulates OFDM carriers by cells produced by the frame building block, inserts pilots, and produces a time domain signal for transmission. In addition, this block subsequently inserts guard intervals, and applies peak-to-average power ratio (PAPR) reduction processing to produce a final RF signal. 
     Specifically, after inserting a preamble at the beginning of each frame, the OFDM generation block  1030  may apply conventional OFDM modulation having a cyclic prefix as a guard interval. For antenna space diversity, a distributed MISO scheme is applied across transmitters. In addition, a PAPR scheme is performed in the time domain. For flexible network planning, the present invention provides a set of various FFT sizes, guard interval lengths and corresponding pilot patterns. 
     In addition, the present invention may multiplex signals of a plurality of broadcast transmission/reception systems in the time domain such that data of two or more different broadcast transmission/reception systems providing broadcast services may be simultaneously transmitted in the same RF signal bandwidth. In this case, the two or more different broadcast transmission/reception systems refer to systems providing different broadcast services. The different broadcast services may refer to a terrestrial broadcast service, mobile broadcast service, etc. 
     The signaling generation block  1040  may create physical layer signaling information used for an operation of each functional block. This signaling information is also transmitted so that services of interest are properly recovered at a receiver side. Signaling information according to an embodiment of the present invention may include PLS data. PLS provides the receiver with a means to access physical layer DPs. The PLS data includes PLS1 data and PLS2 data. 
     The PLS1 data is a first set of PLS data carried in an FSS symbol in a frame having a fixed size, coding and modulation, which carries basic information about the system in addition to the parameters needed to decode the PLS2 data. The PLS1 data provides basic transmission parameters including parameters required to enable reception and decoding of the PLS2 data. In addition, the PLS1 data remains constant for the duration of a frame group. 
     The PLS2 data is a second set of PLS data transmitted in an FSS symbol, which carries more detailed PLS data about the system and the DPs. The PLS2 contains parameters that provide sufficient information for the receiver to decode a desired DP. The PLS2 signaling further includes two types of parameters, PLS2 static data (PLS2-STAT data) and PLS2 dynamic data (PLS2-DYN data). The PLS2 static data is PLS2 data that remains static for the duration of a frame group and the PLS2 dynamic data is PLS2 data that dynamically changes frame by frame. Details of the PLS data will be described later. 
     The above-described blocks may be omitted or replaced by blocks having similar or identical functions. 
       FIG. 19  illustrates a BICM block according to an embodiment of the present invention. 
     The BICM block illustrated in  FIG. 19  corresponds to an embodiment of the BICM block  1010  described with reference to  FIG. 18 . 
     As described above, the broadcast signal transmission apparatus for future broadcast services according to the embodiment of the present invention may provide a terrestrial broadcast service, mobile broadcast service, UHDTV service, etc. 
     Since QoS depends on characteristics of a service provided by the broadcast signal transmission apparatus for future broadcast services according to the embodiment of the present invention, data corresponding to respective services needs to be processed using different schemes. Accordingly, the BICM block according to the embodiment of the present invention may independently process respective DPs by independently applying SISO, MISO and MIMO schemes to data pipes respectively corresponding to data paths. Consequently, the broadcast signal transmission apparatus for future broadcast services according to the embodiment of the present invention may control QoS for each service or service component transmitted through each DP. 
     (a) shows a BICM block applied to a profile (or system) to which MIMO is not applied, and (b) shows a BICM block of a profile (or system) to which MIMO is applied. 
     The BICM block to which MIMO is not applied and the BICM block to which MIMO is applied may include a plurality of processing blocks for processing each DP. 
     Description will be given of each processing block of the BICM block to which MIMO is not applied and the BICM block to which MIMO is applied. 
     A processing block  5000  of the BICM block to which MIMO is not applied may include a data FEC encoder  5010 , a bit interleaver  5020 , a constellation mapper  5030 , a signal space diversity (SSD) encoding block  5040  and a time interleaver  5050 . 
     The data FEC encoder  5010  performs FEC encoding on an input BBF to generate FECBLOCK procedure using outer coding (BCH) and inner coding (LDPC). The outer coding (BCH) is optional coding method. A detailed operation of the data FEC encoder  5010  will be described later. 
     The bit interleaver  5020  may interleave outputs of the data FEC encoder  5010  to achieve optimized performance with a combination of LDPC codes and a modulation scheme while providing an efficiently implementable structure. A detailed operation of the bit interleaver  5020  will be described later. 
     The constellation mapper  5030  may modulate each cell word from the bit interleaver  5020  in the base and the handheld profiles, or each cell word from the cell-word demultiplexer  5010 - 1  in the advanced profile using either QPSK, QAM-16, non-uniform QAM (NUQ-64, NUQ-256, or NUQ-1024) or non-uniform constellation (NUC-16, NUC-64, NUC-256, or NUC-1024) mapping to give a power-normalized constellation point, e t . This constellation mapping is applied only for DPs. It is observed that QAM-16 and NUQs are square shaped, while NUCs have arbitrary shapes. When each constellation is rotated by any multiple of 90 degrees, the rotated constellation exactly overlaps with its original one. This “rotation-sense” symmetric property makes the capacities and the average powers of the real and imaginary components equal to each other. Both NUQs and NUCs are defined specifically for each code rate and the particular one used is signaled by the parameter DP_MOD filed in the PLS2 data. 
     The time interleaver  5050  may operates at a DP level. Parameters of time interleaving (TI) may be set differently for each DP. A detailed operation of the time interleaver  5050  will be described later. 
     A processing block  5000 - 1  of the BICM block to which MIMO is applied may include the data FEC encoder, the bit interleaver, the constellation mapper, and the time interleaver. 
     However, the processing block  5000 - 1  is distinguished from the processing block  5000  of the BICM block to which MIMO is not applied in that the processing block  5000 - 1  further includes a cell-word demultiplexer  5010 - 1  and a MIMO encoding block  5020 - 1 . 
     In addition, operations of the data FEC encoder, the bit interleaver, the constellation mapper, and the time interleaver in the processing block  5000 - 1  correspond to those of the data FEC encoder  5010 , the bit interleaver  5020 , the constellation mapper  5030 , and the time interleaver  5050  described above, and thus description thereof is omitted. 
     The cell-word demultiplexer  5010 - 1  is used for a DP of the advanced profile to divide a single cell-word stream into dual cell-word streams for MIMO processing. 
     The MIMO encoding block  5020 - 1  may process an output of the cell-word demultiplexer  5010 - 1  using a MIMO encoding scheme. The MIMO encoding scheme is optimized for broadcast signal transmission. MIMO technology is a promising way to obtain a capacity increase but depends on channel characteristics. Especially for broadcasting, a strong LOS component of a channel or a difference in received signal power between two antennas caused by different signal propagation characteristics makes it difficult to obtain capacity gain from MIMO. The proposed MIMO encoding scheme overcomes this problem using rotation-based precoding and phase randomization of one of MIMO output signals. 
     MIMO encoding is intended for a 2×2 MIMO system requiring at least two antennas at both the transmitter and the receiver. A MIMO encoding mode of the present invention may be defined as full-rate spatial multiplexing (FR-SM). FR-SM encoding may provide capacity increase with relatively small complexity increase at the receiver side. In addition, the MIMO encoding scheme of the present invention has no restriction on an antenna polarity configuration. 
     MIMO processing is applied at the DP level. NUQ (e 1,i  and e 2,i ) corresponding to a pair of constellation mapper outputs is fed to an input of a MIMO encoder. Paired MIMO encoder output (g 1,i  and g 2,i ) is transmitted by the same carrier k and OFDM symbol l of respective TX antennas thereof. 
     The above-described blocks may be omitted or replaced by blocks having similar or identical functions. 
       FIG. 20  illustrates a BICM block according to another embodiment of the present invention. 
     The BICM block illustrated in  FIG. 20  corresponds to another embodiment of the BICM block  1010  described with reference to  FIG. 18 . 
       FIG. 20  illustrates a BICM block for protection of physical layer signaling (PLS), an emergency alert channel (EAC) and a fast information channel (FIC). The EAC is a part of a frame that carries EAS information data, and the FIC is a logical channel in a frame that carries mapping information between a service and a corresponding base DP. Details of the EAC and FIC will be described later. 
     Referring to  FIG. 20 , the BICM block for protection of the PLS, the EAC and the FIC may include a PLS FEC encoder  6000 , a bit interleaver  6010  and a constellation mapper  6020 . 
     In addition, the PLS FEC encoder  6000  may include a scrambler, a BCH encoding/zero insertion block, an LDPC encoding block and an LDPC parity punturing block. Description will be given of each block of the BICM block. 
     The PLS FEC encoder  6000  may encode scrambled PLS 1/2 data, EAC and FIC sections. 
     The scrambler may scramble PLS1 data and PLS2 data before BCH encoding and shortened and punctured LDPC encoding. 
     The BCH encoding/zero insertion block may perform outer encoding on the scrambled PLS 1/2 data using a shortened BCH code for PLS protection, and insert zero bits after BCH encoding. For PLS1 data only, output bits of zero insertion may be permutted before LDPC encoding. 
     The LDPC encoding block may encode an output of the BCH encoding/zero insertion block using an LDPC code. To generate a complete coded block, C ldpc  and parity bits P ldpc  are encoded systematically from each zero-inserted PLS information block I ldpc  and appended thereto.
 
 C   ldpc =[ I   ldpc   P   ldpc ]=[ i   0   ,i   1   , . . . ,i   K     lpdc     −1   ,p   0   ,p   1   , . . . ,p   N     lpdc     −K     ldpc     −1 ]  [Equation 1]
 
     The LDPC parity puncturing block may perform puncturing on the PLS1 data and the PLS2 data. 
     When shortening is applied to PLS1 data protection, some LDPC parity bits are punctured after LDPC encoding. In addition, for PLS2 data protection, LDPC parity bits of PLS2 are punctured after LDPC encoding. These punctured bits are not transmitted. 
     The bit interleaver  6010  may interleave each of shortened and punctured PLS1 data and PLS2 data. 
     The constellation mapper  6020  may map the bit-ineterleaved PLS1 data and PLS2 data to constellations. 
     The above-described blocks may be omitted or replaced by blocks having similar or identical functions. 
       FIG. 21  illustrates a bit interleaving process of PLS according to an embodiment of the present invention. 
     Each shortened and punctured PLS1 and PLS2 coded block is interleaved bit-by-bit as described in  FIG. 22 . Each block of additional parity bits is interleaved with the same block interleaving structure but separately. 
     In the case of BPSK, there are two branches for bit interleaving to duplicate FEC coded bits in the real and imaginary parts. Each coded block is written to the upper branch first. The bits are mapped to the lower branch by applying modulo N FEC  addition with cyclic shifting value floor(N FEC /2), where N FEC  is the length of each LDPC coded block after shortening and puncturing. 
     In other modulation cases, such as QSPK, QAM-16 and NUQ-64, FEC coded bits are written serially into the interleaver column-wise, where the number of columns is the same as the modulation order. 
     In the read operation, the bits for one constellation symbol are read out sequentially row-wise and fed into the bit demultiplexer block. These operations are continued until the end of the column. 
     Each bit interleaved group is demultiplexed bit-by-bit in a group before constellation mapping. Depending on modulation order, there are two mapping rules. In the case of BPSK and QPSK, the reliability of bits in a symbol is equal. Therefore, the bit group read out from the bit interleaving block is mapped to a QAM symbol without any operation. 
     In the cases of QAM-16 and NUQ-64 mapped to a QAM symbol, the rule of operation is described in  FIG. 23( a ) . As shown in  FIG. 23( a ) , i is bit group index corresponding to column index in bit interleaving. 
       FIG. 21  shows the bit demultiplexing rule for QAM-16. This operation continues until all bit groups are read from the bit interleaving block. 
       FIG. 22  illustrates a configuration of a broadcast signal reception apparatus for future broadcast services according to an embodiment of the present invention. 
     The broadcast signal reception apparatus for future broadcast services according to the embodiment of the present invention may correspond to the broadcast signal transmission apparatus for future broadcast services described with reference to  FIG. 18 . 
     The broadcast signal reception apparatus for future broadcast services according to the embodiment of the present invention may include a synchronization &amp; demodulation module  9000 , a frame parsing module  9010 , a demapping &amp; decoding module  9020 , an output processor  9030  and a signaling decoding module  9040 . A description will be given of operation of each module of the broadcast signal reception apparatus. 
     The synchronization &amp; demodulation module  9000  may receive input signals through m Rx antennas, perform signal detection and synchronization with respect to a system corresponding to the broadcast signal reception apparatus, and carry out demodulation corresponding to a reverse procedure of a procedure performed by the broadcast signal transmission apparatus. 
     The frame parsing module  9010  may parse input signal frames and extract data through which a service selected by a user is transmitted. If the broadcast signal transmission apparatus performs interleaving, the frame parsing module  9010  may carry out deinterleaving corresponding to a reverse procedure of interleaving. In this case, positions of a signal and data that need to be extracted may be obtained by decoding data output from the signaling decoding module  9040  to restore scheduling information generated by the broadcast signal transmission apparatus. 
     The demapping &amp; decoding module  9020  may convert input signals into bit domain data and then deinterleave the same as necessary. The demapping &amp; decoding module  9020  may perform demapping of mapping applied for transmission efficiency and correct an error generated on a transmission channel through decoding. In this case, the demapping &amp; decoding module  9020  may obtain transmission parameters necessary for demapping and decoding by decoding data output from the signaling decoding module  9040 . 
     The output processor  9030  may perform reverse procedures of various compression/signal processing procedures which are applied by the broadcast signal transmission apparatus to improve transmission efficiency. In this case, the output processor  9030  may acquire necessary control information from data output from the signaling decoding module  9040 . An output of the output processor  9030  corresponds to a signal input to the broadcast signal transmission apparatus and may be MPEG-TSs, IP streams (v4 or v6) and generic streams. 
     The signaling decoding module  9040  may obtain PLS information from a signal demodulated by the synchronization &amp; demodulation module  9000 . As described above, the frame parsing module  9010 , the demapping &amp; decoding module  9020  and the output processor  9030  may execute functions thereof using data output from the signaling decoding module  9040 . 
     A frame according to an embodiment of the present invention is further divided into a number of OFDM symbols and a preamble. As shown in (d), the frame includes a preamble, one or more frame signaling symbols (FSSs), normal data symbols and a frame edge symbol (FES). 
     The preamble is a special symbol that enables fast futurecast UTB system signal detection and provides a set of basic transmission parameters for efficient transmission and reception of a signal. Details of the preamble will be described later. 
     A main purpose of the FSS is to carry PLS data. For fast synchronization and channel estimation, and hence fast decoding of PLS data, the FSS has a dense pilot pattern than a normal data symbol. The FES has exactly the same pilots as the FSS, which enables frequency-only interpolation within the FES and temporal interpolation, without extrapolation, for symbols immediately preceding the FES. 
       FIG. 23  illustrates a signaling hierarchy structure of a frame according to an embodiment of the present invention. 
       FIG. 23  illustrates the signaling hierarchy structure, which is split into three main parts corresponding to preamble signaling data  11000 , PLS1 data  11010  and PLS2 data  11020 . A purpose of a preamble, which is carried by a preamble symbol in every frame, is to indicate a transmission type and basic transmission parameters of the frame. PLS1 enables the receiver to access and decode the PLS2 data, which contains the parameters to access a DP of interest. PLS2 is carried in every frame and split into two main parts corresponding to PLS2-STAT data and PLS2-DYN data. Static and dynamic portions of PLS2 data are followed by padding, if necessary. 
     Preamble signaling data according to an embodiment of the present invention carries 21 bits of information that are needed to enable the receiver to access PLS data and trace DPs within the frame structure. Details of the preamble signaling data are as follows. 
     FFT_SIZE: This 2-bit field indicates an FFT size of a current frame within a frame group as described in the following Table 1. 
     
       
         
           
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                 Value 
                 FFT size 
               
               
                   
               
             
            
               
                 00 
                  8K FFT 
               
               
                 01 
                 16K FFT 
               
               
                 10 
                 32K FFT 
               
               
                 11 
                 Reserved 
               
               
                   
               
            
           
         
       
     
     GI_FRACTION: This 3-bit field indicates a guard interval fraction value in a current superframe as described in the following Table 2. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 2 
               
               
                   
                   
               
               
                   
                 Value 
                 GI_FRACTION 
               
               
                   
                   
               
             
            
               
                   
                 000 
                 1/5 
               
               
                   
                 001 
                 1/10 
               
               
                   
                 010 
                 1/20 
               
               
                   
                 011 
                 1/40 
               
               
                   
                 100 
                 1/80 
               
               
                   
                 101 
                 1/160 
               
               
                   
                 110 to 111 
                 Reserved 
               
               
                   
                   
               
            
           
         
       
     
     EAC_FLAG: This 1-bit field indicates whether the EAC is provided in a current frame. If this field is set to ‘1’, an emergency alert service (EAS) is provided in the current frame. If this field set to ‘0’, the EAS is not carried in the current frame. This field may be switched dynamically within a superframe. 
     PILOT_MODE: This 1-bit field indicates whether a pilot mode is a mobile mode or a fixed mode for a current frame in a current frame group. If this field is set to ‘0’, the mobile pilot mode is used. If the field is set to ‘1’, the fixed pilot mode is used. 
     PAPR_FLAG: This 1-bit field indicates whether PAPR reduction is used for a current frame in a current frame group. If this field is set to a value of ‘1’, tone reservation is used for PAPR reduction. If this field is set to a value of ‘0’, PAPR reduction is not used. 
     RESERVED: This 7-bit field is reserved for future use. 
       FIG. 24  illustrates PLS1 data according to an embodiment of the present invention. 
     PLS1 data provides basic transmission parameters including parameters required to enable reception and decoding of PLS2. As mentioned above, the PLS1 data remain unchanged for the entire duration of one frame group. A detailed definition of the signaling fields of the PLS1 data is as follows. 
     PREAMBLE_DATA: This 20-bit field is a copy of preamble signaling data excluding EAC_FLAG. 
     NUM_FRAME_FRU: This 2-bit field indicates the number of the frames per FRU. 
     PAYLOAD_TYPE: This 3-bit field indicates a format of payload data carried in a frame group. PAYLOAD_TYPE is signaled as shown in Table 3. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 3 
               
               
                   
                   
               
               
                   
                 Value 
                 Payload type 
               
               
                   
                   
               
             
            
               
                   
                 1XX 
                 TS is transmitted. 
               
               
                   
                 X1X 
                 IP stream is transmitted. 
               
               
                   
                 XX1 
                 GS is transmitted. 
               
               
                   
                   
               
            
           
         
       
     
     NUM_FSS: This 2-bit field indicates the number of FSSs in a current frame. 
     SYSTEM_VERSION: This 8-bit field indicates a version of a transmitted signal format. SYSTEM_VERSION is divided into two 4-bit fields: a major version and a minor version. 
     Major version: The MSB corresponding to four bits of the SYSTEM_VERSION field indicate major version information. A change in the major version field indicates a non-backward-compatible change. A default value is ‘0000’. For a version described in this standard, a value is set to ‘0000’. 
     Minor version: The LSB corresponding to four bits of SYSTEM_VERSION field indicate minor version information. A change in the minor version field is backwards compatible. 
     CELL_ID: This is a 16-bit field which uniquely identifies a geographic cell in an ATSC network. An ATSC cell coverage area may include one or more frequencies depending on the number of frequencies used per futurecast UTB system. If a value of CELL_ID is not known or unspecified, this field is set to ‘0’. 
     NETWORK_ID: This is a 16-bit field which uniquely identifies a current ATSC network. 
     SYSTEM_ID: This 16-bit field uniquely identifies the futurecast UTB system within the ATSC network. The futurecast UTB system is a terrestrial broadcast system whose input is one or more input streams (TS, IP, GS) and whose output is an RF signal. The futurecast UTB system carries one or more PHY profiles and FEF, if any. The same futurecast UTB system may carry different input streams and use different RFs in different geographical areas, allowing local service insertion. The frame structure and scheduling are controlled in one place and are identical for all transmissions within the futurecast UTB system. One or more futurecast UTB systems may have the same SYSTEM_ID meaning that they all have the same physical layer structure and configuration. 
     The following loop includes FRU_PHY_PROFILE, FRU_FRAME_LENGTH, FRU_GI_FRACTION, and RESERVED which are used to indicate an FRU configuration and a length of each frame type. A loop size is fixed so that four PHY profiles (including an FEF) are signaled within the FRU. IfNUM_FRAME_FRU is less than 4, unused fields are filled with zeros. 
     FRU_PHY_PROFILE: This 3-bit field indicates a PHY profile type of an (i+1) th  (i is a loop index) frame of an associated FRU. This field uses the same signaling format as shown in Table 8. 
     FRU_FRAME_LENGTH: This 2-bit field indicates a length of an (i+1) th  frame of an associated FRU. Using FRU_FRAME_LENGTH together with FRU_GI_FRACTION, an exact value of a frame duration may be obtained. 
     FRU_GI_FRACTION: This 3-bit field indicates a guard interval fraction value of an (i+1) th  frame of an associated FRU. FRU_GI_FRACTION is signaled according to Table 7. 
     RESERVED: This 4-bit field is reserved for future use. 
     The following fields provide parameters for decoding the PLS2 data. 
     PLS2_FEC_TYPE: This 2-bit field indicates an FEC type used by PLS2 protection. The FEC type is signaled according to Table 4. Details of LDPC codes will be described later. 
     
       
         
           
               
               
             
               
                 TABLE 4 
               
               
                   
               
               
                 Content 
                 PLS2 EEC type 
               
               
                   
               
             
            
               
                 00 
                 4K-1/4 and 7K-3/10 LDPC codes 
               
               
                 01 to 11 
                 Reserved 
               
               
                   
               
            
           
         
       
     
     PLS2_MOD: This 3-bit field indicates a modulation type used by PLS2. The modulation type is signaled according to Table 5. 
     
       
         
           
               
               
             
               
                 TABLE 5 
               
               
                   
               
               
                 Value 
                 PLS2_MODE 
               
               
                   
               
             
            
               
                 000 
                 BPSK 
               
               
                 001 
                 QPSK 
               
               
                 010 
                 QAM-16 
               
               
                 011 
                 NUQ-64 
               
               
                 100 to 111 
                 Reserved 
               
               
                   
               
            
           
         
       
     
     PLS2_SIZE_CELL: This 15-bit field indicates C total_partial_block , a size (specified as the number of QAM cells) of the collection of full coded blocks for PLS2 that is carried in a current frame group. This value is constant during the entire duration of the current frame group. 
     PLS2_STAT_SIZE_BIT: This 14-bit field indicates a size, in bits, of PLS2-STAT for a current frame group. This value is constant during the entire duration of the current frame group. 
     PLS2_DYN_SIZE_BIT: This 14-bit field indicates a size, in bits, of PLS2-DYN for a current frame group. This value is constant during the entire duration of the current frame group. 
     PLS2_REP_FLAG: This 1-bit flag indicates whether a PLS2 repetition mode is used in a current frame group. When this field is set to a value of ‘1’, the PLS2 repetition mode is activated. When this field is set to a value of ‘0’, the PLS2 repetition mode is deactivated. 
     PLS2_REP_SIZE_CELL: This 15-bit field indicates C total_partial_block , a size (specified as the number of QAM cells) of the collection of partial coded blocks for PLS2 carried in every frame of a current frame group, when PLS2 repetition is used. If repetition is not used, a value of this field is equal to 0. This value is constant during the entire duration of the current frame group. 
     PLS2_NEXT_FEC_TYPE: This 2-bit field indicates an FEC type used for PLS2 that is carried in every frame of a next frame group. The FEC type is signaled according to Table 10. 
     PLS2_NEXT_MOD: This 3-bit field indicates a modulation type used for PLS2 that is carried in every frame of a next frame group. The modulation type is signaled according to Table 11. 
     PLS2_NEXT_REP_FLAG: This 1-bit flag indicates whether the PLS2 repetition mode is used in a next frame group. When this field is set to a value of ‘1’, the PLS2 repetition mode is activated. When this field is set to a value of ‘0’, the PLS2 repetition mode is deactivated. 
     PLS2_NEXT_REP_SIZE_CELL: This 15-bit field indicates C total_full_block , a size (specified as the number of QAM cells) of the collection of full coded blocks for PLS2 that is carried in every frame of a next frame group, when PLS2 repetition is used. If repetition is not used in the next frame group, a value of this field is equal to 0. This value is constant during the entire duration of a current frame group. 
     PLS2_NEXT_REP_STAT_SIZE_BIT: This 14-bit field indicates a size, in bits, of PLS2-STAT for a next frame group. This value is constant in a current frame group. 
     PLS2_NEXT_REP_DYN_SIZE_BIT: This 14-bit field indicates the size, in bits, of the PLS2-DYN for a next frame group. This value is constant in a current frame group. 
     PLS2_AP_MODE: This 2-bit field indicates whether additional parity is provided for PLS2 in a current frame group. This value is constant during the entire duration of the current frame group. Table 6 below provides values of this field. When this field is set to a value of ‘00’, additional parity is not used for the PLS2 in the current frame group. 
     
       
         
           
               
               
             
               
                 TABLE 6 
               
               
                   
               
               
                 Value 
                 PLS2-AP mode 
               
               
                   
               
             
            
               
                 00 
                 AP is not provided 
               
               
                 01 
                 AP1 mode 
               
               
                 10 to 11 
                 Reserved 
               
               
                   
               
            
           
         
       
     
     PLS2_AP_SIZE_CELL: This 15-bit field indicates a size (specified as the number of QAM cells) of additional parity bits of PLS2. This value is constant during the entire duration of a current frame group. 
     PLS2_NEXT_AP_MODE: This 2-bit field indicates whether additional parity is provided for PLS2 signaling in every frame of a next frame group. This value is constant during the entire duration of a current frame group. Table 12 defines values of this field. 
     PLS2_NEXT_AP_SIZE_CELL: This 15-bit field indicates a size (specified as the number of QAM cells) of additional parity bits of PLS2 in every frame of a next frame group. This value is constant during the entire duration of a current frame group. 
     RESERVED: This 32-bit field is reserved for future use. 
     CRC_32: A 32-bit error detection code, which is applied to all PLS1 signaling. 
       FIG. 25  illustrates PLS2 data according to an embodiment of the present invention. 
       FIG. 25  illustrates PLS2-STAT data of the PLS2 data. The PLS2-STAT data is the same within a frame group, while PLS2-DYN data provides information that is specific for a current frame. 
     Details of fields of the PLS2-STAT data are described below. 
     FIC_FLAG: This 1-bit field indicates whether the FIC is used in a current frame group. If this field is set to ‘1’, the FIC is provided in the current frame. If this field set to ‘0’, the FIC is not carried in the current frame. This value is constant during the entire duration of a current frame group. 
     AUX_FLAG: This 1-bit field indicates whether an auxiliary stream is used in a current frame group. If this field is set to ‘1’, the auxiliary stream is provided in a current frame. If this field set to ‘0’, the auxiliary stream is not carried in the current frame. This value is constant during the entire duration of current frame group. 
     NUM_DP: This 6-bit field indicates the number of DPs carried within a current frame. A value of this field ranges from 1 to 64, and the number of DPs is NUM_DP+1. 
     DP_ID: This 6-bit field identifies uniquely a DP within a PHY profile. 
     DP_TYPE: This 3-bit field indicates a type of a DP. This is signaled according to the following Table 7. 
     
       
         
           
               
               
             
               
                 TABLE 7 
               
               
                   
               
               
                 Value 
                 DP Type 
               
               
                   
               
             
            
               
                 000 
                 DP Type 1 
               
               
                 001 
                 DP Type 2 
               
               
                 010 to 111 
                 Reserved 
               
               
                   
               
            
           
         
       
     
     DP_GROUP_ID: This 8-bit field identifies a DP group with which a current DP is associated. This may be used by the receiver to access DPs of service components associated with a particular service having the same DP_GROUP_ID. 
     BASE_DP_ID: This 6-bit field indicates a DP carrying service signaling data (such as PSI/SI) used in a management layer. The DP indicated by BASE_DP_ID may be either a normal DP carrying the service signaling data along with service data or a dedicated DP carrying only the service signaling data. 
     DP_FEC_TYPE: This 2-bit field indicates an FEC type used by an associated DP. The FEC type is signaled according to the following Table 8. 
     
       
         
           
               
               
             
               
                 TABLE 8 
               
               
                   
               
               
                 Value 
                 FEC_TYPE 
               
               
                   
               
             
            
               
                 00 
                 16K LDPC 
               
               
                 01 
                 64K LDPC 
               
               
                 10 to 11 
                 Reserved 
               
               
                   
               
            
           
         
       
     
     DP_COD: This 4-bit field indicates a code rate used by an associated DP. The code rate is signaled according to the following Table 9. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 9 
               
               
                   
                   
               
               
                   
                 Value 
                 Code rate 
               
               
                   
                   
               
             
            
               
                   
                 0000 
                 5/15 
               
               
                   
                 0001 
                 6/15 
               
               
                   
                 0010 
                 7/15 
               
               
                   
                 0011 
                 8/15 
               
               
                   
                 0100 
                 9/15 
               
               
                   
                 0101 
                 10/15  
               
               
                   
                 0110 
                 11/15  
               
               
                   
                 0111 
                 12/15  
               
               
                   
                 1000 
                 13/15  
               
               
                   
                 1001 to 1111 
                 Reserved 
               
               
                   
                   
               
            
           
         
       
     
     DP_MOD: This 4-bit field indicates modulation used by an associated DP. The modulation is signaled according to the following Table 10. 
     
       
         
           
               
               
             
               
                 TABLE 10 
               
               
                   
               
               
                 Value 
                 Modulation 
               
               
                   
               
             
            
               
                 0000 
                 QPSK 
               
               
                 0001 
                 QAM-16 
               
               
                 0010 
                 NUQ-64 
               
               
                 0011 
                 NUQ-256 
               
               
                 0100 
                 NUQ-1024 
               
               
                 0101 
                 NUC-16 
               
               
                 0110 
                 NUC-64 
               
               
                 0111 
                 NUC-256 
               
               
                 1000 
                 NUC-1024 
               
               
                 1001 to 1111 
                 Reserved 
               
               
                   
               
            
           
         
       
     
     DP_SSD_FLAG: This 1-bit field indicates whether an SSD mode is used in an associated DP. If this field is set to a value of ‘1’, SSD is used. If this field is set to a value of ‘0’, SSD is not used. 
     The following field appears only if PHY_PROFILE is equal to ‘010’, which indicates the advanced profile: 
     DP_MIMO: This 3-bit field indicates which type of MIMO encoding process is applied to an associated DP. A type of MIMO encoding process is signaled according to the following Table 11. 
     
       
         
           
               
               
             
               
                 TABLE 11 
               
               
                   
               
               
                 Value 
                 MIMO encoding 
               
               
                   
               
             
            
               
                 000 
                 FR-SM 
               
               
                 001 
                 FRFD-SM 
               
               
                 010 to 111 
                 Reserved 
               
               
                   
               
            
           
         
       
     
     DP_TI_TYPE: This 1-bit field indicates a type of time interleaving. A value of ‘0’ indicates that one TI group corresponds to one frame and contains one or more TI blocks. A value of ‘1’ indicates that one TI group is carried in more than one frame and contains only one TI block. 
     DP_TI_LENGTH: The use of this 2-bit field (allowed values are only 1, 2, 4, and 8) is determined by values set within the DP_TI_TYPE field as follows. 
     If DP_TI_TYPE is set to a value of ‘1’, this field indicates P 1 , the number of frames to which each TI group is mapped, and one TI block is present per TI group (N TI =1). Allowed values of P I  with the 2-bit field are defined in Table 12 below. 
     If DP_TI_TYPE is set to a value of ‘0’, this field indicates the number of TI blocks N TI  per TI group, and one TI group is present per frame (P I =1). Allowed values of P I  with the 2-bit field are defined in the following Table 12. 
     
       
         
           
               
               
               
             
               
                 TABLE 12 
               
               
                   
               
               
                 2-bit field 
                 P I   
                 N TI   
               
               
                   
               
             
            
               
                 00 
                 1 
                 1 
               
               
                 01 
                 2 
                 2 
               
               
                 10 
                 4 
                 3 
               
               
                 11 
                 8 
                 4 
               
               
                   
               
            
           
         
       
     
     DP_FRAME_INTERVAL: This 2-bit field indicates a frame interval (I JUMP ) within a frame group for an associated DP and allowed values are 1, 2, 4, and 8 (the corresponding 2-bit field is ‘00’, ‘01’, ‘10’, or ‘11’, respectively). For DPs that do not appear every frame of the frame group, a value of this field is equal to an interval between successive frames. For example, if a DP appears on frames 1, 5, 9, 13, etc., this field is set to a value of ‘4’. For DPs that appear in every frame, this field is set to a value of ‘1’. 
     DP_TI_BYPASS: This 1-bit field determines availability of the time interleaver  5050 . If time interleaving is not used for a DP, a value of this field is set to ‘1’. If time interleaving is used, the value is set to ‘0’. 
     DP_FIRST_FRAME_IDX: This 5-bit field indicates an index of a first frame of a superframe in which a current DP occurs. A value of DP_FIRST_FRAME_IDX ranges from 0 to 31. 
     DP_NUM_BLOCK_MAX: This 10-bit field indicates a maximum value of DP_NUM_BLOCKS for this DP. A value of this field has the same range as DP_NUM_BLOCKS. 
     DP_PAYLOAD_TYPE: This 2-bit field indicates a type of payload data carried by a given DP. DP_PAYLOAD_TYPE is signaled according to the following Table 13. 
     
       
         
           
               
               
             
               
                 TABLE 13 
               
               
                   
               
               
                 Value 
                 Payload type 
               
               
                   
               
             
            
               
                 00 
                 TS 
               
               
                 01 
                 IP 
               
               
                 10 
                 GS 
               
               
                 11 
                 Reserved 
               
               
                   
               
            
           
         
       
     
     DP_INBAND_MODE: This 2-bit field indicates whether a current DP carries in-band signaling information. An in-band signaling type is signaled according to the following Table 14. 
     
       
         
           
               
               
             
               
                 TABLE 14 
               
               
                   
               
               
                 Value 
                 In-band mode 
               
               
                   
               
             
            
               
                 00 
                 In-band signaling is not carried. 
               
               
                 01 
                 INBAND-PLS is carried 
               
               
                 10 
                 INBAND-ISSY is carried 
               
               
                 11 
                 INBAND-PLS and INBAND-ISSY are carried 
               
               
                   
               
            
           
         
       
     
     DP_PROTOCOL_TYPE: This 2-bit field indicates a protocol type of a payload carried by a given DP. The protocol type is signaled according to Table 15 below when input payload types are selected. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 15 
               
               
                   
               
               
                   
                 If 
                 If 
                 If 
               
               
                   
                 DP_PAY- 
                 DP_PAY- 
                 DP_PAY- 
               
               
                   
                 LOAD_TYPE 
                 LOAD_TYPE 
                 LOAD_TYPE 
               
               
                 Value 
                 is TS 
                 is IP 
                 is GS 
               
               
                   
               
             
            
               
                 00 
                 MPEG2-TS 
                 IPv4 
                 (Note) 
               
               
                 01 
                 Reserved 
                 IPv6 
                 Reserved 
               
               
                 10 
                 Reserved 
                 Reserved 
                 Reserved 
               
               
                 11 
                 Reserved 
                 Reserved 
                 Reserved 
               
               
                   
               
            
           
         
       
     
     DP_CRC_MODE: This 2-bit field indicates whether CRC encoding is used in an input formatting block. A CRC mode is signaled according to the following Table 16. 
     
       
         
           
               
               
             
               
                 TABLE 16 
               
               
                   
               
               
                 Value 
                 CRC mode 
               
               
                   
               
             
            
               
                 00 
                 Not used 
               
               
                 01 
                 CRC-8 
               
               
                 10 
                 CRC-16 
               
               
                 11 
                 CRC-32 
               
               
                   
               
            
           
         
       
     
     DNP_MODE: This 2-bit field indicates a null-packet deletion mode used by an associated DP when DP_PAYLOAD_TYPE is set to TS (‘00’). DNP_MODE is signaled according to Table 17 below. If DP_PAYLOAD_TYPE is not TS (‘00’), DNP_MODE is set to a value of ‘00’. 
     
       
         
           
               
               
             
               
                 TABLE 17 
               
               
                   
               
               
                 Value 
                 Null-packet deletion mode 
               
               
                   
               
             
            
               
                 00 
                 Not used 
               
               
                 01 
                 DNP-NORMAL 
               
               
                 10 
                 DNP-OFFSET 
               
               
                 11 
                 Reserved 
               
               
                   
               
            
           
         
       
     
     ISSY_MODE: This 2-bit field indicates an ISSY mode used by an associated DP when DP_PAYLOAD_TYPE is set to TS (‘00’). ISSY_MODE is signaled according to Table 18 below. If DP_PAYLOAD_TYPE is not TS (‘00’), ISSY_MODE is set to the value of ‘00’. 
     
       
         
           
               
               
             
               
                 TABLE 18 
               
               
                   
               
               
                 Value 
                 ISSY mode 
               
               
                   
               
             
            
               
                 00 
                 Not used 
               
               
                 01 
                 ISSY-UP 
               
               
                 10 
                 ISSY-BBF 
               
               
                 11 
                 Reserved 
               
               
                   
               
            
           
         
       
     
     HC_MODE_TS: This 2-bit field indicates a TS header compression mode used by an associated DP when DP_PAYLOAD_TYPE is set to TS (‘00’). HC_MODE_TS is signaled according to the following Table 19. 
     
       
         
           
               
               
             
               
                 TABLE 19 
               
               
                   
               
               
                 Value 
                 Header compression mode 
               
               
                   
               
             
            
               
                 00 
                 HC_MODE_TS 1 
               
               
                 01 
                 HC_MODE_TS 2 
               
               
                 10 
                 HC_MODE_TS 3 
               
               
                 11 
                 HC_MODE_TS 4 
               
               
                   
               
            
           
         
       
     
     HC_MODE_IP: This 2-bit field indicates an IP header compression mode when DP_PAYLOAD_TYPE is set to IP (‘01’). HC_MODE_IP is signaled according to the following Table 20. 
     
       
         
           
               
               
             
               
                 TABLE 20 
               
               
                   
               
               
                 Value 
                 Header compression mode 
               
               
                   
               
             
            
               
                 00 
                 No compression 
               
               
                 01 
                 HC_MODE_IP 1 
               
               
                 10 to 11 
                 Reserved 
               
               
                   
               
            
           
         
       
     
     PID: This 13-bit field indicates the PID number for TS header compression when DP_PAYLOAD_TYPE is set to TS (‘00’) and HC_MODE_TS is set to ‘01‘ or’ 10 ’. 
     RESERVED: This 8-bit field is reserved for future use. 
     The following fields appear only if FIC_FLAG is equal to ‘1’. 
     FIC_VERSION: This 8-bit field indicates the version number of the FIC. 
     FIC_LENGTH_BYTE: This 13-bit field indicates the length, in bytes, of the FIC. 
     RESERVED: This 8-bit field is reserved for future use. 
     The following fields appear only if AUX_FLAG is equal to ‘1’. 
     NUM_AUX: This 4-bit field indicates the number of auxiliary streams. Zero means no auxiliary stream is used. 
     AUX_CONFIG_RFU: This 8-bit field is reserved for future use. 
     AUX_STREAM_TYPE: This 4-bit is reserved for future use for indicating a type of a current auxiliary stream. 
     AUX_PRIVATE_CONFIG: This 28-bit field is reserved for future use for signaling auxiliary streams. 
       FIG. 26  illustrates PLS2 data according to another embodiment of the present invention. 
       FIG. 26  illustrates PLS2-DYN data of the PLS2 data. Values of the PLS2-DYN data may change during the duration of one frame group while sizes of fields remain constant. 
     Details of fields of the PLS2-DYN data are as below. 
     FRAME_INDEX: This 5-bit field indicates a frame index of a current frame within a superframe. An index of a first frame of the superframe is set to ‘0’. 
     PLS_CHANGE_COUNTER: This 4-bit field indicates the number of superframes before a configuration changes. A next superframe with changes in the configuration is indicated by a value signaled within this field. If this field is set to a value of ‘0000’, it means that no scheduled change is foreseen. For example, a value of ‘1’ indicates that there is a change in the next superframe. 
     FIC_CHANGE_COUNTER: This 4-bit field indicates the number of superframes before a configuration (i.e., content of the FIC) changes. A next superframe with changes in the configuration is indicated by a value signaled within this field. If this field is set to a value of ‘0000’, it means that no scheduled change is foreseen. For example, a value of ‘0001’ indicates that there is a change in the next superframe. 
     RESERVED: This 16-bit field is reserved for future use. 
     The following fields appear in a loop over NUM_DP, which describe parameters associated with a DP carried in a current frame. 
     DP_ID: This 6-bit field uniquely indicates a DP within a PHY profile. 
     DP_START: This 15-bit (or 13-bit) field indicates a start position of the first of the DPs using a DPU addressing scheme. The DP_START field has differing length according to the PHY profile and FFT size as shown in the following Table 21. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 21 
               
             
            
               
                   
                   
               
               
                   
                 DP_START field size 
                   
               
            
           
           
               
               
               
               
            
               
                   
                 PHY profile 
                 64K 
                 16K 
               
               
                   
                   
               
               
                   
                 Base 
                 13 bits 
                 15 bits 
               
               
                   
                 Handheld 
                 — 
                 13 bits 
               
               
                   
                 Advanced 
                 13 bits 
                 15 its  
               
               
                   
                   
               
            
           
         
       
     
     DP_NUM_BLOCK: This 10-bit field indicates the number of FEC blocks in a current TI group for a current DP. A value of DP_NUM_BLOCK ranges from 0 to 1023. 
     RESERVED: This 8-bit field is reserved for future use. 
     The following fields indicate FIC parameters associated with the EAC. 
     EAC_FLAG: This 1-bit field indicates the presence of the EAC in a current frame. This bit is the same value as EAC_FLAG in a preamble. 
     EAS_WAKE_UP_VERSION_NUM: This 8-bit field indicates a version number of a wake-up indication. 
     If the EAC_FLAG field is equal to ‘1’, the following 12 bits are allocated to EAC_LENGTH_BYTE. If the EAC_FLAG field is equal to ‘0’, the following 12 bits are allocated to EAC COUNTER. 
     EAC_LENGTH_BYTE: This 12-bit field indicates a length, in bytes, of the EAC. 
     EAC_COUNTER: This 12-bit field indicates the number of frames before a frame where the EAC arrives. 
     The following fields appear only if the AUX_FLAG field is equal to ‘1’. 
     AUX_PRIVATE_DYN: This 48-bit field is reserved for future use for signaling auxiliary streams. A meaning of this field depends on a value of AUX_STREAM_TYPE in a configurable PLS2-STAT. 
     CRC_32: A 32-bit error detection code, which is applied to the entire PLS2. 
       FIG. 27  illustrates a logical structure of a frame according to an embodiment of the present invention. 
     As above mentioned, the PLS, EAC, FIC, DPs, auxiliary streams and dummy cells are mapped to the active carriers of OFDM symbols in a frame. PLS1 and PLS2 are first mapped to one or more FSSs. Thereafter, EAC cells, if any, are mapped to an immediately following PLS field, followed next by FIC cells, if any. The DPs are mapped next after the PLS or after the EAC or the FIC, if any. Type 1 DPs are mapped first and Type 2 DPs are mapped next. Details of types of the DPs will be described later. In some cases, DPs may carry some special data for EAS or service signaling data. The auxiliary streams or streams, if any, follow the DPs, which in turn are followed by dummy cells. When the PLS, EAC, FIC, DPs, auxiliary streams and dummy data cells are mapped all together in the above mentioned order, i.e. the PLS, EAC, FIC, DPs, auxiliary streams and dummy data cells, cell capacity in the frame is exactly filled. 
       FIG. 28  illustrates PLS mapping according to an embodiment of the present invention. 
     PLS cells are mapped to active carriers of FSS(s). Depending on the number of cells occupied by PLS, one or more symbols are designated as FSS(s), and the number of FSS(s) NFSS is signaled by NUM_FSS in PLS1. The FSS is a special symbol for carrying PLS cells. Since robustness and latency are critical issues in the PLS, the FSS(s) have higher pilot density, allowing fast synchronization and frequency-only interpolation within the FSS. 
     PLS cells are mapped to active carriers of the FSS(s) in a top-down manner as shown in the figure. PLS1 cells are mapped first from a first cell of a first FSS in increasing order of cell index. PLS2 cells follow immediately after a last cell of PLS1 and mapping continues downward until a last cell index of the first FSS. If the total number of required PLS cells exceeds the number of active carriers of one FSS, mapping proceeds to a next FSS and continues in exactly the same manner as the first FSS. 
     After PLS mapping is completed, DPs are carried next. If an EAC, an FIC or both are present in a current frame, the EAC and the FIC are placed between the PLS and “normal” DPs. 
     Hereinafter, description will be given of encoding an FEC structure according to an embodiment of the present invention. As above mentioned, the data FEC encoder may perform FEC encoding on an input BBF to generate an FECBLOCK procedure using outer coding (BCH), and inner coding (LDPC). The illustrated FEC structure corresponds to the FECBLOCK. In addition, the FECBLOCK and the FEC structure have same value corresponding to a length of an LDPC codeword. 
     As described above, BCH encoding is applied to each BBF (K bch  bits), and then LDPC encoding is applied to BCH-encoded BBF (K ldpc  bits=N bch  bits). 
     A value of N ldpc  is either 64,800 bits (long FECBLOCK) or 16,200 bits (short FECBLOCK). 
     Table 22 and Table 23 below show FEC encoding parameters for the long FECBLOCK and the short FECBLOCK, respectively. 
     
       
         
           
               
               
               
               
               
               
             
               
                 TABLE 22 
               
               
                   
               
               
                 LDPC 
                   
                   
                   
                 BCH error correction 
                 N bch  − 
               
               
                 rate 
                 N ldpc   
                 K ldpc   
                 K bch   
                 capability 
                 K bch   
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 5/15 
                 64800 
                 21600 
                 21408 
                 12 
                 192 
               
               
                 6/15 
                   
                 25920 
                 25728 
               
               
                 7/15 
                   
                 30240 
                 30048 
               
               
                 8/15 
                   
                 34560 
                 34368 
               
               
                 9/15 
                   
                 38880 
                 38688 
               
               
                 10/15  
                   
                 43200 
                 43008 
               
               
                 11/15  
                   
                 47520 
                 47328 
               
               
                 12/15  
                   
                 51840 
                 51648 
               
               
                 13/15  
                   
                 56160 
                 55968 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
               
               
               
             
               
                 TABLE 23 
               
               
                   
               
               
                 LDPC 
                   
                   
                   
                 BCH error correction 
                 N bch  − 
               
               
                 rate 
                 N ldpc   
                 K ldpc   
                 K bch   
                 capability 
                 K bch   
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 5/15 
                 16200 
                 5400 
                 5232 
                 12 
                 168 
               
               
                 6/15 
                   
                 6480 
                 6312 
               
               
                 7/15 
                   
                 7560 
                 7392 
               
               
                 8/15 
                   
                 8640 
                 8472 
               
               
                 9/15 
                   
                 9720 
                 9552 
               
               
                 10/15  
                   
                 10800 
                 10632 
               
               
                 11/15  
                   
                 11880 
                 11712 
               
               
                 12/15  
                   
                 12960 
                 12792 
               
               
                 13/15  
                   
                 14040 
                 13872 
               
               
                   
               
            
           
         
       
     
     Detailed operations of BCH encoding and LDPC encoding are as below. 
     A 12-error correcting BCH code is used for outer encoding of the BBF. A BCH generator polynomial for the short FECBLOCK and the long FECBLOCK are obtained by multiplying all polynomials together. 
     LDPC code is used to encode an output of outer BCH encoding. To generate a completed B ldpc  (FECBLOCK), P ldpc  (parity bits) is encoded systematically from each I ldpc  (BCH-encoded BBF), and appended to I ldpc . The completed B ldpc  (FECBLOCK) is expressed by the following Equation.
 
 B   ldpc =[ I   ldpc   P   ldpc ]=[ i   0   ,i   1   , . . . ,i   K     lpdc     −1   ,p   0   ,p   1   , . . . ,p   N     lpdc     −K     lpdc     −1 ]  [Equation 2]
 
     Parameters for the long FECBLOCK and the short FECBLOCK are given in the above Tables 22 and 23, respectively. 
     A detailed procedure to calculate N ldpc −K ldpc  parity bits for the long FECBLOCK, is as follows. 
     1) Initialize the parity bits
 
 p   0   =p   1   =p   2   = . . . =p   N     lpdc     −K     lpdc     −1 =0  [Equation 3]
 
 p   983   =p   983   ⊕i   0    p   2815   =p   2815   ⊕i   0  
 
 p   4837   =p   4837    i   0    p   4989   =p   4989   ⊕i   0  
 
 p   6138   =p   6138   ⊕i   0    p   645   =p   645   ⊕i   0  
 
 p   6921   =p   6921   ⊕i   0    p   6974   =p   6974   ⊕i   0  
 
 p   7572   =p   7572   ⊕i   0    p   8260   =p   8260   ⊕i   0  
 
 p   8496   =p   8496   ⊕i   0   [Equation 4]
 
     3) For the next 359 information bits, is, s=1, 2, . . . , 359, accumulate is at parity bit addresses using following Equation.
 
{ x +( s  mod 360)× Q   ldpc }mod( N   ldpc   −K   ldpc )  [Equation 5]
 
     Here, x denotes an address of a parity bit accumulator corresponding to a first bit i 0 , and Q ldpc  is a code rate dependent constant specified in the addresses of the parity check matrix. Continuing with the example, Q ldpc =24 for the rate of 13/15, so for an information bit i 1 , the following operations are performed.
 
 p   1007   =p   1007   ⊕i   1    p   2839   =p   2839   ⊕i   1  
 
 p   4861   =p   4861   ⊕i   1    p   5013   =p   5013   ⊕i   1  
 
 p   6162   =p   6162   ⊕i   1    p   6482   =p   6482   ⊕i   1  
 
 p   6945   =p   6945   ⊕i   1    p   6998   =p   6998   ⊕i   1  
 
 p   7596   =p   7596   ⊕i   1    p   8284   =p   8284   ⊕i   1  
 
 p   8520   =p   8520   ⊕i   1   [Equation 6]
 
     4) For a 361th information bit i 360 , an address of the parity bit accumulator is given in a second row of the addresses of the parity check matrix. In a similar manner, addresses of the parity bit accumulator for the following 359 information bits is, s=361, 362, . . . , 719 are obtained using Equation 6, where x denotes an address of the parity bit accumulator corresponding to the information bit i 360 , i.e., an entry in the second row of the addresses of the parity check matrix. 
     5) In a similar manner, for every group of 360 new information bits, a new row from the addresses of the parity check matrix is used to find the address of the parity bit accumulator. 
     After all of the information bits are exhausted, a final parity bit is obtained as below. 
     6) Sequentially perform the following operations starting with i=1.
 
 p   i   =p   i   ⊕p   i−1   ,i= 1,2, . . . , N   ldpc   −K   ldpc −1  [Equation 7]
 
     Here, final content of p i  (i=0, 1, . . . , N ldpc −K ldpc −1) is equal to a parity bit p i . 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 24 
               
               
                   
                   
               
               
                   
                 Code rate 
                 Q ldpc   
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 5/15 
                 120 
               
               
                   
                 6/15 
                 108 
               
               
                   
                 7/15 
                 96 
               
               
                   
                 8/15 
                 84 
               
               
                   
                 9/15 
                 72 
               
               
                   
                 10/15  
                 60 
               
               
                   
                 11/15  
                 48 
               
               
                   
                 12/15  
                 36 
               
               
                   
                 13/15  
                 24 
               
               
                   
                   
               
            
           
         
       
     
     This LDPC encoding procedure for the short FECBLOCK is in accordance with t LDPC encoding procedure for the long FECBLOCK, except that Table 24 is replaced with Table 25, and the addresses of the parity check matrix for the long FECBLOCK are replaced with the addresses of the parity check matrix for the short FECBLOCK. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 25 
               
               
                   
                   
               
               
                   
                 Code rate 
                 Q ldpc   
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 5/15 
                 30 
               
               
                   
                 6/15 
                 27 
               
               
                   
                 7/15 
                 24 
               
               
                   
                 8/15 
                 21 
               
               
                   
                 9/15 
                 18 
               
               
                   
                 10/15  
                 15 
               
               
                   
                 11/15  
                 12 
               
               
                   
                 12/15  
                 9 
               
               
                   
                 13/15  
                 6 
               
               
                   
                   
               
            
           
         
       
     
       FIG. 29  illustrates time interleaving according to an embodiment of the present invention. 
     (a) to (c) show examples of a TI mode. 
     A time interleaver operates at the DP level. Parameters of time interleaving (TI) may be set differently for each DP. 
     The following parameters, which appear in part of the PLS2-STAT data, configure the TI. 
     DP_TI_TYPE (allowed values: 0 or 1): This parameter represents the TI mode. The value of ‘0’ indicates a mode with multiple TI blocks (more than one TI block) per TI group. In this case, one TI group is directly mapped to one frame (no inter-frame interleaving). The value of ‘1’ indicates a mode with only one TI block per TI group. In this case, the TI block may be spread over more than one frame (inter-frame interleaving). 
     DP_TI_LENGTH: If DP_TI_TYPE=‘0’, this parameter is the number of TI blocks N TI  per TI group. For DP_TI_TYPE=‘1’, this parameter is the number of frames P I  spread from one TI group. 
     DP_NUM_BLOCK_MAX (allowed values: 0 to 1023): This parameter represents the maximum number of XFECBLOCKs per TI group. 
     DP_FRAME_INTERVAL (allowed values: 1, 2, 4, and 8): This parameter represents the number of the frames I JUMP  between two successive frames carrying the same DP of a given PHY profile. 
     DP_TI_BYPASS (allowed values: 0 or 1): If time interleaving is not used for a DP, this parameter is set to ‘1’. This parameter is set to ‘0’ if time interleaving is used. 
     Additionally, the parameter DP_NUM_BLOCK from the PLS2-DYN data is used to represent the number of XFECBLOCKs carried by one TI group of the DP. 
     When time interleaving is not used for a DP, the following TI group, time interleaving operation, and TI mode are not considered. However, the delay compensation block for the dynamic configuration information from the scheduler may still be required. In each DP, the XFECBLOCKs received from SSD/MIMO encoding are grouped into TI groups. That is, each TI group is a set of an integer number of XFECBLOCKs and contains a dynamically variable number of XFECBLOCKs. The number of XFECBLOCKs in the TI group of index n is denoted by N xBLOCK_Group (n) and is signaled as DP_NUM_BLOCK in the PLS2-DYN data. Note that N xBLOCK_Group (n) may vary from a minimum value of 0 to a maximum value of N xBLOCK_Group_MAX  (corresponding to DP_NUM_BLOCK_MAX), the largest value of which is 1023. 
     Each TI group is either mapped directly to one frame or spread over P I  frames. Each TI group is also divided into more than one TI block (N TI ), where each TI block corresponds to one usage of a time interleaver memory. The TI blocks within the TI group may contain slightly different numbers of XFECBLOCKs. If the TI group is divided into multiple TI blocks, the TI group is directly mapped to only one frame. There are three options for time interleaving (except an extra option of skipping time interleaving) as shown in the following Table 26. 
     
       
         
           
               
               
             
               
                 TABLE 26 
               
               
                   
               
               
                 Modes 
                 Descriptions 
               
               
                   
               
             
            
               
                 Option 1 
                 Each TI group contains one TI block and is mapped directly to 
               
               
                   
                 one frame as shown in (a). This option is signaled in PLS2- 
               
               
                   
                 STAT by DP_TI_TYPE = ‘0’ and DP_TI_LENGTH = ‘1’ 
               
               
                   
                 (N TI  = 1). 
               
               
                 Option 2 
                 Each TI group contains one TI block and is mapped to more 
               
               
                   
                 than one frame. (b) shows an example, where one TI group is 
               
               
                   
                 mapped to two frames, i.e., DP_TI_LENGTH = ‘2’ (P I  = 2) 
               
               
                   
                 and DP_FRAME_INTERVAL (I JUMP  = 2). This provides 
               
               
                   
                 greater time diversity for low data-rate services. This 
               
               
                   
                 option is signaled in PLS2-STAT by DP_TI_TYPE = ‘1’. 
               
               
                 Option 3 
                 Each TI group is divided into multiple TI blocks and is 
               
               
                   
                 mapped directly to one frame as shown in (c). Each TI 
               
               
                   
                 block may use a full TI memory so as to provide a maximum 
               
               
                   
                 bit-rate for a DP. This option is signaled in PLS2-STAT 
               
               
                   
                 by DP_TI_TYPE = ‘0’ and DP_TI_LENGTH = 
               
               
                   
                 N TI , while P I  = 1. 
               
               
                   
               
            
           
         
       
     
     Typically, the time interleaver may also function as a buffer for DP data prior to a process of frame building. This is achieved by means of two memory banks for each DP. A first TI block is written to a first bank. A second TI block is written to a second bank while the first bank is being read from and so on. 
     The TI is a twisted row-column block interleaver. For an s th  TI block of an n th TI group, the number of rows N r  of a TI memory is equal to the number of cells N cells , i.e., N r =N cells  while the number of columns N c  is equal to the number N xBLOCK_TI (n,s). 
       FIG. 30  illustrates a basic operation of a twisted row-column block interleaver according to an embodiment of the present invention. 
       FIG. 30( a )  shows a write operation in the time interleaver and  FIG. 30( b )  shows a read operation in the time interleaver. A first XFECBLOCK is written column-wise into a first column of a TI memory, and a second XFECBLOCK is written into a next column, and so on as shown in (a). Then, in an interleaving array, cells are read diagonal-wise. During diagonal-wise reading from a first row (rightwards along a row beginning with a left-most column) to a last row, N r  cells are read out as shown in (b). In detail, assuming z n,s,i  (i=0, . . . , N r N c ) as a TI memory cell position to be read sequentially, a reading process in such an interleaving array is performed by calculating a row index R n,s,i , a column index C n,s,i , and an associated twisting parameter T n,s,i  as in the following Equation. 
     
       
         
           
             
               
                 
                   
                     GENERATE 
                     ⁡ 
                     
                       ( 
                       
                         
                           R 
                           
                             n 
                             , 
                             s 
                             , 
                             i 
                           
                         
                         , 
                         
                           C 
                           
                             n 
                             , 
                             s 
                             , 
                             i 
                           
                         
                       
                       ) 
                     
                   
                   = 
                   
                     
 
                   
                   ⁢ 
                   
                     { 
                     
                       
 
                     
                     ⁢ 
                     
                       
                         
                           R 
                           
                             n 
                             , 
                             s 
                             , 
                             i 
                           
                         
                         = 
                         
                           mod 
                           ⁡ 
                           
                             ( 
                             
                               i 
                               , 
                               
                                 N 
                                 r 
                               
                             
                             ) 
                           
                         
                       
                       , 
                       
                         
 
                       
                       ⁢ 
                       
                         
                           T 
                           
                             n 
                             , 
                             s 
                             , 
                             i 
                           
                         
                         = 
                         
                           mod 
                           ⁡ 
                           
                             ( 
                             
                               
                                 
                                   S 
                                   shift 
                                 
                                 × 
                                 
                                   R 
                                   
                                     n 
                                     , 
                                     s 
                                     , 
                                     i 
                                   
                                 
                               
                               , 
                               
                                 N 
                                 c 
                               
                             
                             ) 
                           
                         
                       
                       , 
                       
                         
 
                       
                       ⁢ 
                       
                         
                           C 
                           
                             n 
                             , 
                             s 
                             , 
                             i 
                           
                         
                         = 
                         
                           mod 
                           ⁡ 
                           
                             ( 
                             
                               
                                 
                                   T 
                                   
                                     n 
                                     , 
                                     s 
                                     , 
                                     i 
                                   
                                 
                                 + 
                                 
                                   ⌊ 
                                   
                                     i 
                                     
                                       N 
                                       r 
                                     
                                   
                                   ⌋ 
                                 
                               
                               , 
                               
                                 N 
                                 c 
                               
                             
                             ) 
                           
                         
                       
                     
                     ⁢ 
                     
                       
 
                     
                     } 
                   
                 
               
               
                 
                   [ 
                   
                     Equation 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     8 
                   
                   ] 
                 
               
             
           
         
       
     
     Here, S shift  is a common shift value for a diagonal-wise reading process regardless of N xBLOCK_TI (n,s), and the shift value is determined by N xBLOCK_TI_MAX  given in PLS2-STAT as in the following Equation. 
     
       
         
           
             
               
                 
                   for 
                   ⁢ 
                   
                     { 
                     
                       
                         
                           
                             
                               
                                 
                                   N 
                                   
                                     xBLOCK_TI 
                                     ⁢ 
                                     _MAX 
                                   
                                   ′ 
                                 
                                 = 
                                 
                                   
                                     N 
                                     
                                       xBLOCK_TI 
                                       ⁢ 
                                       _MAX 
                                     
                                     ′ 
                                   
                                   + 
                                   1 
                                 
                               
                               , 
                             
                           
                           
                             
                               
                                 
                                   if 
                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
                                   
                                     N 
                                     
                                       xBLOCK_TI 
                                       ⁢ 
                                       _MAX 
                                     
                                   
                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
                                   mod 
                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
                                   2 
                                 
                                 = 
                                 0 
                               
                               ⁢ 
                               
                                   
                               
                             
                           
                         
                         
                           
                             
                               
                                 
                                   N 
                                   
                                     xBLOCK_TI 
                                     ⁢ 
                                     _MAX 
                                   
                                   ′ 
                                 
                                 = 
                                 
                                   N 
                                   
                                     xBLOCK_TI 
                                     ⁢ 
                                     _MAX 
                                   
                                 
                               
                               , 
                             
                           
                           
                             
                               
                                 if 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 
                                   N 
                                   
                                     xBLOCK_TI 
                                     ⁢ 
                                     _MAX 
                                   
                                 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 mod 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                               
                               = 
                               1 
                             
                           
                         
                       
                       , 
                       
                         
 
                       
                       ⁢ 
                       
                         
                           S 
                           shift 
                         
                         = 
                         
                           
                             
                               N 
                               
                                 xBLOCK_TI 
                                 ⁢ 
                                 _MAX 
                               
                               ′ 
                             
                             - 
                             1 
                           
                           2 
                         
                       
                     
                   
                 
               
               
                 
                   [ 
                   
                     Equation 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     9 
                   
                   ] 
                 
               
             
           
         
       
     
     As a result, cell positions to be read are calculated by coordinates z n,s,i =N r C n,s,i +R n,s,i . 
       FIG. 31  illustrates an operation of a twisted row-column block interleaver according to another embodiment of the present invention. 
     More specifically,  FIG. 31  illustrates an interleaving array in a TI memory for each TI group, including virtual XFECBLOCKs when N xBLOCK_TI (0,0)=3, N xBLOCK_TI (1,0)=6 and N xBLOCK_TI (2,0)=5 
     A variable number N xBLOCK_TI (n,s)=N r  may be less than or equal to N xBLOCK_TI ′. Thus, in order to achieve single-memory deinterleaving at a receiver side regardless of N xBLOCK_TI (n,s), the interleaving array for use in the twisted row-column block interleaver is set to a size of N r ×N c =N cells ×N xBLOCK_TI_MAX ′ by inserting the virtual XFECBLOCKs into the TI memory and a reading process is accomplished as in the following Equation. 
     
       
         
           
             
               
                 
                   
                     
                       
                         p 
                         = 
                         0 
                       
                       ; 
                     
                     ⁢ 
                     
                       
 
                     
                     ⁢ 
                     
                       
                         
                           for 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           i 
                         
                         = 
                         0 
                       
                       ; 
                       
                         i 
                         &lt; 
                         
                           
                             N 
                             cells 
                           
                           ⁢ 
                           
                             N 
                             
                               xBLOCK_TI 
                               ⁢ 
                               _MAX 
                             
                             ′ 
                           
                         
                       
                       ; 
                       
                         i 
                         = 
                         
                           i 
                           + 
                           1 
                         
                       
                     
                   
                   ⁢ 
                   
                     
 
                   
                   ⁢ 
                   
                     { 
                     
                       
                         GENERATE 
                         ⁡ 
                         
                           ( 
                           
                             
                               R 
                               
                                 n 
                                 , 
                                 s 
                                 , 
                                 i 
                               
                             
                             , 
                             
                               C 
                               
                                 n 
                                 , 
                                 s 
                                 , 
                                 j 
                               
                             
                           
                           ) 
                         
                       
                       ; 
                       
                         
 
                       
                       ⁢ 
                       
                         
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     The number of TI groups is set to 3. An option of the time interleaver is signaled in the PLS2-STAT data by DP_TI_TYPE=‘0’, DP_FRAME_INTERVAL=‘1’, and DP_TI_LENGTH=‘1’, i.e., N TI =1, IJUMP=1, and PI=1. The number of XFECBLOCKs, each of which has Ncells=30 cells, per TI group is signaled in the PLS2-DYN data by NxBLOCK_TI(0,0)=3, NxBLOCK_TI(1,0)=6, and NxBLOCK_TI(2,0)=5, respectively. A maximum number of XFECBLOCKs is signaled in the PLS2-STAT data by NxBLOCK_Group_MAX, which leads to └N xBLOCK_Group_MAX /N TI ┘=N xBLOCK_TI_MAX =6. 
     The purpose of the Frequency Interleaver, which operates on data corresponding to a single OFDM symbol, is to provide frequency diversity by randomly interleaving data cells received from the frame builder. In order to get maximum interleaving gain in a single frame, a different interleaving-sequence is used for every OFDM symbol pair comprised of two sequential OFDM symbols. 
     Therefore, the frequency interleaver according to the present embodiment may include an interleaving address generator for generating an interleaving address for applying corresponding data to a symbol pair. 
       FIG. 32  illustrates an interleaving address generator including a main pseudo-random binary sequence (PRBS) generator and a sub-PRBS generator according to each FFT mode according to an embodiment of the present invention. 
     (a) shows the block diagrams of the interleaving-address generator for 8K FFT mode, (b) shows the block diagrams of the interleaving-address generator for 16K FFT mode and (c) shows the block diagrams of the interleaving-address generator for 32K FFT mode. 
     The interleaving process for the OFDM symbol pair is described as follows, exploiting a single interleaving-sequence. First, available data cells (the output cells from the Cell Mapper) to be interleaved in one OFDM symbol O m,l  is defined as O m,l =[x m,l,0 , . . . , x m,l,p , . . . , x m,l,N     data     −1 ] for l=0, . . . , N sym −1, where X m,l,p  is the p th  cell of the l th  OFDM symbol in the m th  frame and N data  is the number of data cells: N data =C FSS  for the frame signaling symbol(s), N data =C data  for the normal data, and N data =C FES  for the frame edge symbol. In addition, the interleaved data cells are defined as P m,l =[v m,l,0 , . . . , v m,l,N     data     −1 ] for l=0, . . . , N sym −1. 
     For the OFDM symbol pair, the interleaved OFDM symbol pair is given by v m,l,H     l   (p)=x m,l,p , p=0, . . . , N data −1, for the first OFDM symbol of each pair v m,l,H     l   (p)=x m,l,H     l     (p) , p=0, . . . , N data −1, for the second OFDM symbol of each pair, where H l (p) is the interleaving 
     address generated by a PRBS generator. 
       FIG. 33  illustrates a main PRBS used for all FFT modes according to an embodiment of the present invention. 
     (a) illustrates the main PRBS, and (b) illustrates a parameter Nmax for each FFT mode. 
       FIG. 34  illustrates a sub-PRBS used for FFT modes and an interleaving address for frequency interleaving according to an embodiment of the present invention. 
     (a) illustrates a sub-PRBS generator, and (b) illustrates an interleaving address for frequency interleaving. A cyclic shift value according to an embodiment of the present invention may be referred to as a symbol offset. 
       FIG. 35  illustrates a write operation of a time interleaver according to an embodiment of the present invention. 
       FIG. 35  illustrates a write operation for two TI groups. 
     A left block in the figure illustrates a TI memory address array, and right blocks in the figure illustrate a write operation when two virtual FEC blocks and one virtual FEC block are inserted into heads of two contiguous TI groups, respectively. 
     Hereinafter, description will be given of a configuration of a time interleaver and a time interleaving method using both a convolutional interleaver (CI) and a block interleaver (BI) or selectively using either the CI or the BI according to a physical layer pipe (PLP) mode. A PLP according to an embodiment of the present invention is a physical path corresponding to the same concept as that of the above-described DP, and a name of the PLP may be changed by a designer. 
     A PLP mode according to an embodiment of the present invention may include a single PLP mode or a multi-PLP mode according to the number of PLPs processed by a broadcast signal transmitter or a broadcast signal transmission apparatus. The single PLP mode corresponds to a case in which one PLP is processed by the broadcast signal transmission apparatus. The single PLP mode may be referred to as a single PLP. 
     The multi-PLP mode corresponds to a case in which one or more PLPs are processed by the broadcast signal transmission apparatus. The multi-PLP mode may be referred to as multiple PLPs. 
     In the present invention, time interleaving in which different time interleaving schemes are applied according to PLP modes may be referred to as hybrid time interleaving. Hybrid time interleaving according to an embodiment of the present invention is applied for each PLP (or at each PLP level) in the multi-PLP mode. 
       FIG. 36  illustrates an interleaving type applied according to the number of PLPs in a table. 
     In a time interleaving according to an embodiment of the present invention, an interleaving type may be determined based on a value of PLP_NUM. PLP_NUM is a signaling field indicating a PLP mode. When PLP_NUM has a value of 1, the PLP mode corresponds to a single PLP. The single PLP according to the present embodiment may be applied only to a CI. 
     When PLP_NUM has a value greater than 1, the PLP mode corresponds to multiple PLPs. The multiple PLPs according to the present embodiment may be applied to the CI and a BI. In this case, the CI may perform inter-frame interleaving, and the BI may perform intra-frame interleaving. 
       FIG. 37  is a block diagram including a first example of a structure of a hybrid time interleaver described above. 
     The hybrid time interleaver according to the first example may include a BI and a CI. The time interleaver of the present invention may be positioned between a BICM chain block and a frame builder. 
     The BICM chain block illustrated in  FIGS. 37 and 38  may include the blocks in the processing block  5000  of the BICM block illustrated in  FIG. 19  except for the time interleaver  5050 . The frame builder illustrated in  FIGS. 37 and 38  may perform the same function as that of the frame building block  1020  of  FIG. 18 . 
     As described in the foregoing, it is possible to determine whether to apply the BI according to the first example of the structure of the hybrid time interleaver depending on values of PLP_NUM. That is, when PLP_NUM=1, the BI is not applied (BI is turned OFF) and only the CI is applied. When PLP_NUM&gt;1, both the BI and the CI may be applied (BI is turned ON). A structure and an operation of the CI applied when PLP_NUM&gt;1 may be the same as or similar to a structure and an operation of the CI applied when PLP_NUM=1. 
       FIG. 38  is a block diagram including a second example of the structure of the hybrid time interleaver described above. 
     An operation of each block included in the second example of the structure of the hybrid time interleaver is the same as the above description in  FIG. 20 . It is possible to determine whether to apply a BI according to the second example of the structure of the hybrid time interleaver depending on values of PLP_NUM. Each block of the hybrid time interleaver according to the second example may perform operations according to embodiments of the present invention. In this instance, an applied structure and operation of a CI may be different between a case of PLP_NUM=1 and a case of PLP_NUM&gt;1. 
       FIG. 39  is a block diagram including a first example of a structure of a hybrid time deinterleaver. 
     The hybrid time deinterleaver according to the first example may perform an operation corresponding to a reverse operation of the hybrid time interleaver according to the first example described above. Therefore, the hybrid time deinterleaver according to the first example of  FIG. 39  may include a convolutional deinterleaver (CDI) and a block deinterleaver (BDI). 
     A structure and an operation of the CDI applied when PLP_NUM&gt;1 may be the same as or similar to a structure and an operation of the CDI applied when PLP_NUM=1. 
     It is possible to determine whether to apply the BDI according to the first example of the structure of the hybrid time deinterleaver depending on values of PLP_NUM. That is, when PLP_NUM=1, the BDI is not applied (BDI is turned OFF) and only the CDI is applied. 
     The CDI of the hybrid time deinterleaver may perform inter-frame deinterleaving, and the BDEI may perform intra-frame deinterleaving. Details of inter-frame deinterleaving and intra-frame deinterleaving are the same as the above description. 
     A BICM decoding block illustrated in  FIGS. 39 and 40  may perform a reverse operation of the BICM chain block of  FIGS. 37 and 38 . 
       FIG. 40  is a block diagram including a second example of the structure of the hybrid time deinterleaver. 
     The hybrid time deinterleaver according to the second example may perform an operation corresponding to a reverse operation of the hybrid time interleaver according to the second example described above. An operation of each block included in the second example of the structure of the hybrid time deinterleaver may be the same as the above description in  FIG. 39 . 
     It is possible to determine whether to apply a BDI according to the second example of the structure of the hybrid time deinterleaver depending on values of PLP_NUM. Each block of the hybrid time deinterleaver according to the second example may perform operations according to embodiments of the present invention. In this instance, an applied structure and operation of a CDI may be different between a case of PLP_NUM=1 and a case of PLP_NUM&gt;1. 
       FIG. 41  is a block diagram illustrating a hybrid broadcast reception apparatus according to an embodiment of the present invention. A hybrid broadcast system can transmit broadcast signals in connection with terrestrial broadcast networks and the Internet. The hybrid broadcast reception apparatus can receive broadcast signals through terrestrial broadcast networks (broadcast networks) and the Internet (broadband). The hybrid broadcast reception apparatus may include physical layer module(s), physical layer I/F module(s), service/content acquisition controller, Internet access control module(s), a signaling decoder, a service signaling manager, a service guide manager, an application signaling manager, an alert signal manager, an alert signaling parser, a targeting signaling parser, a streaming media engine, a non-real time file processor, a component synchronizer, a targeting processor, an application processor, an A/V processor, a device manager, a data sharing and communication unit, redistribution module(s), companion device(s) and/or an external management module. 
     The physical layer module(s) can receive a broadcast related signal through a terrestrial broadcast channel, process the received signal, convert the processed signal into an appropriate format and deliver the signal to the physical layer I/F module(s). 
     The physical layer I/F module(s) can acquire an IP datagram from information obtained from the physical layer module. In addition, the physical layer I/F module can convert the acquired IP datagram into a specific frame (e.g., RS frame, GSE, etc.). 
     The service/content acquisition controller can perform control operation for acquisition of services, content and signaling data related thereto through broadcast channels and/or broadband channels. 
     The Internet access control module(s) can control receiver operations for acquiring service, content, etc. through broadband channels. 
     The signaling decoder can decode signaling information acquired through broadcast channels. 
     The service signaling manager can extract signaling information related to service scan and/or content from the IP datagram, parse the extracted signaling information and manage the signaling information. 
     The service guide manager can extract announcement information from the IP datagram, manage a service guide (SG) database and provide a service guide. 
     The application signaling manager can extract signaling information related to application acquisition from the IP datagram, parse the signaling information and manage the signaling information. 
     The alert signaling parser can extract signaling information related to alerting from the IP datagram, parse the extracted signaling information and manage the signaling information. 
     The targeting signaling parser can extract signaling information related to service/content personalization or targeting from the IP datagram, parse the extracted signaling information and manage the signaling information. In addition, the targeting signaling parser can deliver the parsed signaling information to the targeting processor. 
     The streaming media engine can extract audio/video data for A/V streaming from the IP datagram and decode the audio/video data. 
     The non-real time file processor can extract NRT data and file type data such as applications, decode and manage the extracted data. 
     The component synchronizer can synchronize content and services such as streaming audio/video data and NRT data. 
     The targeting processor can process operations related to service/content personalization on the basis of the targeting signaling data received from the targeting signaling parser. 
     The application processor can process application related information and downloaded application state and represent parameters. 
     The A/V processor can perform audio/video rendering related operations on the basis of decoded audio/video data and application data. 
     The device manager can perform connection and data exchange with external devices. In addition, the device manager can perform operations of managing external devices connectable thereto, such as addition/deletion/update of the external devices. 
     The data sharing and communication unit can process information related to data transmission and exchange between a hybrid broadcast receiver and external devices. Here, data that can be transmitted and exchanged between the hybrid broadcast receiver and external devices may be signaling data, A/V data and the like. 
     The redistribution module(s) can acquire information related to future broadcast services and content when the broadcast receiver cannot directly receive terrestrial broadcast signals. In addition, the redistribution module can support acquisition of future broadcast services and content by future broadcast systems when the broadcast receiver cannot directly receive terrestrial broadcast signals. 
     The companion device(s) can share audio, video or signaling data by being connected to the broadcast receiver according to the present invention. The companion device may be an external device connected to the broadcast receiver. 
     The external management module can refer to a module for broadcast services/content provision. For example, the external management module can be a future broadcast services/content server. The external management module may be an external device connected to the broadcast receiver. 
       FIG. 42  is a block diagram illustrating a hybrid broadcast receiver according to an embodiment of the present invention. 
     The hybrid broadcast receiver can receive hybrid broadcast services through interworking of terrestrial broadcasting and a broadband network in DTV services of a future broadcast system. The hybrid broadcast receiver can receive broadcast audio/video (A/V) content transmitted through terrestrial broadcasting and receive enhancement data related thereto or part of broadcast A/V content through the broadband network in real time. In the specification, the broadcast A/V content can be referred to as media content. 
     The hybrid broadcast receiver may include a physical layer controller D 55010 , a tuner D 55020 , a physical frame parser D 55030 , a link layer frame parser D 55040 , an IP/UDP datagram filter D 55050 , an ATSC 3.0 digital TV (DTV) control engine D 55060 , an ALC/LCT+ client D 55070 , a timing controller D 55080 , a signaling parser D 55090 , a dynamic adaptive streaming over HTTP (DASH) client D 55100 , an HTTP access client D 55110 , an ISO base media file format (BMFF) parser D 55120  and/or a media decoder D 55130 . 
     The physical layer controller D 55010  can control operations of the tuner D 55020  and the physical frame parser D 55030  using radio frequency (RF) information of a terrestrial broadcast channel that the hybrid broadcast receiver intends to receive. 
     The tuner D 55020  can receive a broadcast related signal through a terrestrial broadcast channel, process the received signal and convert the signal into an appropriate format. For example, the tuner D 55020  can convert a received terrestrial broadcast signal into physical frames. 
     The physical frame parser D 55030  can parse a received physical frame and acquire a link layer frame through processing related thereto. 
     The link layer parser D 55040  can execute related operations for acquisition of link layer signaling or an IP/UDP datagram from the link layer frame. The link layer parser D 55040  can output at least one IP/UDP datagram. 
     The IP/UDP datagram filter D 55050  can filter a specific IP/UDP datagram from the received at least one IP/UDP datagram. That is, the IP/UDP datagram filter D 55050  can selectively filter an IP/UDP datagram, which is selected by the ATSC 3.0 DTV control engine, from the at least one IP/UDP datagram output from the link layer parser D 55040 . The IP/UDP datagram filter D 55050  can output an application layer transport protocol packet such as ALC/LCT+. 
     The ATSC 3.0 DTV control engine D 55060  can serve as an interface between modules included in the hybrid broadcast receiver. In addition, the ATSC 3.0 DTV control engine D 55060  can deliver parameters necessary for each module to each module and control operation of each module through the parameters. In the present invention, the ATSC 3.0 DTV control engine D 55060  can transfer media presentation description (MPD) and/or an MPD URL to the DASH client D 55100 . In addition, the ATSC 3.0 DTV control engine D 55060  can transfer a delivery mode and/or a transport session identifier (TSI) to the ALC/LCT+ client D 55070 . Here, the TSI indicates an identifier of a session in which a transport packet including a signaling message such as MPD or MPD URL related signaling is transmitted, for example, ALC/LCT+ session corresponding to application layer transport protocol or FLUTE session. In addition, the TSI can correspond to an asset ID of an MMT. 
     The ALC/LCT+ client D 55070  can generate one or more ISO base media file format (ISO MMFF) objects by processing an application layer transport protocol packet such as ALC/LCT+ and collecting and processing a plurality of packets. The application layer transport protocol packet may include an ALC/LCT packet, an ALC/LCT+ packet, a ROUTE packet and/or an MMTP packet. 
     The timing controller D 55080  can process a packet including system time information and control a system clock according thereto. 
     The signaling parser D 55090  can acquire and parse DTV broadcast service related signaling, and generate and manage a channel map on the basis of the parsed signaling. In the present invention, the signaling parser can parse MPD or MPD related information extended from signaling information. 
     The DASH client D 55100  can execute operations related to real-time streaming or adaptive streaming. The DASH client D 55100  can receive DASH content from an HTTP server through the HTTP access client D 55110 . The DASH client D 55100  can process a received DASH segment and output an ISO BMFF object. In the present invention, the DASH client D 55100  can deliver a fully qualified representation ID or a segment URL to the ATSC 3.0 DTV control engine D 55060 . Here, the fully qualified representation ID can refer to an ID corresponding to a combination of an MPD URL, period@id and represenstation@id, for example. In addition, the DASH client D 55100  can receive the MPD or MPD URL from the ATSC 3.0 DTV control engine D 55060 . The DASH client D 55100  can receive a desired media stream or DASH segment from the HTTP server using the received MPD or MPD URL. In the specification, the DASH client D 55100  may be referred to as a processor. 
     The HTTP access client D 55110  can request that the HTTP server provide specific information, receive a response to the request from the HTTP server and process the response. Here, the HTTP server can process the request received from the HTTP access client and provide a response to the request. 
     The ISO BMFF parser D 55120  can extract audio/video data from the ISO BMFF object. 
     The media decoder D 55130  can decode the received audio/video data and perform processing for presentation of the decoded audio/video data. 
     To provide hybrid broadcast services through interworking of a terrestrial broadcast network and a broadband network according to the hybrid broadcast receiver of the present invention, MPD needs to be extended or modified. The aforementioned terrestrial broadcast system can transmit extended or modified MPD and the hybrid broadcast receiver can receive content through broadcasting or a broadband network using the extended or modified MPD. That is, the hybrid broadcast receiver can receive the extended or modified MPD through terrestrial broadcasting and receive content through terrestrial broadcasting or a broadband network on the basis of the MPD. A description will be given of elements or attributes that need to be additionally included in the extended or modified MPD, compared to the conventional MPD. In the following, the extended or modified MPD is referred to as MPD. 
     The MPD can be extended or modified to represent ATSC 3.0 service. The extended or modified MPD can additionally include MPD@anchorPresentationTime, Common@presentable, Common.Targeting, Common.TargetDevice and/or Common@associatedTo. 
     MPD@anchorPresentationTime can indicate presentation time anchor of segments included in the MPD, that is, base time. In the following, MPD@anchorPresentationTime can be used as effective time of the MPD. MPD@anchorPresentationTime can indicate the earliest playback time from among segments included in the MPD. 
     The MPD may further include common attributes and elements. The common attributes and elements can be applied to AdaptionSet and Representation in the MPD. Common@presentable can indicate that media described by the MPD is a presentable component. 
     Common.Targeting can indicate targeting properties and/or personalization properties of the media described by the MPD. 
     Common.TargetDevice can indicate a target device or target devices of the media described by the MPD. 
     Common@associatedTo can indicate adaptationSet and/or representation related to the media described by the MPD. 
     In addition, MPD@id, Period@id and AdaptationSet@id included in the MPD may be necessary to specify media content described by the MPD. That is, the DASH client can specify content to be received on the basis of the MPD using MPD@id, Period@id and AdaptationSet@id and signal the content to the ATSC 3.0 DTV control engine. The ATSC 3.0 DTV control engine can receive the corresponding content and deliver the content to the DASH client. 
       FIG. 43  illustrates a protocol stack of a future hybrid broadcast system according to an embodiment of the present invention. As shown in the figure, a future broadcast transmission system supporting IP based hybrid broadcasting can encapsulate audio or video data of broadcast services in the ISO base media file format (BMFF). Here, a DASH segment or a media processing unit (MPU) of an MMT can be used for encapsulation. In addition, the future broadcast system can equally transmit the encapsulated data through a broadcast network and the Internet or differently transmit the encapsulated data through the broadcast network and the Internet according to attributes of the respective networks. Furthermore, the future broadcast system can equally transmit the encapsulated data using at least one of broadcast or broadband. In the case of a broadcast network using broadcast, the broadcast system can transmit data encapsulated in the ISO BMFF through an application layer transport protocol packet which supports real-time object transmission. For example, the broadcast system can encapsulate data in a real-time object delivery over unidirectional transport (ROUTE) or MMTP transport packet. The broadcast system can process the encapsulated data into an IP/UDP datagram, load the IP/UDP datagram in a broadcast signal and transmit the broadcast signal. When broadband is used, the broadcast system can deliver the encapsulated data to a receiving side through streaming such as DASH. 
     In addition, the broadcast system can transmit broadcast service signaling information as follows. In the case of a broadcast network using broadcast, the broadcast system can transmit signaling information through physical layers of the future broadcast transmission system and the broadcast network according to signaling attributes. Here, the broadcast system can transmit the signaling information through a specific data pipe (DP) of a transport frame included in a broadcast signal. Signaling information transmitted through broadcast may have a form of being encapsulated in a bitstream or IP/UDP datagram. When broadband is used, the broadcast system can return and deliver signaling data to a receiver in response to a request of the receiver. 
     In addition, the broadcast system can transmit broadcast service ESG or NRT content through the following method. In the case of a broadcast network using broadcast, the broadcast system can encapsulate the ESG or NRT content in an application layer transport protocol packet, for example, real-time object delivery over unidirectional transport (ROUTE) or MMTP transport packet. The broadcast system can generate an IP/UDP datagram with the encapsulated ESG or NRT content, load the IP/UDP datagram in a broadcast signal and transmit the broadcast signal. When broadband is used, the broadcast system can return and deliver the ESG or NRT content to a receiver in response to a request of the receiver. 
       FIG. 44  illustrates a structure of a transport frame delivered to a physical layer of the future broadcast transmission system according to an embodiment of the present invention. The future broadcast system can transmit a transport frame using broadcast. In the figure, P 1  located at the front of the transport frame can refer to a symbol including information for transport signal detection. P 1  can include tuning information and a receiver can decode a part L 1  following P 1  on the basis of a parameter included in the symbol P 1 . The broadcast system can include, in the part L 1 , information about transport frame configuration and characteristics of data pipes. That is, the receiver can obtain the information about the transport frame configuration and characteristics of data pipes by decoding the part L 1 . In addition, the receiver can acquire information that needs to be shared between DPs through a common DP. According to an embodiment, the transport frame may not include the common DP. 
     Components such as audio, video and data in the transport frame are included in an interleaved DP region composed of DP 1  to DPn and transmitted. Here, DPs through which components constituting each service (channel) are transmitted can be signaled through L 1  or a common PLP. 
     In addition, the future broadcast system can transmit information for rapidly acquiring information about services included in a transport frame. That is, the future broadcast system enables a future broadcast receiver to rapidly acquire broadcast services and content related information included in a transport frame. When services/content generated by one or more broadcasting stations are present in the corresponding frame, the future broadcast system can enable the receiver to efficiently recognize the services/content according to the broadcasting stations. That is, the future broadcast system can include, in a transport stream, service list information about services included in the transport stream, and transmit the transport stream including the service list information. 
     When an additional channel, for example, a fast information channel (FIC) is present, the broadcast system can transmit broadcast service related information through the additional channel such that the receiver can rapidly scan broadcast services and content in a corresponding frequency. As shown in  FIG. 44 , the broadcast system can include, in the transport stream, information for broadcast service scan and acquisition and transmit the same. Here, the region including the information for broadcast service scan and acquisition may be referred to as an FIC. The receiver can acquire information about broadcast services generated and transmitted by one or more broadcasting stations and easily and rapidly scan broadcast services available therein using the information. 
     In addition, a specific DP included in the transport stream can serve as a base DP capable of rapidly and robustly delivering signaling about broadcast services and content transmitted in the corresponding transport frame. Data transmitted through each DP of the transport frame of the physical layer is as shown in the lower part of  FIG. 44 . That is, link layer signaling or an IP datagram can be encapsulated in a generic packet in a specific format and then transmitted through a DP. Here, the IP datagram can include signaling data. Link (low) layer signaling can include signaling related to fast service scan/acquisition, context information of IP header compression and emergency alert. 
       FIG. 45  illustrates a transport packet of an application layer transport protocol according to an embodiment of the present invention. An application layer transport session can be composed of a combination of an IP address and a port number. When the application layer transport protocol corresponds to ROUTE, a ROUTE session can be composed of one or more layered coding transport (LCT) sessions. For example, when a single media component (e.g., DASH representation) is delivered through a single LCT transport session, one or more media components can be multiplexed and delivered through a single application transport session. Furthermore, one or more transport objects can be delivered through a single LCT transport session, and each transport object can be a DASH segment associated with DASH representation delivered through the transport session. 
     For example, when the application layer transport protocol is an LCT based protocol, a transport packet can be configured as follows. The transport packet can include an LCT header, a ROUTE header and payload data. A plurality of fields included in the transport packet is as follows. 
     The LCT header can include the following fields. A version field V can indicate version information of the corresponding transport protocol packet. A field C can include a flag related to the length of a congestion control information field which will be described below. A field PSI can indicate protocol-specific information, that is, information specific to the corresponding protocol. A field S can indicate a flag associated with the length of a transport session identifier (TSI) field. A field O can indicate a flag associated with the length of a transport object identifier (TOI) field. A field H can indicate whether a half-word (16 bits) is added to the lengths of the TSI field and the TOI field. A field A (close session flag) can indicate that a session is closed or closure of the session is imminent. A field B (close object flag) can indicate that an object being transmitted is closed or closure of the object is imminent. A code point field can indicate information related to encoding or decoding of a payload of the corresponding packet. For example, payload type can correspond to the information. A congestion control information field can indicate information related to congestion control. For example, the information related to congestion control can be a current time slot index (CTSI), a channel number or a packet sequence number in the corresponding channel. A transport session identifier field can indicate a transport field identifier. A transport object identifier field can indicate an identifier of an object transmitted through the corresponding transport session. 
     A ROUTE (ALC) header can include additional information of the preceding LCT header, such as a payload identifier related to a forward error correction scheme. 
     Payload data can indicate a data part of the payload of the corresponding packet. 
       FIG. 46  illustrates a method for transmitting signaling data by the future broadcast system according to an embodiment of the present invention. Signaling data of the future broadcast system can be transmitted as shown in the figure. To enable the receiver to support fast service/content scan and acquisition, the future broadcast transmission system can transmit signaling data with respect to a broadcast service delivered through a corresponding physical layer frame, via a fast information channel (FIC). In the specification, the FIC can refer to information about a service list. Unless an additional FIC is present, the signaling data may be delivered through a path through which link layer signaling is delivered. That is, signaling information including information about services and components (audio and video) thereof can be encapsulated in an IP/UDP datagram and transmitted through one or more DPs in the physical layer frame. According to an embodiment, signaling information about services and service components can be encapsulated in an application layer transport packet (e.g. a ROUTE packet or an MMTP packet) and transmitted. 
     The upper part of  FIG. 46  illustrates an example of delivering the aforementioned signaling data through an FIC or one or more DPs. That is, signaling data for supporting fast service scan/acquisition can be delivered through the FIC and signaling data including detailed information about services can be encapsulated in an IP datagram and transmitted through a specific DP. In the specification, the signaling data including detailed information about services may be referred to as service layer signaling. 
     The middle part of  FIG. 46  illustrates an example of delivering the aforementioned signaling data through an FIC and one or more DPs. That is, signaling data for supporting fast service scan/acquisition can be delivered through the FIC and signaling data including detailed information about services can be encapsulated in an IP datagram and transmitted through a specific DP. In addition, part of signaling data including information about a specific component included in a service may be delivered through one or more transport sessions in the application layer transport protocol. For example, part of the signaling data can be delivered through one or more transport sessions in a ROUTE session. 
     The lower part of  FIG. 46  illustrates an example of delivering the aforementioned signaling data through an FIC and one or more DPs. That is, signaling data for supporting fast service scan/acquisition can be delivered through the FIC and signaling data including detailed information about services can be delivered through one or more sessions in a ROUTE session. 
       FIG. 47  is a table showing signaling data transmitted, by the future broadcast system according to an embodiment of the present invention, for fast broadcast service scan of a receiver. The specification proposes signaling information for allowing a future broadcast reception apparatus to scan and acquire broadcast services. In the future broadcast system, broadcast services and content generated by one or more broadcasting stations can be transmitted within a specific frequency. The receiver can use the aforementioned signaling information to rapidly and easily scan broadcasting stations and services/contents thereof, included in the corresponding frequency. The signaling information can be represented by the illustrated syntax and expressed in other formats such as XML. 
     The signaling information for fast service scan and acquisition can be delivered to a fast information channel (FIC) corresponding to an additional channel in a physical layer transport frame. Furthermore, the aforementioned signaling information may be delivered through a common DP capable of carrying information that can be shared between data pipes of the physical layer. The signaling information may be delivered through a path through which link layer signaling is transmitted. The signaling information may be encapsulated in an IP datagram and delivered through a specific DP. Furthermore, the signaling information may be delivered via a service signaling channel through which service signaling is transmitted or a transport session of an application layer. 
     The signaling information (FIC information) for fast service scan and acquisition can include at least one of the following fields. In the specification, the FIC information can be referred to as service acquisition information. An FIC_portocol_version field can indicate the version of the structure of the signaling information. A TSID field can indicate an identifier of the overall broadcast stream. An FIC data version field can indicate the data version of the FIC information. The value of the FIC data version field can increase when the FIC is changed. A numpartitions field can indicate the number of partitions of a broadcast stream. To use the numpartitions field, it is assumed that each broadcast stream can be segmented into one or more partitions and transmitted. Each partition can include a plurality of DPs of a single broadcaster. Each partition can indicate a part of a broadcast stream used by a single broadcaster. A partition_protocol_version field can indicate the version of the aforementioned partition structure. A base_DP_ID field can indicate the identifier of a base DP of the corresponding partition. The base DP can include a service signaling table. The service signaling table can include a list of all services in the corresponding partition. That is, the service signaling table can list transmitted services. In addition, the service signaling table can define basic attributes of each service. The base DP may be a robust DP in the corresponding partition and may include another signaling table with respect to the corresponding partition. A base_DP_version field can indicate version information representing change of data transmitted through the base DP. For example, when serving signaling information is delivered through the base DP, the base_DP_version field can increase by 1 if the serving signaling information is changed. A num_services field can indicate the number of one or more components belonging to the corresponding partition. A service_id field can indicate a service identifier. A channel number field can indicate a channel number associated with the corresponding service. A service_category field can indicate the category of the corresponding service. For example, the service_category field can indicate A/V, audio, ESG, CoD, etc. A short_service_name_length field can indicate the length of the name of the corresponding service. A short_Service_name field can indicate the name of the corresponding service. A service_status field can indicate the status of the corresponding service. The service_status field can indicate an “active”, “suspended”, “hidden” or “shown” attribute. A service_distribution field can have an attribute similar to “multi-ensemble” flag of the ATSC M/H document. For example, the service_distribution field can indicate information about whether the corresponding service is included in the corresponding partition, the service is presentable only with the corresponding partition although the service is partially included in the partition, another partition is necessary for presentation, or other broadcast streams are necessary for presentation. An sp_indicator field is a service protection flag and can indicate whether one or more components necessary for presentation are protected. 
       FIG. 48  is a table showing signaling data transmitted, by the future broadcast system according to an embodiment of the present invention, for fast broadcast service scan of a receiver. The FIC information (service acquisition information) for supporting fast broadcast service scan and service/component acquisition can include information about an application layer transport session for delivering service and component data. As illustrated, the FIC information can be represented in a binary format. However, the FIC information may be represented in other formats such as XML according to embodiments. The FIC information can include the following fields. An FIC_portocol_version field can indicate the version of the structure of the signaling information. A TSID field can indicate an identifier of the overall broadcast stream. An FIC data version field can indicate the data version of the FIC information. The value of the FIC_data_version field can increase when the FIC is changed. A num_partitions field can indicate the number of partitions of a broadcast stream. To use the num_partitions field, it is assumed that each broadcast stream can be segmented into one or more partitions and transmitted. Each partition can include a plurality of DPs of a single broadcaster. Each partition can indicate a part of a broadcast stream used by a single broadcaster. A partition_id field can indicate the identifier of the corresponding partition. A partition_protocol_version field can indicate the version of the aforementioned partition structure. A num_services field can indicate the number of one or more components belonging to the corresponding partition. A service_id field can indicate a service identifier. A service_data_version field can indicate a change of service loop data in the FIC or a change of serving signaling data related to the corresponding service. The value of the service_data_version field can increase by 1 whenever included service data is changed. The receiver can detect data change in a service loop of the FIC or change of signaling related to the corresponding service using the service_data_version field. A channel_number field can indicate a channel number associated with the corresponding service. A service_category field can indicate the category of the corresponding service. For example, the service_category field can indicate A/V, audio, ESG, CoD, etc. A short_service_name_length field can indicate the length of the name of the corresponding service. A short_Service_name field can indicate the name of the corresponding service. A service_status field can indicate the status of the corresponding service. The service_status field can indicate an attribute “active”, “suspended”, “hidden” or “shown”. A service_distribution field can have an attribute similar to the “multi-ensemble” flag of the ATSC M/H document. For example, the service_distribution field can indicate information about whether the corresponding service is included in the corresponding partition, the service is presentable only with the corresponding partition although the service is partially included in the partition, another partition is necessary for presentation, or other broadcast streams are necessary for presentation. An sp_indicator field is a service protection flag and can indicate whether one or more components necessary for presentation are protected. An IP_version_flag field can indicate the following IP address format. The IP_version_flag field can indicate that IPv4 is used when the value thereof is 0 and indicate that IPv6 is used when the value thereof is 1. A source_IP_address_flag field can indicate whether the FIC information includes source IP_addr. The source_IP_address_flag field can indicate presence of source_IP_addr when the value thereof is 1. A num_transport_session field can indicate the number of transport sessions (e.g. ROUTE or MMTP sessions) in which component data of the corresponding service is transmitted in a broadcast stream. A source_IP_addr field can indicate the source IP address of an IP datagram including the component data of the corresponding service when the source_IP_address_flag is 1. A dest IP_addr field can indicate the destination IP address of the IP datagram including the component data of the corresponding service. A dest_UDP_port field can indicate the UDP port number of the IP datagram including the component data of the corresponding service. An LSID_DP field can indicate the identifier of a data pipe of a physical layer, which delivers signaling including detailed information about a transport session. In the case of ROUTE, for example, the signaling including the detailed information about the transport session can be an LCT session instance description including information about an LCT transport session of a ROUTE session. A service_signaling_flag field can indicate whether service signaling is transmitted through the corresponding transport session. The service_signaling_flag field can indicate that data transmitted through the corresponding transport session (e.g. ROUTE or MMTP session) includes the service signaling when the value thereof is 1. A transport session descriptors field can include transport session level descriptors. Each descriptor can be extended and include a num_descriptors field. Each descriptor can include as many descriptor loops as a number corresponding to a value indicated by the num_descriptors field. The transport session descriptors field can include transport session level descriptors. A service descriptors field can include service level descriptors. A partition descriptors field can include a partition level descriptor, and one partition can indicate part of broadcast streams used by a single broadcaster. An FIC session descriptors field can include FIC level descriptors. According to an embodiment, the fields included in the FIC may be included in a table other than the FIC and transmitted along with a broadcast signal. 
       FIG. 49  illustrates a method for transmitting FIC based signaling according to an embodiment of the present invention. The aforementioned example of delivering FIC based signaling is shown in the figure. In the specification, FIC based signaling can be referred to as service acquisition information or service acquisition signaling. As shown in the figure, physical layer signaling can include a field with respect to the service acquisition information. The field with respect to the service acquisition information can indicate whether the service acquisition information FIC is parsed to the receiver. The receiver can check whether service signaling data has been changed through service_data_version information by parsing the service acquisition information. When the service signaling data has been changed, the broadcast signal receiver can confirm a data pipe identifier of the physical layer which delivers signaling including detailed information about the corresponding transport session, using an LSID_DP field. The broadcast receiver can confirm detailed information about the transport session by parsing a DP indicated by the DP identifier. That is, the signaling method of the future broadcast system can include a sequence of confirming detailed information about the transport session by signaling whether the service acquisition information is parsed through the physical layer signaling and signaling the position of the detailed information about the transmission session through the service acquisition information. Here, the detailed information about the transport session can include an MPD transport table, an application signaling table, a transport session descriptor (LSID) and/or a component mapping table (CMT). 
       FIG. 50  illustrates signaling data transmitted, by the future broadcast system according to an embodiment, for fast broadcast service scan of a receiver. The FIC information (service acquisition information) for supporting fast broadcast service scan and service/component acquisition can include information about an application layer transport session for delivering service and component data. As illustrated, the FIC information can be represented in a binary format. However, the FIC information may be represented in other formats such as XML according to embodiments. The FIC information can include the following fields. An FIC_portocol_version field can indicate the version of the structure of the signaling information. A TSID field can indicate an identifier of the overall broadcast stream. An FIC data version field can indicate the data version of the FIC information. The value of the FIC data version field can increase when the FIC is changed. A num_partitions field can indicate the number of partitions of a broadcast stream. To use the num_partitions field, it is assumed that each broadcast stream can be segmented into one or more partitions and transmitted. Each partition can include a plurality of DPs of a single broadcaster. Each partition can indicate a part of a broadcast stream used by a single broadcaster. A partition_id field can indicate the identifier of the corresponding partition. A partition_protocol_version field can indicate the version of the aforementioned partition structure. A num_services field can indicate the number of one or more components belonging to the corresponding partition. A service_id field can indicate a service identifier. A service_data_version field can indicate a change of service loop data in the FIC or a change of serving signaling data related to the corresponding service. The value of the service_data_version field can increase by 1 whenever included service data is changed. The receiver can detect data change in a service loop of the FIC or change of signaling related to the corresponding service using the service_data_version field. A channel_number field can indicate a channel number associated with the corresponding service. A service_category field can indicate the category of the corresponding service. For example, the service_category field can indicate A/V, audio, ESG, CoD, etc. A short_service_name_length field can indicate the length of the name of the corresponding service. A short_Service_name field can indicate the name of the corresponding service. A service_status field can indicate the status of the corresponding service. The service_status field can indicate an “active”, “suspended”, “hidden” or “shown” attribute. A service_distribution field can have an attribute similar to “multi-ensemble” flag of the ATSC M/H document. For example, the service_distribution field can indicate information about whether the corresponding service is included in the corresponding partition, whether the service is presentable only with the corresponding partition although the service is partially included in the partition, whether another partition is necessary for presentation, or whether other broadcast streams are necessary for presentation. An sp_indicator field is a service protection flag and can indicate whether one or more components necessary for presentation are protected. An IP_version_flag field can indicate the following IP address format. The IP_version_flag field can indicate that IPv4 is used when the value thereof is 0 and indicate that IPv6 is used when the value thereof is 1. A source_IP_address_flag field can indicate whether the FIC information includes source_IP_addr. The source_IP_address_flag field can indicate presence of source IP_addr when the value thereof is 1. A num_transport_session field can indicate the number of transport sessions (e.g. ROUTE or MMTP sessions) in which component data of the corresponding service is transmitted in a broadcast stream. A source_IP_addr field can indicate the source IP address of an IP datagram including the component data of the corresponding service when the source_IP_address_flag is 1. A dest_IP_addr field can indicate the destination IP address of the IP datagram including the component data of the corresponding service. A dest_UDP_port field can indicate the UDP port number of the IP datagram including the component data of the corresponding service. An LSID_DP field can indicate the identifier of a data pipe of a physical layer, which delivers signaling including detailed information about a transport session. In the case of ROUTE, for example, the signaling including the detailed information about the transport session can be LCT session instance description including information about an LCT transport session of a ROUTE session. A service_signaling_flag field can indicate whether service signaling is transmitted through the corresponding transport session. The service_signaling_flag field can indicate presence of a DP including service signaling when the value thereof is 1. A signaling_data_version field can indicate a change of related service signaling data. The value of the signaling_data_version field can increase by 1 whenever the service signaling data is changed. The receiver can detect a change of signaling related to the corresponding service using the signaling_data_version field. A signaling_DP field can indicate the identifier of a data pipe of the physical layer, which delivers service signaling. A transport session descriptors field can include transport session level descriptors. Each descriptor can be extended and include a num_descriptors field. Each descriptor can include as many descriptor loops as a number corresponding to a value indicated by the num_descriptors field. The transport session descriptors field can include transport session level descriptors. A service descriptors field can include service level descriptors. A partition descriptors field can include a partition level descriptor, and one partition can indicate part of broadcast streams used by a single broadcaster. An FIC session descriptors field can include FIC level descriptors. According to an embodiment, the fields included in the FIC may be included in a table other than the FIC and transmitted along with a broadcast signal. 
       FIG. 51  illustrates a method for transmitting FIC based signaling according to another embodiment of the present invention. The aforementioned example of delivering FIC based signaling is as shown in the figure. In the specification, FIC based signaling can be referred to as service acquisition information or service acquisition signaling. As shown in the figure, physical layer signaling can include a field with respect to the service acquisition information. The field with respect to the service acquisition information can indicate whether the service acquisition information FIC is parsed to the receiver. The receiver can check whether service signaling data has been changed through service_data_version information by parsing the service acquisition information. When the service signaling data has been changed, the broadcast signal receiver can acquire LSID or an LSID table, which includes detailed information about the corresponding transport session, using an LSID_DP field through a DP identified from the LSID_DP field. In addition, the receiver can recognize a change of signaling data using information such as the service_signaling_flag, signaling_data_version and signaling DP and acquire the signaling data through an identified DP. 
     That is, the signaling method of the future broadcast system can include a sequence of confirming detailed information about the transport session by signaling whether the service acquisition information is parsed through the physical layer signaling and signaling the position of the detailed information about the transmission session through the service acquisition information. Here, the detailed information about the transport session can include an MPD transport table, an application signaling table, a transport session descriptor (LSID) and/or a component mapping table (CMT), and detailed information of transmission sessions can be delivered according to different examples. 
       FIG. 52  illustrates a service signaling message format of the future broadcast system according to an embodiment of the present invention. In the specification, a service signaling message can be referred to as signaling data or service layer signaling including detailed information about services. The service signaling message may include a signaling message header and a signaling message. The signaling message can be represented in a binary or XML format. The signaling message can be included in an IP datagram or a payload of an application layer transport packet (e.g. ROUTE or MMTP packet) and transmitted. The signaling message header may have the following syntax and can be represented in a format such as XML. The signaling message header can include the following fields. A signaling_id field can indicate a signaling message identifier. For example, when the signaling message is represented in the form of a section, the signaling id field can indicate the ID of a signaling table section. A signaling length field can indicate the length of the signaling message. A signaling_id_extension field can indicate extension information about the identifier of the signaling message. The signaling_id_extension field can be used as signaling identification information along with the signaling_id field. For example, the signaling_id_extension field can include the protocol version of the signaling message. A version_number field can indicate version information of the signaling message. The version_number field can be changed when the contents of the signaling message are changed. A current_next_indicator field can indicate whether the signaling message is currently available. The current_next_indicator field can indicate that the signaling message is currently available when the value thereof is 1. The current_next_indicator field can indicate that the signaling message is not currently available and a signaling message including the same signaling_id, signaling_id_extension or fragment_number may be available in the future when the value thereof is 0. A fragmentation_indicator field can indicate whether the signaling message has been fragmented. The fragmentation_indicator field indicates that the corresponding signaling message has been fragmented when the value thereof is 1. In this case, inclusion of part of signaling data can be indicated through signaling_message_data( ). When the value of the fragmentation_indicator field is 0, inclusion of the entire signaling data can be indicated through signaling_message_data( ). A payload_format_indicator field can indicate whether the current signaling message header includes a payload_format value. A payload_format_indicator field value of 1 can indicate that the signaling message header includes a payload_format value. An expiration_indicator field can indicate whether the current signaling message header includes an expiration value. An expiration_indicator field value of 1 can indicate that the signaling message header includes an expiration value. A fragment_number field can indicate a fragment number of the current signaling message when a single signaling message is divided into multiple fragments and transmitted. A last_fragment_number field can indicate the number of a fragment including the last data of the corresponding signaling message when a single signaling message is divided into multiple fragments and transmitted. A payload_format field can indicate the format of signaling message data included in a payload. In an embodiment, the payload_format field can be represented in a binary or XML format. An expiration field can indicate effective time of the signaling message included in the payload. 
       FIG. 53  shows service signaling tables used in the future broadcast system according to an embodiment of the present invention. Service signaling tables/messages according to the present invention are as described below and can include the following information and be signaled. Information included in tables/messages can be individually transmitted per table and is not limited to the illustrated embodiments. According to an embodiment, signaling information belonging to different tables may be merged into one table and transmitted. A service mapping table can include service attributes and service related information. For example, attribute information of services can include information such as IDs, names and categories of the services, and information related to services can include information about paths through which the services can be acquired. An MPD delivery table can include DASH MPD related to services/content or information on paths through which DASH MPD can be acquired. A component mapping table can include component information in services and component related information. The component information can include related DASH representation information, and the component related information can include information on paths through which components can be acquired. An LSID table can include information about transport sessions for delivering services/components and transport packet configurations. An initialization segment delivery table can include initialization segment information about DASH representation related to components in services or information about paths through which the initialization segment information can be acquired. An application parameter table can include detailed information about applications relate to broadcast services and information about paths through which the detailed information can be obtained. When such signaling messages/tables are transmitted through a broadcast network, the signaling messages/tables can be transmitted through a fast information channel (FIC), a service signaling channel (SSC), an application layer transport session (e.g., ROUTE or MMTP session) or the like. Furthermore, the signaling messages/tables can be transmitted over the Internet (broadband). 
       FIG. 54  shows a service mapping table used in the future broadcast system according to an embodiment of the present invention. The following description may be transmitted by being included in a service signaling message part following a signaling message header. 
     The service mapping table can include information about service mapping signaling and can be represented in XML or binary format. The service mapping table corresponding to service signaling information can include service identifier information, service type information, service name information, channel number information, ROUTE session related information, MPD related information and component signaling position information. The service identifier can indicate information identifying a service and can be represented as an id attribute. The service type information can indicate the type of the service and can be represented as a serviceType attribute. The service name information can indicate the name of the service and can be represented as a serviceName attribute. The channel number information can indicate a channel number related to the service and can be represented as a channelNumber attribute. 
     The ROUTE session related information can include sourceIP, destinationIP and destinationPort attributes. The sourceIP attribute can indicate a source address of IP datagrams carrying associated data. The destinationIP attribute can indicate a destination address of the IP datagrams carrying associated data. The destinationPort attribute can indicate a destination port number of the IP datagrams carrying associated data. 
     In addition, the ROUTE session related information can include detailed information (LSID) about transport sessions. For example, the ROUTE session related information can include LSID location information and delivery mode information of LSID location information. Furthermore, the detailed information LSID about transport sessions can include bootstrap information. The bootstrap information included in LSID can include LSID bootstrap information according to delivery mode. Attributes included in the bootstrap information will be described in detail below. 
     The MPD related information can include information about MPD or MPD signaling location. The information about MPD can include a version attribute and indicate the version of MPD. The MPD signaling location information can indicate a location where signaling related to MPD or MPD URL can be acquired. Delivery mode information included in MPD signaling location can indicate a delivery mode of the MPD location signaling. Bootstrap information included in the MPD signaling location can include bootstrap information of MPD or MPD URL according to the delivery mode. 
     The component signaling location related information can include a delivery mode attribute. The delivery mode attribute can indicate a delivery mode of corresponding component signaling location information. The bootstrap information included in the MPD signaling location can include bootstrap information of corresponding component location signaling according to the delivery mode. 
     The bootstrap information can include at least one of the following attributes according to delivery mode. 
     A sourceIP attribute can indicate a source address of IP datagrams carrying associated data. A destinationIP attribute can indicate a destination address of the IP datagrams carrying associated data. A destinationPort attribute can indicate a destination port number of the IP datagrams carrying associated data. A tsi attribute can include the identifier of a transport session delivering transport packets carrying associated data. A URL attribute can indicate a URL where associated data can be acquired. A packetid attribute can indicate the identifier of transport packets carrying associated data. 
       FIG. 55  shows a service signaling table of the future broadcast system according to an embodiment of the present invention. The future broadcast system can provide broadcast service signaling such that the receiver can receive broadcast services and content. This allows the receiver to acquire related signaling when signaling data is transmitted through the same transport session identifier TSI. The service signaling table can be represented in a binary format as illustrated and may be represented in other formats such as XML according to embodiments. In addition, the service signaling table can encapsulated in the aforementioned signaling message format. The service signaling table can include the following fields. An SST_portocol_version field can indicate the version of the service signaling table. A partition_id field can indicate the identifier of a corresponding partition. An SST_data_version field can indicate the data version of the corresponding service signaling table. A num_services field can indicate the number of one or more services included in the corresponding partition. A service_id field can indicate the identifier of the corresponding service. A service_name field can indicate the name of the corresponding service. An MPD_availability field can indicate whether MPD can be acquired through broadcast, a cellular network and/or Wi-Fi/Ethernet. A CMT_availability field can indicate whether a component mapping table (CMT) can be used through broadcast, a cellular network and/or Wi-Fi/Ethernet. An ASL_availability field can indicate whether an application signaling table (AST) can be used through broadcast, a cellular network and/or Wi-Fi/Ethernet. A DP_ID field can indicate the identifier of a DP carrying the MPD, CMT and/or ASL through broadcast. An LCT_IP_address field can indicate the IP address of an LCT channel delivering the MPD, CMT and/or ASL. An LCTUDP_port field can indicate a UDP port of the LCT channel delivering the MPD, CMT and/or ASL. An LCT_TSI field can indicate a transport session identifier (TSI) of the LCT channel delivering the MPD, CMT and/or ASL. An MPD_TOI field can indicate the transport object identifier of the MPD when the MPD is delivered through broadcast. A CMT TOI field can indicate the transport object identifier of the CMT when the CMT is delivered through broadcast. An AST_TOI field can indicate the transport object identifier of the AST when the AST is delivered through broadcast. An MPD_URL field can indicate a URL where the MPD can be acquired through broadband. A CMT_URL field can indicate a URL where the CMT can be acquired through broadband. An AST_URL field can indicate a URL where the AST can be acquired through broadband. 
       FIG. 56  shows a component mapping table used in the future broadcast system according to an embodiment of the present invention. The following description may be transmitted by being included in a service signaling message part following a signaling message header. The component mapping table can include information about component mapping signaling and can be represented in XML or binary format. The component mapping table corresponding to service signaling information can include the following fields. A Signaling_id field can include an identifier indicating that the corresponding table is the component mapping table. A protocol_version field can indicate a protocol version of the component mapping table, such as a component mapping table syntax. A Signaling version field can indicate a change of signaling data of the component mapping table. A Service_id field can indicate the identifier of a service associated with corresponding components. A Num_component field can indicate the number of components included in the corresponding service. An Mpd_id field can indicate a DASH MPD identifier associated a component. A Period_id field can indicate a DASH period identifier associated with the component. A representation_id field can indicate a DASH representation identifier associated with the component. A Source_IP field can indicate a source IP address of IP/UDP datagrams carrying corresponding component data. A Dest_IP field can indicate a destination IP address of the IP/UDP datagrams carrying the corresponding component data. A port field can indicate a port number of the IP/UDP datagrams carrying the corresponding component data. A tsi field can indicate the identifier of an application layer transport session carrying the corresponding component data. A DP_id field can indicate the identifier of a physical layer data pipe carrying the corresponding component data. The CMT can define components associated with each service and signal, to the receiver, locations or paths where the corresponding components can be received through the aforementioned information. 
       FIG. 57  illustrates component mapping table description according to an embodiment of the present invention. Component mapping description can signal information about transport paths of components included in broadcast services in the future broadcast system. Component mapping table description may be represented in XML format or as a binary bitstream. Component mapping table description can include the following elements and attributes. A service_id attribute can indicate the identifier of a service associated with a component. BroadcastComp can indicate one or more components transmitted through the same broadcast stream. BroadcastComp can include mpdID, perID, reptnID, baseURL and/or datapipeID attributes. The mpdID attribute can indicate a DASH MPD identifier associated with BroadcastComp. The perID attribute can indicate an associated period identifier in corresponding MPD. The reptnID attribute can indicate a DASH representation identifier associated with the corresponding component. The baseURL attribute can indicate a base URL of a DASH segment associated with the corresponding component. The datapipeID attribute can indicate the identifier of a data pipe carrying corresponding component data in a broadcast stream. 
     BBComp can indicate one or more components transmitted through a broadband network. BBComp can include mpdID, perID, reptnID and/or baseURL attributes. The mpdID attribute can indicate a DASH MPD identifier associated with BBComp. The perID attribute can indicate an associated period identifier in corresponding MPD. The reptnID attribute can indicate a DASH representation identifier associated with the corresponding component. The baseURL attribute can indicate a base URL of a DASH segment associated with the corresponding component. 
     ForeignComp can indicate one or more components transmitted through other broadcast streams. ForeignComp can include mpdID, perID, reptnID, baseURL, transportStreamID, sourceIPAddr, destIPAddr, destUDPPort and/or datapipeID attributes. The mpdID attribute can indicate a DASH MPD identifier associated with ForeignComp. The perID attribute can indicate an associated period identifier in corresponding MPD. The reptnID attribute can indicate a DASH representation identifier associated with the corresponding component. The baseURL attribute can indicate a base URL of a DASH segment associated with the corresponding component. The transportStreamID attribute can indicate the identifier of a broadcast stream including corresponding component data. The sourceIPAddr attribute can indicate a source IP address of IP datagrams carrying the corresponding component data. The destIPAddr attribute can indicate a destination IP address of the IP datagrams carrying the corresponding component data. The destUDPPort attribute can indicate a destination UDP port number of the IP datagrams carrying the corresponding component data. The datapipeID attribute can indicate the identifier of a data pipe through which the corresponding component data is transmitted in the corresponding broadcast stream. The aforementioned component mapping description can be transmitted by being encapsulated in an XML file or the above-described signaling message format. As shown in the lower part of  FIG. 57 , a signaling message header can have the aforementioned format and component mapping description or part thereof can be included in the service message part. The CMT can define components associated with each service and signal, to the receiver, locations or paths where the corresponding components can be received through the aforementioned information. 
       FIG. 58  illustrates a syntax of the component mapping table of the future broadcast system according to an embodiment of the present invention. The future broadcast system can signal the component mapping table such that the receiver can acquire components of broadcast services. The component mapping table can be represented in binary, XML or other formats and can be encapsulated in the aforementioned signaling message format. The component mapping table can include the following fields. A CMT_portocol_version field can indicate the version of the structure of the component mapping table (CMT). A service_id field can indicate the identifier of a service related to a component position provided by the corresponding CMT. A CMT data version field can indicate the data version of the CMT. A num_broadcast_streams field can indicate the number of broadcast streams including at least one component related to the corresponding service. A TSID field can indicate a transport session identifier of a corresponding broadcast stream. A num_partitions field can indicate the number of partitions of a broadcast stream including at least one component related to the corresponding service. The CMT can include a plurality of partitions. A partition_id field can indicate the identifier of a corresponding partition. A num_data_pipes field can indicate the number of data pipes in a partition including at least one component related to the corresponding service. A DP_ID field can indicate the identifier of each data pipe. A num_ROUTE_sessions field can indicate the number of transport sessions (e.g. ROUTE sessions) included in each data pipe. Each data pipe can include at least one component associated with the corresponding service. An IP_address field can indicate the IP address of each transport session. A UDP_port field can indicate a UDP port of each transport session. A num_LCT_channels field can indicate the number of LCT channels in a transport session including a component associated with the corresponding service. An LCT_TSI field can indicate a transport session identifier (TSI). A Representation_ID field can indicate the identifier of representation carried by a corresponding LCT channel. An Internet_availability field can be an identifier indicating whether corresponding representation can be received through the Internet or broadband. A num_internet_only_reptns field can indicate the number of representations which can be received only through the Internet or broadband. A Representation_ID field can indicate the identifier of representation which can be received only through the Internet or broadband in a loop of num_internet_only_reptns. The CMT can define components associated with each service and signal, to the receiver, locations or paths where the corresponding components can be received through the aforementioned information. 
       FIG. 59  illustrates a method for delivering signaling related each service through a broadband network in the future broadcast system according to an embodiment of the present invention. The future broadcast system can transmit signaling related to a service to the receiver through a broadband network. The future broadcast system can transmit signaling to the receiver through the broadband network using URL signaling table description. The URL signaling table description can be represented in XML or binary format. The URL signaling table description can include the following attributes. A service_id attribute can indicate the identifier of a service associated with signaling. An mpdURL attribute can indicate the URL of broadband MPD. A cstURL attribute can indicate the URL of a broadband CMT. The CMT can include information about a path through which component data in a broadcast service is acquired. An astURL attribute can indicate the URL of a broadband AST. The AST can include information about an application related to a broadcast service. The receiver can receive the description and receive the corresponding signaling on the basis of the URL of each signaling. The aforementioned URL signaling table description can be encapsulated in a single XML file or the aforementioned signaling message format and transmitted. As shown in the lower part of the figure, a signaling message header can take the aforementioned format and the URL signaling table description or part thereof can follow the signaling message header. 
       FIG. 60  illustrates a method for signaling MPD in the future broadcast system according to an embodiment of the present invention. As shown in the upper part of the figure, a signaling message about MPD of a broadcast service available in a future broadcast network can be composed of a signaling message header and the signaling message. The signaling message header can take the aforementioned format and MPD delivery table information can include the following information. Signaling_id information can indicate that the corresponding signaling message is a signaling message including MPD or information about a path through which the MPD can be acquired. protocol_version information can indicate a protocol version of an MPD delivery table, such as the syntax of the signaling message. Signaling version information can indicate a change of signaling data of the MPD delivery table. Service_id information can indicate the identifier of a service associated with the corresponding signaling information. Mpd_id information can indicate the identifier of DASH MPD associated with the signaling message. MPD_version information is version information indicating a change of the corresponding MPD. Delivery_mode information can indicate whether the signaling message includes the corresponding MPD or is delivered through a different path. MPD_data( ) information can include MPD data when the signaling message includes the MPD. MPD_path information can include information about a path through which the MPD can be acquired. For example, the path can indicate a URL. 
     MPD delivery table description can include the following information. A service_id attribute can indicate the identifier of a service associated with signaling. An MPD_id attribute can indicate the identifier of the MPD. MPD_version is version information indicating a change of the MPD. An MPD_URL attribute can include information about a URL through which the MPD can be acquired. An MPD element can include MPD information. The MPD delivery table description can be encapsulated in a single XML file or the aforementioned signaling message format and transmitted. That is, the signaling message header can take the aforementioned format and the MPD delivery table description or part thereof can follow the signaling message header. 
       FIG. 61  illustrates a syntax of an MPD delivery table of the future broadcast system according to an embodiment of the present invention. Information of the MPD delivery table or part thereof can follow a signaling message header. The information of the MPD delivery table can include the following fields. A service_id field can indicate the identifier of an associated broadcast service. An MPD_idlength field can indicate the length of the following MPD id bytes( ). An MPD id bytes field can indicate the identifier of an MPD filed included in a signaling message. An MPD_version field can indicate version information such as a change of data of the corresponding MPD. An MPD_URL_availability field can indicate presence or absence of URL information of the MPD in the corresponding signaling table/message. An MPD_data_availabilty field can indicate whether the corresponding signaling table/message includes the MPD. The MPD_data_availabilty field can indicate that the signaling table/message includes the MPD when the value thereof is 1. An MPD_URL_length field can indicate the length of the following MPD_URL_byteso. An MPD_URL_bytes field can indicate an MPD URL included in the signaling message. An MPD_coding field can indicate an encoding scheme of an MPD field included in the signaling message. As shown in the lower part of the figure, an MPD file can be encoded according to different encoding schemes according to values of the MPD_coding field. For example, an MPD_coding field value of “0x00” can indicate that the signaling table/message includes a plain MPD field represented in XML. An MPD_coding field value of “0x01” can indicate that the signaling table/message includes an MPD field compressed by gzip. If an MPD field compressed by gzip is segmented and respectively transmitted through a plurality of messages/tables, corresponding multiple MPD bytes( ) can be concatenated and then ungzipped. An MPD byte_length field can indicate the length of the following MPD bytes( ). An MPD_bytes field can include data of the MPD field included in the signaling message according to the encoding scheme indicated by the MPD_coding field. The future broadcast system enables the receiver to receive or acquire service related MPD through the MPD delivery table including the aforementioned fields. 
       FIG. 62  illustrates transport session instance description of the future broadcast system according to an embodiment of the present invention. When an application layer transmission method corresponds to real-time object delivery over unidirectional transport (ROUTE), a ROUTE session can be composed of one or more layered coding transport (LCT) sessions. Detailed information about one or more transport sessions can be signaled through transport session instance description. In the case of ROUTE, the transport session instance description may be referred to as LCT session instance description (LSID). Particularly, the transport session instance description can define what is delivered through each LCT transport session constituting the ROUTE session. Each transport session can be uniquely identified by a transport session identifier (TSI). The TSI can be included in an LCT header. The transport session instance description can describe all transport sessions carried by the corresponding session. For example, LSID can describe all LCT sessions carried by a ROUTE. The transport session instance description may be delivered through the same ROUTE session as transport sessions or through a different ROUTE session or unicast. 
     When delivered through the same ROUTE session, the transport session instance description can be delivered through a transport session having a TSI of 0. While an object referred to in the transport session instance description may be delivered through the transport session with TSI=0, the object can have a TOI value different from that of the transport session instance description. Otherwise, the object may be delivered through a separate transport session with TSI≠0. The transport session instance description can be updated using at least one of the version number, validity information and expiration information. The transport session instance description can be represented in a bitstream in addition to the illustrated format. 
     The transport session instance description can include version, validFrom and expiration attributes and include a TSI attribute and SourceFlow and RepairFlow information with respect to each transport session. The version attribute can indicate the version information of the transport session instance description, and the version information can increase whenever contents thereof are updated. Transport session instance description having a highest version number is the currently valid version. The validFrom attribute can indicate the data and time from which the corresponding transport session instance description is valid. The validFrom attribute may not be included in the transport session instance description according to embodiment. In this case, the receiver can assume that the corresponding transport session instance description is valid immediately. The expiration attribute can indicate the date and time when the corresponding transport session instance description expires. The expiration attribute may not be included in the transport session instance description. In this case, the receiver can assume that the corresponding transport session instance description is valid for all time. If transport session instance description having an expiration attribute is received, the transport session instance description can conform to the corresponding expiration attribute. The TSI attribute can indicate a transport session identifier. A SourceFlow element provides information of a source flow transmitted with the corresponding TSI. The SourceFlow element will be described in detail below. A RepairFlow element can provide information of a repair flow transmitted with the corresponding TSI. 
       FIG. 63  illustrates shows a SourceFlow element of the future broadcast system according to an embodiment of the present invention. The Sourceflow element can include an EFDT element, an idRef attribute, a realtime attribute, a minBufferSize attribute, an Application Identifier element and a PayloadFormat element. The EFDT element can specify detailed information of file delivery data. The EFDT element indicates an extended file delivery table (FDT) instance and will be described in detail below. The idRef attribute can indicate an EFDT identifier and can be represented as a URI by the corresponding transport session. The realtime attribute can indicate that corresponding LCT packets include extension headers. The extended headers can include timestamps indicating presentation time of an included delivery object. The minBufferSize attribute can define the maximum amount of data that needs to be stored in the receiver. The Application Identifier element can provide additional information that can be mapped to the application carried in the corresponding transport session. For example, representation ID of DASH content or Application Set parameters of a DASH representation can be provided as additional information in order to select a transport session for rendering. The PayloadFormat element can define payload formats of ROUTE packets carrying objects of the source flow. The PayloadFormat element can include a codePoint attribute, a deliveryObjectFormat attribute, a fragmentation attribute, a deliveryOrder attribute, a sourceFecPayloadID attribute and/or an FECParameters element. The codePoint attribute can define a code point used in the corresponding payload. This can indicate the value of the CP field in the LCT header. The deliveryObjectFormat attribute can indicate the payload format of the corresponding delivery object. The fragmentation attribute can define the type of fragmentation. The deliveryOrder attribute can indicate the order of delivery of objects. The sourceFecPayloadID attribute can define the format of a source FEC payload identifier. The FECParameters element can define FEC parameters. This includes an FEC encoding id, an instance id, etc. 
       FIG. 64  shows an EFDT of the future broadcast system according to an embodiment of the present invention. The EFDT can include detailed information of file delivery data. The EFDT can include an idRef attribute, a version attribute, a maxExpiresDelta attribute, a maxTransportSize attribute and a FileTemplate element. The idRef attribute can indicate the identifier of the EFDT. The version attribute can indicate the version of an EFDT instance descriptor. This attribute can be increased by 1 when the EFDT is updated. A received EFDT with the highest version number can be the currently valid version. The maxExpiresDelta attribute can indicate a maximum expiry time for an object after sending a first packet associated to the object. The maxTransportSize attribute can indicate a maximum transport size of an object described by the corresponding EFDT. The FileTemplate element can specify the file URL or file template in the body. 
     The aforementioned transport session instance descriptor (LSID) element can be transmitted according to a transport session instance descriptor (LSID) table shown in the lower part of the figure. The LSID table can be delivered through the aforementioned signaling message which is divided into a signaling message header and a signaling message data part. The signaling message data part can include the transport session instance descriptor (LSID) or part thereof. Signaling message data can include the LSID table and the following fields. A Signaling_id field is identifier information indicating that the corresponding table is a signaling table including the LSID. A protocol_version field can indicate the protocol version of signaling, such as a signaling syntax including the LSID. A Signaling version field can indicate a change of signaling data including the LSID. In addition, the LSID table may further include the contents of the aforementioned transport session instance descriptor (LSID) element. 
       FIG. 65  illustrates a method for transmitting an initialization segment delivery table (ISDT) used in the future broadcast system according to an embodiment of the present invention. The future broadcast system can deliver signaling information about an initialization segment of DASH representation associated with a component in a broadcast service by transmitting an ISDT. The signaling information about the initialization segment of DASH representation associated with the component in the broadcast service may include a header and data. The signaling message header can have the aforementioned format and the signaling message data can include initialization segment delivery information or part thereof. The initialization segment delivery information can include the following information. Signaling_id information can identify a signaling message including the initialization segment or information on the path thereof. protocol_version information can indicate the protocol version of the ISDT, such as the syntax of the corresponding signaling message. Sequence_number information can indicate the instance identifier of the ISDT. Signaling version information can indicate a change of signaling data of the ISDT. Service_id information can identify a service associated with the corresponding component. Mpd_id information can indicate a DASH MPD identifier associated with the corresponding component. period_id information can indicate a DASH Period identifier associated with the corresponding component. representation_id information can indicate a DASH representation identifier associated with the corresponding component. 
     Initialization_segment_version information can be version information indicating a change of the corresponding MPD. Delivery_mode information can indicate whether the ISDT includes the initialization segment or is delivered through a different path. Initialization_segment_data( ) information can include the initialization segment data itself. Initialization segment path information can include information about a path through which the initialization segment can be acquired, such as the URL of the initialization segment. The receiver can receive information about the initialization segment of DASH representation associated with the corresponding component through the ISDT. 
       FIG. 66  illustrates a delivery structure of a signaling message of the future broadcast system according to an embodiment of the present invention. The aforementioned signaling data can be delivered as illustrated when transmitted based on application layer transport, for example, ROUTE. That is, some signaling can be transmitted through a fast information channel in order to support fast service scan. Some signaling can be transmitted through a specific transport session and delivered along with component data. 
     Signaling information for supporting fast service scan and acquisition can be received through a separate channel from a transport session. Here, the separate channel can refer to a separate data pipe (DP). Detailed information about a service can be received through a separate designated transport session. Here, the transport session can have a value of TSI=0. Information delivered through the designated transport session can include an MPD delivery table, an application signaling table, a transport session instance description table and/or a component mapping table. Some signaling information can be delivered through a transport session along with component data. For example, the initialization segment delivery table can be delivered along with component data. 
     The lower part of the figure illustrates an example of acquiring broadcast services in the future broadcast network. When a service is selected, the receiver can tune to broadcast, acquire information for fast service scan and acquisition and parse the information. Upon determination of the location of service layer signaling or transport session instance description (TSID or LSID) from the information for fast service scan and acquisition, the receiver can acquire and parse the corresponding description. In addition, the receiver can check the transport session including the signaling, acquire a signaling table from the transport session, parse the signaling table and determine a desired component. Through this process, the receiver can present the desired component. That is, broadcast services can be provided to a user by acquiring information about a transport session from information for fast service scan and acquisition, confirming the location of a desired component from the information about the transport session and reproducing the component. 
       FIG. 67  shows signaling data transmitted, by the future broadcast system according to an embodiment of the present invention, for fast broadcast service scan. FIC information (service acquisition information) for supporting fast broadcast service scan and service/component acquisition can include information about an application layer transport session delivering service and component data. As illustrated, the FIC information can be represented in a binary format. However, the FIC information may be represented in other formats such as XML according to embodiments. The FIC information can include the following fields. An FIC_portocol_version field can indicate the version of the structure of signaling information. A TSID field can indicate the identifier of a broadcast stream. An FIC data version field can indicate the data version of the corresponding FIC information. An FIC_data_version field can be increased when the contents of the FIC are changed. A num_partitions field can indicate the number of partitions of a broadcast stream. It is assumed that each broadcast stream can be divided into one or more partitions and transmitted in order to use the num_partitions field. Each partition can include a plurality of DPs by a single broadcaster. Each partition can indicate a part of a broadcast steam, used by a single broadcaster. A partition_id field can indicate the identifier of the corresponding partition. A partition_protocol_version field can indicate the version of the aforementioned partition structure. A num_services field can indicate the number of one or more components included in the corresponding partition. A service_id field can indicate a service identifier. A service_data version field can indicate a change of service loop data in the FIC or a change of service signaling data associated with the corresponding service. A service_data_version field can be increased by 1 whenever included service data is changed. The receiver can detect a service loop data change of the FIC or a change of signaling associated with the corresponding service using the service_data_version field. A channel_number field can indicate the channel number associated with the corresponding service. A service_category field can indicate the category of the corresponding service. For example, the service_category field can indicate A/V, audio, ESG, CoD, etc. A short_service_name_length field can indicate the length of the name of the corresponding service. A short_service_name field can indicate the name of the corresponding service. A service_status field can indicate the status of the corresponding service and represent an active or suspended attribute and a hidden or shown attribute according to the value thereof. A service distribution field can have an attribute similar to “multi-ensemble” flag of ATSC M/H. For example, the service_distribution field can indicate information about whether the corresponding service is included in the corresponding partition, the service is presentable only with the corresponding partition although the service is partially included in the partition, another partition is necessary for presentation, or other broadcast streams are necessary for presentation. An sp_indicator field is a service protection flag and can indicate whether one or more components necessary for presentation are protected. An IP_version_flag field can indicate the following IP address format. The IP_version_flag field can indicate that IPv4 is used when the value thereof is 0 and indicate that IPv6 is used when the value thereof is 1. A source_IP_address_flag field can indicate whether the FIC information includes source IP_addr. The source_IP_address_flag field can indicate presence of source_IP_addr when the value thereof is 1. A num_transport_session field can indicate the number of transport sessions (e.g. ROUTE or MMTP sessions) in which component data of the corresponding service is transmitted in a broadcast stream. A source_IP_addr field can indicate the source IP address of an IP datagram including the component data of the corresponding service when the source_IP_address_flag is 1. A dest_IP_addr field can indicate the destination IP address of the IP datagram including the component data of the corresponding service. A dest_UDP_port field can indicate the UDP port number of the IP datagram including the component data of the corresponding service. An LSID_DP field can indicate the identifier of a data pipe of a physical layer, which delivers signaling including detailed information about a transport session. In the case of ROUTE, for example, the signaling including the detailed information about the transport session can be LCT session instance description including information about an LCT transport session of a ROUTE session. An LSID_tsi field can indicate the identifier of a transport session through which transport session instance description that is signaling including detailed information about transport sessions is transmitted. Here, the transport session instance description can be LSID in the case of an LCT transmission session. In addition, signaling associated with the corresponding service can be delivered through the transport session in which the transport session instance description is transmitted. A service_signaling_flag field can indicate whether service signaling is transmitted through the corresponding transport session. The service_signaling_flag field can indicate presence of a DP including service signaling when the value thereof is 1. A signaling_data_version field can indicate a change of related service signaling data. The value of the signaling_data_version field can increase by 1 whenever the service signaling data is changed. The receiver can detect a change of signaling related to the corresponding service using the signaling_data_version field. A signaling_DP field can indicate the identifier of a data pipe of the physical layer, which delivers service signaling. A signaling tsi field can indicate the identifier of a transport session delivering service signaling. A transport session descriptors field can include transport session level descriptors. Each descriptor can be extended and include a num_descriptors field. Each descriptor can include as many descriptor loops as the number indicated by the num_descriptors field. The transport session descriptors field can include transport session level descriptors. A service descriptors field can include service level descriptors. A partition descriptors field can include a partition level descriptor, and one partition can indicate part of broadcast streams used by a single broadcaster. An FIC session descriptors field can include FIC level descriptors. According to an embodiment, the fields included in the FIC may be included in a table other than the FIC and transmitted along with a broadcast signal. 
       FIG. 68  shows signaling data transmitted, by the future broadcast system according to an embodiment of the present invention, for fast broadcast service scan. FIC information (service acquisition information) for supporting fast broadcast service scan and service/component acquisition can include information about an application layer transport session delivering service and component data. As illustrated, the FIC information can be represented in a binary format. However, the FIC information may be represented in other formats such as XML according to embodiments. The FIC information can include the following fields. An FIC_portocol_version field can indicate the version of the structure of signaling information. A num_partitions field can indicate the number of partitions of a broadcast stream. It is assumed that each broadcast stream can be divided into one or more partitions and transmitted in order to use the num_partitions field. Each partition can include a plurality of DPs by a single broadcaster. Each partition can indicate a part of a broadcast steam, used by a single broadcaster. A partition_id field can indicate the identifier of the corresponding partition. A partition_protocol_version field can indicate the version of the aforementioned partition structure. A num_services field can indicate the number of one or more services included in the corresponding partition. Each service can include a plurality of signaling tables. For example, each service can include DASH MPD containing components and information about segments thereof, a CMT containing identifiers of components included in broadband and other broadcast streams, an application signaling table (AST) and a URL signaling table (UST) including at least one of the URLs of the MPD, CMT and AST. These signaling tables can be included in a signaling channel of the corresponding service. A service_id field can indicate a service identifier. A service data version field can indicate a change of service loop data in the FIC or a change of service signaling data associated with the corresponding service. A service_data_version field can be increased by 1 whenever included service data is changed. For example, a service_data_version field can be increased by 1 when the FIC, MPD, CMT, AST or UST is changed. The receiver can detect a service loop data change of the FIC or a change of signaling associated with the corresponding service using the service data version field. A service channel number field can indicate the channel number associated with the corresponding service. A service_category field can indicate the category of the corresponding service. For example, the service_category field can indicate A/V, audio, ESG, CoD, etc. A short_service_name_length field can indicate the length of the name of the corresponding service. A short_service_name field can indicate the name of the corresponding service. A service_status field can indicate the status of the corresponding service and represent an active or suspended attribute and a hidden or shown attribute according to the value thereof. A service_distribution field can have an attribute similar to the “multi-ensemble” flag of ATSC M/H. For example, the service_distribution field can indicate information about whether the corresponding service is included in the corresponding partition, the service is presentable only with the corresponding partition although the service is partially included in the partition, another partition is necessary for presentation, or other broadcast streams are necessary for presentation. An sp_indicator field is a service protection flag and can indicate whether one or more components necessary for presentation are protected. An IP_version_flag field can indicate the following IP address format. The IP_version_flag field can indicate that IPv4 is used when the value thereof is 0 and indicate that IPv6 is used when the value thereof is 1. A num ROUTE sessions field can indicate the number of transport sessions delivering component data of the corresponding service in a broadcast stream. For example, transport session can be ROUTE sessions. The following information can be set per ROUTE session. A source IP_addr field can indicate the source IP address of an IP datagram including the component data of the corresponding service. A dest_IP_addr field can indicate the destination IP address of the IP datagram including the component data of the corresponding service. A dest_UDP_port field can indicate the UDP port number of the IP datagram including the component data of the corresponding service. An LSID_DP field can indicate the identifier of a data pipe of a physical layer, which delivers signaling including detailed information about a transport session. In the case of ROUTE, for example, the signaling including the detailed information about the transport session can be LCT session instance description including information about an LCT transport session of a ROUTE session. An LSID_tsi field can indicate the identifier of a transport session through which transport session instance description that is signaling including detailed information about transport sessions is transmitted. Here, the transport session instance description can be LSID in the case of an LCT transmission session. In addition, signaling associated with the corresponding service can be delivered through the transport session in which the transport session instance description is transmitted. A component_signaling_flag field can indicate whether service signaling of the corresponding service is transmitted through the corresponding transport session. When the component_signaling_flag is 1, this can indicate that data transmitted through the corresponding transport session includes service signaling (e.g. MPD (DASH Media Presentation Description), CMT or the like). Here, the CMT is a component mapping table and can include identifiers of components delivered through broadband and also include information about components included in other broadcast streams. Each service can include service signaling channels. The service signaling channels can include an MPD, a CMT, an AST and/or a UST. A service signaling channel may be a signaling channel from among a plurality of route sessions for services, and presence or absence thereof can be indicated through the component signaling flag. When signaling and service components are transmitted through a plurality of transport sessions (ROUTE or MMTP sessions), the aforementioned service signaling tables can be preferably delivered by a single transport session. 
     A ROUTE session descriptors field can include transport session level descriptors. Each descriptor can be extended and include a num_descriptors field. Each descriptor can include as many descriptor loops as the number indicated by the num_descriptors field. A transport session descriptors field can include transport session level descriptors. A service descriptors field can include service level descriptors. A partition descriptors field can include a partition level descriptor, and one partition can indicate part of broadcast streams used by a single broadcaster. An FIC session descriptors field can include FIC level descriptors. 
     According to an embodiment, the fields included in the FIC may be included in a table other than the FIC and transmitted along with a broadcast signal. 
       FIG. 69  illustrates component mapping table description according to an embodiment of the present invention. Component mapping description can signal information about transport paths of components included in broadcast services in the future broadcast system. Component mapping table description may be represented in XML format or a binary bitstream. Component mapping table description can include the following elements and attributes. A service_id attribute can indicate the identifier of a service associated with a component. BroadcastComp can indicate one or more components transmitted through the same broadcast stream. BroadcastComp can include mpdID, perID, reptnID, baseURL and/or datapipeID attributes. The mpdID attribute can indicate a DASH MPD identifier associated with BroadcastComp. The perID attribute can indicate an associated period identifier in corresponding MPD. The reptnID attribute can indicate a DASH representation identifier associated with the corresponding component. The baseURL attribute can indicate a base URL of segments constituting DASH representation associated with the corresponding component. The datapipeID attribute can indicate the identifier of a data pipe carrying corresponding component data in a broadcast stream. 
     BBComp can indicate one or more components transmitted through a broadband network. BBComp can include mpdID, perID, reptnID and/or baseURL attributes. The mpdID attribute can indicate a DASH MPD identifier associated with BBComp. The perID attribute can indicate an associated period identifier in corresponding MPD. The reptnID attribute can indicate a DASH representation identifier associated with the corresponding component. The baseURL attribute can indicate a base URL of segments constituting DASH representation associated with the corresponding component. 
     ForeignComp can indicate one or more components transmitted through other broadcast streams. ForeignComp can include mpdID, perID, reptnID, baseURL, transportStreamID, sourceIPAddr, destIPAddr, destUDPPort and/or datapipeID attributes. The mpdID attribute can indicate a DASH MPD identifier associated with ForeignComp. The perID attribute can indicate an associated period identifier in corresponding MPD. The reptnID attribute can indicate a DASH representation identifier associated with the corresponding component. The baseURL attribute can indicate a base URL of segments constituting DASH representation associated with the corresponding component. The transportStreamID attribute can indicate the identifier of a broadcast stream including corresponding component data. The sourceIPAddr attribute can indicate a source IP address of IP datagrams carrying the corresponding component data. The destIPAddr attribute can indicate a destination IP address of the IP datagrams carrying the corresponding component data. The destUDPPort attribute can indicate a destination UDP port number of the IP datagrams carrying the corresponding component data. The datapipeID attribute can indicate the identifier of a data pipe through which the corresponding component data is transmitted in the corresponding broadcast stream. The sourceIPAddr, destIPAddr, destUDPPort and datapipeID attributes can be optional according to embodiments and selectively included in the CMT. The aforementioned component mapping description can be transmitted by being encapsulated in an XML file or the above-described signaling message format. As shown in the lower part of the figure, a signaling message header can have the aforementioned format and component mapping description or part thereof can be included in the service message part. The CMT can define components associated with each service and signal, to the receiver, locations or paths where the corresponding components can be received through the aforementioned information. 
       FIG. 70  illustrates component mapping table description according to an embodiment of the present invention. Component mapping description can signal information about transport paths of components included in broadcast services in the future broadcast system. Component mapping table description may be represented in XML format or a binary bitstream. Component mapping table description can include the following elements and attributes. A service_id attribute can indicate the identifier of a service associated with a component. BroadcastComp can indicate one or more components transmitted through the same broadcast stream. BroadcastComp can include mpdID, perID, reptnID, baseURL, tsi and/or datapipeID attributes. The mpdID attribute can indicate a DASH MPD identifier associated with BroadcastComp. The perID attribute can indicate an associated period identifier in corresponding MPD. The reptnID attribute can indicate a DASH representation identifier associated with the corresponding component. The baseURL attribute can indicate a base URL of segments constituting DASH representation associated with the corresponding component. The tsi attribute can indicate the identifier of a transport session through which corresponding component data is transmitted in a broadcast stream. The datapipeID attribute can indicate the identifier of a data pipe carrying the corresponding component data in the broadcast stream. 
     BBComp can indicate one or more components transmitted through a broadband network. BBComp can include mpdID, perID, reptnID and/or baseURL attributes. The mpdID attribute can indicate a DASH MPD identifier associated with BBComp. The perID attribute can indicate an associated period identifier in corresponding MPD. The reptnID attribute can indicate a DASH representation identifier associated with the corresponding component. The baseURL attribute can indicate a base URL of segments constituting DASH representation associated with the corresponding component. 
     ForeignComp can indicate one or more components transmitted through other broadcast streams. ForeignComp can include mpdID, perID, reptnID, baseURL, transportStreamID, sourceIPAddr, destIPAddr, destUDPPort, tsi and/or datapipeID attributes. The mpdID attribute can indicate a DASH MPD identifier associated with ForeignComp. The perID attribute can indicate an associated period identifier in corresponding MPD. The reptnID attribute can indicate a DASH representation identifier associated with the corresponding component. The baseURL attribute can indicate a base URL of segments constituting DASH representation associated with the corresponding component. The transportStreamID attribute can indicate the identifier of a broadcast stream including corresponding component data. The sourceIPAddr attribute can indicate a source IP address of IP datagrams carrying the corresponding component data. The destIPAddr attribute can indicate a destination IP address of the IP datagrams carrying the corresponding component data. The destUDPPort attribute can indicate a destination UDP port number of the IP datagrams carrying the corresponding component data. The tsi attribute can indicate the identifier of a transport session through which the corresponding component data is transmitted in the corresponding broadcast stream. The datapipeID attribute can indicate the identifier of a data pipe through which the corresponding component data is transmitted in the corresponding broadcast stream. The sourceIPAddr, destIPAddr, destUDPPort and datapipeID attributes can be optional according to embodiments and selectively included in the CMT. The aforementioned component mapping description can be transmitted by being encapsulated in an XML file or the above-described signaling message format. As shown in the lower part of the figure, a signaling message header can have the aforementioned format and component mapping description or part thereof can be included in the service message part. The CMT can define components associated with each service and signal, to the receiver, locations or paths where the corresponding components can be received through the aforementioned information. 
       FIGS. 71 and 72  illustrate component mapping table description according to an embodiment of the present invention. Component mapping description can signal information about transport paths of components included in broadcast services in the future broadcast system. Component mapping table description may be represented in XML format or as a binary bitstream. Component mapping table description can include a delivery parameter element and a payload format element along with the DASH associated identifiers. 
     Component mapping table description can include the following elements and attributes. A service_id attribute can indicate the identifier of a service associated with a component. A component element can indicate components in the corresponding broadcast service. The component element can include an mpdID attribute, a perID attribute, a reptnID attribute, a baseURL attribute, the delivery parameter element and/or the payload format element. The mpdID attribute can indicate a DASH MPD identifier associated with a component. The perID attribute can indicate an associated period identifier in corresponding MPD. The reptnID attribute can indicate a DASH representation identifier associated with the corresponding component. The baseURL attribute can indicate a base URL of segments constituting DASH representation associated with the corresponding component. 
     The delivery parameter element can include detailed information about a path through which the corresponding component is transmitted. The delivery parameter element can include transportStreamID, sourceIPAddr, destIPAddr, destUDPPort, tsi, datapipeID and/or URL attributes. The transportStreamID attribute can indicate the identifier of a broadcast stream including corresponding component data. The sourceIPAddr attribute can indicate a source IP address of IP datagrams carrying the corresponding component data. The destIPAddr attribute can indicate a destination IP address of the IP datagrams carrying the corresponding component data. The destUDPPort attribute can indicate a destination UDP port number of the IP datagrams carrying the corresponding component data. The tsi attribute can indicate the identifier of a transport session through which the corresponding component data is transmitted in the corresponding broadcast stream. The datapipeID attribute can indicate the identifier of a physical layer data pipe through which the corresponding component data is transmitted in the corresponding broadcast stream. The URL attribute can indicate URL information by which the corresponding component data can be acquired through the Internet. The sourceIPAddr, destIPAddr, destUDPPort, datapipeID and/or URL attributes can be optional according to embodiments and selectively included in the delivery parameter element. 
     The payload format element can include a codePoint attribute, a deliveryObjectFormat attribute, a fragmentation attribute, a deliveryOrder attribute, a sourceFecPayloadID attribute and/or an FECParameters element. The codePoint attribute can define a code point used in the corresponding payload. This can indicate the value of the CP field of the LCT header. The deliveryObjectFormat attribute can indicate the payload format of the corresponding delivery object. The fragmentation attribute can define the type of fragmentation. The deliveryOrder attribute can indicate the order of delivery of objects. The sourceFecPayloadID attribute can define the format of a source FEC payload identifier. The FECParameters element can define FEC parameters and include an FEC encoding id, an instance id, etc. 
       FIG. 73  illustrates component mapping table description according to an embodiment of the present invention. Component mapping description can signal information about transport paths of components included in broadcast services in the future broadcast system. Component mapping table description may be represented in XML format or as a binary bitstream. Component mapping table can include a service_id attribute, an mpd_id attribute, a per id attribute, a BroadcastComp element, a BBComp element and a ForeignComp element. Component mapping table description can include the following elements and attributes. The service_id attribute can indicate the identifier of a service associated with a component. The CMT description can include mpdID and perID attributes at the same level as the service_id attribute. That is, the mpdID and perID attributes commonly applied to the BroadcastComp, BBComp and ForeignComp elements can be described at the same level as the service_id attribute instead of being redundantly described. The mpdID attribute can indicate a DASH MPD identifier associated with the corresponding service. The perID attribute can indicate an associated period identifier in corresponding MPD. 
     BroadcastComp can indicate one or more components transmitted through the same broadcast stream. BroadcastComp can include reptnID, baseURL, tsi and/or datapipeID attributes. The reptnID attribute can indicate a DASH representation identifier associated with the corresponding component. The baseURL attribute can indicate a base URL of segments constituting DASH representation associated with the corresponding component. The tsi attribute can indicate the identifier of a transport session through which the corresponding component data is transmitted in the corresponding broadcast stream. The datapipeID attribute can indicate the identifier of a data pipe through which the corresponding component data is transmitted in the corresponding broadcast stream. 
     BBComp can indicate one or more components transmitted through a broadband network. BBComp can include reptnID and/or baseURL attributes. The reptnID attribute can indicate a DASH representation identifier associated with the corresponding component. The baseURL attribute can indicate a base URL of segments constituting DASH representation associated with the corresponding component. 
     ForeignComp can indicate one or more components transmitted through other broadcast streams. ForeignComp can include reptnID, baseURL, transportStreamID, sourceIPAddr, destIPAddr, destUDPPort, tsi and/or datapipeID attributes. The reptnID attribute can indicate a DASH representation identifier associated with the corresponding component. The baseURL attribute can indicate a base URL of segments constituting DASH representation associated with the corresponding component. The transportStreamID attribute can indicate the identifier of a broadcast stream including corresponding component data. The sourceIPAddr attribute can indicate a source IP address of IP datagrams carrying the corresponding component data. The destIPAddr attribute can indicate a destination IP address of the IP datagrams carrying the corresponding component data. The destUDPPort attribute can indicate a destination UDP port number of the IP datagrams carrying the corresponding component data. The tsi attribute can indicate the identifier of a transport session through which the corresponding component data is transmitted in the corresponding broadcast stream. The datapipeID attribute can indicate the identifier of a data pipe through which the corresponding component data is transmitted in the corresponding broadcast stream. The sourceIP Addr, destIPAddr, destUDPPort and datapipeID attributes can be optional according to embodiments and selectively included in the CMT. The aforementioned component mapping description can be transmitted by being encapsulated in an XML file or the above-described signaling message format. The CMT can define components associated with each service and inform the receiver of locations or paths where the corresponding components can be received through the aforementioned information. 
       FIG. 74  shows common attributes and elements of MPD according to an embodiment of the present invention. The future broadcast system may provide DASH based hybrid broadcast services. In the future broadcast system, segments associated with representation in DASH MPD are delivered through different distribution paths. The common attributes and elements of the MPD can be commonly present in adaptation set, representation and sub-representation elements and include location information of associated representation as illustrated. The future broadcast system can enable a DASH client to recognize the associated representation or locations of segments using the location information of the associated representation, included in the common attributes and elements of the MPD. The common attributes and elements of the MPD can include the following attributes and elements. @profiles attribute can indicate profiles of the associated representation. @width attribute can indicate the horizontal visual presentation size of a video media type to be represented. @height attribute can indicate the vertical visual presentation size of the video media type to be represented. @sar attribute can indicate the sample aspect ratio of video media component type. @frameRate attribute can indicate the output frame rate of the video media type in the representation. @audioSamplingRate attribute can indicate the sampling rate of an audio media component type. @mimeType attribute can indicate the MIME type of concatenation of the initialization segment. @segmentProfiles attribute can indicate profiles of segments that are essential to process the representation. @codecs attribute can indicate the codec used in the representation. @maximumSAPPeriod attribute can indicate the maximum stream access point (SAP) interval of contained media streams. @startWithSAP attribute can indicate the number of media segments that start with an SAP. @maxPlayoutRate attribute can indicate the maximum playout rate. @codingDependency attribute can indicate presence or absence of at least one access unit that depends on one or more other access units for decoding. @scanType attribute can indicate the scan type of the source material of the video media component type. A FramePacking element can specify frame-packing information of the video media component type. An AudioChannelConfiguration element can specify the audio channel configuration of the audio media component type. A ContentProtection element can specify information about content protection schemes used for the associated representation. An EssentialProperty element can indicate information about an element that is essentially considered in processing. A SupplementalProperty element can specify supplemental information used to optimize processing. An InbandEventStream element can specify presence or absence of an inband event stream in the associated representation. A Location element can specify information on a location at which the associated representation can be acquired. The Location element can include information about a broadcast stream or physical channel data pipes carrying the associated representation. The DASH client or the future broadcast reception apparatus can obtain the associated representation using the Location element. That is, the reception apparatus of the future broadcast system can obtain information about the location of the associated representation using location information included in the common attributes and elements of the MPD without using the aforementioned CMT and acquire the associated representation on the basis of the obtained information. The aforementioned representation can be described as a component according to an embodiment. 
     In another embodiment, the future broadcast system can allocate information about a transport path, such as the associated representation, to a @servicelocation attribute of the base URL element in the DASH MPD. The future broadcast system can enable the DASH client to be aware of information about paths through which segments associated with the corresponding representation are delivered using @servicelocation attribute. 
       FIG. 75  illustrates transport session instance description according to an embodiment of the present invention. When an application layer transmission method corresponds to real-time object delivery over unidirectional transport (ROUTE), a ROUTE session can be composed of one or more layered coding transport (LCT) sessions. Detailed information about one or more transport sessions can be signaled through transport session instance description. In the case of ROUTE, the transport session instance description may be referred to as LCT session instance description (LSID). Particularly, the transport session instance description can define what is delivered through each LCT transport session constituting the ROUTE session. Each transport session can be uniquely identified by a transport session identifier (TSI). The TSI can be included in an LCT header. The transport session instance description can describe all transport sessions carried by the corresponding session. For example, LSID can describe all LCT sessions carried by ROUTE. The transport session instance description may be delivered through the same ROUTE session as transport sessions or through a different ROUTE session or unicast. 
     When delivered through the same ROUTE session, the transport session instance description can be delivered through a transport session having a TSI of 0. While an object referred to in the transport session instance description may be delivered through the transport session with TSI=0, the object can have a TOI value different from that of the transport session instance description. Otherwise, the object may be delivered through a separate transport session with TSI≠0. The transport session instance description can be updated using at least one of the version number, validity information and expiration information. The transport session instance description can be represented in a bitstream in addition to the illustrated format. 
     The transport session instance description can include version, validFrom and expiration attributes. For each transport session, the transport session instance description can include a TSI attribute, a SourceFlow element, a RepairFlow element and a TransportSessionProperty element. The version attribute can indicate the version information of the transport session instance description, and the version information can increase whenever contents thereof are updated. Transport session instance description having a highest version number is the currently valid version. The validFrom attribute can indicate the data and time from which the corresponding transport session instance description is valid. The validFrom attribute may not be included in the transport session instance description according to embodiment. In this case, the receiver can assume that the corresponding transport session instance description is valid immediately. The expiration attribute can indicate the date and time when the corresponding transport session instance description expires. The expiration attribute may not be included in the transport session instance description. In this case, the receiver can assume that the corresponding transport session instance description is valid for all time. If transport session instance description having an expiration attribute is received, the transport session instance description can conform to the corresponding expiration attribute. The TSI attribute can indicate a transport session identifier. The SourceFlow element provides information of a source flow transmitted with the corresponding TSI. The SourceFlow element will be described in detail below. The RepairFlow element can provide information of a repair flow transmitted with the corresponding TSI. The TransportSessionProperty element can provide additional property information about the corresponding transport session. The transport session instance description can include additional property information about a transport session in the TransportSessionProperty element. For example, the additional information can include service signaling information about the transport session. 
       FIG. 76  illustrates shows a SourceFlow element of the future broadcast system according to an embodiment of the present invention. The Sourceflow element can include an EFDT element, an idRef attribute, a realtime attribute, a minBufferSize attribute, an Application Identifier element, a PayloadFormat element and/or a SourceFlowProperty element. The EFDT element can specify detailed information of file delivery data. The EFDT element indicates an extended file delivery table (FDT) instance and will be described in detail below. The idRef attribute can indicate an EFDT identifier and can be represented as a URI by the corresponding transport session. The realtime attribute can indicate that corresponding LCT packets include extension headers. The extended headers can include timestamps indicating presentation time of an included delivery object. The minBufferSize attribute can define the maximum amount of data that needs to be stored in the receiver. The Application Identifier element can provide additional information that can be mapped to the application carried in the corresponding transport session. For example, representation ID of DASH content or Application Set parameters of a DASH representation can be provided as additional information in order to select a transport session for rendering. The PayloadFormat element can define payload formats of ROUTE packets carrying objects of the source flow. The PayloadFormat element can include a codePoint attribute, a deliveryObjectFormat attribute, a fragmentation attribute, a deliveryOrder attribute, a sourceFecPayloadID attribute and/or an FECParameters element. The codePoint attribute can define a code point used in the corresponding payload. This can indicate the value of the CP field in the LCT header. The deliveryObjectFormat attribute can indicate the payload format of the corresponding delivery object. The fragmentation attribute can define the type of fragmentation. The deliveryOrder attribute can indicate the order of delivery of objects. The sourceFecPayloadID attribute can define the format of a source FEC payload identifier. The FECParameters element can define FEC parameters. This includes an FEC encoding id, an instance id, etc. The SourceFlowProperty element can provide property information about the corresponding source flow. For example, the property information can include location information of a broadcast stream carrying the corresponding source flow data. Here, the location information of the broadcast stream may include information about a data pipe or physical layer pipe (PLP) in the broadcast stream. 
       FIG. 77  shows signaling data transmitted, by the future broadcast system according to another embodiment of the present invention, for fast broadcast service scan. Illustrated service acquisition information may further include information about link layer signaling in addition to the aforementioned service acquisition information. The information about link layer signaling can include flag information indicating presence of link layer signaling, version information of the link layer signaling data and information about a data pipe or a PLP through which link layer signaling is delivered. FIC information (service acquisition information) for supporting fast broadcast service scan and service/component acquisition can include information about an application layer transport session delivering service and component data. As illustrated, the service acquisition information can be represented in a binary format. However, the FIC information may be represented in other formats such as XML according to embodiments. 
     The service acquisition information can include the following fields. An FIC_portocol_version field can indicate the version of the structure of signaling information. A TSID field can indicate the identifier of a broadcast stream. An FIC data version field can indicate the data version of the corresponding FIC information. An FIC_data_version field can be increased when the contents of the FIC are changed. A num_partitions field can indicate the number of partitions of a broadcast stream. It is assumed that each broadcast stream can be divided into one or more partitions and transmitted in order to use the num_partitions field. Each partition can include a plurality of DPs by a single broadcaster. Each partition can indicate a part of a broadcast steam, used by a single broadcaster. A partition_id field can indicate the identifier of the corresponding partition. A partition_protocol_version field can indicate the version of the aforementioned partition structure. A num_services field can indicate the number of one or more components included in the corresponding partition. A service_id field can indicate a service identifier. A service_data version field can indicate a change of service loop data in the FIC or a change of service signaling data associated with the corresponding service. A service_data_version field can be increased by 1 whenever included service data is changed. The receiver can detect a service loop data change of the FIC or a change of signaling associated with the corresponding service using the service_data_version field. A channel_number field can indicate the channel number associated with the corresponding service. A service_category field can indicate the category of the corresponding service. For example, the service_category field can indicate A/V, audio, ESG, CoD, etc. A short_service_name_length field can indicate the length of the name of the corresponding service. A short_service_name field can indicate the name of the corresponding service. A service_status field can indicate the status of the corresponding service and represent an active or suspended attribute and a hidden or shown attribute according to the value thereof. A service distribution field can have an attribute similar to “multi-ensemble” flag of ATSC M/H. For example, the service_distribution field can indicate information about whether the corresponding service is included in the corresponding partition, the service is presentable only with the corresponding partition although the service is partially included in the partition, another partition is necessary for presentation, or other broadcast streams are necessary for presentation. An sp_indicator field is a service protection flag and can indicate whether one or more components necessary for presentation are protected. An IP_version_flag field can indicate the following IP address format. The IP_version_flag field can indicate that IPv4 is used when the value thereof is 0 and can indicate that IPv6 is used when the value thereof is 1. A source_IP_address_flag field can indicate whether the FIC information includes source IP_addr. The source_IP_address_flag field can indicate presence of source_IP_addr when the value thereof is 1. A num_transport_session field can indicate the number of transport sessions (e.g. ROUTE or MMTP sessions) in which component data of the corresponding service is transmitted in a broadcast stream. A source_IP_addr field can indicate the source IP address of an IP datagram including the component data of the corresponding service when the source_IP_address_flag is 1. A dest_IP_addr field can indicate the destination IP address of the IP datagram including the component data of the corresponding service. A dest_UDP_port field can indicate the UDP port number of the IP datagram including the component data of the corresponding service. An LSID_DP field can indicate the identifier of a data pipe of a physical layer, which delivers signaling including detailed information about a transport session. In the case of ROUTE, for example, the signaling including the detailed information about the transport session can be LCT session instance description including information about an LCT transport session of a ROUTE session. An LSID_tsi field can indicate the identifier of a transport session through which transport session instance description, which is signaling including detailed information about transport sessions, is transmitted. Here, the transport session instance description can be LSID in the case of an LCT transmission session. In addition, signaling associated with the corresponding service can be delivered through the transport session in which the transport session instance description is transmitted. A service_signaling_flag field can indicate whether service signaling is transmitted through the corresponding transport session. The service_signaling_flag field can indicate presence of a DP including service signaling when the value thereof is 1. A signaling_data_version field can indicate a change of related service signaling data. The value of the signaling_data_version field can increase by 1 whenever the service signaling data is changed. The receiver can detect a change of signaling related to the corresponding service using the signaling_data_version field. A signaling_DP field can indicate the identifier of a data pipe of the physical layer, which delivers service signaling. A signaling tsi field can indicate the identifier of a transport session delivering service signaling. A link_layer_signaling_flag field can indicate whether the service acquisition information carries link layer (or low layer) signaling. A link_layer_signaling_data_version field can indicate a change of associated link layer (or low layer) signaling data. This field can be increased by 1 whenever the link layer signaling data is changed. The receiver can detect variation in link layer (or low layer) signaling using the link_layer_signaling_data version field. A link_layer_signaling_DP field can indicate the identifier of a physical layer data pipe carrying link layer (or low layer) signaling that can be used in the L2 layer. A transport session descriptors field can include transport session level descriptors. Each descriptor can be extended and include a num_descriptors field. Each descriptor can include as many descriptor loops as the number indicated by the num_descriptors field. The transport session descriptors field can include transport session level descriptors. A service descriptors field can include service level descriptors. A partition descriptors field can include a partition level descriptor, and one partition can indicate part of broadcast streams used by a single broadcaster. An FIC session descriptors field can include FIC level descriptors. According to an embodiment, the fields included in the FIC may be included in a table other than the FIC and transmitted along with a broadcast signal. 
       FIG. 78  shows signaling data transmitted by the future broadcast system according to another embodiment of the present invention for fast broadcast service scan. FIC information (service acquisition information) for supporting fast broadcast service scan and service/component acquisition can include information about an application layer transport session delivering service and component data. The service acquisition information may further include information about link layer signaling. As illustrated, the service acquisition information can be represented in a binary format. However, the FIC information may be represented in other formats such as XML according to embodiments. 
     The service acquisition information can include the following fields. An FIC_portocol_version field can indicate the version of the structure of signaling information. A num_partitions field can indicate the number of partitions of a broadcast stream. It is assumed that each broadcast stream can be divided into one or more partitions and transmitted in order to use the num_partitions field. Each partition can include a plurality of DPs corresponding to a single broadcaster. Each partition can indicate a part of a broadcast steam, used by a single broadcaster. A partition_id field can indicate the identifier of the corresponding partition. A partition_protocol_version field can indicate the version of the aforementioned partition structure. A num services field can indicate the number of one or more services included in the corresponding partition. Each service can include a plurality of signaling tables. For example, each service can include DASH MPD including components and information about segments thereof, a CMT including identifiers of components included in broadband and other broadcast streams, an application signaling table (AST) and a URL signaling table (UST) including at least one of the URLs of the MPD, CMT and AST. These signaling tables can be included in a signaling channel of the corresponding service. A service_id field can indicate a service identifier. A service_data_version field can indicate a change of service loop data in the FIC or a change of service signaling data associated with the corresponding service. A service_data_version field can be increased by 1 whenever included service data is changed. For example, service_data_version field can be increased by 1 when the FIC, MPD, CMT, AST or UST is changed. The receiver can detect a service loop data change of the FIC or a change of signaling associated with the corresponding service using the service_data_version field. A service_channel_number field can indicate the channel number associated with the corresponding service. A service_category field can indicate the category of the corresponding service. For example, the service_category field can indicate A/V, audio, ESG, CoD, etc. A short_service_name_length field can indicate the length of the name of the corresponding service. A short_service_name field can indicate the name of the corresponding service. A service_status field can indicate the status of the corresponding service and represent an active or suspended attribute and a hidden or shown attribute according to the value thereof. A service distribution field can have an attribute similar to “multi-ensemble” flag of ATSC M/H. For example, the service_distribution field can indicate information about whether the corresponding service is included in the corresponding partition, the service is presentable only with the corresponding partition although the service is partially included in the partition, another partition is necessary for presentation, or other broadcast streams are necessary for presentation. An sp_indicator field is a service protection flag and can indicate whether one or more components necessary for presentation are protected. An IP_version_flag field can indicate the following IP address format. The IP_version_flag field can indicate that IPv4 is used when the value thereof is 0 and indicate that IPv6 is used when the value thereof is 1. A num_ROUTE_sessions field can indicate the number of transport sessions delivering component data of the corresponding service in a broadcast stream. For example, transport session can be ROUTE sessions. The following information can be set per ROUTE session. A source_IP_addr field can indicate the source IP address of an IP datagram including the component data of the corresponding service. A dest_IP_addr field can indicate the destination IP address of the IP datagram including the component data of the corresponding service. A dest UDP_port field can indicate the UDP port number of the IP datagram including the component data of the corresponding service. An LSID_DP field can indicate the identifier of a data pipe of a physical layer, which delivers signaling including detailed information about a transport session. In the case of ROUTE, for example, the signaling including the detailed information about the transport session can be LCT session instance description including information about an LCT transport session of a ROUTE session. An LSID_tsi field can indicate the identifier of a transport session through which transport session instance description that is signaling including detailed information about transport sessions is transmitted. Here, the transport session instance description can be LSID in the case of an LCT transmission session. In addition, signaling associated with the corresponding service can be delivered through the transport session in which the transport session instance description is transmitted. A component_signaling_flag field can indicate whether service signaling of the corresponding service is transmitted through the corresponding transport session. When the component_signaling_flag is 1, this can indicate that data transmitted through the corresponding transport session includes service signaling (e.g. MPD (DASH Media Presentation Description), CMT or the like). Here, the CMT is a component mapping table and can include identifiers of components delivered through broadband and can also include information about components included in other broadcast streams. Each service can include service signaling channels. The service signaling channels can include an MPD, a CMT, an AST and/or a UST. A service signaling channel may be a signaling channel from among a plurality of route sessions for services, and presence or absence thereof can be indicated through the component signaling flag. When signaling and service components are transmitted through a plurality of transport sessions (ROUTE or MMTP sessions), the aforementioned service signaling tables can be preferably delivered by a single transport session. A link_layer_signaling_flag field can indicate whether the service acquisition information carries link layer (or low layer) signaling. A link_layer_signaling_data_version field can indicate a change of associated link layer (or low layer) signaling data. This field can be increased by 1 whenever the link layer signaling data is changed. The receiver can detect a variation in link layer (or low layer) signaling using the link_layer_signaling_data_version field. A link_layer signaling_DP field can indicate the identifier of a physical layer data pipe carrying link layer (or low layer) signaling that can be used in the L2 layer. 
     A ROUTE session descriptors field can include transport session level descriptors. Each descriptor can be extended and include a num_descriptors field. Each descriptor can include as many descriptor loops as a number corresponding to a value indicated by the num_descriptors field. A transport session descriptors field can include transport session level descriptors. A service descriptors field can include service level descriptors. A partition descriptors field can include a partition level descriptor, and one partition can indicate part of broadcast streams used by a single broadcaster. An FIC session descriptors field can include FIC level descriptors. 
     According to an embodiment, the fields included in the FIC may be included in a table other than the FIC and transmitted along with a broadcast signal. 
       FIG. 79  illustrates a method for acquiring service layer signaling in the future broadcast system according to an embodiment of the present invention. The upper part of the figure shows a service layer signaling format used in the future broadcast system according to the present invention. Service layer signaling can be encapsulated in the illustrated format. For example, encapsulated service layer signaling can include a Generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH), a signaling message header (SMH) and a signaling message. When the future broadcast system uses the aforementioned service signaling, the future broadcast system can deliver the service signaling as shown in the lower part of the figure. A broadcast signal of the future broadcast system can be transmitted through physical layer frames. Broadcast signal frames can include physical layer signaling. Physical layer signaling information can include a field with respect to fast service acquisition information. This field can include version information of the fast service acquisition information. In other words, the field can indicate whether a physical layer frame includes the fast service acquisition information or whether the fast service acquisition information needs to be parsed. The receiver can acquire the fast service acquisition information using the field of physical layer signaling. A broadcast signal of the future broadcast system can include the fast service acquisition information in a physical layer frame. The fast service acquisition information may include a service identifier and information about a data pipe or a PLP through which at least one of service layer signaling information and a transport session instance descriptor is delivered. That is, the receiver can identify the PLP through which at least one of the service layer signaling information and transport session instance descriptor is delivered using data pipe or PLP identifier information included in the fast service acquisition information and acquire the service layer signaling information or transport session instance descriptor included therein. As illustrated, the service layer signaling information or the transport session instance descriptor can be delivered by a 0-th transport session in the corresponding PLP. That is, the service layer signaling information can be delivered by the transport session corresponding to tsi=0 in the PLP indicated by the PLP identifier included in the service acquisition information. In other words, the identifier of the transport session through which service layer signaling is delivered can be fixed to 0. 
     As illustrated, the service layer signaling can be encapsulated as described above. That is, the service layer signaling format can include a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH), a signaling message header (SMH) and a signaling message. Here, the signaling message may include MPD delivery description, component mapping description or URL signaling description according to type of a message delivered by the service layer signaling. 
     In addition, the transport session instance descriptor can have the aforementioned encapsulation format, as illustrated. That is, the transport session instance descriptor can include a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH), a signaling message header (SMH) and a signaling message. Here, the signaling message can include the transport session instance descriptor. In the present invention, the transport session instance descriptor may be included in service layer signaling and delivered. 
       FIG. 80  illustrates a method for acquiring service layer signaling and link layer signaling in the future broadcast system according to an embodiment of the present invention. When the future broadcast system uses the aforementioned service layer signaling, the future broadcast system can deliver the service layer signaling as shown in the figure. A broadcast signal of the future broadcast system can be transmitted through physical layer frames. Broadcast signal frames can include physical layer signaling. Physical layer signaling information can include a field with respect to fast service acquisition information. This field can include version information of the fast service acquisition information. In other words, the field can indicate whether a physical layer frame includes the fast service acquisition information or whether the fast service acquisition information needs to be parsed. The receiver can acquire the fast service acquisition information using the field of physical layer signaling. A broadcast signal of the future broadcast system can include the fast service acquisition information in a physical layer frame. The fast service acquisition information may include a service identifier and information about a data pipe or a PLP through which at least one of service layer signaling information and a transport session instance descriptor is delivered. That is, the receiver can identify the PLP through which at least one of the service layer signaling information and transport session instance descriptor is delivered using data pipe or PLP identifier information included in the fast service acquisition information and acquire the service layer signaling information or transport session instance descriptor included therein. As illustrated, the service layer signaling information or the transport session instance descriptor can be delivered by a 0-th transport session in the corresponding PLP. That is, the service layer signaling information can be delivered by the transport session corresponding to tsi=0 in the PLP indicated by the PLP identifier included in the service acquisition information. In other words, the identifier of the transport session through which service layer signaling is delivered can be fixed to 0. 
     As illustrated, the service layer signaling can be encapsulated as described above. That is, the service layer signaling format can include a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH), a signaling message header (SMH) and a signaling message. Here, the signaling message may include MPD delivery description, component mapping description or URL signaling description according to type of a message delivered by the service layer signaling. 
     In addition, the transport session instance descriptor can have the aforementioned encapsulation format, as illustrated. That is, the transport session instance descriptor can include a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH), a signaling message header (SMH) and a signaling message. Here, the signaling message can include the transport session instance descriptor. In the present invention, the transport session instance descriptor may be included in service layer signaling and delivered. 
     In addition, the fast service acquisition information may include information about a data pipe or a PLP through which link layer signaling is delivered. That is, the receiver can identify the PLP through which the link layer signaling is delivered using data pipe or PLP identifier information included in the fast service acquisition information and acquire the link layer signaling included therein. As illustrated, a transport link layer signaling format can include a Generic packet header (GPH) and a signaling message. The signaling message can include information about link layer signaling. The receiver can acquire link layer signaling (or low layer signaling) through a data pipe and obtain service/component signaling such as a component mapping table through the application transport protocol. 
       FIG. 81  illustrates a method for acquiring service layer signaling in the future broadcast system according to an embodiment of the present invention. When the future broadcast system uses 3GPP eMBMS signaling for service/component signaling, the future broadcast system can deliver the signaling as shown in the figure. Here, service layer signaling can include User Service Bundle Description (USBD), MPD, Session Description Protocol and may further include transport session instance description. A broadcast signal of the future broadcast system can be transmitted through physical layer frames. Broadcast signal frames can include physical layer signaling. Physical layer signaling information can include a field with respect to fast service acquisition information. This field can include version information of the fast service acquisition information. In other words, the field can indicate whether a physical layer frame includes the fast service acquisition information or whether the fast service acquisition information needs to be parsed. The receiver can acquire the fast service acquisition information using the field of physical layer signaling. A broadcast signal of the future broadcast system can include the fast service acquisition information in a physical layer frame. The fast service acquisition information may include a service identifier and information about a data pipe or a PLP through which at least one of service layer signaling information and a transport session instance descriptor is delivered. That is, the receiver can identify the PLP through which at least one of the service layer signaling information and transport session instance descriptor is delivered using data pipe or PLP identifier information included in the fast service acquisition information and acquire the service layer signaling information or transport session instance descriptor included therein. As illustrated, the service layer signaling information or the transport session instance descriptor can be delivered by a 0-th transport session in the corresponding PLP. That is, the service layer signaling information can be delivered by the transport session corresponding to tsi=0 in the PLP indicated by the PLP identifier included in the service acquisition information. In other words, the identifier of the transport session through which service layer signaling is delivered can be fixed to 0. 
     As illustrated, the service layer signaling can be encapsulated as described above. That is, the service layer signaling format can include a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH), a signaling message header (SMH) and a signaling message. Here, the signaling message may include MPD delivery description, component mapping description or URL signaling description according to type of a message delivered by the service layer signaling. 
     In addition, the transport session instance descriptor can have the aforementioned encapsulation format, as illustrated. That is, the transport session instance descriptor can include a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH), a signaling message header (SMH) and a signaling message. Here, the signaling message can include the transport session instance descriptor. In the present invention, the transport session instance descriptor may be included in service layer signaling and delivered. 
       FIG. 82  illustrates a method for acquiring service layer signaling and link layer signaling in the future broadcast system according to an embodiment of the present invention. When the future broadcast system uses 3GPP eMBMS signaling, the future broadcast system can deliver the signaling as shown in the figure. A broadcast signal of the future broadcast system can be transmitted through physical layer frames. Broadcast signal frames can include physical layer signaling. Physical layer signaling information can include a field with respect to fast service acquisition information. This field can include version information of the fast service acquisition information. In other words, the field can indicate whether a physical layer frame includes the fast service acquisition information or whether the fast service acquisition information needs to be parsed. The receiver can acquire the fast service acquisition information using the corresponding field of physical layer signaling. A broadcast signal of the future broadcast system can include the fast service acquisition information in a physical layer frame. The fast service acquisition information may include a service identifier and information about a data pipe or a PLP through which at least one of service layer signaling information and a transport session instance descriptor is delivered. That is, the receiver can identify the PLP through which at least one of the service layer signaling information and transport session instance descriptor is delivered using data pipe or PLP identifier information included in the fast service acquisition information and acquire the service layer signaling information or transport session instance descriptor included therein. As illustrated, the service layer signaling information or the transport session instance descriptor can be delivered by a 0-th transport session in the corresponding PLP. That is, the service layer signaling information can be delivered by the transport session corresponding to tsi=0 in the PLP indicated by the PLP identifier included in the service acquisition information. In other words, the identifier of the transport session through which service layer signaling is delivered can be fixed to 0. 
     As illustrated, the service layer signaling can be encapsulated as described above. That is, the service layer signaling format can include a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH), a signaling message header (SMH) and a signaling message. Here, the signaling message may include MPD delivery description, component mapping description or URL signaling description according to type of a message delivered by the service layer signaling. 
     In addition, the transport session instance descriptor can have the aforementioned encapsulation format, as illustrated. That is, the transport session instance descriptor can include a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH), a signaling message header (SMH) and a signaling message. Here, the signaling message can include the transport session instance descriptor. In the present invention, the transport session instance descriptor may be included in service layer signaling and delivered. 
     In addition, the fast service acquisition information may include information about a data pipe or a PLP through which link layer signaling is delivered. That is, the receiver can identify the PLP through which the link layer signaling is delivered using data pipe or PLP identifier information included in the fast service acquisition information and acquire the link layer signaling included therein. As illustrated, a transport link layer signaling format can include a generic packet header (GPH) and a signaling message. The signaling message can include information about link layer signaling. The receiver can acquire link layer signaling (or low layer signaling) through a data pipe and obtain service/component signaling such as a component mapping table through the application transport protocol. That is, the future broadcast system can include, in physical layer frames, signaling information about a data pipe or a PLP including link layer signaling. 
       FIG. 83  illustrates a method for delivering service layer signaling in the future broadcast system according to an embodiment of the present invention. The upper part of the figure shows a service layer signaling format used in the future broadcast system of the present invention. Service layer signaling can be encapsulated in the illustrated format. For example, encapsulated service layer signaling can be composed of a combination of a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH) and a signaling message, as shown in the left upper part of the figure. Alternatively, encapsulated service layer signaling can be composed of a combination of a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH), a signaling message header (SMH) and a signaling message, as shown in the right upper part of the figure. The ATPH may include a filtering index with respect to the service layer signaling. Here, the filtering index can include a signaling id, a version, etc. The signaling id can include identifier information about service layer signaling and the version can indicate the version of information included in the service layer signaling. 
     When the future broadcast system uses the aforementioned service signaling, the future broadcast system can deliver the service signaling as shown in the lower part of the figure. A broadcast signal of the future broadcast system can be transmitted through physical layer frames. Broadcast signal frames can include physical layer signaling. Physical layer signaling information can include a field with respect to fast service acquisition information. This field can include version information of the fast service acquisition information. In other words, the field can indicate whether a physical layer frame includes the fast service acquisition information or whether the fast service acquisition information needs to be parsed. The receiver can acquire the fast service acquisition information using the corresponding field of physical layer signaling. A broadcast signal of the future broadcast system can include the fast service acquisition information in a physical layer frame. The fast service acquisition information may include a service identifier and information about a data pipe or a PLP through which at least one of service layer signaling information and a transport session instance descriptor is delivered. That is, the receiver can identify the PLP through which at least one of the service layer signaling information and transport session instance descriptor is delivered using data pipe or PLP identifier information included in the fast service acquisition information and acquire the service layer signaling information or transport session instance descriptor included therein. As illustrated, the service layer signaling information or the transport session instance descriptor can be delivered by a 0-th transport session in the corresponding PLP. That is, the service layer signaling information can be delivered by the transport session corresponding to tsi=0 in the PLP indicated by the PLP identifier included in the service acquisition information. In other words, the identifier of the transport session through which service layer signaling is delivered can be fixed to 0. 
     As illustrated, the service layer signaling can be encapsulated as described above. That is, the service layer signaling format can include a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH), a signaling message header (SMH) and a signaling message. Here, the signaling message may include MPD delivery description, component mapping description or URL signaling description according to type of a message delivered by the service layer signaling. As described above, the ATPH can include the filtering index with respect to the service layer signaling. Here, the filtering index can include a signaling id, a version, etc. The signaling id can include identifier information about service layer signaling and the version can indicate the version of information included in the service layer signaling. For example, service layer signaling including MPD delivery description can have a value of 0xF1 as the signaling id thereof and a value of 0x01 as the version information thereof. The version information can be changed when the contents of the MPD delivery description corresponding to the signaling message of the corresponding service layer signaling is changed. Service layer signaling including component mapping description can have a value of 0xF2 as the signaling id thereof and a value of 0x01 as the version information thereof. The version information can be changed when the contents of the component mapping description corresponding to the signaling message of the corresponding service layer signaling is changed. Service layer signaling including URL signaling description can have a value of 0xF3 as the signaling id thereof and a value of 0x01 as the version information thereof. The version information can be changed when the contents of the URL signaling description corresponding to the signaling message of the corresponding service layer signaling are changed. Accordingly, the receiver can filter desired service layer signaling using signaling id and version information corresponding to filtering information included in the application transport protocol header of the service layer signaling. For example, when the receiver intends to receive the MPD delivery description, the receiver can receive the service layer signaling having a signaling id of 0xF1. In addition, the receiver can check the version information and, only when the MPD delivery description has been updated from the previously received MPD delivery description, parse the corresponding service layer signaling. Accordingly, the receiver can reduce unnecessary parsing operation with respect to service layer signaling and decrease processing overhead. As described above, the future broadcast system can support the receiver such that the receiver can filter desired information by including, in the transport protocol header of service layer signaling, signaling ID and version information. 
       FIG. 84  illustrates a method for transmitting service layer signaling and link layer signaling in the future broadcast system according to an embodiment of the present invention. Service layer signaling used in the future broadcast system of the present invention can be encapsulated. For example, encapsulated service layer signaling can be composed of a combination of a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH) and a signaling message. Otherwise, encapsulated service layer signaling can be composed of a combination of a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH), a signaling message header (SMH) and a signaling message. The ATPH can include a filtering index with respect to the service layer signaling. Here, the filtering index can include a signaling id and a version. The signaling id is identifier information about the service layer signaling and the version indicates the version of information included in the service layer signaling. 
     When the future broadcast system uses the aforementioned service signaling, the future broadcast system can deliver the service signaling as illustrated in the figure. A broadcast signal of the future broadcast system can be transmitted through physical layer frames. Broadcast signal frames can include physical layer signaling. Physical layer signaling information can include a field with respect to fast service acquisition information. This field can include version information of the fast service acquisition information. In other words, the field can indicate whether a physical layer frame includes the fast service acquisition information or whether the fast service acquisition information needs to be parsed. The receiver can acquire the fast service acquisition information using the field of physical layer signaling. A broadcast signal of the future broadcast system can include the fast service acquisition information in a physical layer frame. The fast service acquisition information may include a service identifier and information about a data pipe or a PLP through which at least one of service layer signaling information and a transport session instance descriptor is delivered. That is, the receiver can identify the PLP through which at least one of the service layer signaling information and transport session instance descriptor is delivered using data pipe or PLP identifier information included in the fast service acquisition information and acquire the service layer signaling information or transport session instance descriptor included therein. As illustrated, the service layer signaling information or the transport session instance descriptor can be delivered by a 0-th transport session in the corresponding PLP. That is, the service layer signaling information can be delivered by the transport session corresponding to tsi=0 in the PLP indicated by the PLP identifier included in the service acquisition information. In other words, the identifier of the transport session through which service layer signaling is delivered can be fixed to 0. 
     As illustrated, the service layer signaling can be encapsulated as described above. That is, the service layer signaling format can include a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH), a signaling message header (SMH) and a signaling message. Here, the signaling message may include MPD delivery description, component mapping description or URL signaling description according to type of a message delivered by the service layer signaling. As described above, the ATPH can include the filtering index with respect to the service layer signaling. Here, the filtering index can include a signaling id, a version, etc. The signaling id can include identifier information about service layer signaling and the version can indicate the version of information included in the service layer signaling. For example, service layer signaling including MPD delivery description can have a value of 0xF1 as the signaling id thereof and a value of 0x01 as the version information thereof. The version information can be changed when the contents of the MPD delivery description corresponding to the signaling message of the corresponding service layer signaling are changed. Service layer signaling including component mapping description can have a value of 0xF2 as the signaling id thereof and a value of 0x01 as the version information thereof. The version information can be changed when the contents of the component mapping description corresponding to the signaling message of the corresponding service layer signaling are changed. Service layer signaling including URL signaling description can have a value of 0xF3 as the signaling id thereof and has a value of 0x01 as the version information thereof. The version information can be changed when the contents of the URL signaling description corresponding to the signaling message of the corresponding service layer signaling is changed. Accordingly, the receiver can filter desired service layer signaling using signaling id and version information corresponding to filtering information included in the application transport protocol header of the service layer signaling. For example, when the receiver intends to receive the MPD delivery description, the receiver can receive the service layer signaling having a signaling id of 0xF1. In addition, the receiver can check the version information and, only when the MPD delivery description has been updated from the previously received MPD delivery description, parse the corresponding service layer signaling. Accordingly, the receiver can reduce unnecessary parsing operation with respect to service layer signaling and decrease processing overhead. As described above, the future broadcast system can support the receiver such that the receiver can filter desired information by including, in the transport protocol header of service layer signaling, signaling ID and version information. 
     In addition, the fast service acquisition information may include information about a data pipe or a PLP through which link layer signaling is delivered. That is, the receiver can identify the PLP through which the link layer signaling is delivered using data pipe or PLP identifier information included in the fast service acquisition information and acquire the link layer signaling included therein. As illustrated, a transport link layer signaling format can include a generic packet header (GPH) and a signaling message. The signaling message can include information about link layer signaling. The receiver can acquire link layer signaling (or low layer signaling) through a data pipe and obtain service/component signaling such as a component mapping table through the application transport protocol. That is, the future broadcast system can include, in physical layer frames, signaling information about a data pipe or a PLP including link layer signaling. 
       FIG. 85  illustrates a method for delivering service layer signaling in the future broadcast system according to an embodiment of the present invention. Service layer signaling used in the future broadcast system of the present invention can be encapsulated. For example, encapsulated service layer signaling can be composed of a combination of a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH) and a signaling message. Otherwise, encapsulated service layer signaling can be composed of a combination of a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH), a signaling message header (SMH) and a signaling message. The ATPH can include a filtering index with respect to the service layer signaling. Here, the filtering index can include a signaling id and a version. The signaling id is identifier information about the service layer signaling and the version indicates the version of information included in the service layer signaling. 
     When the future broadcast system uses 3GPP eMBMS signaling, the signaling can be delivered as illustrated. When the future broadcast system uses the aforementioned service signaling, the service signaling can be delivered as shown in the lower part of the figure. A broadcast signal of the future broadcast system can be transmitted through physical layer frames. Broadcast signal frames can include physical layer signaling. Physical layer signaling information can include a field with respect to fast service acquisition information. This field can include version information of the fast service acquisition information. In other words, the field can indicate whether a physical layer frame includes the fast service acquisition information or whether the fast service acquisition information needs to be parsed. The receiver can acquire the fast service acquisition information using the field of physical layer signaling. A broadcast signal of the future broadcast system can include the fast service acquisition information in a physical layer frame. The fast service acquisition information may include a service identifier and information about a data pipe or a PLP through which at least one of service layer signaling information and a transport session instance descriptor is delivered. That is, the receiver can identify the PLP through which at least one of the service layer signaling information and transport session instance descriptor is delivered using data pipe or PLP identifier information included in the fast service acquisition information and acquire the service layer signaling information or transport session instance descriptor included therein. As illustrated, the service layer signaling information or the transport session instance descriptor can be delivered by a 0-th transport session in the corresponding PLP. That is, the service layer signaling information can be delivered by the transport session corresponding to tsi=0 in the PLP indicated by the PLP identifier included in the service acquisition information. In other words, the identifier of the transport session through which service layer signaling is delivered can be fixed to 0. 
     As illustrated, the service layer signaling can be encapsulated as described above. That is, the service layer signaling format can include a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH), a signaling message header (SMH) and a signaling message. Here, the signaling message may include User Service Bundle Description (USBD), MPD and Session Description Protocol according to type of a message delivered by the service layer signaling. As described above, the ATPH can include the filtering index with respect to the service layer signaling. Here, the filtering index can include a signaling id, a version, etc. The signaling id can include identifier information about service layer signaling and the version can indicate the version of information included in the service layer signaling. For example, service layer signaling including the User Service Bundle Description can have a value of 0xF4 as the signaling id thereof and a value of 0x01 as the version information thereof. The version information can be changed when the contents of the User Service Bundle Description corresponding to the signaling message of the corresponding service layer signaling are changed. Service layer signaling including the Session Description Protocol can have a value of 0xF5 as the signaling id thereof and a value of 0x01 as the version information thereof. The version information can be changed when the contents of the Session Description Protocol corresponding to the signaling message of the corresponding service layer signaling are changed. Service layer signaling including the MPD can have a value of 0xF6 as the signaling id thereof and a value of 0x02 as the version information thereof. The version information can be changed when the contents of the MPD corresponding to the signaling message of the corresponding service layer signaling are changed. Accordingly, the receiver can filter desired service layer signaling using signaling id and version information corresponding to filtering information included in the application transport protocol header of the service layer signaling. For example, when the receiver intends to receive the User Service Bundle Description, the receiver can receive the service layer signaling having a signaling id of 0xF4. In addition, the receiver can check the version information and, only when the User Service Bundle Description has been updated from the previously received User Service Bundle Description, parse the corresponding service layer signaling. Accordingly, the receiver can reduce unnecessary parsing operation with respect to service layer signaling and decrease processing overhead. As described above, the future broadcast system can support the receiver such that the receiver can filter desired information by including, in the transport protocol header of service layer signaling, signaling ID and version information. 
       FIG. 86  illustrates a method for transmitting service layer signaling and link layer signaling in the future broadcast system according to an embodiment of the present invention. Service layer signaling used in the future broadcast system of the present invention can be encapsulated. For example, encapsulated service layer signaling can be composed of a combination of a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH) and a signaling message. Otherwise, encapsulated service layer signaling can be composed of a combination of a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH), a signaling message header (SMH) and a signaling message. The ATPH can include a filtering index with respect to the service layer signaling. Here, the filtering index can include a signaling id and a version. The signaling id is identifier information about the service layer signaling and the version indicates the version of information included in the service layer signaling. 
     When the future broadcast system uses 3GPP eMBMS signaling, the signaling can be delivered as illustrated in the figure. A broadcast signal of the future broadcast system can be transmitted through physical layer frames. Broadcast signal frames can include physical layer signaling. Physical layer signaling information can include a field with respect to fast service acquisition information. This field can include version information of the fast service acquisition information. In other words, the field can indicate whether a physical layer frame includes the fast service acquisition information or whether the fast service acquisition information needs to be parsed. The receiver can acquire the fast service acquisition information using the corresponding field of physical layer signaling. A broadcast signal of the future broadcast system can include the fast service acquisition information in a physical layer frame. The fast service acquisition information may include a service identifier and information about a data pipe or a PLP through which at least one of service layer signaling information and a transport session instance descriptor is delivered. That is, the receiver can identify the PLP through which at least one of the service layer signaling information and transport session instance descriptor is delivered using data pipe or PLP identifier information included in the fast service acquisition information and acquire the service layer signaling information or transport session instance descriptor included therein. As illustrated, the service layer signaling information or the transport session instance descriptor can be delivered by a 0-th transport session in the corresponding PLP. That is, the service layer signaling information can be delivered by the transport session corresponding to tsi=0 in the PLP indicated by the PLP identifier included in the service acquisition information. In other words, the identifier of the transport session through which service layer signaling is delivered can be fixed to 0. 
     As illustrated, the service layer signaling can be encapsulated as described above. That is, the service layer signaling format can include a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH), a signaling message header (SMH) and a signaling message. Here, the signaling message may include User Service Bundle Description (USBD), MPD and Session Description Protocol according to type of a message delivered by the service layer signaling. As described above, the ATPH can include the filtering index with respect to the service layer signaling. Here, the filtering index can include a signaling id, a version, etc. The signaling id can include identifier information about service layer signaling and the version can indicate the version of information included in the service layer signaling. For example, service layer signaling including the User Service Bundle Description can have a value of 0xF4 as the signaling id thereof and a value of 0x01 as the version information thereof. The version information can be changed when the contents of the User Service Bundle Description corresponding to the signaling message of the corresponding service layer signaling are changed. Service layer signaling including the Session Description Protocol can have a value of 0xF5 as the signaling id thereof and a value of 0x01 as the version information thereof. The version information can be changed when the contents of the Session Description Protocol corresponding to the signaling message of the corresponding service layer signaling are changed. Service layer signaling including the MPD can have a value of 0xF6 as the signaling id thereof and a value of 0x02 as the version information thereof. The version information can be changed when the contents of the MPD corresponding to the signaling message of the corresponding service layer signaling are changed. Accordingly, the receiver can filter desired service layer signaling using signaling id and version information corresponding to filtering information included in the application transport protocol header of the service layer signaling. For example, when the receiver intends to receive the User Service Bundle Description, the receiver can receive the service layer signaling having a signaling id of 0xF4. In addition, the receiver can check the version information and, only when the User Service Bundle Description has been updated from the previously received User Service Bundle Description, parse the corresponding service layer signaling. Accordingly, the receiver can reduce unnecessary parsing operation with respect to service layer signaling and decrease processing overhead. As described above, the future broadcast system can support the receiver such that the receiver can filter desired information by including, in the transport protocol header of service layer signaling, signaling ID and version information. 
     In addition, the fast service acquisition information may include information about a data pipe or a PLP through which link layer signaling is delivered. That is, the receiver can identify the PLP through which the link layer signaling is delivered using data pipe or PLP identifier information included in the fast service acquisition information and acquire the link layer signaling included therein. As illustrated, a transport link layer signaling format can include a generic packet header (GPH) and a signaling message. The signaling message can include information about link layer signaling. The receiver can acquire link layer signaling (or low layer signaling) through a data pipe and obtain service/component signaling such as a component mapping table through the application transport protocol. That is, the future broadcast system can include, in physical layer frames, signaling information about a data pipe or a PLP including link layer signaling. 
       FIG. 87  illustrates a method for transmitting service layer signaling of the future broadcast system according to an embodiment of the present invention. Service layer signaling may include the aforementioned signaling or 3GPP eMBMS signaling. When a fast information channel is not present in a broadcast signal of the future broadcast system, signaling data for supporting fast service scan and acquisition can be transmitted through a common data pipe, a data pipe or a PLP in a physical frame as illustrated. In this case, the signaling data associated with fast service scan and acquisition can be encapsulated in the form of link (or low) layer signaling and transmitted along with other link (or low) layer signaling. That is, the PLP in the frame can carry the signaling data including service acquisition information. Furthermore, the signaling data may be transmitted through the same data pipe or PLP as that used to transmit service/component signaling or component data or a separate data pipe or PLP. As the service/component signaling, the aforementioned signaling or 3GPP eMBMS signaling may be transmitted. The corresponding signaling can include a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH), a signaling message header (SMH) and a signaling message, as described above. Here, the SMH may not be included in the signaling format according to an embodiment. The ATPH can include a filtering index with respect to service layer signaling. Here, the filtering index can include a signaling id and a version. The signaling id is identifier information about the service layer signaling and the version indicates the version of information included in the service layer signaling. 
     The lower part of the figure shows a method for acquiring service layer signaling using service acquisition information included in link layer signaling. A PLP of a broadcast signal frame can include link layer signaling. The link layer signaling can include the aforementioned fast service scan and acquisition information. The fast service scan and acquisition information can include a service identifier and PLP identifier information including service layer signaling with respect to the corresponding service. The PLP indicated by the corresponding PLP identifier can include service layer signaling. The service layer can include a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH), a signaling message header (SMH) and a signaling message. The signaling message of the service layer signaling can include transport session instance description, MPD delivery description, component mapping description or URL signaling description. The future broadcast signal receiver can acquire a desired service by parsing the service layer signaling. 
       FIG. 88  illustrates a method for delivering service layer signaling of the future broadcast system according to an embodiment of the present invention. Service layer signaling may include the aforementioned signaling or 3GPP eMBMS signaling. A PLP of a broadcast signal frame can include link layer signaling. The link layer signaling can include the aforementioned fast service scan and acquisition information. The fast service scan and acquisition information can include a service identifier and PLP identifier information including service layer signaling with respect to the corresponding service. The PLP indicated by the corresponding PLP identifier can include service layer signaling. The service layer can include a generic packet header (GPH), an IP packet header (IPH), a UDP datagram header (UDPH), an application transport protocol (e.g. ROUTE or MMTP) header (ATPH) and a signaling message. The signaling message of the service layer signaling can include transport session instance description, MPD delivery description, component mapping description or URL signaling description. The future broadcast signal receiver can acquire a desired service by parsing the service layer signaling. Here, the ATPH can include a filtering index with respect to service layer signaling. Here, the filtering index can include a signaling id and a version. The signaling id is identifier information about the service layer signaling and the version indicates the version of information included in the service layer signaling. The method for filtering the service layer signaling using the filtering index has been described above. 
       FIG. 89  illustrates a syntax of a header of a signaling message according to another embodiment of the present invention. 
     The signaling message according to another embodiment of the present invention can be represented in XML. Here, signaling information included in the signaling message in XML may correspond to the signaling information as described above or below. 
     The header of the signaling message according to another embodiment of the present invention can include signaling_id, signaling length, signaling_id_extension, version_number, current_next_indicator, indicator_flags, fragmentation_indicator, payload_format_indicator, expiration_indicator, validfrom_indicator, fragment_number, last_fragment_number, payload format, validfrom and/or expiration information. 
     For description of signaling information having names identical or similar to those of the signaling information included in the aforementioned signaling message header, from among the signaling information included in the signaling message header according to the present embodiment, refer to the above description. 
     The validfrom_indicator information indicates whether the signaling message header part includes a value of validfrom information. For example, a validfrom_indicator information value of 1 can indicate that the signaling message header part includes the validfrom information. 
     The validfrom information can indicate the time from which the signaling message included in a payload is available. The receiver can recognize the time from which the signaling message included in the payload is available using the validfrom information and use the data included in the payload as signaling information from the corresponding time. 
     Here, the payload refers to a region in a broadcast signal including data of broadcast services or broadcast content data (broadcast service data). That is, signaling information is generally transmitted through a region, which is physically or logically separated from broadcast service data, in a broadcast signal. According to the present invention, however, the signaling information can be transmitted through a payload region in a broadcast signal when the payload has a spare region or signaling information, which exceeds a region allocated for signaling information transmission, needs to be transmitted. 
       FIG. 90  illustrates a protocol stack for processing a DASH initialization segment according to an embodiment of the present invention. 
     The DASH initialization segment can be transmitted in the same format as the aforementioned initialization segment delivery table or in XML. 
     The DASH initialization segment includes metadata (signaling information) necessary to represent media streams (broadcast signals) encapsulated into a plurality of segments. Here, a segment is a data unit associated with HTTP-URL. A segment includes data for broadcast services or broadcast content. Representation is a data unit including one or more media streams in a transport format. The representation can include one or more segments. 
     The DASH initialization segment can be processed according to the illustrated protocol stack in the transmitter or the receiver. The DASH initialization segment can be transmitted through one or more paths on the protocol stack. 
     In the protocol stack, signaling information or broadcast service data can be processed according to protocols of multiple layers. In the figure, a signaling channel and data pipes may correspond to the first layer, an FIC and link layer frames may correspond to the second layer, Internet protocol (IP) may correspond to the third layer, a user datagram protocol (UDP) may correspond to the fourth layer and ROUTE may correspond to the fifth layer. A link layer frame may include a link layer packet described in the specification. 
     In the protocol stack processing the DASH initialization segment, when signaling data such as the initialization segment is directly loaded in IP/IUDP and transmitted through the illustrated path (1), the initialization segment may be transmitted as information in the format of the aforementioned initialization segment delivery table or the initialization segment itself may be transmitted in the form of an IP datagram through processing of the protocol stack. The aforementioned information for service signaling and/or component signaling may also be transmitted through the path (1). 
     According to an embodiment of the present invention, the DASH initialization segment can be transmitted along with media data through a specific session for transmitting signaling data, such as a path (2), or through a session for transmitting component data, such as a path (3). For example, the application transport protocol can use real-time object delivery over unidirectional transport (ROUTE). A ROUTE session may include a session for transmitting signaling information and/or a session for transmitting broadcast media data. The broadcast system fixes the TSI of a session for transmitting signaling information to a specific value such that the receiver can recognize that data transmitted through the session corresponding to the TSI is signaling information. 
     When the signaling information (data) such as the initialization segment is transmitted through the illustrated path (2) and/or path (3), information indicating locations of data in the aforementioned signaling message format and the initialization segment in a transport stream or a transport object and/or information for identifying the data in the signaling message format or the initialization segment from among data transmitted along therewith can be provided in the form of fields in a transport protocol packet or separate signaling information. 
       FIG. 91  shows part of layered coding transport (LCT) session instance description (LSID) according to an embodiment of the present invention. 
     The LCT session instance descriptor can provide information indicating locations of data in the aforementioned signaling message format and the initialization segment in a broadcast signal and/or information for identifying the data in the signaling message format or the initialization segment from among data transmitted along therewith can be provided in the form of fields in a transport protocol packet or separate signaling information. 
     The LCT session instance descriptor can include a PayloadFormat element. The PayloadFormat element can include @codePoint, @deliveryObjectFormat, @fragmentation, @deliveryOrder and/or @sourceFecPayloadID information. 
     Each element can be used to provide information as illustrated in the figure. 
     According to an embodiment of the present invention, a broadcast receiver or a broadcast transmitter can use @deliveryObjectFormat information (or field) of the PayloadFormat element in the SourceFlow element of the LSID in order to identify a ROUTE packet including the initialization segment. 
     In one embodiment, @deliveryObjectFormat information can indicate that the corresponding ROUTE packet includes a signaling message format when the value thereof is 0. When the @deliveryObjectFormat information has a value of 0, the @deliveryObjectFormat information can indicate that a ROUTE packet having the same code point (CP) in an LCT packet header as the value of @codePoint information allocated to the PayloadFormat element carries data in the aforementioned signaling message format. The initialization segment can be included in the signaling message format and transmitted. Transmission of other signaling data such as service signaling data and component signaling data in the signaling message format through ROUTE packets using the same method as the one above can be recognized through the @deliveryObjectFormat information. 
     When the @deliveryObjectFormat information has a value of 4, the @deliveryObjectFormat field can indicate that the corresponding ROUTE packet includes metadata (signaling information) containing the initialization segment. When the @deliveryObjectFormat field has a value of 4, the @deliveryObjectFormat information can indicate transmission of a metadata format including the initialization segment through a ROUTE packet or direct transmission of the initialization segment through the ROUTE packet. 
     According to an embodiment of the present invention, the broadcast system (broadcast receiver and/or broadcast transmitter) can signal direct transmission of other signaling data such as service signaling (service level signaling information) and/or component signaling (component level signaling information) through ROUTE packets by allocating a new value (e.g. a value equal to or greater than 5) to the @deliveryObjectFormat information. 
     According to another embodiment of the present invention, the broadcast system may identify a ROUTE packet carrying signaling data such as the initialization segment through other fields or new additional fields in the LSID in addition to the method of using the @deliveryObjectFormat information described in the present embodiment. 
       FIG. 92  shows signaling object description (SOD) providing information for filtering a service signaling message according to an embodiment of the present invention. 
     The signaling object description according to an embodiment of the present invention can include @protocolVersion, @dataVersion, @validFrom, @expiration, Signaling Object element, @toi, @type, @version, @instance Id, @validFrom, @expiration and/or @payloadFormat. 
     The @protocolVersion information indicates the version of the signaling object description. 
     The @dataVersion information indicates the version of instances of the signaling object description. The @dataVersion information can be changed when the contents of the signaling object description are varied. 
     The @validfrom information indicates the time from when the instances of the signaling object description start are available. The receiver can recognize the time from which the signaling object description is available using the @validfrom information and use information included in the signaling object description from the corresponding time. 
     The @expiration information indicates the time at which availability of the instance of the signaling object description expires. The receiver can recognize the time at which availability of the signaling object description expires and manage information of the signaling object description using the @validfrom information. 
     The Signaling Object element indicates an object including signaling information. The signaling object description can include signaling information about one or more signaling objects. 
     The @toi information indicates a transmission object identifier (TOI) allocated to a signaling object. The @toi information can be used to identify a packet associated with the signaling object. The receiver can identify the following information including the type and/or version of a signaling message transmitted through each object by mapping the @toi information to a TOI of an LCT packet. 
     The @type information identifies the type of a signaling message included in an object. For example, the @type information can indicate transmission of LSID (LCT Session Instance Description) as a signaling message in the corresponding object when the value thereof is 0, transmission of CMD (Component Mapping Description) as a signaling message in the corresponding object when the value thereof is 1, transmission of ASD (Application Signaling Description) as a signaling message in the corresponding object when the value thereof is 2, transmission of MPD (Media Presentation Description) as a signaling message in the corresponding object when the value thereof is 3, transmission of USD (URL Signaling Description) as a signaling message in the corresponding object when the value thereof is 4, and transmission of the IS (Initialization Segment) as a signaling message in the corresponding object when the value there of is 5. 
     The @version information indicates the version of a signaling message. The receiver can recognize change of the signaling message through variation of the value of this field. 
     The @instance Id information identifies an instance of a signaling message. This information can be used for the receiver to identify instances of signaling messages, which can be present in one service, such as initialization segments. 
     The @validFrom information indicates the time from which a signaling message included in an object is available. The receiver can recognize the time from which the signaling message included in the corresponding object is available using this information and use the signaling message included in the object from the corresponding time. 
     The @expiration information indicates the time for which the signaling message included in the object is valid. The receiver can recognize the time at which availability of the signaling message included in the object expires and manage the signaling message using this information. 
     The @payloadFormat information indicates the format of signaling message data included in the corresponding object. For example, a signaling message can be provided in a binary format or XML and the @payloadFormat information indicates this format. 
     When signaling messages are transmitted with an LCT based protocol such as ROUTE, each signaling message can be set as an object and processed. Since an object can be identified by the unique TOI thereof in the aforementioned protocol, signaling messages can be filtered by mapping signaling message related information such as version and type to each TOI. The aforementioned SOD (Signaling Object Description) provides filtering information of signaling objects corresponding to a single transport session. The signaling object description can be transmitted through internal or external means of a signaling transport session. When the signaling object description is transmitted through the internal means, the receiver can identify the signaling object description with a unique TOI value (e.g. 0 or 0xFFFF) and interpret the signaling object description prior to other signaling messages transmitted along therewith. When the signaling object description is transmitted through the external means, the signaling object description is transmitted through a fast information channel (FIC), a service list table (SLT), a separate IP datagram or a different ROUTE session prior to other objects delivered in the corresponding session such that the receiver can previously acquire information of the corresponding signaling message. 
       FIG. 93  illustrates an object including a signaling message according to an embodiment of the present invention. 
     When signaling messages are transmitted using an LCT based protocol such as ROUTE, each signaling message can be set as an object and processed. An object can be identified by the unique TOI thereof in the aforementioned protocol. The receiver can filter signaling messages by mapping signaling message related information such as version and type to each TOI. Objects containing different content may be assigned different TOIs. In this case, the broadcast system can process signaling messages through a method compatible with a conventional object processing method since all objects can be uniquely identified. 
       FIG. 93  illustrates an embodiment in which part of a TOI field is used for description of fixed-length signaling message related information. In the present embodiment, a 32-bit TOI field is used, and the type and version of signaling data transmitted through the corresponding object can be identified through a 16-bit type field and a 16-bit version field. In the same manner, additional information of the aforementioned sequence number information, validfrom information, expiration information and/or payload format information may be delivered by allocating part of the TOI field to fixed-length fields. 
     The object according to an embodiment of the present invention can include V, C, PSI, S, O, H, A, B, HDR_LEN, Codepoint, Congestion Control Information, Transport Session Identifier (TSI), Transport Object Identifier (TOI), Header Extensions, FEC payload ID and/or Encoding Symbols elements. Here, an element may be referred to as information or a field. 
     The PSI element can include an X element and/or a Y element. 
     The TOI element can include a Type element and/or a Version element. 
     The V element indicates the version number of a packet. The V element can indicate the version of ALC/LCT. The V element can indicate that packets conforming to ALC/LCT+ are transmitted through the corresponding object. 
     The C element corresponds to a congestion control flag. The C element indicates the length of a congestion control information (CCI) element. For example, the C element can indicate a CCI length of 32 bits when the value thereof is 0, a CCI length of 64 bits when the value thereof is 1, a CCI length of 96 bits when the value thereof is 2, and a CCI length of 128 bits when the value thereof is 3. 
     The PSI element may correspond to protocol-specific indication (PSI). The PSI element can be used as an indicator of a specific purpose for an upper protocol of ALC/LCT+. The PSI element can indicate whether the current packet corresponds to a source packet or an FEC repair packet. 
     The X element may correspond to information indicating a source packet. When different FEC payload ID formats are respectively used for source data and repair data, the X element indicates the FEC payload ID format for the source data when the value thereof is 1 and indicates the FEC payload ID format for the repair data when the value thereof is 0. When the X element is set to 0 in the transmitter, the receiver may ignore this element or packet and may not process the same. 
     The S element may correspond to a transport session identifier flag. The S element indicates the length of the transport session identifier element 
     The O element may correspond to a transport object identifier flag. The O element indicates the length of the transport object identifier element. An object refers to one field and the aforementioned TOI is identification information of each object. A file corresponding to a TOI of 0 can include signaling information associated therewith. 
     The H element may correspond to a half-word flag. The H element indicates whether to add a half-word (16 bits) to the TSI and TOI fields. 
     The A element may correspond to a close session flag. The A element indicates that a session is closed or closure of the session is imminent. 
     The B element may correspond to a close object flag. The B element indicates that an object is closed or closure of the object is imminent. 
     The HDR_LEN element indicates the length of a header of a packet. 
     The Codepoint element indicates the type of a payload transmitted by the packet. An additional payload header can be inserted into a prefix of payload data according to payload type. 
     The congestion control information (CCI) element may include congestion control information such as layer numbers, logical channel numbers and sequence numbers. The CCI element may include necessary congestion control related information. 
     The transport session identifier (TSI) element is a unique identifier of a session. The TSI element indicates one of all sessions from a specific sender. The TSI element identifies a transport session. The value of the TSI element can be used for one track. 
     The transport object identifier (TOI) element is a unique identifier of an object. The TOI element indicates an object to which the corresponding packet belongs in a session. The value of the TOI element can be used for one piece of ISO BMFF object data. The TOI element can include the ID of an ISO BMFF file and the ID of a chunk. The TOI element can have a combination of the ISO BMFF file ID and the chunk ID as a value thereof. 
     The Type element identifies the type of data transmitted through the corresponding object. For example, the Type element can indicate that the data transmitted through the corresponding object is a signaling message. 
     The Version element identifies the version of the data transmitted through the corresponding object. For example, the Version element can include information indicating whether the structure and/or contents of the data identified through the Type object have been changed. 
     The Header Extensions element may include additional header information. 
     The FEC payload ID element is an FEC payload identifier. The FEC payload ID element includes identification information of a transmission block or an encoding symbol. The FEC Payload ID indicates an identifier when the file has been FEC-encoded. For example, when the FLUTE protocol file has been FEC encoded, the FEC Payload ID can be allocated by a broadcaster or a broadcast server to identify the same. 
     The Encoding Symbols element may include data of the transmission block or encoding symbol. 
       FIG. 94  illustrates TOI configuration description (TCD) according to an embodiment of the present invention. 
     As described above, part of the TOI field can be used for description of variable-length signaling message related information. For description of signaling message related information in the variable-length TOI field, TOI field configuration information may be separately transmitted. In an embodiment, the TOI configuration description as shown in the table can be transmitted and/or received to provide TOI field configuration information. In the present embodiment, the TCD provides TOI field configuration information of transport packets corresponding to one transport session. The TCD can be transmitted through internal means and/or external means of a signaling transport session. When the TCD is transmitted through the internal means, the TCD can be identified with a unique TOI value, e.g. 0 or 0xFFFF and interpreted prior to other signaling messages transmitted along therewith. When the TCD is transmitted through the external means, the TCD is transmitted through an FIC, separate IP datagram or a different ROUTE session prior to objects delivered in the corresponding session such that the receiver can previously recognize TOI field configuration information included in each packet. @typeBits and following fields respectively indicate the lengths of fields in TOI and represent that field information corresponding to the respective lengths is described in the order of bits from the TOI start bit. 
     The TCD according to an embodiment of the present invention can include @protocolVersion, @dataVersion, @validFrom, @expiration, @typeBits, @versionBits, @instanceIdBits, @validFromBits, @expirationBits and/or @payloadFormatBits information. 
     The @protocolVersion identifies the version of the TCD. The @protocolVersion information indicates a variation in the protocol or structure of the TCD if the variation is present. 
     The @dataVersion information identifies the version of an instance of the TCD. The @dataVersion indicates variation in the contents of the TCD if the contents of the TCD are changed. 
     The @validFrom information indicates the time from which instances of the TCD are available. The receiver can recognize the time from which the TCD is available using the @validFrom information and use information of the TCD from the corresponding time. 
     The @expiration information indicates the time at which availability of the instances of the TCD expires. The receiver can recognize the time at which availability of the TCD expires and terminate use of information of the TCD using the @expiration information. The receiver can manage TCD information using the @expiration information. 
     The @typeBits information indicates the length of the type field in the TOI field. The @typeBits information can represent the length of the type field in bits. 
     The @versionBits information indicates the length of the version field in the TOI field. The @versionBits information can represent the length of the version field in bits. 
     The @instanceIdBits information indicates the length of the instanceID field in the TOI field in bits. 
     The @validFromBits information indicates the length of the validFrom field in the TOI field in bits. 
     The @expirationBits information indicates the length of the expiration field in the TOI field in bits. 
     The @payloadFormatBits information indicates the length of the payloadFormat field in the TOI field in bits. 
       FIG. 95  illustrates a payload format element of a transport packet according to an embodiment of the present invention. 
     According to an embodiment of the present invention, a signaling message can be transmitted through a payload of a transport packet. To this end, the transport packet may include the payload format element shown in the figure. The transport packet corresponds to a packet carrying objects including broadcast data. The name of the transport packet according to the present invention may depend on the protocol by which the packet is processed. For example, when the packet is processed through ROUTE, the packet can be called a ROUTE packet. 
     The payload format element can be included in LSID as described above. 
     The payload format element of the transport packet according to the present invention can include @codePoint, @deliveryObjectFormat, @fragmentation, @deliveryOrder, @sourceFecPayloadID and/or TCID (TOI Configuration Instance Description) information. 
     The @codePoint information defines what code point is used for the corresponding payload. This information may play the same role as the aforementioned CP element or may have the same value as the CP element. 
     The @deliveryObjectFormat information specifies the payload format of an object for data delivery. For example, this information can indicate that the object carries a signaling message, a file, an entity, a package or metadata including an initialization segment. 
     The @fragmentation information specifies the type of fragmentation. 
     The @deliveryOrder information specifies the order of delivery of objects. For example, this information can be used to specify the order of objects transmitted through the current payload. 
     The @sourceFecPayloadID information defines the format of the Source FEC Payload ID. 
     When part of the TCID is used for description of variable-length signaling message related information, the TCID can include TOI field configuration information. 
       FIG. 96  illustrates TOI configuration instance description (TCID) according to an embodiment of the present invention. 
     Part of the TOI field is used for description of variable-length signaling message related information and a TOI field configuration can be dynamically changed in one transport session. 
     For description of signaling message related information in the variable-length TOI field, TPO field configuration information can be separately transmitted. Such TOI field configuration information may be transmitted in the illustrated format. 
     In the present embodiment, the TCID provides TOI field configuration information of transport packets corresponding to a group of packets mapped to one code point value. The TCID can be included in PayloadFormat in SourceFlow of the LSID. Internal fields of the TCID may correspond to those of the aforementioned TCD and indicate a TOI configuration of packets having the same CP value as @codePoint included along with the TCID in PayloadFormat. A method of configuring the TOI may correspond to the aforementioned TCD configuration method. 
     The TCID according to an embodiment of the present invention can include @typeBits, @versionBits, @instanceIdBits, @validFromBits, @expirationBits and/or @payloadFormatBits information. For description of such information, refer to description of the aforementioned information having the same names. 
       FIG. 97  illustrates a syntax of a fast information channel (FIC) payload according to an embodiment of the present invention. 
     While signaling data including information for service scan or acquisition is referred to as FIC in the present invention, the name of the signaling data is not limited thereto. A description will be given of signaling data providing information for acquiring broadcast services more effectively at a lower layer of the service layer (or level). For example, such signaling data can be called a service list table or a service list element. 
     While the signaling data structure is shown in the form of a binary table for convenience of description in the present invention, identical or similar information belonging to the table may be implemented in XML. 
     FIC according to an embodiment of the present invention can include FIC_protocol_version information, transport_stream_id information, num_partitions information, partition_id information, partition_protocol_version information, num_services information, service_id information, service data version information, service channel number information, service_category information, short_service_name_length information, short_service_name information, service_status information, service_distribution information, sp_indicator information, IP_version_flag information, SSC_source_IP_address_flag information, SSC source IP address information, SSC destination IP address information, SSC_destination_UDP_port information, SSC_TSI information, SSC_DP_ID information, num_partition_level_descriptors information, a partition_level_descriptor( ) element, num_FIC_level_descriptors information and/or an FIC_level_descriptor( ) element. 
     The FIC_protocol_version information specifies the version of the structure of the FIC. 
     The transport_stream_id information specifies a broadcast stream. This information may correspond to information specifying a whole broadcast stream. 
     The num_partitions information indicates the number of partitions in a broadcast stream. A single broadcast stream can be divided into one or more partitions and each partition can include one or more data pipes used by a single broadcaster (or broadcast source). 
     The partition_id information specifies a partition. 
     The partition_protocol_version information specifies the version of the structure of a partition. 
     The num_services information indicates the number of broadcast services one or more components of which are transmitted through the partition. 
     The service_id information specifies a service (or broadcast service). 
     The service_data_version information specifies a variation in a service entry for a service signaled by the FIC when the variation is present. In addition, the service data_version information specifies a variation in a signaling table for services, included in a service signaling channel (or service level signaling) when the variation is present. The value of the service_data_version information can be increased whenever the variation is present to indicate the variation. 
     The service_channel_number information indicates the channel number for a service. 
     The service_category information indicates the category of a service. For example, the service_category information can indicate that a broadcast service is an A/V service, an audio service, an ESG (Electronic Service Guide), an App based service and/or CoD (Content on Demand). 
     The short_service_name_length information indicates the length of the short_service_name information. The short_service_name_length may have a value of 0 when the short_service_name information is not present. 
     The short_service_name information indicates the short name of a service. Each character indicated by the short_service_name information can be encoded per UTF-8. When there is an odd number of bytes in the short name, the second byte of the last of the byte pair per pair count indicated by the short_service_name_length field can contain 0x00. 
     The service_status information indicates the status of a service. The service_status information can indicate that the broadcast service is active, inactive, suspended, hidden and/or shown. 
     The service_distribution information specifies whether representation of broadcast services or broadcast content is possible only with the current partition, the current partition is necessary for the representation although the representation is impossible only with the current partition, other partitions are necessary for the representation, or other broadcast streams are necessary for the representation. 
     The sp_indicator information indicates application of service protection. The sp_indicator information specifies whether one or more components of a broadcast service, which are necessary for significant representation, are protected. 
     The IP_version_flag information specifies whether the IP address indicated by the SSC source IP address information and/or the SSC destination IP address is an IPv4 address or an IPv6 address. 
     The SSC_source_IP_address_flag information specifies presence of the SSC source IP address information for services. 
     The SSC_source_IP_address information is present when the value of the SSC_source_IP_address_flag information is set to 1 and not present when the value of the SSC_source_IP_address_flag information is set to 0. The SSC_source_IP_address information indicates the source IP address of an IP datagram (or data unit) carrying signaling information for a service. The SSC source IP address information can be 128 bits when an IPv6 address is used. 
     The SSC_destination_IP_address information indicates the destination IP address of the IP datagram (or data unit) carrying the signaling information for the service. The SSC destination IP address information can be 128 bits when an IPv6 address s is used. 
     The SSC_destination_UDP_port information indicates the destination UDP port number for UDP/IP streams carrying the signaling information for the service. 
     The SSC_TSI information indicates a transport session identifier (TSI) of an LCT channel through which signaling information (or signaling table) for a service is transmitted. 
     The SSC_DP_ID information specifies a data pipe including signaling information (or a signaling table) for a service. The data pipe through which the signaling information is transmitted may correspond to the most robust data pipe in the current partition or broadcast stream. 
     The num_partition_level_descriptors information indicates the number of partition level descriptors defined for partitions. 
     The partition_level_descriptor( ) element includes one or more partition level descriptors. A partition level descriptor may include information necessary for the receiver to access, acquire or use partitions. 
     The num_FIC_level_descriptors information indicates the number of FIC level descriptors defined for the FIC. 
     The FIC_level_descriptor( ) element includes one or more FIC level descriptors. An FIC level descriptor can include additional signaling information for the FIC. 
       FIG. 98  illustrates a syntax of a payload of the FIC according to another embodiment of the present invention. 
     The payload of the FIC according to another embodiment of the present invention may additionally include SSC_delivery_type, SSC_URL_length and/or SSC_URL_data information in addition to the FIC payload in the aforementioned embodiment. 
     The SSC_delivery_type information specifies a path through which signaling information (e.g. service signaling channel or service level signaling) associated with a service is delivered. The SSC_delivery_type information can specify whether service level signaling data is transmitted through a broadband network (Internet). For example, the SSC_delivery_type information can indicate that service level signaling is transmitted through a broadcast network when the value thereof is 0x01. The SSC_delivery_type information can indicate that service level signaling is transmitted through the Internet when the value thereof is 0x02. 
     The SSC_URL_length information indicates the length of the SSC_URL_data information. 
     The SSC_URL_data information indicates the URL of a service or location providing signaling information associated with a service. 
     For description of information which is not described in the present embodiment, refer to the aforementioned corresponding description. 
       FIG. 99  illustrates a syntax of service level signaling according to another embodiment of the present invention. 
     Information necessary for the receiver to receive a broadcast service and/or broadcast content that a viewer desires may be referred to as service level signaling. The service level signaling includes information describing attributes of broadcast services and components included in broadcast services. 
     Service level signaling data according to another embodiment of the present invention may include a signaling message header and/or a service signaling message. 
     The service level signaling data according to another embodiment of the present invention can include @service_id information, @service_category information, @service_name information, @channel_number information, @service_status information, @service_distribution information, @SP_indicator information, a ROUTE Session element, @sourceIPAddr information, @destIPAddr information, @destUDPPort information, @LSID_DP information, a Targeting element, a Content Advisory element, a Right Issuer Service element, a Current Program element, an Original Service Identification element, a Content Labeling element, a Genre element, a Caption element and/or a Protection element. 
     The @service_id information specifies a broadcast service. 
     The @service_category information specifies the category of the broadcast service. For example, the @service_category information can specify whether the broadcast service is an audio service, a real-time broadcast service, a non-real time broadcast service, a linear broadcast service, an app-based broadcast service or a service guide. 
     The @service_name information indicates the name of the broadcast service. 
     The @channel_number information indicates the channel number corresponding to the channel through which the broadcast service is transmitted. This channel number may correspond to a logical/physical channel number. This channel number may be used as information specifying a logical path or a transport unit through which service level signaling data is transmitted as necessary. 
     The @service_status information indicates the status of the broadcast service. The @service_status information may include information specifying whether the broadcast service is active or inactive. The @service_status information may include information specifying whether the broadcast service is hidden. 
     The @service_distribution information indicates how data or components for the broadcast service are distributed and transmitted. 
     The @SP_indicator information specifies whether service protection has been applied to the broadcast service or at least one component included in the broadcast service. The @SP_indicator information may correspond to information specifying whether service protection has been applied to data units or components for meaningful representation of the broadcast service. 
     The ROUTE Session element includes information about a ROUTE session through which the broadcast service or components included in the broadcast service are transmitted. 
     The @sourceIPAddr information indicates the source IP address of IP datagrams (or data units) carrying a ROUTE packet. 
     The @destIPAddr information indicates the destination IP address of the IP datagrams (or data units) carrying the ROUTE packet. 
     The @destUDPPort information indicates the destination port number of the IP datagrams (or data units) carrying the ROUTE packet. 
     The @LSID_DP information specifies a data pipe through which information (e.g. LSID) that describes transport parameters associated with the ROUTE session and/or lower sessions of the ROUTE session is delivered. 
     The Targeting element includes information for providing personalized broadcast services (targeted broadcast). This element can be included in service level signaling as a separate signaling structure. In this case, this element can include link information about the service level signaling. 
     The Content Advisory element includes information about rating of the broadcast service. This element can be included in service level signaling as a separate signaling structure. In this case, this element can include link information about the service level signaling. The Right Issuer Service element includes information related to the right to appropriately consume the broadcast service. This element can be included in service level signaling as a separate signaling structure. In this case, this element can include link information about the service level signaling. 
     The Current Program element includes information about the current broadcast program. This element can be included in service level signaling as a separate signaling structure. In this case, this element can include link information about the service level signaling. 
     The Original Service Identification element includes information for specifying the original service associated with the current broadcast service. This element can be included in service level signaling as a separate signaling structure. In this case, this element can include link information about the service level signaling. 
     The Content Labeling element includes information about content labeling. This element can be included in service level signaling as a separate signaling structure. In this case, this element can include link information about the service level signaling. The Genre element includes information for classifying the genre of the broadcast service. This element can be included in service level signaling as a separate signaling structure. In this case, this element can include link information about the service level signaling. 
     The Caption element includes information about the closed caption/subtitle of the broadcast service. This element can be included in service level signaling as a separate signaling structure. In this case, this element can include link information about the service level signaling. 
     The Protection element includes information about protection for the broadcast service. When the aforementioned @SP_indicator information specifies that protection has been applied to the broadcast service or broadcast components, the Protection element can provide detailed information about the protection. This element can be included in service level signaling as a separate signaling structure. In this case, this element can include link information about the service level signaling. 
       FIG. 100  illustrates component mapping description according to another embodiment of the present invention. 
     The component mapping description according to another embodiment of the present invention may further include @partitionID information in addition to the information or elements included in the component mapping description according to the aforementioned embodiment. 
     The @partitionID information specifies a partition indicating a broadcast station in a broadcast stream. The @partitionID information can be used as information that specifies the transmission source of broadcast components. 
     Description of other information or elements included in the component mapping description is replaced with the aforementioned description of information or elements in the same names. 
       FIG. 101  illustrates a syntax of URL signaling description according to another embodiment of the present invention. 
     As described above, signaling information that describes a broadcast service can be transmitted through a broadband network as well as a broadcast network. When the signaling information that describes a broadcast service is transmitted through the broadband network, the receiver can acquire the signaling information through the URL signaling description. 
     The URL signaling description according to another embodiment of the present invention can include @service_id, @smtURL, @mpdURL, @cmtURL, @astURL, @gatURL and/or @eatURL information. 
     The @service_id information specifies a service. 
     The @smtURL information indicates the URL of a server or location providing a service map table (SMT) when the SMT is transmitted through the broadband network. 
     The @mpdURL information indicates the URL of a server or location providing an MPD when the MPD is transmitted through the broadband network. 
     The @cmtURL information indicates the URL of a server or location providing a component mapping table (CMT) when the CMT is transmitted through the broadband network. 
     The @astURL information indicates the URL of a server or location providing an application signaling table (AST) when the AST is transmitted through the broadband network. 
     The @gatURL information indicates the URL of a server or location providing a guide access table (GAT) when the GAT is transmitted through the broadband network. The GAT corresponds to a signaling message including information for bootstrapping of an electronic service guide (ESG). That is, the GAT can correspond to a signaling message including information necessary for the receiver to access the ESG. 
     The @eatURL information indicates the URL of a server or location providing an emergency alert table (EAT) when the EAT is transmitted through the broadband network. The EAT corresponds to a signaling message including emergency alert related information and an emergency alert message. 
       FIG. 102  illustrates a SourceFlow element according to another embodiment of the present invention. 
     Broadcast service data can be transmitted per object through a ROUTE session. Objects can be individually recovered. A source protocol can be defined to transmit objects within one session, and the SourceFlow element including information related to source (object) delivery can be defined in the source protocol. 
     The SourceFlow element according to another embodiment of the present invention can further include @location information in addition to the information/attributes/elements included in the aforementioned SourceFlow element. 
     The @location information indicates a location or a data unit carrying source flow data. The @location information specifies a data pipe in a broadcast stream. The receiver can recognize that the source flow data is transmitted through the data pipe. 
     Description of other information/attributes/elements included in the SourceFlow element is replaced by description of the aforementioned SourceFlow element. 
       FIG. 103  illustrates a process of acquiring signaling information through a broadcast network according to another embodiment of the present invention. 
     The receiver can access a location carrying data of a service signaling channel associated with a desired broadcast service using information that specifies services included in an FIC. 
     The receiver acquires information about the source IP address, destination IP address and/or UDP port number of IP datagrams carrying the data of the service signaling channel, in the FIC. 
     The receiver acquires information that specifies a data pipe including the data of the service signaling channel, in the FIC. The receiver can access the data pipe carrying the data of the service signaling channel through the acquired information. 
     The receiver can access an LCT session through which the data of the service signaling channel is transmitted using information that specifies the LCT session, which is included in the FIC. The LCT session through which the data of the service signaling channel is transmitted may be fixed to an LCT session having a specific TSI. In this case, the receiver can access the LCT session having the specific TSI in order to acquire the data of the service signaling channel without additional information. The receiver can access the corresponding location to acquire the data of the service signaling channel. 
     The receiver may access an LCT session through which the aforementioned LSID is transmitted. In this case, the TSI of the LCT session may be fixed, and the receiver can access the LCT session having the TSI to acquire the LSID. The receiver can acquire components included in the broadcast service using information of the LSID. 
       FIG. 104  illustrates a process of acquiring signaling information through a broadcast network and a broadband network according to another embodiment of the present invention. 
     The receiver can access a location carrying data of a service signaling channel associated with a desired broadcast service using information that specifies services included in an FIC. 
     The receiver acquires information about the source IP address, destination IP address and/or UDP port number of IP datagrams carrying the data of the service signaling channel, in the FIC. 
     The receiver acquires information that specifies a data pipe including the data of the service signaling channel, in the FIC. The receiver can access the data pipe carrying the data of the service signaling channel through the acquired information. 
     The receiver accesses the data of the service signaling channel to acquire the aforementioned URL signaling table or URL signaling description. The receiver can access a server or location providing service level signaling using information included in the URL signaling table to acquire the service level signaling through the broadband network. 
       FIG. 105  illustrates a process of acquiring signaling information through a broadband network according to another embodiment of the present invention. 
     When information specifying the transport type of a service signaling channel, included in an FIC, indicates that data of the service signaling channel is transmitted through the broadband network, the receiver acquires URL information about a service or location providing the data of the service signaling channel in the FIC. In this case, the URL information can indicate the URL of a single server or location providing the whole data of the service signaling channel or URLs of servers or locations respectively providing signaling structures (SMT, MPD, CMT, etc.) that can be included in the service signaling channel. 
     The receiver accesses the server or location indicated by the URL information to acquire the data of the service signaling channel through the broadband network. 
       FIG. 106  illustrates a process of acquiring an electronic service guide (ESG) through a broadcast network according to another embodiment of the present invention. 
     The receiver can recognize that a broadcast service corresponds to an ESG from information specifying the category of the service, which is included in an FIC, and acquire information specifying a data pipe through which data of a service signaling channel with respect to the corresponding service is transmitted. 
     The receiver can access the specified data pipe to acquire data of the ESG, transmitted through the data pipe. 
     While the ESG is regarded as a broadcast service, the ESG can be efficiently acquired through the aforementioned process since the complicated signaling structure to access general broadcast services need not be interpreted. 
       FIG. 107  illustrates a process of acquiring video segments and audio segments of a broadcast service through a broadcast network according to another embodiment of the present invention. 
     The receiver acquires data of a service signaling channel and obtains a signaling structure (e.g. CMT) including information that describes components of the broadcast service, which is included in the data of the service signaling channel. 
     The receiver acquires information specifying a data pipe through which a video component of the broadcast service is transmitted in the signaling structure and accesses the data pipe using the acquired information. The receiver acquires a signaling structure (e.g. LSID) that describes an LCT session in a ROUTE session through which the data pipe is transmitted. 
     The receiver accesses the LCT session through which the video component of the broadcast service is transmitted to acquire the video component from the signaling structure that describes the LCT session. 
     The receiver acquires information specifying a data pipe through which an audio component of the broadcast service is transmitted and accesses the data pipe using the acquired information. The receiver acquires a signaling structure (e.g. LSID) that describes an LCT session in a ROUTE session through which the data pipe is transmitted. 
     The receiver accesses the LCT session through which the audio component of the broadcast service is transmitted to acquire the audio component from the signaling structure that describes the LCT session. 
     According to the present invention, it is possible to efficiently acquire components included in the broadcast service through the aforementioned signaling structure even when the components are transmitted through respective transport paths. In addition, the transmitter can freely transmit components of broadcast services through a region having a margin and thus can efficiently transmit a larger amount of broadcast data. 
       FIG. 108  illustrates a process of acquiring video segments of a broadcast service through a broadcast network and acquiring audio segments of the broadcast service through a broadband network according to another embodiment of the present invention. 
     The receiver acquires data of a service signaling channel and obtains a signaling structure (e.g. CMT) including information that describes components of the broadcast service, which is included in the data of the service signaling channel. 
     The receiver acquires information specifying a data pipe through which a video component of the broadcast service is transmitted in the signaling structure and accesses the data pipe using the acquired information. The receiver acquires a signaling structure (e.g. LSID) that describes an LCT session in a ROUTE session through which the data pipe is transmitted. 
     The receiver accesses the LCT session through which the video component of the broadcast service is transmitted to acquire the video component from the signaling structure that describes the LCT session. 
     The receiver recognizes that an audio component is transmitted through the broadband network from the signaling structure including the information that describes the components of the broadcast service and acquires the address of a server or location carrying the audio component. Alternatively, the receiver acquires the address providing segments of the audio component using MPD and obtains the segments of the audio component from the address. 
     According to the present invention, even when components belonging to one broadcast service are respectively transmitted through heterogeneous networks, it is possible to efficiently access the components of the broadcast service through the aforementioned signaling structure. 
       FIG. 109  illustrates a configuration of a clock_reference_bootstrap_descriptor according to an embodiment of the present invention. 
     An embodiment of the present invention can provide a method for transmitting and/or signaling a clock reference. The clock reference according to an embodiment of the present invention can provide a reference time at which the receiver synchronizes and consumes content and services transmitted from the future broadcast system. 
     The clock reference according to an embodiment of the present invention can include consecutive and periodic clock reference values. The clock reference can be transmitted in the form of a signaling message and/or an independent stream. Here, the signaling message may correspond to signaling information and include a Fast Information Channel (FIC) and a Service Map Table (SMT). The FIC may correspond to a Service List Table (SLT) and the SMT may correspond to a User Service Description (USD). 
     The clock_reference_bootstrap_descriptor according to an embodiment of the present invention can provide information used for the receiver to access the clock reference when the clock reference is transmitted in the form of an independent stream. A clock_reference_value_descriptor according to an embodiment of the present invention, which will be described later, can provide clock reference values when the clock reference is directly transmitted through a signaling message. 
     According to an embodiment of the present invention, the clock reference can be included in a physical layer and transmitted. The clock reference can be included in a preamble and/or a base PLP part of a physical frame and transmitted. The clock reference is information necessary for synchronization of the transmitter and the receiver and can be included in the relatively robust physical layer in order to reduce errors. 
     The clock_reference_bootstrap_descriptor and/or the clock_reference_value_descriptor according to an embodiment of the present invention can be represented in various formats such as the binary format and XML. The clock_reference_bootstrap_descriptor and/or the clock_reference_value_descriptor according to an embodiment of the present invention can be present in various locations in a signaling message. Here, the signaling message can include a low level signaling message and a service level signaling message. The low level signaling message can include an SLT and an RRT (Rating Region Table) and the service level signaling message can include USBD/USD (User Service Bundle Description/User Service Description), S-TSID (Service-based Transport Session Instance Description) and MPD (Media Presentation Description). Here, the SLT may correspond to the FIC and/or PAT and the USBD/USD may correspond to the SMT. 
     The clock_reference_bootstrap_descriptor according to an embodiment of the present invention can include descriptor tag, descriptor length, IP_version_flag, source_IP_address_flag, TSI_flag, DP_ID flag, source_IP_address, TSI_flag, DP_ID_flag, source_IP_address, destination_IP_address, destination_UDP_port, TSI and/or DP_ID fields. 
     The descriptor tag field specifies that the corresponding descriptor is the clock_reference_bootstrap_descriptor by being assigned a unique value. 
     The descriptor length field indicates the length of the corresponding descriptor in bytes. 
     The IP_version_flag field indicates the format of the following IP address field. This field can indicate that IPv4 address format is used when the value there of is 0 and IPv6 address format is used when the value thereof is 1. 
     The source_IP_address_flag field indicates whether the corresponding descriptor includes the IP_address field. The source_IP_address_flag field indicates that the descriptor includes the source_IP_address field when the value thereof is 1. 
     The TSI_flag field indicates whether the corresponding descriptor includes the TSI field. The TSI_flag field indicates that the descriptor includes the TSI field when the value thereof is 1. 
     The DP ID flag field indicates whether the corresponding descriptor includes the DP_ID field. The DP ID flag field indicates that the descriptor includes the DP_ID field when the value thereof is 1. 
     The source_IP_address field indicates the source IP address of IP datagrams including a clock reference stream. Here, the clock reference stream refers to a stream carrying the clock reference when the clock reference is transmitted as an independent stream. 
     The destination_IP_address field indicates the destination IP address of the IP datagrams including the clock reference stream. 
     The destination_UDP_port field indicates the destination UDP port number of the IP datagrams including the clock reference stream. 
     The TSI field indicates the session identifier of an LCT session including the clock reference stream. 
     The DP_ID field indicates the identifier of a data pipe through which the clock reference stream is transmitted. Here, the data pipe may correspond to a physical layer pipe. 
       FIG. 110  illustrates a configuration of a clock_reference_value_descriptor according to an embodiment of the present invention. 
     The clock_reference_value_descriptor according to an embodiment of the present invention can provide clock reference values when the clock reference is directly transmitted through a signaling message. 
     The clock_reference_value_descriptor according to an embodiment of the present invention can include descriptor tag, descriptor length, clock_reference_value_version and/or clock_reference_value fields. 
     The descriptor_tag field specifies that the corresponding descriptor is the clock_reference_value_descriptor by being assigned a unique value. 
     The descriptor length field indicates the length of the corresponding descriptor in bytes. 
     The clock_reference_value_version field indicates the format of the following clock_reference_value field. According to an embodiment of the present invention, a 32-bit NTP timestamp can be used when the clock_reference_value_version field is 0 and a 64-bit NTP timestamp can be used when this field is 1, and an 80-bit PTP timestamp can be used when this field is 2. 
     The clock_reference_value field indicates the value of the clock reference represented in the timestamp format determined by the aforementioned clock_reference_value_version field. According to an embodiment of the present invention, the clock_reference_value field can indicate the current time of the transmitter and the time when the clock_reference_value_descriptor is generated. According to an embodiment of the present invention, the clock_reference_value field can be used for system clock synchronization between the transmitter and the receiver. 
       FIG. 111  illustrates a configuration of a Fast Information Channel (FIC) according to an embodiment of the present invention. 
     According to an embodiment of the present invention, the aforementioned clock_reference_bootstrap_descriptor and/or clock_reference_value_descriptor can be transmitted at a dedicated channel level, a partition level and/or a service level. 
     According to an embodiment of the present invention, when the sequence of a single clock reference is transmitted through a single dedicated channel, all content and services transmitted through the dedicated channel can be synchronized through the clock reference. 
     According to an embodiment of the present invention, the clock_reference_bootstrap_descriptor and/or the clock_reference_value_descriptor can be located in the FIC_level_descriptor of the aforementioned FIC. That is, the clock_reference_bootstrap_descriptor and/or the clock_reference_value_descriptor can be transmitted at the dedicated channel level. According to an embodiment of the present invention, when the clock_reference_bootstrap_descriptor is located in the FIC_level_descriptor of the FIC, the clock reference is transmitted in the form of a stream and the receiver can access the stream through which the clock reference is transmitted using bootstrap information included in the clock_reference_bootstrap_descriptor. According to an embodiment of the present invention, when the clock_reference_value_descriptor is located in the FIC_level_descriptor of the FIC, the clock reference values can be directly transmitted through the FIC. According to another embodiment of the present invention, the clock reference values instead of the clock_reference value_descriptor can be located in the FIC_level_descriptor of the FIC. 
     According to another embodiment of the present invention, a single dedicated channel can be divided into multiple partitions and each partition can be allocated per broadcaster. According to an embodiment of the present invention, when the sequence of a single clock reference is transmitted through a single partition, all content and services in the partition can be synchronized through the clock reference. 
     According to an embodiment of the present invention, the clock_reference_bootstrap_descriptor and/or the clock_reference_value_descriptor can be located in the aforementioned partition_level_descriptor of the FIC. That is, the clock_reference_bootstrap_descriptor and/or the clock_reference_value_descriptor can be transmitted at the partition level. According to an embodiment of the present invention, when the clock_reference_bootstrap_descriptor is located in the partition_level_descriptor of the FIC, the clock reference is transmitted in the form of a stream and the receiver can access the stream through which the clock reference is transmitted using bootstrap information included in the clock_reference_bootstrap_descriptor. According to an embodiment of the present invention, when the clock_reference_value_descriptor is located in the partition_level_descriptor of the FIC, the clock reference values can be directly transmitted through the FIC. According to another embodiment of the present invention, the clock reference values instead of the clock_reference value_descriptor can be located in the partition_level_descriptor of the FIC. 
     The FIC according to an embodiment of the present invention can include FIC_protocolversion, transport_stream_id, numpartitions, partition_id, num_partition_level_descriptors, partition_level_descriptor, num_FIC_level_descriptors and/or FIC_level_descriptor fields. 
     The FIC_protocol_version field indicates the version of the FIC. 
     The transport_stream_id field specifies a broadcast stream. 
     The num_partitions field indicates the number of partitions included in the broadcast stream. Here, a partition may refer to a broadcasting station. 
     The partition_id field specifies a partition. 
     The num_partition_level_descriptors field indicates the number of descriptors included in the partition level. 
     The partition_level_descriptor indicates descriptors included in the partition level. According to an embodiment of the present invention, the partition_level_descriptor can include the clock_reference_bootstrap_descriptor and/or the clock_reference_value_descriptor. 
     The num_FIC_level_descriptors field indicates the number of descriptors included in the dedicated channel level. The dedicated channel level may correspond to the FIC and/or broadcast stream levels. 
     The FIC_level_descriptor field indicates descriptors included in the dedicated channel level. According to an embodiment of the present invention, the clock_reference_bootstrap_descriptor and/or the clock_reference_value_descriptor can be included in this descriptor. 
       FIG. 112  illustrates a configuration of an FIC according to another embodiment of the present invention. 
     According to an embodiment of the present invention, when the clock reference is transmitted in the form of a stream at the partition level, the clock reference can be allocated to a single service and information used to access the stream through which the clock reference is transmitted can be signaled. 
     According to an embodiment of the present invention, the clock reference stream can be transmitted through a single service constituting a partition. According to an embodiment of the present invention, whether the service carries the clock reference stream can be signaled through a service_category field and a specific value for the clock reference stream can be allocated to the service_category field. When the corresponding service is identified as a service through which the clock reference stream is transmitted through the service_category field according to an embodiment of the present invention, IP_version_flag, SSC_source_IP_address_flag, SSC_source_IP_address, SSC_destination_IP_address, SSC_destination_UDP_port, SSC_TSI and/or SSC_DP_ID fields, which follow the service_category field, can be used as bootstrap information for accessing the clock reference stream. 
     The FIC according to an embodiment of the present invention can include FIC_protocolversion, transport_stream_id, num_partitions, partition_id, service_id, service_category, IP_version_flag, SSC_source_IP_address_flag, SSC_source_IP_address, SSC_destination_IP_address, SSC_destination_UDPport, SSC_TSI and/or SSC_DP_ID fields. 
     The FIC_protocol_version field indicates the version of the FIC. 
     The transport_stream_id field specifies a broadcast stream. 
     The numpartitions field indicates the number of partitions included in the broadcast stream. Here, a partition may refer to a broadcasting station. 
     The partition_id field specifies a partition. 
     The service_id field specifies that the corresponding service includes the clock reference stream. 
     The service_category field indicates the type of the service and can be used to specify that the service according to an embodiment of the present invention is a service through which the clock reference stream is transmitted. 
     The IP_version_flag field indicates the format of the following IP address field. This field can indicate that IPv4 address format is used when the value thereof is 0 and indicate that IPv6 address format is used when the value thereof is 1. 
     The SSC_source_IP_address_flag field indicates whether the corresponding service includes the source IP address field. This field indicates that the service includes the source IP address field when the value thereof is 1. 
     The SSC_source_IP_address field indicates the source IP address of IP datagrams including the clock reference stream. Here, the clock reference stream can refer to a stream carrying the clock reference when the clock reference is transmitted as an independent stream. 
     The SSC_destination_IP_address field indicates the destination IP address of the IP datagrams including the clock reference stream. 
     The SSC_destination_UDPport field indicates the destination UDP port number of the IP datagrams including the clock reference stream. 
     The SSC_TSI field indicates the session identifier of an LCT session including the clock reference stream. 
     The SSC_DP_ID field indicates the identifier of a data pipe through which the clock reference stream is transmitted. Here, the data pipe may correspond to a physical layer pipe. 
       FIG. 113  illustrates a configuration of service description according to an embodiment of the present invention. 
     According to an embodiment of the present invention, when a sequence of a single clock reference is transmitted in a single service, all content and streams in the service can be synchronized through the clock reference. 
     According to an embodiment of the present invention, bootstrap information of the clock reference corresponding to a single service can be transmitted. Here, the bootstrap information can refer to information for accessing the clock reference stream. 
     According to an embodiment of the present invention, a sequence of clock reference values can be configured as an additional clock reference stream and transmitted through a payload of the corresponding stream packet or included in a header of a stream packet carrying a component and transmitted. 
     According to an embodiment of the present invention, when the clock reference values are included in the header of the stream packet carrying the component, the clock reference values can be delivered using EXT_TIME extension of an LCT packet header. 
     According to an embodiment of the present invention, when the clock reference is transmitted through an internal stream constituting a single service, the stream carrying the clock reference can be identified through @ClockRef_TSI field. The @ClockRef_TSI field indicates TSI information of an LCT session through which the clock reference is transmitted from among LCT sessions constituting a ROUTE session. According to an embodiment of the present invention, the IP address and UDP port information of the clock reference stream can be identified through other fields present before the @ClockRef_TSI field in the ROUTE session. According to an embodiment of the present invention, information about a DP through which the clock reference stream is transmitted can be signaled through the aforementioned LSID and CMT. Here, the LSID may correspond to S-TSID (Service-based Transport Session Instance Description) and the CMT may correspond to MPD (Media Presentation Description). 
     According to another embodiment of the present invention, information for accessing the clock reference stream can be signaled by including a Clock Reference Bootstrap field in the Service Description. The Clock Reference Bootstrap field according to an embodiment of the present invention can include information of the stream carrying the clock reference, such as the IP address, UDP port, TSI and DP, like the aforementioned clock_reference_bootstrap_descriptor. 
     While the illustrated Service Description includes both the @ClockRef_TSI field and Clock Reference Bootstrap field, the Service Description may include only one of the two fields according to an embodiment of the present invention and can signal the information (bootstrap information) for accessing the clock reference stream using one of the two fields. 
     The Service Description according to an embodiment of the present invention may correspond to USBD/USD and include @service_id, @service_category, @service_name, @channel_number, @service_status, @service_distribution, @SP_indicator, ROUTE Session, @sourceIPAddr, @destIPAddr, @destUDPPort, @LSID_DP, @ClockRef_TSI, Targeting, Content Advisory, Right Issuer Service, Current Program, Original Service Identification, Content Labeling, Genre, Caption, Protection and/or Clock Reference Bootstrap fields. 
     The @service_id field specifies a service. 
     The @service_category field indicates the type of the service. 
     The @service_name field indicates the name of the service. 
     The @channel_number field indicates the channel number corresponding to the service. 
     The @service_status field indicates the status of the service. This field can indicate whether the corresponding service is active or inactive. 
     The @service_distribution field indicates whether the whole service is included in the corresponding partition, whether presentation of the service is possible only with the partition although the service is partially included in the partition, whether another partition is necessary for the presentation or whether another broadcast stream is necessary for the presentation. 
     The @SP_indicator field indicates whether one or more components of the service have been protected. That is, this field can indicate whether the corresponding service has been protected. 
     The ROUTE session field indicates information about a ROUTE session through which the service is transmitted. 
     The @sourceIPAddr field indicates the source IP address of the ROUTE session. 
     The @destIPAddr field indicates the destination IP address of the ROUTE session. 
     The @destUDPPort field indicates the destination UDP port number of the ROUTE session. 
     The @LSID_DP field specifies a data pipe through which LSID including information such as transport parameters of the ROUTE session is delivered. According to an embodiment of the present invention, this field can specify LSID including information about one or more LCT sessions constituting the ROUTE session. 
     The @ClockRef_TSI field indicates TSI information of an LCT session through which the clock reference is transmitted from among LCT sessions constituting the ROUTE session. 
     The targeting field indicates a targeting parameter with respect to the corresponding service. This field has been described above in detail. 
     The Content Advisory field indicates content advisory information about the corresponding service. According to an embodiment of the present invention, this field can include content advisory rating related information. This field has been described above in detail. 
     The Rights Issuer Service field may include information about rights issues with respect to the corresponding service. This field has been described above in detail. 
     The Current Program field may include information about the current program. 
     This field has been described above in detail. 
     The Original Service Identification field may include information specifying the original service. This field has been described above in detail. 
     The Content Labeling field may include content labeling related information. 
     This field has been described above in detail. 
     The genre field may include information about the genre of the corresponding service. 
     The caption field may include caption related information of the corresponding service. 
     The protection field may include protection related information of the corresponding service. 
     The Clock Reference Bootstrap field may include information of the clock reference stream, such as the IP address, UDP port, TSI and DP, like the aforementioned clock_reference_bootstrap_descriptor. That is, this field can include information for accessing the clock reference stream. 
       FIG. 114  illustrates a configuration of Component Mapping Description according to an embodiment of the present invention. 
     According to an embodiment of the present invention, it is possible to identify a clock reference stream from among streams transmitted through the current broadcast stream or other broadcast streams by adding @clockRefFlag field to the aforementioned component mapping description. 
     According to an embodiment of the present invention, the @clockRefFlag field can indicate that the corresponding component includes and carries the clock reference when the value thereof is 1. 
     According to an embodiment of the present invention, the TSI and DP information of a stream carrying the clock reference can be identified by lower fields of the aforementioned BroadcastComp field, and the IP address and UDP port information of the stream carrying the clock reference can be identified by lower fields of the ROUTE session field of the aforementioned Service Description and information provided by the LSID. According to an embodiment of the present invention, when the stream carrying a clock reference is transmitted through another broadcast stream, this can be identified through lower fields of the ForignComp field. 
     Fields illustrated in the figure have been described in detail. 
       FIG. 115  is a flowchart illustrating a method for transmitting a broadcast signal according to an embodiment of the present invention. 
     The method for transmitting a broadcast signal according to an embodiment of the present invention may include a step SL 128010  of encoding a broadcast service, first signaling information for fast acquisition of the broadcast service, second signaling information for discovering the broadcast service and third signaling information for a session in which the broadcast service and components included in the broadcast service are transmitted, a step SL 128020  of generating a broadcast signal including the encoded broadcast service, first signaling information, second signaling information and third signaling information and/or a step SL 128030  of transmitting the broadcast signal. Here, the broadcast service may be an ATSC 3.0 service. The first signaling information may refer to the aforementioned FIC and/or the SLT. The second signaling information may refer to the aforementioned SMT, service description and/or USD/USBD. The third signaling information may refer to the aforementioned SMT, service description, LSID and/or S-TSID. 
     According to another embodiment of the present invention, at least one of the first signaling information, second signaling information and third signaling information may include time information for synchronization between a transmission side and a reception side. Here, the time information may correspond to the clock reference, clock reference values and/or the clock_reference_value_descriptor, which have been described in detail above with reference to  FIGS. 110 and 111 . 
     According to another embodiment of the present invention, at least one of the first signaling information, second signaling information and third signaling information may include access information for accessing a stream carrying the time information for synchronization of the transmission side and the reception side. The access information may refer to the fields included in the clock_reference_bootstrap_descriptor and/or the clock_reference_bootstrap_descriptor, which have been described in detail above with reference to  FIGS. 109, 111 and 113 . 
     According to another embodiment of the present invention, the time information may include information indicating a reference time value and/or the type of the reference time value, which are used for synchronization of the transmission side and the reception side. Here, the reference time value may correspond to the clock_reference_value field and the type of the reference time value may correspond to the clock_reference_value_version field. The clock_reference_value field and the clock_reference_value version field have been described in detail above with reference to  FIG. 110 . 
     According to another embodiment of the present invention, the access information may include destination IP address information of an IP datagram including the stream carrying the time information, the UDP port number of the IP datagram including the stream carrying the time information, information for identifying a session including the stream carrying the time information and/or information for identifying a data pipe through which the stream carrying the time information is transmitted. The information has been described in detail above with reference to  FIG. 109 . 
     According to another embodiment of the present invention, the first signaling information may include information about one or more services transmitted through a single broadcast stream, and the time information may be included in the service level of the first signaling information to be used for synchronization of all components in a single service. This has been described in detail above with reference to  FIGS. 112, 113 and 114 . 
     According to another embodiment of the present invention, the broadcast service may correspond to a broadcast service providing the time information for synchronization between the transmission side and the reception side, and the first signaling information may include information for accessing the broadcast service. This has been described in detail above with reference to  FIG. 112 . 
       FIG. 116  is a flowchart illustrating a method for receiving a broadcast signal according to an embodiment of the present invention. 
     The method for receiving a broadcast signal according to an embodiment of the present invention may include a step SL 129010  of receiving a broadcast signal including a broadcast service, first signaling information for fast acquisition of the broadcast service, second signaling information for discovering the broadcast service and third signaling information for a session in which the broadcast service and components included in the broadcast service are transmitted, a step SL 129020  of extracting the broadcast service, the first signaling information, the second signaling information and the third signaling information from the received broadcast signal and/or a step SL 129030  of decoding the extracted broadcast service, first signaling information, second signaling information and third signaling information. Here, the broadcast service may be an ATSC 3.0 service. The first signaling information may refer to the aforementioned FIC and/or the SLT. The second signaling information may refer to the aforementioned SMT, service description and/or USD/USBD. The third signaling information may refer to the aforementioned SMT, service description, LSID and/or S-TSID. 
     According to another embodiment of the present invention, at least one of the first signaling information, second signaling information and third signaling information may include time information for synchronization between the transmission side and the reception side. Here, the time information may correspond to the clock reference, clock reference values and/or the clock_reference_value_descriptor, which have been described in detail above with reference to  FIGS. 110 and 111 . 
     According to another embodiment of the present invention, at least one of the first signaling information, second signaling information and third signaling information may include access information for accessing a stream carrying the time information for synchronization between the transmission side and the reception side. The access information may indicate the fields included in the clock_reference_bootstrap_descriptor and/or the clock_reference_bootstrap_descriptor, which have been described in detail above with reference to  FIGS. 109, 111 and 113 . 
     According to another embodiment of the present invention, the time information may include information indicating a reference time value and/or the type of the reference time value, which are used for synchronization between the transmission side and the reception side. Here, the reference time value may correspond to the clock_reference_value field and the type of the reference time value may correspond to the clock_reference_value_version field. The clock_reference_value field and the clock_reference_value version field have been described in detail above with reference to  FIG. 110 . 
     According to another embodiment of the present invention, the access information may include destination IP address information of an IP datagram including the stream carrying the time information, the UDP port number of the IP datagram including the stream carrying the time information, information for identifying a session including the stream carrying the time information and/or information for identifying a data pipe through which the stream carrying the time information is transmitted. The information has been described in detail above with reference to  FIG. 109 . 
     According to another embodiment of the present invention, the first signaling information may include information about one or more services transmitted through a single broadcast stream, and the time information may be included in the service level of the first signaling information to be used for synchronization between all components in a single service. This has been described in detail above with reference to  FIGS. 112, 113 and 114 . 
       FIG. 117  is a block diagram illustrating a configuration of an apparatus for transmitting a broadcast signal according to an embodiment of the present invention. 
     The apparatus L 130010  for transmitting a broadcast signal according to an embodiment of the present invention may include an encoder L 130020  for encoding a broadcast service, first signaling information for fast acquisition of the broadcast service, second signaling information for discovering the broadcast service and third signaling information for a session in which the broadcast service and components included in the broadcast service are transmitted, a generation unit L 130030  for generating a broadcast signal including the encoded broadcast service, first signaling information, second signaling information and third signaling information and/or a transmission unit L 130040  for transmitting the broadcast signal. Here, the broadcast service may be an ATSC 3.0 service. The first signaling information may refer to the aforementioned FIC and/or the SLT. The second signaling information may refer to the aforementioned SMT, service description and/or USD/USBD. The third signaling information may refer to the aforementioned SMT, service description, LSID and/or S-TSID. 
       FIG. 118  is a block diagram illustrating a configuration of an apparatus for receiving a broadcast signal according to an embodiment of the present invention. 
     The apparatus L 131010  for receiving a broadcast signal according to an embodiment of the present invention may include a reception unit L 131020  for receiving a broadcast signal including a broadcast service, first signaling information for fast acquisition of the broadcast service, second signaling information for discovering the broadcast service and third signaling information for a session in which the broadcast service and components included in the broadcast service are transmitted, an extraction unit L 131030  for extracting the broadcast service, the first signaling information, the second signaling information and the third signaling information from the received broadcast signal and/or a decoder L 131040  for decoding the extracted broadcast service, first signaling information, second signaling information and third signaling information. Here, the broadcast service may be an ATSC 3.0 service. The first signaling information may refer to the aforementioned FIC and/or the SLT. The second signaling information may refer to the aforementioned SMT, service description and/or USD/USBD. The third signaling information may refer to the aforementioned SMT, service description, LSID and/or S-TSID. 
       FIG. 119  illustrates service description information when the session description information is included in service description information and delivered according to an embodiment of the present invention. 
     The present invention proposes a method for transmitting the session description information through a path outside of a transport session. The session description information may include information such as transport characteristics, protocol and packet structure of the corresponding transport session. According to an embodiment, the session description information may correspond to the aforementioned LSID. In addition, the session description information may correspond to a plurality of LS elements in the aforementioned S-TSID. In this case, the service description information may correspond to the S-TSID. 
     The session description information may be delivered to the receiver through the corresponding transport session or a path outside of the transport session. The session description information may be included in a signaling message and transmitted or transmitted through a path such as a service signaling channel present inside/outside of the corresponding transport session. When the session description information is transmitted through the service signaling channel, the session description information may be transmitted along with other signaling messages. 
     A description will be given of a case in which the session description information is included in a signaling message other than the service description information. 
     The session description information may be included in the aforementioned signaling message. The signaling message may be USBD, S-TSID, MPD, SMT or CMT. In the illustrated embodiment, the session description information is included in the service description information. Here, the service description information may correspond to the aforementioned SMT and S-TSID. 
     In this case, the session description information may be included in the LSID element of the service description information. The LSIS element may be a lower element of the ROUTE session element of the service description information. The session description information may include information of a ROUTE session (transport session) indicated by the ROUTE session element. The ROUTE session can be indicated by information of the ROUTE session element, such as @sourceIPAddr, @destIPAddr and @destUDPPort. When the session description information is directly included in the service description information and transmitted in this manner, the session description information may not be delivered in the transport session described by the session description information in order to prevent redundancy. 
     The elements of the service description information have been described above. 
     @service_id indicates the identifier of the service described by the service description information. @service_category indicates the category of the service. @service_name indicates the name of the service. @channel_number indicates a channel number associated with the service. @service_status indicates status information of the service. @service_distribution indicates distribution related information about the service. @SP_indicator indicates whether the service is protected. Here, if at least one of service components of the service is protected, @SP_indicator can indicate that the service is protected. 
     The ROUTE session element may include information about the ROUTE session through which the service or service components are delivered. A plurality of ROUTE session elements may be present in the service description information. @sourceIPAddr, @destIPAddr and @destUDPPort respectively indicate the source IP address, destination IP address and destination UDP port number of an IP datagram carrying corresponding ROUTE packets. That is, this information can indicate the ROUTE session. 
     @LSID_DP specifies a DP (or PLP) through which the session description information of the corresponding ROUTE session is delivered. Here, the corresponding ROUTE session may refer to the ROUTE session indicated by the source IP address, destination IP address and destination UDP port number. 
     @LSIDInstanceID is the identifier of a session description table delivering the session description information and specifies a session description table having the session description information of the corresponding ROUTE session. This field can be used when the session description information is included in the session description table and delivered. The session description table may be transmitted along with other signaling messages through a service signaling channel. 
     @LSIDurl may include URL information for identifying the location of the session description information of the corresponding ROUTE session when the session description information is transmitted through a broadband network. This field can be used when the session description information is transmitted through the broadband network. 
     Targeting field indicates the targeting parameter of the service. That is, this field can specify whether the corresponding service is a service for the receiver or a companion device. A Content Advisory field may include content advisory information about the service, that is, information about rating of the service. Right Issuer Service may include information about rights issues associated with the service. Current Program may include information about the current program. Original Service Identification may include identification information about the original service. Content Labeling may include content labeling information of the service. Genre may include information on the genre of the service. Caption may include information about captioning of the service. Protection may include information about protection of the service. 
     While the case in which the transport session is a ROUTE session has been described, the present invention is not limited thereto. That is, the embodiments can be equally applied to other transport sessions such as MMTP sessions. 
       FIG. 120  illustrates message formats for session description information delivery when the session description information is delivered through a service signaling channel according to an embodiment of the present invention. 
     As described above, the session description information can be delivered through a path such as a service signaling channel. In this case, the session description information can be delivered along with other signaling messages. The service signaling channel may be delivered through a separate transport session or through a sub-session of the corresponding transport session such as a ROUTE session according to an embodiment. 
     When a single service is divided into a plurality of transport sessions and delivered therethrough, description information about the plurality of transport sessions may be necessary. In this case, session description information about each transport session may be transmitted through a service signaling channel. Here, session description may need to be mapped to each transport session. For mapping, the aforementioned @LSIDInstanceID information can be used. Session description information about ROUTE sessions indicated by service description information can be acquired using the @LSIDInstanceID information. This can be performed by identifying a session description table mapped to the corresponding information. The aforementioned mapping may not be necessary when session description information is included in the service description information and transmitted. 
     According to an embodiment, a service signaling channel may refer to an LCT session in a ROUTE session through which SLS is transmitted. The LCT session may be specified such that the LCT session has TSI=0, as described above. 
     An embodiment t 2010  illustrated in the figure may be a message format having an extended structure for session description information transmission on the basis of the aforementioned signaling message format. For session description information transmission, a signaling_id extension field can be divided into LSIDT_protocol_version and LSIDT instance ID and defined. 
     The LSIDT_protocol_version field indicates the version or protocol version of the corresponding session description table. The LSIDT_instance_ID field indicates the identifier of session description information transmitted through the corresponding table and may have a value corresponding to @LSIDInstanceID included in the aforementioned service description information. Accordingly, the ROUTE session can be mapped to the session description information. LCT_session_instance_description( ) may include the session description information in binary or XML format. That is, data of the session description information can be included in LCT_session_instance_description( ). Other information of the session description table may correspond to those described in the aforementioned signaling message format. 
     Another embodiment t 2020  illustrated in the figure describes another session description table for session description information delivery. In the present embodiment, the session description table may have an MPEG-2 TS private section based field configuration. LSIDT_protocol_version, LSIDT_instance_ID and LCT_session_instance_description( ) may correspond to those in the aforementioned embodiment. Other information of the session description table may correspond to those described in the aforementioned signaling message format. 
       FIG. 121  illustrates a method for transmitting session description information through a path outside of a session according to an embodiment of the present invention. 
     In the present embodiment, a single service can be transmitted through two ROUTE sessions. Session description information of the first ROUTE session can be transmitted through the corresponding ROUTE session (first ROUTE session) and session description information of the second ROUTE session can be transmitted through a service signaling channel corresponding to a path outside of the second ROUTE session. Here, the service signaling channel may be located inside of the first ROUTE session. 
     A description will be given of a procedure of acquiring each signaling message and/or service component data in the present embodiment. 
     The receiver may acquire bootstrap information of the service signaling channel from an FIC. The receiver may access the service signaling channel using the bootstrap information. The receiver can access the service signaling channel using IP address and UDP port information of the FIC. According to an embodiment, TSI information and/or PLP ID information may be needed. This operation may correspond to the aforementioned operation of accessing the SLS using the SLT. In this case, the SLT corresponds to the FIC, the LCT session carrying the SLS corresponds to the service signaling channel and the SLS corresponds to information included in the service signaling channel. While the FIC is delivered through a separate channel of a physical signal frame in the present embodiment, the SLT can be encapsulated through IP/UDP and delivered through a PLP. 
     Information of the SMT can be acquired from the service signaling channel accessed using the bootstrap information. The session description information about each ROUTE session can be acquired from the SMT. The session description information about the first ROUTE session can be acquired using the @LSID_DP information. The session description information about the first ROUTE session can be acquired by accessing the PLP indicated by @LSID_DP. The session description information about the second ROUTE session can be acquired using the @LSIDT_instance_ID information. The session description information about the second ROUTE session can be acquired by identifying the session description table indicated by @LSIDT_instance_ID. 
     This process may correspond to the process of accessing the LCT session of the ROUTE session carrying the SLS to acquire information of the SLS in the aforementioned embodiment. The session description information, that is, information about sub-sessions (LCT sessions) of the ROUTE sessions, through which service components are delivered, can be acquired from the information of the SLS. Information about LS elements in the S-TSID of the SLS may correspond to the session description information. In this case, a separate session description table may not be needed. In addition, since the session description information is included in the SLS and delivered, the session description information is transmitted through the same PLP as the SLS. Accordingly, PLP ID information about the PLP through which the session description information is delivered may not be needed. 
     Subsequently, the PLP IDs of the service component can be acquired from the CMT. TSI information of the first and second ROUTE sessions can be acquired using the obtained session description information. The TSI information may be TSI information of the LCT session carrying the service components. The service components can be acquired using the TSI information. In addition, representation IDs of the service components can be acquired from the MPD. 
     This process may correspond to the process of accessing LCT sessions to acquire service components using the information (TSI, etc.) in the SLS in the aforementioned embodiment. In this case, the S-TSID may include PLP ID information, and thus an additional CMT may not be needed. A plurality of LCT sessions in the plurality of ROUTE sessions can be respectively accessed using the session description information in the S-TSID. For the acquired service components, representation IDs can be obtained from the MPD. 
       FIG. 122  illustrates a method for transmitting session description information through a path outside of a transport session according to another embodiment of the present invention. 
     In the present embodiment, a single service can be transmitted through two ROUTE sessions. Both session description information of the first ROUTE session and session description information of the second ROUTE session can be transmitted through a service signaling channel delivered through the first ROUTE session. 
     In the present embodiment, a procedure of acquiring each signaling message and/or service component data corresponds to that of the aforementioned embodiment. In the present invention, however, both the session description information of the first ROUTE session and the session description information of second ROUTE session are delivered through session description tables. Accordingly, two session description tables indicated by @LSIDT_instance_ID can be obtained first and then service components delivered through the two ROUTE sessions can be accessed using the session description information in the tables. 
     The present embodiment corresponds to the aforementioned embodiment using the SLT-SLS. When a channel/path through which the SLS is delivered is accessed using the SLT, a path through which service components of the corresponding service are delivered can be accessed using information included in the SLS. In this case, the service component delivery path can be present over the plurality of ROUTE sessions, and the service components can be delivered through a plurality of LCT sessions in the plurality of ROUTE sessions. 
       FIG. 123  illustrates a method for transmitting session description information through a path outside of a transport session according to another embodiment of the present invention. 
     In the present embodiment, a single service can be transmitted through two ROUTE sessions. Both session description information of the first ROUTE session and session description information of the second ROUTE session can be transmitted through a service signaling channel delivered through the first ROUTE session. 
     In the present embodiment, a procedure of acquiring each signaling message and/or service component data corresponds to that of the aforementioned embodiment. In the present invention, however, the service signaling channel can be delivered through a separate channel identified by a separate PLP (DP), IP and UDP rather than being delivered through a single LCT session of a specific ROUTE session. In this case, the session description information about the ROUTE sessions is delivered through the outside path, and thus the service signaling channel may have session description tables for the respective sessions. Service components delivered through the two ROUTE sessions can be accessed using the session description information included in the session description tables. 
     In this case, since the service signaling channel is not delivered through a single sub-session (LCT session) of a specific ROUTE session, bootstrap information of the FIC or SLT may not include TSI information. 
       FIG. 124  illustrates a signaling message extended for initialization information delivery according to an embodiment of the present invention. 
     The present invention proposes a method for delivering initialization information associated with service components of services in the aforementioned broadcast system. As described above, service components of each service can be formatted into DASH segments and delivered as a DASH representation through LCT sessions. Initialization information for the service components may be needed. Here, the initialization information may correspond to a DASH initialization segment. 
     The initialization information can be transmitted through a service signaling channel present inside/outside of a transport session or transmitted along with media data in each LCT session. Here, the media data may refer to media segments. 
     Firstly, when the initialization information is transmitted through a service signaling channel, the initialization information can be transmitted along with other signaling messages. When a single service is composed of a plurality of components and transmitted, a plurality of pieces of initialization information can be included in a single signaling channel and transmitted. Here, each piece of initialization information may need to be mapped to each piece of media data (service component). 
     An identifier for mapping of initialization information and media data may be defined and called @isdInstanceID. According to this information, an initialization table including the initialization information can be mapped to each component. Each service component can be initialized using the initialization information. 
     While the illustrated component mapping description corresponds to the aforementioned one, the component mapping description in the present embodiment is extended to further include @isdInstanceID information. The @isdInstanceID information is located under the BroadcastComp element that specifies a component delivered through a broadcast network and specifies an initialization table having initialization information mapped to the component. Other fields in the component mapping description have been described above. According an embodiment, one of signaling information constituting the SLT or SLS may be extended to further include the @isdInstanceID information instead of the component mapping description. 
     Secondly, the initialization information may be delivered through media data, that is, a path such as service components. That is, initialization information associated with a service component (media segment) may be delivered with the service component through an LCT session through which the service component is delivered. In this case, whether corresponding data is a normal media segment or initialization information can be indicated by transport packet header information. Such header information may be a TOI value. 
       FIG. 125  illustrates message formats for initialization information delivery according to an embodiment of the present invention. 
     A message format for initialization information delivery refers to the format of an initialization table. An embodiment t 7010  illustrated in the figure may be a message format having an extended structure for initialization information delivery on the basis of the aforementioned signaling message format. For initialization information delivery, the signaling_id extension field can be divided into ISDT_protocol_version and ISDT_instance_ID and defined. 
     The ISDT_protocol_version field indicates the version or protocol version of the corresponding initialization table. The ISDT_instance_ID field indicates the identifier of initialization information transmitted through the corresponding table and may have a value corresponding to @isdInstanceID included in the aforementioned extended signaling information. Accordingly, each service component can be mapped to an initialization table. This ID can be uniquely assigned in a service signaling channel. Initialization_segment_data may include the initialization information in binary or XML format. That is, all or some data of the initialization information can be included in Initialization_segment_data. Other information of the Initialization_segment_data table may correspond to those described in the aforementioned signaling message format. 
     Another embodiment t 7020  illustrated in the figure describes another initialization table for initialization information delivery. In the present embodiment, the initialization table may have an MPEG-2 TS private section based field configuration. ISDT_protocol_version and Initialization_segment_data (Initialization_segment_delivery_description_data) may correspond to those in the aforementioned embodiment. Other information of the initialization table may correspond to those described in the aforementioned signaling message format. 
     An example t 7030  of an Initialization_segment_delivery_description_data structure is illustrated in the figure. This element may include @url, which is URL information of the corresponding initialization information, and InitializationSegmentData field corresponding to the data part of the initialization information. The URL may have the same value as the URL of an initialization segment described in the MPD. This URL information may be used for mapping between individual initialization information and a representation. 
       FIG. 126  illustrates a message format for session description information delivery when session description information is delivered through a service signaling channel according to another embodiment of the present invention. 
     The aforementioned session description table for session description information delivery may have the illustrated structure t 8010 . LSIDT_protocol_version is as described above, and LSID_delivery_description_data may include data corresponding to all or part of LSID Delivery Description, which will be described later, in the XML or binary format. The LSID Delivery Description may be a description of session description information delivery. Other information in the session description table may correspond to those described in the aforementioned signaling message format. 
     An example t 8020  of the LSID Delivery Description structure is illustrated. The LSID Delivery Description may include @sourceIPAddr, @destIPAddr, @destUDPPort and/or LSID. @sourceIPAddr, @destIPAddr and @destUDPPort may respectively indicate the source IP address, destination IP address and destination UDP port number of a ROUTE session described by the corresponding session description information. LSID may include the corresponding session description information. 
       FIG. 127  is a flowchart illustrating a method for processing service data according to an embodiment of the present invention. 
     The method for processing service data according to an embodiment of the present invention may include the steps of generating service components of a broadcast service, generating first signaling data and second signaling data, encapsulating the service components and the second signaling data into transport packets, processing the first signaling data and/or the transport packets into a broadcast stream and/or transmitting the broadcast stream. Here, the method for processing service data has been described on the basis of operation of a transmission side. 
     Specifically, service components of a broadcast service may be generated (t 9010 ). The broadcast service may include one or more service components. The first signaling data and/or the second signaling data may be generated (t 9020 ). Here, the first signaling data may correspond to the aforementioned SLT and the second signaling data may correspond to the aforementioned SLS. As described above, the first signaling data can include information for indicating the location of the second signaling data and the second signaling data can signal the broadcast service. The service components, the first signaling data and/or the second signaling data may be generated by a first module. Here, the first module may be a module for generating service data in a service provider. 
     The generated service components and the second signaling data may be encapsulated into transport packets (t 9030 ). The transport packets may refer to packets delivered through the aforementioned transport session. According to an embodiment, the transport packets may be ROUTE packets or MMTP packets. These transport packets may be transmitted sub-sessions of a first transport session or a second transport session. The transport sessions may be a ROUTE sessions or MMTP sessions. The sub-sessions may refer to LCT sessions of a ROUTE session or MMTP packet flow of an MMTP session. The encapsulation process may refer to encapsulation of the data into ROUTE/MMTP packets. The encapsulation process may be performed by a second module. The second module may be a module which handles a layer of performing encapsulation into ROUTE/MMTP packets. 
     Subsequently, the first signaling data and/or the transport packets may be processed into a broadcast stream (t 9040 ). This process may refer to encapsulation of the SLT and the data, which has been encapsulated into the ROUTE/MMTP packets, in IP/UDP packets. In addition, this process may refer to physical layer processing of the data, processed into IP/UDP packets, in the physical layer. The process of performing IP/UDP encapsulation and then physical layer processing may be performed by a third module. The third module may be a module which handles IP/UDP encapsulation and the physical layer. 
     The generated broadcast stream may be transmitted (t 9050 ). This process may be performed by a fourth module. The fourth module may correspond to a transmission module for transmitting broadcast streams. 
     In a method for processing service data according to another embodiment of the present invention, the second service signaling data may be transmitted through a specific sub-session of the first transport session. This may correspond to the aforementioned process of delivering the SLS through a specific LCT session of a ROUTE session, that is, an LCT session corresponding to TSI=0. Furthermore, this process may correspond to delivery of the SLS through a service signaling channel. The sub-session (LCT session) carrying the SLS, which is identified by TSI=0, may be called a service signaling channel according to an embodiment. The service components may be transmitted through sub-sessions of the first transport session or the second transport session. The service components may be delivered through sub-sessions (LCT sessions or MMTP packet flow) of a ROUTE/MMTP session, as described above. 
     In a method for processing service data according to another embodiment of the present invention, the first signaling data may include information for indicating the first transport session through which the second signaling data is transmitted. This may correspond to the above embodiment in which the SLS includes bootstrap information for indicating a ROUTE/MMTP session through which the SLS is transmitted. The second signaling data may include information for accessing the service components of the broadcast service. The SLS, particularly, the S-TSID of the SLS, may include TSI information of LCT sessions through which the service components are delivered. In addition, the MPT message of the SLS may include packet ID information of MMTP packet flow through which each service component is delivered. 
     In a method for processing service data according to another embodiment of the present invention, the second signaling data may include information for identifying sub-sessions through which the service components of the broadcast service are transmitted, from among the sub-sessions of the first transport session. This may correspond to the above embodiment in which the SLS has information for accessing service components delivered through the ROUTE/MMTP session through which the SLS is transmitted. In this case, the SLS can identify a sub-session including a service component using only TSI information or packet information. Information such as an IP address may not be additionally needed since the same session is used. 
     In a method for processing service data according to another embodiment of the present invention, the second signaling data may further include information for indicating the second session through which the service components of the broadcast service are transmitted. When the service components are delivered through a transport session (second transport session) different from the transport session through which the SLS is transmitted, the SLS may include information for accessing the service components. This information may be an IP address and UDP port number. 
     In a method for processing service data according to another embodiment of the present invention, the second signaling data may further include information identifying sub-sessions through which the service components of the broadcast service are transmitted, from among the sub-sessions of the second transport session. When the service components are delivered through a transport session (second transport session) different from the transport session through which the SLS is transmitted, as described above, the SLS can identify the sub-sessions including the service components using only TSI information or packet ID information to access the service components. 
     In a method for processing service data according to another embodiment of the present invention, the second signaling data may further include information indicating a physical path through which the sub-sessions carrying the service components of the broadcast service are delivered. Here, the physical path may refer to a PLP or a DP. When the service components are delivered through a transport session (second transport session) different from the transport session through which the SLS is transmitted, as described above, the SLS can include ID information of the PLP through which the service components are delivered to access the service components. 
     In a method for processing service data according to another embodiment of the present invention, the sub-sessions, through which the service components of the broadcast service are transmitted, may further deliver transport packets including initialization information associated with the service components. This may correspond to delivery of the aforementioned initialization information through LCT sessions along with media segments. A transport packet including initialization information may be identified using the header information of the transport packet. As described above, the initialization information can be identified using information such as TOI of the packet header. 
     A description will be given of a method for processing service data at a reception side according to an embodiment of the present invention, which is not shown. 
     The method for processing service data at the reception side according to an embodiment of the present invention may include the steps of receiving a broadcast signal, parsing the broadcast signal, acquiring first signaling data from the broadcast signal and acquiring second signaling data using the first signaling data, acquiring service components of the corresponding broadcast service using the second signaling data and/or providing the service using the service components. 
     The method for processing service data at the reception side may be performed by hardware modules (e.g. a reception module, a parsing module, a reproduction module, etc.) of the reception side, which correspond to modules of the transmission side. The method for processing service data at the reception side may be implemented in embodiments corresponding to the embodiments of the aforementioned method for processing service data at the transmission side. 
     The aforementioned steps may be omitted or replaced by other steps of performing similar/identical operations according to embodiments. 
       FIG. 128  is a block diagram illustrating an apparatus for processing service data according to an embodiment of the present invention. 
     The apparatus for processing service data according to an embodiment of the present invention may include the aforementioned first module, second module, third module and/or fourth module. Blocks and modules included in the apparatus have been described above. 
     The apparatus for processing service data and internal modules/blocks thereof according to an embodiment of the present invention can perform the embodiments of the aforementioned method for processing service data according to the present invention. 
     A description will be given of an apparatus for processing service data at the reception side according to an embodiment of the present invention, which is not shown. 
     The apparatus for processing service data at the reception side according to an embodiment of the present invention may include the aforementioned hardware modules of the reception side. Blocks and modules included in the apparatus have been described above. 
     The apparatus for processing service data at the reception side according to an embodiment of the present invention can perform the embodiments of the aforementioned method for processing service data according to the present invention. 
     The aforementioned internal blocks/modules of the apparatus may be processors which execute consecutive processes stored in a memory and may be hardware elements provided to the inside/outside of the apparatus according to an embodiment. 
     The aforementioned modules may be omitted or replaced by other modules for performing similar/identical operations according to embodiments. 
       FIG. 129  illustrates ESG bootstrap information according to an embodiment of the present invention. 
     An embodiment of the present invention can provide a method for signaling ESG bootstrapping description available in the future broadcast network. The ESG bootstrapping description includes the following information and may be defined in binary or XML format according to signaling transport location. 
     Electronic Service Guide (ESG) data may include a Service Guide Delivery Unit (SGDU) and/or a Service Guide Delivery Descriptor (SGDD). The SGDD may include information indicating a delivery path through which the SGDU is transmitted. The SGDU may include information associated with services and/or programs. For example, the SGDU can include service information, program information, channel numbers, broadcasting station information, caption, rating and/or summary. The service information may include the name and/or the identifier of a service. The program information may include the name and/or the identifier of a program, program start time information and/or program close time information. The SGDU is configured per fragment. Fragment type may include at least one of a service fragment, a content fragment and a schedule fragment. Both the SGDD and the SGDU may be XML files. The ESG can be represented as a Service Guide (SG) and/or an Electronic Program Guide (EPG). The ESG data can be simply represented as ESG. 
     The ESG bootstrapping description may include information for bootstrapping of the ESG. The ESG bootstrapping description may be represented by ESG bootstrap information and/or bootstrapping information for the ESG. The broadcast reception apparatus can receive, acquire and/or process the ESG on the basis of the ESG bootstrapping description and/or the ESG bootstrap information. 
     The ESG bootstrapping description may include at least one Service Guide (SG) Provider element. 
     An SG provider may refer to a provider providing information related to the ESG. The SG provider element may include a name attribute and/or at least one bootstrap element. 
     The name attribute may indicate the name of the SG provider. 
     The bootstrap element may include at least one piece of bootstrap information. The bootstrap element may include a network_type attribute, a sourceIPAddr element, a destIPAddr element, a destUDPPort element, a transportStreamID element, a partitionID element, a datapipeID element, a tsi element and/or a downloadURL element. For example, the bootstrap element can be ESG bootstrap information. 
     The network_type element may indicate an ESG data transmission type. Specifically, the network_type element can indicate an SGDD transmission type. One network_type attribute may be included in the bootstrap element. The bootstrap element may selectively include bootstrap information defined below according to the value of the network_type attribute. For reference, “ESG bootstrapping description transmission type” can be interpreted as “ESG data transmission type”. Specifically, “ESG bootstrapping description transmission type” can be interpreted as “SGDD transmission type”. 
     The sourceIPAddr element may indicate the source ID addresses of the ESG data and/or SG data. For example, the sourceIPAddr element can include the IP source addresses of packets carrying service layer signaling information for a service and/or ESG. Specifically, the sourceIPAddr element can indicate the IP source address corresponding to the SGDD. 
     The destIPAddr element may indicate the destination IP address of the ESG data and/or SG data. For example, the destIPAddr element can include the IP destination addresses of packets carrying service layer signaling information for a service and/or ESG. Specifically, the destIPAddr element can indicate the IP destination address corresponding to the SGDD. 
     The destUDPPort element may indicate the destination port number of the ESG data and/or SG data. For example, the destUDPPort element can include the port number of packets carrying service layer signaling information for a service and/or ESG. Specifically, the destUDPPort element can indicate the destination port number corresponding to the SGDD. 
     The sourceIPAddr element, the destIPAddr element and/or the destUDPPort element refer to information described in the header of the IP packet carrying the ESG data. 
     The transportStreamID element may indicate the transport stream identifier corresponding to a foreign frequency when the ESG data is transmitted through the foreign Frequency. This value can be selectively included in the bootstrap element according to the value of the network_type attribute. Specifically, the transportStreamID element can indicate the transport stream identifier corresponding to the transport stream carrying the SGDD. 
     The partitionID element may indicate the partition identifier corresponding to a foreign frequency when the ESG data is transmitted through the foreign Frequency. For example, the partition identifier identifies a broadcaster. This value can be selectively included in the bootstrap element according to the value of the network_type attribute. Specifically, the partitionID element can indicate the partition identifier corresponding to the SGDD. 
     The datapipeID element may indicate the identifier identifying a PLP and/or a DP through which the ESG data is transmitted. This value can be selectively included in the bootstrap element according to the value of the network_type attribute. For example, when the ESG data is transmitted through a broadcast network, the datapipeID element can have a single value. Specifically, the datapipeID element can indicate the identifier identifying the PLP and/or DP through which the SGDD is transmitted. 
     To signal information of the ESG data transmitted through the foreign frequency, the bootstrap element may selectively include the transportStreamID element, the partitionID element and/or the datapipeID element. 
     The tsi element may indicate the identifier identifying the transport session and/or an LCT session through which the ESG data is transmitted. This value can be selectively included in the bootstrap element according to the value of the network_type attribute. For example, when the ESG data is transmitted through a broadcast network, the tsi element can include at least one value. Specifically, the tsi element can indicate the identifier identifying the transport session and/or an LCT session through which the SGDD is transmitted. 
     The downloadURL element may indicate the URL by which the ESG data transmitted through a broadband network can be accessed. This value can be selectively included in the bootstrap element according to the value of the network_type attribute. For example, when the ESG data is transmitted through a broadband network, the downloadURL element can have a single value. Specifically, the downloadURL element can indicate the URL corresponding to the SGDD. 
     The bootstrap element can include at least one of the tsi element and the downloadURL element according to whether the ESG data is transmitted through the broadcast network or the broadband network. 
     The broadcast transmission apparatus can transmit a broadcast signal including service data and signaling information. The signaling information can include ESG bootstrap information. The broadcast reception apparatus can receive the broadcast signal including the service data and the signaling information. The broadcast reception apparatus can acquire and/or process ESG data on the basis of ESG bootstrap information included in the signaling information. 
       FIG. 130  illustrates ESG bootstrap information transmission types according to an embodiment of the present invention. 
     The network_type attribute can indicate an ESG data transmission type. The value of the network_type attribute can be variable. When the ESG data is transmitted in multiple types, a plurality of bootstrap elements having network_type attribute values respectively corresponding to the types can be transmitted. 
     When the network_type attribute has a value of 0x01, the ESG data is transmitted through ATSC3.0 broadcast at the same frequency. In this case, the broadcast reception apparatus can receive the ESG data at the same frequency. 
     When the network_type attribute has a value of 0x02, the ESG data is transmitted through the ATSC3.0 broadcast at a different frequency. In this case, the broadcast reception apparatus can receive the ESG data at the different frequency. 
     When the network_type attribute has a value of 0x03, the ESG data is transmitted through IP broadcast other than the ATSC3.0 broadcast. In this case, the broadcast reception apparatus can receive the ESG data through the IP broadcast. 
     When the network_type attribute has a value of 0x04, the ESG data is transmitted through a broadband network. In this case, the broadcast reception apparatus can receive the ESG data through the broadband network. 
       FIG. 131  illustrates signaling of the ESG bootstrap information according to a first embodiment of the present invention. 
     The first embodiment of the present invention can provide a method for transmitting the ESG bootstrap information in the form of an ESG bootstrapping descriptor of a fast information channel (FIC) in the future broadcast network. 
     In the first embodiment of the present invention, the ESG is not defined as a broadcast service. The FIC may refer to the Service List Table (SLT). The SLT is a signaling information table used to build a basic service list and to bootstrap discovery of service layer signaling information (SLS). 
     Referring to the figure, a broadcast signal and/or an actual stream can include at least one broadcast stream at a specific frequency. For example, the actual stream can include a broadcast stream having a frequency of ‘Frqncy-z’. 
     Each broadcast stream can include at least one partition. Each partition may correspond to each broadcaster. Otherwise, each partition may be a broadcast stream transmitted from each broadcaster. 
     Each partition can include at least one DL (or PLP) and/or an FIC. For example, a first partition A can include a first DP, a second DP, a third DP and/or the FIC. The DP ID of the first DP may be “1”. The DP ID of the second DP may be “2”. The DP ID of the third DP may be “3”. 
     A single DP can include a single Real-Time Object Delivery over Unidirectional Transport (ROUTE) session. A plurality of DPs may include a single ROUTE session. A ROUTE session can include at least one service and/or at least one component. The ROUTE session may include IP/UDP datagrams. 
     For example, the first DL can include a first ROUTE session. That is, the first ROUTE session is transmitted through the first DP. The first ROUTE session may be specified by a first source IP address, a first destination IP address and/or a first UDP Port number. The first ROUTE session may include a first service (A/V service). 
     The first ROUTE session may include at least one transport session (or LCT session). For example, the first ROUTE session can include a first transport session (tsi-v), a second transport session (tsi-a), a third transport session (tsi-s) and/or a fourth transport session (tsi-0). 
     The first transport session (tsi-v) may include a video component. The video component may include at least one video segment including video data. The second transport session (tsi-a) may include an audio component. The audio component may include at least one audio segment including audio data. The third transport session (tsi-s) may include a service signaling channel component. The service signaling channel component may include a Service Map Table (SMT), a Component Mapping Table (CMT), a Guide Access Table (GAT) and/or a DASH Media Presentation Description (MPD). The fourth transport session (tsi-0) may include an LCT session instance description (LSID). The LSID may be referred to as a Service-based Transport Session Instance Description (S-TSID). The S-TSID may include whole session description information for at least one transport session through which at least one content component of a service is transmitted. 
     The second DP and the third DP may include a second ROUTE session. That is, the second ROUTE session is transmitted through the second DP and/or the third DP. The second ROUTE session may be specified by a second source IP address, a second destination IP address and/or a second UDP Port number. 
     The second ROUTE session may include at least one transport session (or LCT session). For example, the second ROUTE session can include a fifth transport session (tsi-0), a sixth transport session (tsi-101) and/or a seventh transport session (tsi-102). A transport session (or LCT session) may include at least one transport object. 
     The fifth transport session (tsi-0) may include an LSID. 
     The sixth transport session (tsi-101) may include a first transport object (toi-0) and/or a second transport object (toi-1). The first transport object (toi-0) may include a File Delivery Table (FDT) providing files transmitted in a file delivery session and/or attributes associated with file delivery. Otherwise, the first transport object (toi-0) may include an EFDT which specifies details of file delivery data. The second transport object (toi-1) may include Service Guide Delivery Descriptor (SGDD) which describes information about a delivery path through which a Service Guide Delivery Unit (SGDU) is delivered. 
     The seventh transport session (toi-102) may include a third transport object (toi-0), a fourth transport object (toi-1) and/or a fifth transport object (toi-2). The third transport object (toi-0) may include an FDT and/or an EFDT. The fourth transport object (toi-1) may include an SGDU. The fifth transport object may include an SGDU. The SGDU is configured per fragment, and fragment type may include at least one of a service fragment, a content fragment and a schedule fragment. The SGDU may include ESG data. Both the SGDD and the SGDU may be XML files. 
     The broadcast transmission apparatus can transmit a broadcast signal including service data and signaling information. For example, the signaling information can include an FIC and/or an LSID. 
     The broadcast transmission apparatus can transmit a broadcast signal including the FIC. 
     The FIC may include at least one PartitionID element that specifies a partition, a ServiceID element that specifies a service, a Service Category element that indicates the category of the service, an SSC IP/Port element that specifies an IP address/port through which an SSC is transmitted, an SSC DP_ID element that specifies a DP through which the SSC is transmitted, a TSI element that specifies a transport session through which the SSC is transmitted and/or a partition level descriptor. 
     The SSC bootstrap information (SSC IP/Port element, SSC DP_ID element and/or TSI element) may include information related to the service signaling channel (SSC) through which the SMT and/or the CMT are transmitted. Since the ESG is not defined as a single service in the first embodiment of the present invention, the FIC may not include the SSC bootstrap information in a service loop. 
     The FIC according to the first embodiment of the present invention may include the ESG bootstrap information in the form of a partition level descriptor. 
     The ESG bootstrap information may include the same information as the aforementioned ESG bootstrap information and/or ESG bootstrapping description. For example, the ESG bootstrap information can include the num_of_Provider element and/or at least one provider element. 
     The num_of_Provider element indicates the number of providers. 
     The provider element may include information about a provider. For example, the provider element can include the ESG bootstrap information. In addition, the provider element may include ESG data and/or information about a provider providing ESG related information. The provider element may indicate the aforementioned SG provider element. Each provider element may include a bootstrap_network_type attribute, a ts_ID attribute, a partitionID attribute, a Route_session element, a tsi attribute, a DP attribute and/or a URL attribute. 
     The bootstrap_network_type attribute indicates ESG data transmission type. The bootstrap_network_type attribute may indicate the aforementioned network_type attribute. 
     The ts_ID attribute indicates the transport stream ID of a foreign frequency when the ESG data is transmitted through the foreign frequency. The ts_ID attribute may indicate the aforementioned transportStreamID element. 
     The partitionID attribute indicates the partition ID of a foreign frequency when the ESG data is transmitted through the foreign frequency. The partitionID attribute may indicate the aforementioned partitionID element. 
     The ROUTE_session element may include information specifying a ROUTE session. The Route_session element may include ROUTE session bootstrap information. The ROUTE session bootstrap information may include transport path of the ROUTE session. For example, the Route_session element can include an IP(src/dest) attribute and/or a port attribute. The IP(src/dest) attribute may include the aforementioned sourceIPAddr element and destIPAddr element. The port attribute may indicate the aforementioned destUDPPort element. A combination of the sourceIPAddr element, destIPAddr element and port element may specify a specific ROUTE session. 
     The tsi attribute may indicate the identifier identifying a transport session and/or an LCT session through which the ESG data is transmitted. For example, the tsi attribute can indicate the identifier identifying a transport session and/or an LCT session through which the SGDD is transmitted. Referring to the figure, the tsi attribute can have a value of “tsi-101”, for example. 
     The DP attribute may specify a PLP and/or a DP through which the ESG data is transmitted. The DP attribute may indicate the aforementioned datapipeID element. For example, the DP attribute can indicate a PLP and/or a DP through which the SGDD is transmitted. Referring to the figure, the DP attribute can have a value of “2”, for example. 
     The URL attribute may specify a URL by which the ESG data can be accessed. The URL attribute may indicate the aforementioned downloadURL element. 
     The FIC according to an embodiment of the present invention may be included in an IP/UDP packet and transmitted. 
     The broadcast transmission apparatus can transmit a broadcast signal including LSID. 
     For example, the LSID included in the fifth transport session (tsi-0) can include a sixth transport session element TSI-101 containing information about the sixth transport session and/or a seventh transport session element TSI-102 containing information about the seventh transport session. 
     Each of the sixth transport session element TSI-101 and the seventh transport session element TSI-102 may include a DP attribute that specifies a DP through which the corresponding transport session is transmitted, a SourceFlow element that provides information about a source flow included in the transport session and/or a RepairFlow element that provide information about a repair flow included in the transport session. The SourceFlow element may include a realtime attribute that indicates whether the SourceFlow element carries streaming media data. For example, when the realtime attribute is “true”, the realtime attribute indicates real-time transmission of the SourceFlow element. When the realtime attribute is “false”, the realtime attribute indicates non-real time transmission of the SourceFlow element. 
     While the broadcast reception apparatus can acquire the seventh transport session element TSI-102 through the SGDD, the broadcast reception apparatus may not acquire information about the DP corresponding to the SGDU transmitted through the corresponding transport session. Accordingly, the broadcast transmission apparatus according to the first embodiment may transmit LSID including DP information. 
     The broadcast reception apparatus can receive a broadcast signal including service data and signaling information. The signaling information may include an FIC and/or LSID. 
     The broadcast reception apparatus can acquire the FIC. The FIC may be transmitted through an IP/UDP packet. 
     The broadcast reception apparatus can acquire ESG bootstrap information and/or LSID on the basis of the FIC. The broadcast reception apparatus can acquire the ESG bootstrap information on the basis of the partition level descriptor of the FIC. The ESG bootstrap information may be included in the FIC in the form of the partition level descriptor. Since ESG is not defined as a single service in the first embodiment of the present invention, the FIC may not include SSC bootstrap information in the service loop. The LSID may include transport data pipeline information (or PLP ID) per transport session. The broadcast reception apparatus may acquire the LSID on the basis of ROUTE session bootstrap information included in the ESG bootstrap information. In this case, the LSID can be transmitted through a predetermined transport session, and the broadcast reception apparatus can acquire the LSID on the basis of the ROUTE session bootstrap information and/or information on the predetermined transport session. Alternatively, the broadcast reception apparatus may acquire the LSID on the basis of additional LSID transport path information included in the FIC. 
     The broadcast reception apparatus may acquire ESG data and/or an ESG service on the basis of the ESG bootstrap information and/or the LSID. 
     To acquire ESG Announcement Channel information and transmit (or deliver) ESG data, the broadcast transmission apparatus according to the first embodiment of the present invention can add transport data pipeline information (or PLP ID) per transport session in the LSID. Consequently, the broadcast transmission apparatus can transmit an SGDU. The broadcast reception apparatus can receive the LSID including the data pipeline information (or PLP ID) per transport session and acquire the SGDU on the basis of the LSID. 
     In addition, the broadcast transmission apparatus according to the first embodiment of the present invention can add ATSC 3.0 Profile to the syntax of the SGDD to add data pipeline information. In this case, the broadcast reception apparatus can receive SGDD and acquire the SGDU on the basis of the data pipeline information of the SGDD. 
       FIG. 132  illustrates signaling of ESG bootstrap information according to a second embodiment of the present invention. 
     The second embodiment of the present invention provides a method for transmitting the ESG bootstrap information in the form of an ESG bootstrapping descriptor of an FIC in the future broadcast network. In the second embodiment of the present invention, the ESG can be defined as a single broadcast service. In addition, the Service Category element can indicate that the corresponding service is ESG service in the service loop of the FIC. The broadcast reception apparatus can receive ESG bootstrap information in the form of an ESG bootstrapping descriptor in the FIC. In addition, the broadcast reception apparatus can acquire ESG through the ESG bootstrap information. 
     Referring to the figure, an actual stream according to the second embodiment of the present invention may include a broadcast stream having a frequency of ‘Frqncy-z’. The broadcast stream according to an embodiment of the present invention may include a first partition A. The first partition A may include a first DP, a second DP, a third DP and/or the FIC. The first DP may include a first ROUTE session. The first ROUTE session may include a first service (A/V service). The first ROUTE session may include a first transport session (tsi-v), a second transport session (tsi-a), a third transport session (tsi-s) and/or a fourth transport session (tsi-0). The second DP and the third DP may include a second ROUTE session. The second ROUTE session may include a second service. For example, the second service can include an ESG service. The second ROUTE session may include a fifth transport session (tsi-0), a sixth transport session (tsi-101) and/or a seventh transport session (tsi-102). The FIC according to the second embodiment of the present invention may be included in an IP/UDP packet and transmitted. The actual stream illustrated in  FIG. 132  may correspond to the aforementioned actual stream. 
     The broadcast transmission apparatus can transmit a broadcast signal including service data and signaling information. For example, the service data can include ESG data. The signaling information can include an FIC and/or an LSID. 
     The broadcast transmission apparatus can transmit a broadcast signal including the FIC. 
     The FIC may include at least one PartitionID element that specifies a partition, a ServiceID element that specifies a service, a Service Category element that indicates the category of the service, an SSC IP/Port element that specifies an IP address/port through which an SSC is transmitted, an SSC DP_ID element that specifies a DP through which the SSC is transmitted, a TSI element that specifies a transport session through which the SSC is transmitted and/or a partition level descriptor. The SSC IP/Port element may include a source IP Address, a destination IP Address and/or a UDP Port number corresponding to the SSC. 
     A transport session through which an SGDD is transmitted may differ from a transport session through which LSID is transmitted. In this case, SSC bootstrap information (SSC IP/Port element, SSC DP_ID element and/or TSI element) may be replaced by ESG bootstrapping information. For example, the SSC IP/Port element, SSC DP_ID element and/or TSI element can be ESG bootstrap information that specifies ESG data transmitted through ATSC3.0 Broadcast at the same frequency. In this case, the SSC IP/Port element, SSC DP_ID element and/or TSI element may not include information related to the SSC. Information indicating that the SSC IP/Port element, SSC DP_ID element and/or TSI element include the ESG bootstrap information may be included in semantics of the FIC. The ESG bootstrap information may be information that specifies a path through which ESG data and/or SGDD are transmitted. The FIC may additionally include bootstrap information and/or transport path information about the SSC and/or LSID. In addition, the SSC and/or LSID may be transmitted through a predetermined specific transport session. 
     The transport session through which the SGDD is transmitted may be identical to the transport session through which the LSID is transmitted. That is, the LSID may include the SGDD. In this case, the SSC bootstrap information may correspond to the ESG bootstrap information. That is, the SSC bootstrap information and/or the ESG bootstrapping information may specify the SSC, LSID, ESG data and/or SGDD. For example, the SSC IP/Port element can specify IP/Ports through which the SSC, LSID, ESG data and/or SGDD are transmitted. The SSC DP_ID element can specify a DP through which the SSC, LSID, ESG data and/or SGDD are transmitted. The TSI element can specify a transport session through which the SSC, LSID, ESG data and/or SGDD are transmitted. The SSC IP/Port element may include source IP Addresses, destination IP Addresses and/or UDP Port numbers associated with transmission of the SSC, LSID, ESG data and/or SGDD. In this case, the SSC and/or LSID may be transmitted through a predetermined specific transport session. 
     The partition level descriptor of the FIC may further include additional ESG bootstrap information. For example, the ESG bootstrap information included in the partition level descriptor can include a num_of_Provider element and/or at least one provider element. For example, the provider element can include information about a provider. In addition, the provider element can include information about a provider providing information about ESG data and/or ESG. The provider element may include a bootstrap_network_type attribute, a ts_ID attribute, a partitionID attribute, a Service ID attribute and/or a URL attribute. The Service ID attribute specifies a service. The elements and attributes included in the ESG bootstrap information correspond to the aforementioned ones. 
     The ESG according to the second embodiment of the present invention can be defined as a single service. The SSC bootstrap information in the FIC service loop can be used as ESG bootstrap information. 
     Accordingly, while an additional definition scheme is needed when semantics of the SSC bootstrap information in the FIC service loop are defined, FIC size increase can be reduced by the length of the information. ESG bootstrap information, which is transmitted through a network_type that cannot be represented using the SSC bootstrap information, is transmitted through the partition level descriptor. 
     The Service Category element according to the second embodiment of the present invention can indicate an ESG service. 
     The broadcast transmission apparatus can transmit a broadcast signal including LSID. 
     For example, the LSID included in the fifth transport session (tsi-0) can include a sixth transport session element TSI-101 containing information about the sixth transport session and/or a seventh transport session element TSI-102 containing information about the seventh transport session. The LSID according to the second embodiment of the present invention may correspond to the aforementioned LSID. 
     While the broadcast reception apparatus can acquire the seventh transport session element TSI-102 through the SGDD, the broadcast reception apparatus may not acquire information about the DP corresponding to the SGDU transmitted through the corresponding transport session. Accordingly, the broadcast transmission apparatus according to the first embodiment may transmit LSID including DP information. 
     The broadcast reception apparatus can receive a broadcast signal including service data and signaling information. For example, the service data may include ESG data. The signaling information may include an FIC and/or LSID. 
     The broadcast reception apparatus can acquire the FIC. The FIC may be transmitted through an IP/UDP packet. 
     The broadcast reception apparatus may acquire SSC bootstrap information and/or ESG bootstrap information on the basis of the FIC. The FIC may include the ESG bootstrap information. 
     When a transport session through which an SGDD is transmitted differs from a transport session through which LSID is transmitted, SSC bootstrap information (SSC IP/Port element, SSC DP_ID element and/or TSI element) of the FIC may be replaced by ESG bootstrapping information. The FIC may further include additional information for bootstrapping and/or identifying the SSC and/or LSID. 
     When the transport session through which the SGDD is transmitted is identical to the transport session through which the LSID is transmitted, the SSC bootstrap information may correspond to the ESG bootstrap information. That is, the SSC bootstrap information and/or the ESG bootstrapping information may specify the SSC, LSID, ESG data and/or SGDD. The following description is based on a case in which the transport session through which the SGDD is transmitted is identical to the transport session through which the LSID is transmitted 
     The partition level descriptor of the FIC may further include additional ESG bootstrap information. The LSID may include transport data pipeline information (or PLP ID) per transport session. 
     The broadcast reception apparatus may acquire the LSID on the basis of the FIC. For example, the broadcast reception apparatus can acquire the LSID on the basis of the SSC bootstrap information included in the FIC. 
     The broadcast reception apparatus may acquire the ESG bootstrap information on the basis of the FIC. For example, the SSC bootstrap information can correspond to the ESG bootstrap information. 
     The broadcast reception apparatus may acquire ESG data and/or ESG service on the basis of the ESG bootstrap information and/or the LSID. 
     To acquire ESG Announcement Channel information and transmit (or deliver) ESG data, the broadcast transmission apparatus according to the second embodiment of the present invention can add transport data pipeline information (or PLP ID) per transport session in the LSID. Consequently, the broadcast transmission apparatus can transmit an SGDU. The broadcast reception apparatus can receive the LSID including the data pipeline information (or PLP ID) per transport session and acquire the SGDU on the basis of the LSID. 
     In addition, the broadcast transmission apparatus according to the second embodiment of the present invention can add ATSC 3.0 Profile to the syntax of the SGDD to add data pipeline information. In this case, the broadcast reception apparatus can receive SGDD and acquire the SGDU on the basis of the data pipeline information of the SGDD. 
       FIG. 133  illustrates signaling of ESG bootstrapping description according to a third embodiment of the present invention. 
     The third embodiment of the present invention provides a method for transmitting the ESG bootstrap information using the ROUTE session element of the SMT in the future broadcast system. The ESG can be defined as a separate broadcast service. The Service Category element can indicate ESG service in the service loop of the FIC. The SMT and the CMT can be transmitted through the SSC. However, definition of the SMT semantics needs to be modified. 
     Referring to the figure, an actual stream according to the third embodiment of the present invention may include a broadcast stream having a frequency of ‘Frqncy-z’. The broadcast stream according to an embodiment of the present invention may include a first partition A. The first partition A may include a first DP, a second DP, a third DP, a fourth DP and/or the FIC. The first DL may include a first ROUTE session. The first ROUTE session may include a first service (A/V service). The first ROUTE session may include a first transport session (tsi-v), a second transport session (tsi-a), a third transport session (tsi-s) and/or a fourth transport session (tsi-0). The first ROUTE session illustrated in the figure may correspond to the aforementioned ROUTE session. 
     The second DP, the third DP and the fourth DP may include a second ROUTE session. The second ROUTE session may include a second service. For example, the second service can include an ESG service. The second ROUTE session may include a fifth transport session (tsi-0), a sixth transport session (tsi-ssc), a seventh transport session (tsi-101) and/or an eighth transport session (tsi-102). 
     The fifth transport session (tsi-0) may include an LSID. 
     The sixth transport session (tsi-ssc) may include an SMT and/or a component mapping table (CMT). 
     The seventh transport session (tsi-101) may include a first transport object (toi-0) and/or a second transport object (toi-1). The first transport object (toi-0) may include an FDT and/or an EFDT. The second transport object (toi-1) may include an SGDD. 
     The eighth transport session (toi-102) may include a third transport object (toi-0), a fourth transport object (toi-1) and/or a fifth transport object (toi-2). The third transport object (toi-0) may include an FDT and/or an EFDT. The fourth transport object (toi-1) may include an SGDU. The fifth transport object may include an SGDU. The SGDU may include ESG data. 
     The broadcast transmission apparatus can transmit a broadcast signal including service data and signaling information. For example, the service data can include ESG data and the signaling information can include an FIC, SMT, CMT and/or LSID. 
     The broadcast transmission apparatus can transmit a broadcast signal including the FIC. 
     The FIC may include at least one PartitionID element that specifies a partition, a ServiceID element that specifies a service, a Service Category element that indicates the category of the service, an SSC IP/Port element that specifies an IP address/port through which an SSC is transmitted, an SSC DP_ID element that specifies a DP through which the SSC is transmitted, a TSI element that specifies a transport session through which the SSC is transmitted and/or a partition level descriptor. 
     The SSC IP/Port element, SSC DP_ID element and/or TSI element may be SSC bootstrap information. The SSC bootstrap information may include information about a transport path of the SSC through which the SMT and/or the CMT are transmitted. For example, the SSC IP/Port element, SSC DP_ID element and/or TSI element can be SSC bootstrapping information transmitted through ATSC3.0 Broadcast at the same frequency. The FIC according to the third embodiment of the present invention may be included in an IP/UDP packet and transmitted. 
     The service category element according to the third embodiment of the present invention may indicate the ESG service. 
     The broadcast transmission apparatus can transmit a broadcast signal including the SMT, CMT and/or LSID. 
     The SMT may include a serviceID element, a category element, a num_of LSID element, at least one LSID element, a num_of Provider element and/or at least one provider element. 
     The serviceID element may specify a service. The category element may specify the category of the service. For example, the service category can include the ESG service. 
     The num_of LSID element may indicate the number of LSIDs. The LSID element may include information about LSIDs. 
     The LSID element may include ROUTE session bootstrap information. For example, the LSID element can include a bootstrap_network_type attribute, a ts_ID attribute, a partitionID attribute, a Route_session element (or announcement_session element) and/or a URL element. The Route_session element may include an IP(src/dest) element, a port element, a tsi element and/or a DP element. The elements and/or attributes included in the LSID element correspond to the aforementioned ones. Even when the LSID element according to the present embodiment has elements and attributes different from those of the LSID element according to the above embodiment, the LSID element may include the same information as the LSID element according to the above embodiment. The Route_session element may include ROUTE session bootstrap information. The ROUTE session bootstrap information may include information about an LSID transmission path. 
     The num_of Provider element may indicate the number of providers providing information about ESG. The provider element may include information about a provider. 
     The provider element may include ESG bootstrap information. In addition, the provider element may include information about a provider providing information related to ESG data and/or ESG. For example, the provider element can include a bootstrap_network_type attribute, a ts_ID attribute, a partitionID attribute, a Route_session element (or announcement_session element) and/or a URL element. The Route_session element may include an IP(src/dest) element, a port element, a tsi element and/or a DP element. The elements and/or attributes included in the provider element correspond to the aforementioned ones. Even when the provider element according to the present embodiment has elements and attributes different from those of the provider element according to the above embodiment, the provider element may include the same information as the provider element according to the above embodiment. The Route_session element or announcement_session element may include ESG bootstrap information. The ESG bootstrap information may include information about ESG data transport path. For example, the IP(src/dest) element and the port element can indicate the second ROUTE session, the tsi element can indicate the fifth transport session (tsi-101) and the DP element can indicate the second DP (DP ID=2). 
     The LSID included in the fifth transport session may include a sixth transport element (not shown) including information about the sixth transport session, a seventh transport element TSI-101 including information about the seventh transport session and/or an eighth transport element TSI-102 including information about the eighth transport session. Each of the seventh transport session element TSI-101 and the eighth transport session element TSI-102 may include a SourceFlow element and/or a RepairFlow element. The SourceFlow element may include a realtime attribute. For example, when the realtime attribute is “false”, the realtime attribute indicates non-real time transmission of the SourceFlow element. 
     The CMT may include information about an acquisition path and/or a transport path of component data in the service. In addition, the CMT may include information about components transmitted through a broadband network. Furthermore, the CMT may include information about components included in other broadcast streams. The CMT may correspond to the aforementioned CMT. For example, the CMT can include a serviceID attribute and/or a component element. The serviceID attribute can specify the corresponding service. The serviceID attribute is an identifier of a service associated with corresponding components. The component element may include information about components in the corresponding service. For example, the component element can include information about components transmitted through the same broadcast stream, information about components transmitted through a broadband network and/or information about components transmitted through other broadcast streams. The component element may include at least one of a contentLinkage attribute mapped to contentLinkage defined in the FDT of FLUTE, a tsi attribute that specifies a transport session through which the corresponding component in the broadcast stream is transmitted, and a DP attribute that specifies a DP through which the corresponding component in the broadcast stream is transmitted. The broadcast reception apparatus may acquire service components on the basis of the FIC. 
     The broadcast reception apparatus may receive a broadcast signal including service data and signaling information. For example, the service data can include ESG data and the signaling information can include the FIC, SMT, CMT and/or LSID. 
     The broadcast reception apparatus may acquire the FIC. The FIC may be transmitted through an IP/UDP packet. 
     The broadcast reception apparatus may acquire SSC bootstrap information on the basis of the FIC. The SSC may include the SMT and/or the CMT. 
     The broadcast reception apparatus may acquire the SMT on the basis of the SSC bootstrap information included in the FIC. The SMT may include an LSID element and/or a provider element. The LSID element may include a ROUTE session element. The ROUTE session element of the LSID element may include LSID transport path information. The ROUTE session element of the provider element may include ESG bootstrap information. 
     When the Service Category element indicates the ESG service, the SMT may include the ESG bootstrap information. For example, when the Service Category element indicates the ESG service, the LSID transport path information described in the SMT can be replaced by the ESG bootstrap information. The SMT may include both the LSID transport path information and the ESG bootstrap information. 
     The broadcast reception apparatus may acquire the LSID and/or the ESG bootstrap information on the basis of the SMT. When the Service Category indicates the ESG service, the LSID transport path information described in the SMT can be replaced by the ESG bootstrap information. Specifically, the IP(src/dest) element, port element, tsi element and/or DP element included in the SMT may be the ESG bootstrap information. The ROUTE session element may include both the LSID and the ESG bootstrap information, and the broadcast reception apparatus may acquire both the LSID transport path information and the ESG bootstrap information on the basis of the SMT. 
     The broadcast reception apparatus may acquire the CMT on the basis of the SSC bootstrap information included in the FIC. 
     The broadcast reception apparatus may acquire component matching information on the basis of the CMT. For example, the CMT can include a ContentLinkage attribute, a tsi attribute and/or a DP attribute. 
     The broadcast reception apparatus may acquire ESG data and/or an ESG service on the basis of the SMT, CMT and/or LSID. For example, the broadcast reception apparatus can acquire the ESG data and/or the ESG service on the basis of the LSID, ESG bootstrap information and/or the component matching information of the CMT. For example, the broadcast reception apparatus can acquire a transport session described in the LSID on the basis of the tsi attribute of the CMT and acquire DP information mapped thereto. That is, the broadcast reception apparatus can acquire an actual component on the basis of the tsi attribute and/or the DP attribute of the CMT. For example, the actual component can be a component for the ESG service. 
     Specifically, the broadcast reception apparatus can acquire an SGDD for the ESG data and/or the ESG service on the basis of the LSID, ESG bootstrap information and/or the component matching information of the CMT. Then, the broadcast reception apparatus can acquire an SGDU for the ESG service on the basis of the SSDD. 
     Since the ESG data can be defined as a file, the broadcast reception apparatus can map the ESG data to contentLinkage defined in the FDT of the FLUTE on the basis of the contentLinkage attribute included in the CMT. That is, the broadcast reception apparatus can acquire the ESG data for the ESG service on the basis of the contentLinkage attribute. In this case, the ESG service can be provided as a file including the ESG data. 
     To acquire ESG Announcement Channel information and transmit (or deliver) ESG data, the broadcast transmission apparatus according to the third embodiment of the present invention can add transport data pipeline information (or PLP ID) per transport session in the LSID. That is, each transport session element of the LSID may include a DP attribute. Consequently, the broadcast transmission apparatus can transmit an SGDU. The broadcast reception apparatus can receive the LSID including the data pipeline information (or PLP ID) per transport session and acquire the SGDU on the basis of the LSID. 
     In addition, the broadcast transmission apparatus according to the third embodiment of the present invention can add ATSC 3.0 Profile to the syntax of the SGDD to add data pipeline information. In this case, the broadcast reception apparatus can receive SGDD and acquire the SGDU on the basis of the data pipeline information of the SGDD. 
       FIG. 134  illustrates signaling of ESG bootstrap information according to a fourth embodiment of the present invention. 
     The fourth embodiment of the present invention provides a method for transmitting the ESG bootstrap information using a service level descriptor of the SMT in the future broadcast system. The ESG can be defined as a separate broadcast service. The Service Category element can indicate ESG service in the service loop of the FIC, and the SMT and the CMT can be transmitted through the SSC. The SMT mapped to an ESG service may include an ESG bootstrap descriptor and the ESG bootstrap descriptor may be defined as a service level descriptor. 
     Referring to the figure, an actual stream according to the fourth embodiment of the present invention may include a broadcast stream having a frequency of ‘Frqncy-z’. The broadcast stream according to an embodiment of the present invention may include a first partition A. The first partition A may include a first DP, a second DP, a third DP, a fourth DP and/or the FIC. The first DP may include a first ROUTE session. The first ROUTE session may include a first service (A/V service). The first ROUTE session may include a first transport session (tsi-v), a second transport session (tsi-a), a third transport session (tsi-s) and/or a fourth transport session (tsi-0). The first ROUTE session illustrated in the figure may correspond to the aforementioned first ROUTE session. 
     The second DP, the third DP and the fourth DP may include a second ROUTE session. The second ROUTE session may include a second service. For example, the second service can include an ESG service. The second ROUTE session may include a fifth transport session (tsi-0), a sixth transport session (tsi-ssc), a seventh transport session (tsi-101) and/or an eighth transport session (tsi-102). The second ROUTE session illustrated in the figure may correspond to the aforementioned second ROUTE session. 
     The broadcast transmission apparatus can transmit a broadcast signal including service data and signaling information. For example, the service data can include ESG data and the signaling information can include an FIC, SMT, CMT and/or LSID. 
     The broadcast transmission apparatus can transmit a broadcast signal including the FIC. 
     The FIC may correspond to the aforementioned FIC. For example, the FIC can include at least one PartitionID element that specifies a partition, a ServiceID element that specifies a service, a Service Category element that indicates the category of the service, an SSC IP/Port element that specifies a IP/port through which an SSC is transmitted, an SSC DP_ID element that specifies a DP through which the SSC is transmitted, a TSI element that specifies a transport session through which the SSC is transmitted and/or a partition level descriptor. 
     The SSC IP/Port element, SSC DP_ID element and/or TSI element may be SSC bootstrap information. The SSC bootstrap information may include information about a transport path of the SSC through which the SMT and/or the CMT are transmitted. For example, the SSC IP/Port element, SSC DP_ID element and/or TSI element can be SSC bootstrapping information transmitted through ATSC3.0 Broadcast at the same frequency. The FIC according to the fourth embodiment of the present invention may be included in an IP/UDP packet and transmitted. 
     The service category element according to the fourth embodiment of the present invention may indicate the ESG service. 
     The broadcast transmission apparatus can transmit a broadcast signal including the SMT, CMT and/or LSID. 
     The SMT may correspond to the aforementioned SMT. For example, the SMT can include a serviceID attribute that specifies a service, a category attribute that specifies the category of the service, at least one ROUTE session element including information about a ROUTE session and/or at least one service level descriptor. The ROUTE session element may include ROUTE session bootstrap information. The ROUTE session element may include LSID bootstrap information (or LSID transport path information). The category attribute may indicate an ESG service. 
     The service level descriptor may include ESG bootstrap information. When the service category element according to the fourth embodiment of the present invention indicates the ESG service, the SMT may include the service level descriptor including the ESG bootstrap information. The broadcast transmission apparatus may transmit the ESG bootstrap information through the service level descriptor. 
     The LSID may correspond to the aforementioned LSID. For example, the LSID can include a seventh transport element TSI-101 including information about the seventh transport session and/or an eighth transport element TSI-102 including information about the eighth transport session. Each of the seventh transport session element TSI-101 and the eighth transport session element TSI-102 may include a SourceFlow element that provides information about a source flow included in the corresponding transport session and/or a RepairFlow element that provides information about a repair flow included in the transport session. The SourceFlow element may include a realtime attribute that indicates whether the SourceFlow element carries streaming media data. For example, when the realtime attribute is “true”, the realtime attribute indicates real-time transmission of the SourceFlow element. When the realtime attribute is “false”, the realtime attribute indicates non-real time transmission of the SourceFlow element. 
     The CMT may correspond to the aforementioned CMT. For example, the CMT can include a serviceID attribute that specifies the corresponding service and/or a component element containing information about a component in the service. The component element may include at least one of a contentLinkage attribute mapped to contentLinkage defined in the FDT of FLUTE, a tsi attribute that specifies a transport session through which the corresponding component in the broadcast stream is transmitted, and a DP attribute that specifies a DP through which the corresponding component in the broadcast stream is transmitted. 
     The broadcast reception apparatus may receive a broadcast signal including service data and signaling data. For example, the service data can include ESG data and the signaling information can include the FIC, SMT, CMT and/or LSID. 
     The broadcast reception apparatus may acquire the FIC. The FIC may be transmitted through an IP/UDP packet. For example, the service category element can indicate an ESG service. The FIC can include SSC bootstrap information in the service loop. The SSC can include the SMT and/or the CMT. 
     The broadcast reception apparatus may acquire the SMT on the basis of the SSC bootstrap information included in the FIC. The SMT may include at least one ROUTE session element and/or at least one service level descriptor. 
     The broadcast reception apparatus may acquire the LSID on the basis of the ROUTE session element included in the SMT. The ROUTE session element may include ROUTE session bootstrap information. The ROUTE session bootstrap information may include LSID transport path information. 
     In addition, the broadcast reception apparatus may acquire ESG bootstrap information from the service level descriptor included in the SMT. When the service category element indicates the ESG service, the SMT may include the service level descriptor including the ESG bootstrap information. 
     The broadcast reception apparatus may acquire the CMT on the basis of the SSC bootstrap information included in the FIC. The broadcast reception apparatus may acquire component matching information on the basis of the CMT. For example, the CMT can include a ContentLinkage attribute, a tsi attribute and/or a DP attribute. 
     The broadcast reception apparatus may acquire ESG data and/or an ESG service on the basis of the SMT, CMT and/or LSID. For example, the broadcast reception apparatus can acquire the ESG data and/or the ESG service on the basis of the LSID, ESG bootstrap information and/or the component matching information of the CMT. For example, the broadcast reception apparatus can acquire a transport session described in the LSID on the basis of the tsi attribute of the CMT and acquire DP information mapped thereto. That is, the broadcast reception apparatus can acquire an actual component on the basis of the tsi attribute and/or the DP attribute of the CMT. For example, the actual component can be a component for the ESG service. 
     Specifically, the broadcast reception apparatus can acquire an SGDD for the ESG data and/or the ESG service on the basis of the LSID, ESG bootstrap information and/or the component matching information of the CMT. Then, the broadcast reception apparatus can acquire an SGDU for the ESG service on the basis of the SSDD. 
     Since the ESG data can be defined as a file, the broadcast reception apparatus can map the ESG data to contentLinkage defined in the FDT of FLUTE on the basis of the contentLinkage attribute included in the CMT. That is, the broadcast reception apparatus can acquire the ESG data for the ESG service on the basis of the contentLinkage attribute. In this case, the ESG service can be provided as a file including the ESG data. 
     To acquire ESG Announcement Channel information and transmit (or deliver) ESG data, the broadcast transmission apparatus according to the fourth embodiment of the present invention can add transport data pipeline information (or PLP ID) per transport session in the LSID. That is, each transport session element of the LSID may include a DP attribute. Consequently, the broadcast transmission apparatus can transmit an SGDU. The broadcast reception apparatus can receive the LSID including the data pipeline information (or PLP ID) per transport session and acquire the SGDU on the basis of the LSID. 
     In addition, the broadcast transmission apparatus according to the fourth embodiment of the present invention can add an ATSC 3.0 Profile to the syntax of the SGDD to add data pipeline information. In this case, the broadcast reception apparatus can receive SGDD and acquire the SGDU on the basis of the data pipeline information of the SGDD. 
       FIG. 135  illustrates signaling of ESG bootstrap information according to a fifth embodiment of the present invention. 
     The fifth embodiment of the present invention provides a method for transmitting the ESG bootstrap information using a guide access table (GAT) in the future broadcast network. An ESG may be defined as a service, the service category may indicate the ESG service in the FIC service loop and the SMT, GAT and/or CMT may be transmitted through an SSC. The SMT mapped to the ESG service may include information on a ROUTE session through which LSID is transmitted. In the fifth embodiment of the present invention, the SSC with respect to the ESG service may include the GAT and the GAT may include ESG bootstrap information. 
     Referring to the figure, an actual stream according to the fifth embodiment of the present invention may include a broadcast stream having a frequency of ‘Frqncy-z’. The broadcast stream according to an embodiment of the present invention may include a first partition A. The first partition A may include a first DP, a second DP, a third DP, a fourth DP and/or the FIC. The first DP may include a first ROUTE session. The first ROUTE session may include a first service (A/V service). The first ROUTE session may include a first transport session (tsi-v), a second transport session (tsi-a), a third transport session (tsi-s) and/or a fourth transport session (tsi-0). The first ROUTE session illustrated in the figure may correspond to the aforementioned first ROUTE session. 
     The second DP, the third DP and the fourth DP may include a second ROUTE session. The second ROUTE session may include a second service. For example, the second service can include an ESG service. The second ROUTE session may include a fifth transport session (tsi-0), a sixth transport session (tsi-ssc), a seventh transport session (tsi-101) and/or an eighth transport session (tsi-102). The second ROUTE session illustrated in the figure may correspond to the aforementioned second ROUTE session. 
     The broadcast transmission apparatus can transmit a broadcast signal including service data and signaling information. For example, the service data can include ESG data and the signaling information can include an FIC, SMT, GAT, CMT and/or LSID. 
     The broadcast transmission apparatus can transmit a broadcast signal including the FIC. 
     The FIC may correspond to the aforementioned FIC. For example, the FIC can include at least one PartitionID element that specifies a partition, a ServiceID element that specifies a service, a Service Category element that indicates the category of the service, an SSC IP/Port element that specifies an IPaddress/port through which an SSC is transmitted, an SSC DP_ID element that specifies a DP through which the SSC is transmitted, a TSI element that specifies a transport session through which the SSC is transmitted and/or a partition level descriptor. 
     The SSC IP/Port element, SSC DP_ID element and/or TSI element may be SSC bootstrap information. The SSC bootstrap information may include information about a transport path of the SSC through which the SMT and/or the CMT are transmitted. For example, the SSC IP/Port element, SSC DP_ID element and/or TSI element can be SSC bootstrapping information transmitted through ATSC3.0 Broadcast at the same frequency. The FIC according to the fifth embodiment of the present invention may be included in an IP/UDP packet and transmitted. 
     The service category element according to the fifth embodiment of the present invention may indicate the ESG service. In addition, when the service category element indicates the ESG service, the GAT can be essentially transmitted. 
     The broadcast transmission apparatus can transmit a broadcast signal including the SMT, CMT, GAT and/or LSID. 
     The SMT may correspond to the aforementioned SMT. For example, the SMT can include a serviceID attribute that specifies a service and at least one ROUTE session element including information about a ROUTE session. The ROUTE session element may include ROUTE session bootstrap information (or LSID bootstrap information and LSID transport path information). 
     The GAT may include information about service guide (SG) data sources associated with the corresponding service. For example, the GAT can include a serviceID attribute that specifies the corresponding service, a num_of provider element that indicates the number of service guide providers and/or at least one provider element (service guide provider element) that includes information about service guide providers. 
     The provider element may include ESG bootstrap information. For example, the provider element can include ESG data and/or information about a provider providing ESG related information. The ESG bootstrap information may include a bootstrap_network_type attribute, a ts_ID attribute, a partitionID attribute, a Route_session element and/or a URL attribute. 
     The bootstrap_network_type attribute indicates ESG bootstrap information transmission type. The bootstrap_network_type attribute may indicate the aforementioned network_type attribute. 
     The ts_ID attribute indicates the transport stream ID of a foreign frequency when the ESG bootstrap information is transmitted through the foreign frequency. The ts_ID attribute may indicate the aforementioned transportStreamID element. 
     The partitionID attribute indicates the partition ID of a foreign frequency when the ESG bootstrap information is transmitted through the foreign frequency. The partitionID attribute may indicate the aforementioned partitionID element. 
     The Route_session element may include information specifying a ROUTE session. For example, the Route_session element can include at least one of an IP(src/dest) attribute, a port attribute, an announcement_tsi element and an announcement_DP element. The IP (src/dest) attribute may include the aforementioned sourceIPAddr element and destIPAddr element. The port attribute may indicate the aforementioned destUDPPort element. A combination of the sourceIPAddr element, destIPAddr element and port element may specify a specific ROUTE session. The announcement_tsi element may indicate the identifier that identifies a transport session and/or an LCT session through which the ESG service and/or ESG bootstrap information are transmitted. The announcement_DP element may indicate the identifier that identifies a PLP and/or a DP through which the ESG service and/or ESG bootstrap information are transmitted. The announcement_DP element may indicate the aforementioned datapipeID element. 
     The URL attribute may specify a URL by which signaling information for the ESG bootstrap information and/or ESG can be accessed. The URL attribute may indicate the aforementioned downloadURL element. 
     The CMT may correspond to the aforementioned CMT. For example, the CMT can include a serviceID attribute that specifies the corresponding service and/or a component element containing information about a component in the service. The component element may include at least one of a contentLinkage attribute mapped to contentLinkage defined in the FDT of FLUTE, a tsi attribute that specifies a transport session through which the corresponding component in the broadcast stream is transmitted, and a DP attribute that specifies a DP through which the corresponding component in the broadcast stream is transmitted. 
     The LSID may correspond to the aforementioned LSID. For example, the LSID can include a seventh transport element TSI-101 including information about the seventh transport session and/or an eighth transport element TSI-102 including information about the eighth transport session. Each of the seventh transport session element TSI-101 and the eighth transport session element TSI-102 may include a SourceFlow element that provides information about a source flow included in the corresponding transport session and/or a RepairFlow element that provides information about a repair flow included in the transport session. The SourceFlow element may include a realtime attribute that indicates whether the SourceFlow element carries streaming media data. For example, when the realtime attribute is “true”, the realtime attribute indicates real-time transmission of the SourceFlow element. When the realtime attribute is “false”, the realtime attribute indicates non-real time transmission of the SourceFlow element. 
     The broadcast reception apparatus may receive a broadcast signal including service data and signaling data. For example, the service data can include ESG data and the signaling information can include the FIC, SMT, GAT, CMT and/or LSID. 
     The broadcast reception apparatus may acquire the FIC. The FIC may be transmitted through an IP/UDP packet. For example, the service category element can indicate an ESG service. The FIC can include SSC bootstrap information in the service loop. When the service category element indicates the ESG service, the GAT may be essentially transmitted. 
     The broadcast reception apparatus may acquire SSC bootstrap information on the basis of the FIC. The SSC may include the SMT, CMT and/or GAT. 
     The broadcast reception apparatus may acquire the SMT on the basis of the SSC bootstrap information included in the FIC. The broadcast reception apparatus may acquire ROUTE bootstrap information (or LSID bootstrap information and LSID transport path information) on the basis of the ROUTE session element included in the SMT. In addition, the broadcast reception apparatus may acquire the LSID on the basis of the SMT. Specifically, the broadcast reception apparatus may acquire the LSID on the basis of the ROUTE bootstrap information of the SMT. 
     The broadcast reception apparatus may acquire the GAT on the basis of the SSC bootstrap information included in the FIC. In addition, the broadcast reception apparatus may acquire the ESG bootstrap information from the GAT. 
     The broadcast reception apparatus may acquire the CMT on the basis of the SSC bootstrap information included in the FIC. The broadcast reception apparatus may acquire component matching information on the basis of the CMT. For example, the CMT can include a ContentLinkage attribute, a tsi attribute and/or a DP attribute. 
     The broadcast reception apparatus may acquire ESG data and/or an ESG service on the basis of the SMT, GAT, CMT and/or LSID. For example, the broadcast reception apparatus can acquire the ESG data and/or the ESG service on the basis of the LSID, ESG bootstrap information and/or the component matching information of the CMT. For example, the broadcast reception apparatus can acquire a transport session described in the LSID on the basis of the tsi attribute of the CMT and acquire DP information mapped thereto. That is, the broadcast reception apparatus can acquire an actual component on the basis of the tsi attribute and/or the DP attribute of the CMT. For example, the actual component can be a component for the ESG service. 
     Specifically, the broadcast reception apparatus can acquire an SGDD for the ESG data and/or the ESG service on the basis of the LSID, ESG bootstrap information and/or the component matching information of the CMT. Then, the broadcast reception apparatus can acquire an SGDU for the ESG service on the basis of the SSDD. 
     Since the ESG data can be defined as a file, the broadcast reception apparatus can map the ESG data to contentLinkage defined in the FDT of FLUTE on the basis of the contentLinkage attribute included in the CMT. That is, the broadcast reception apparatus can acquire the ESG data for the ESG service on the basis of the contentLinkage attribute. In this case, the ESG service can be provided as a file including the ESG data. 
     To acquire ESG Announcement Channel information and transmit (or deliver) ESG data, the broadcast transmission apparatus according to the fifth embodiment of the present invention can add transport data pipeline information (or PLP ID) per transport session in the LSID. That is, each transport session element of the LSID may include a DP attribute. Consequently, the broadcast transmission apparatus can transmit an SGDU. The broadcast reception apparatus can receive the LSID including the data pipeline information (or PLP ID) per transport session and acquire the SGDU on the basis of the LSID. 
     In addition, the broadcast transmission apparatus according to the fifth embodiment of the present invention can add ATSC 3.0 Profile to the syntax of the SGDD to add data pipeline information. In this case, the broadcast reception apparatus can receive SGDD and acquire the SGDU on the basis of the data pipeline information of the SGDD. 
       FIG. 136  illustrates the GAT according to the fifth embodiment of the present invention. 
     A signaling information format available in the future broadcast network according to the present invention is described. Signaling information may include a signaling message header and a signaling message. The signaling message may be represented in binary or XML format. The signaling message may be included as a payload such as an IP datagram or application layer transport packet (e.g. ROUTE or MMT) and transmitted. For example, the signaling message can include the GAT. 
     The signaling message header may include a signaling_id element and a service_id element. The signaling_id element indicates the identifier of a signaling message. For example, the signaling_id element can indicate a GAT signaling message. The service_id element indicates the identifier of a service. For example, the service_id element can indicate an ESG service. The SMT may include an identifier mapped to the service_id element. 
     The GAT may include at least one service level descriptor. For example, the GAT can include ESG bootstrapping description. 
     The ESG bootstrapping description may include information for bootstrapping of an ESG. The ESG bootstrapping information may include ESG bootstrap information and/or bootstrapping information for the ESG. The broadcast reception apparatus may receive, acquire and/or process the ESG on the basis of the ESG bootstrapping description and/or the ESG bootstrap information. 
     The ESG bootstrapping description may include at least one service guide (SG) provider element. 
     An SG provider indicates a provider that provides information related to an ESG. The SG provider element may include a name attribute and/or at least one bootstrap element. 
     The name attribute indicates the name of the SG provider. 
     The bootstrap element may include at least one piece of bootstrapping information. The bootstrap element may include a network_type attribute, a sourceIPAddr element, a destIPAddr element, a destUDPPort element, a transportStreamID element, a partitionID element, a datapipeID element, a tsi element and/or a downloadURL element. For example, the bootstrap element can be ESG bootstrap information. 
     The network_type element may indicate an ESG data transmission type. 
     The sourceIPAddr element may indicate the source ID addresses of ESG data and/or SG data. For example, the sourceIPAddr element can include the IP source addresses of packets carrying service layer signaling information for a service and/or ESG. 
     The destIPAddr element may indicate the destination IP address of the ESG data and/or SG data. For example, the destIPAddr element can include the destination IP addresses of packets carrying service layer signaling information for a service and/or ESG. 
     The destUDPPort element may indicate the destination port number of the ESG data and/or SG data. For example, the destUDPPort element can include the port number of packets carrying service layer signaling information for a service and/or ESG. 
     The transportStreamID element may indicate the transport stream identifier corresponding to a foreign frequency when the ESG data is transmitted through the foreign frequency. This value can be selectively included in the bootstrap element according to the value of the network_type attribute. 
     The partitionID element may indicate the partition identifier corresponding to a foreign frequency when the ESG data is transmitted through the foreign frequency. For example, the partition identifier identifies a broadcaster. This value can be selectively included in the bootstrap element according to the value of the network_type attribute. 
     The datapipeID element may indicate the identifier identifying a PLP and/or a DP through which the ESG data is transmitted. This value can be selectively included in the bootstrap element according to the value of the network_type attribute. For example, when the ESG data is transmitted through a broadcast network, the datapipeID element can have a single value. 
     The tsi element may indicate the identifier identifying the transport session and/or an LCT session through which the ESG data is transmitted. This value can be selectively included in the bootstrap element according to the value of the network_type attribute. For example, when the ESG data is transmitted through a broadcast network, the tsi element can include at least one value. 
     The downloadURL element may indicate the URL by which the ESG data transmitted through a broadband network can be accessed. This value can be selectively included in the bootstrap element according to the value of the network_type attribute. For example, when the ESG data is transmitted through a broadband network, the downloadURL element can have a single value. 
     The broadcast transmission apparatus can transmit a broadcast signal including service data and signaling information. The signaling information can include the GAT and the GAT can include ESG bootstrap information in the service level descriptor. The broadcast reception apparatus can acquire and/or process an ESG service on the basis of the ESG bootstrap information included in the signaling information. 
       FIG. 137  illustrates effects of the first to fifth embodiments of the present invention. 
     Effects of the first embodiment of the present invention will now be described. 
     As to FIC purpose (fast channel scan), information irrelevant to fast scan is repeatedly transmitted in the first embodiment of the present invention. For example, the FIC can include ESG bootstrap information in the partition level descriptor. Accordingly, the ESG bootstrap information can be repeatedly delivered in the first embodiment of the present invention. 
     With reference to FIC size, since the ESG is not defined as a service in the first embodiment of the present invention, the FIC size is reduced by a size excluded from the service loop. For example, the FIC size can be decreased by a size corresponding to SSC bootstrap information excluded from the service loop. In addition, the FIC size may be increased by the ESG bootstrap information. 
     As to FIC semantics, since the ESG is not defined as a service in the first embodiment of the present invention, FIC semantics are clearly defined. For example, the service loop does not include the ESG bootstrap information and the partition level descriptor includes the ESG bootstrap information. 
     With regard to ESG bootstrap information acquisition time, the FIC is continuously changed when the ESG bootstrap information is varied in the first embodiment of the present invention. Accordingly, the ESG bootstrap information included in the FIC can be rapidly acquired in the first embodiment of the present invention. 
     As to clear semantics definition, the ESG is not defined as a service in the first embodiment of the present invention and thus FIC semantics are clearly defined. 
     With regard to LSID extension, definition of mapping between TSIs and DPs in the LSID is necessary for mapping of DP information in the first embodiment of the present invention. 
     In the first embodiment of the present invention, the FIC maintains consistency and the SSC may not be present. 
     Effects of the second embodiment of the present invention will now be described. 
     As to FIC purpose (fast channel scan), information irrelevant to fast scan is repeatedly transmitted in the second embodiment of the present invention. For example, the SSC bootstrap information of the service loop of the FIC can be replaced by the ESG bootstrap information. The SSC bootstrap information may correspond to the ESG bootstrap information. Accordingly, the ESG bootstrap information can be repeatedly delivered in the second embodiment of the present invention. 
     With reference to FIC size, the FIC size is not increased when the FIC includes the source IP address, destination IP address, destination port number, TSI information and/or DP information for ESG bootstrap information in the second embodiment of the present invention. However, when the FIC includes broadcast information and broadband information regarding a foreign frequency for the ESG bootstrap information, the FIC size may be increased. 
     As to FIC semantics, purpose of the SSC depends on service category in the second embodiment of the present invention. For example, when the service category indicates an ESG service, the SSC bootstrap information can be replaced by the ESG bootstrap information. Otherwise, the SSC bootstrap information can correspond to the ESG bootstrap information. When the service category does not indicate the ESG service, the SSC bootstrap information can be used for the original purpose thereof. 
     With regard to ESG bootstrap information acquisition time, the FIC is continuously changed when the ESG bootstrap information is varied in the second embodiment of the present invention. Accordingly, the ESG bootstrap information included in the FIC can be rapidly acquired in the second embodiment of the present invention. 
     As to clear semantics definition, definition of the SSC bootstrap information according to the service category can be changed in the second embodiment of the present invention. In addition, signaling information may not include the SMT and/or the CMT in the second embodiment of the present invention. 
     As to LSID extension, definition of mapping between TSIs and DPs in the LSID is necessary for mapping of DP information in the second embodiment of the present invention. 
     As to consistency, signaling information may not include the SMT and/or the CMT even though a service belongs to service category in the second embodiment of the present invention. 
     Effects of the third embodiment of the present invention will now be described. 
     As to the FIC size, an FIC size for an ESG service may correspond to an FIC size for an A/V service in the third embodiment of the present invention. 
     As to FIC semantics definition, the FIC can include the SSC bootstrap information that indicates information regarding SSC delivery in the third embodiment of the present invention. 
     With reference to ESG bootstrap information acquisition time, since the ESG bootstrap information is not included in the FIC in the third embodiment, it takes a longer time to acquire the ESG bootstrap information, compared to the first and second embodiments. 
     As to a service signaling bandwidth, efficiency in terms of signaling bandwidth may be deteriorated when the ESG bootstrap information is included in the descriptor, considering that the SMT needs to be frequently transmitted in the third embodiment of the present invention. 
     As to clear semantics definition, definition of LSID transmission information of the SMT needs to be discriminated from definition of providers in the third embodiment of the present invention. 
     With reference to LSID extension, while LSID extension is not essential to the third embodiment of the present invention, the CMT may need to be extended. The CMT can include DP configuration information according to TSI and/or DP configuration information according to ContentLinkage. 
     Effects of the fourth embodiment of the present invention will now be described. 
     As to the FIC size, an FIC size for an ESG service may correspond to an FIC size for an A/V service in the fourth embodiment of the present invention. 
     As to FIC semantics definition, the FIC can include the SSC bootstrap information that indicates information regarding SSC delivery in the fourth embodiment of the present invention. 
     With reference to ESG bootstrap information acquisition time, since the ESG bootstrap information is not included in the FIC in the fourth embodiment, it takes a longer time to acquire the ESG bootstrap information, compared to the first and second embodiments. However, the ESG bootstrap information acquisition time according to the fourth embodiment of the present invention may correspond to the ESG bootstrap information acquisition time according to the third embodiment of the present invention. 
     As to a service signaling bandwidth, efficiency in terms of signaling bandwidth may be deteriorated when the ESG bootstrap information is included in the descriptor, considering that the SMT needs to be frequently transmitted in the fourth embodiment of the present invention. 
     As to clear semantics definition, the FIC includes the SSC bootstrap information and the SMT includes the ESG bootstrap information in the fourth embodiment of the present invention, and thus clear semantics can be defined. 
     With reference to LSID extension, while LSID extension is not essential in the fourth embodiment of the present invention, the CMT may need to be extended. The CMT can include DP configuration information according to TSI and/or DP configuration information according to ContentLinkage. 
     As to consistency, ESG bootstrap information delivery to the service level descriptor of the SMT may not be consistent in the fourth embodiment of the present invention. 
     Effects of the fifth embodiment of the present invention will now be described. 
     As to the FIC size, an FIC size for an ESG service may correspond to an FIC size for an A/V service in the fifth embodiment of the present invention. 
     As to FIC semantics definition, the FIC can include the SSC bootstrap information that indicates information regarding SSC delivery in the fifth embodiment of the present invention. 
     With reference to ESG bootstrap information acquisition time, the ESG bootstrap information acquisition time according to the fifth embodiment of the present invention may be longer than the ESG bootstrap information acquisition time according to the fourth embodiment of the present invention. 
     As to a service signaling bandwidth, the bandwidth can be saved if the GAT is not transmitted more frequently than the SMT in the fifth embodiment of the present invention. 
     As to clear semantics definition, the FIC includes the SSC bootstrap information, the SMT includes the ROUTE bootstrap information (LSID transport path information) and the GAT includes the ESG bootstrap information in the fifth embodiment of the present invention, and thus clear semantics can be defined. 
     With reference to LSID extension, while LSID extension is not essential to the fifth embodiment of the present invention, the CMT may need to be extended. The CMT can include DP configuration information according to TSI and/or DP configuration information according to ContentLinkage. 
       FIG. 138  is a flowchart illustrating operation of a broadcast reception apparatus according to an embodiment of the present invention. 
     The broadcast reception apparatus according to an embodiment of the present invention may include a broadcast interface, a broadband interface and/or a controller. The broadcast interface, the broadband interface and/or the controller according to an embodiment of the present invention may include the above description. 
     For example, the broadcast interface can receive a broadcast signal through a broadcast network. The broadcast interface can include a physical layer module and a physical layer IP frame module. Otherwise, the broadcast interface can include at least one of a tuner and a physical frame parser. 
     For example, the broadband interface can transmit and/or receive data over the Internet. The broadband interface can include an Internet access control module. 
     For example, the controller can include the aforementioned signaling decoder, database, service signaling manager, alert signaling manager, service guide manager, application signaling manager, targeting signaling manager, streaming media engine, non-real time file processor, component synchronizer, targeting processor, application processor, alert processor, A/V processor, redistribution module, service/content acquisition controller and/or companion screen interface. The companion screen interface can include a data sharing unit and/or a device manager. Components included in the controller according to an embodiment of the present invention may include the aforementioned corresponding components. 
     In addition, the controller can include at least one of the aforementioned physical layer controller, link layer frame parser (or link layer frame processor), IP/UDP datagram filter, application layer transport client, timing controller, system clock, DTV control engine, user input receiver, signaling parser, channel map database, HTTP access client, HTTP access cache, DASH client, ISO BMFF parser, media decoder and file database. Components included in the controller according to an embodiment of the present invention may include the aforementioned corresponding components. 
     The broadcast reception apparatus may receive a broadcast signal including service data and signaling information using the broadcast interface (CS1330100). 
     The signaling information may include first signaling information for service acquisition. For example, the first signaling information can include an SMT, a GAT, a CMT and/or an LSID. 
     In addition, the signaling information may include second signaling information providing bootstrap discovery. That is, the signaling information can include the second signaling information containing bootstrap information for services. For example, the second signaling information can include an FIC. 
     The service data may include ESG data. 
     The signaling information may include ESG bootstrap information for electronic service guide (ESG) data. 
     The broadcast reception apparatus may acquire the service data on the basis of the signaling information using the controller (CS1330200). 
     Subsequently, the broadcast reception apparatus may decode the service data using the controller (CS1330300). 
     For example, the ESG bootstrap information can include type information (or network_type attribute) that indicates a transmission type of ESG data. 
     For example, the ESG bootstrap information can include at least one of a source IP address element (or sourceIPAddr element) that indicates the source IP address of the ESG data, a destination IP address element (or destIPAddr element) that indicates the destination IP address of the ESG data and a destination port number element (or destUDPPort element) that indicates the destination port number of the ESG data. 
     For example, the ESG bootstrap information can include a transportStreamID element that specifies a frequency at which the ESG data is transmitted, a partitionID element that specifies a partition corresponding to the frequency, a PLP ID element (or datapipeID element) that specifies a physical layer pipe (PLP) through which the ESG data is transmitted, a TSI element (or tsi element) that indicates a transport session through which the ESG data is transmitted and/or a URL element (or downloadURL attribute) that indicates the location of the ESG data transmitted through broadband. 
     The second signaling information can include ESG bootstrap information. In addition, the second signaling information can include category information (or service category element) that indicates service category. The category information can indicate an ESG service. 
     The first signaling information can include a transport session element containing information about a transport session, and the transport session element can include a PLP ID element (or DP attribute) that indicates a PLP for the transport session. 
     While the broadcast reception apparatus has been described, a broadcast transmission apparatus capable of executing reverse functions of those of the broadcast reception apparatus can be provided according to an embodiment of the present invention. For example, the broadcast transmission apparatus can include a controller and/or a transmitter. The controller can generate the aforementioned service data and/or the signaling information. The transmitter can transmit a broadcast signal including the service data and/or the signaling information. 
       FIG. 139  illustrates a channel map configuration method according to an embodiment of the present invention. 
     A method for configuring a channel map depending on device capability can be provided according to an embodiment of the present invention. To identify device capability necessary per service, an FIC according to an embodiment of the present invention may include a device_capa_code attribute in the FIC loop. The device_capa_code attribute can specify device capability. The broadcast reception apparatus can receive the FIC and configure (generate) a channel map corresponding to device capability on the basis of the device_capa_code attribute of the FIC. 
     A description will be given of a structure of a broadcast signal according to an embodiment of the present invention with reference to the figure. 
     A broadcast signal having a specific frequency may include signaling information. For example, the signaling information can include an FIC and/or an SLS. The FIC may be referred to as an SLT. The FIC may be included in an IP/UDP packet and transmitted. 
     A broadcast signal having a specific frequency may include a high definition (HD) video service and an ultra-high definition (UHD) video service containing the same content. Each service may be transmitted through at least one real-time object delivery over unidirectional transport (ROUTE) session. To this end, the broadcast signal may include at least one ROUTE session. Each ROUTE session may include service layer signaling information and at least one component. In addition, each ROUTE session can be specified by a combination of a source IP address, a destination IP address and a destination port number. Furthermore, each ROUTE session may be transmitted through at least one DP and a PLP. Each ROUTE session may include at least one transport session (or LCT session). Each transport session can be specified by a TSI. In addition, each transport session may include signaling information and/or a content component. For example, the signaling information included in the signaling information can include service layer signaling information (SLS). The content component may include a video component and/or an audio component. 
     The broadcast signal may include a first ROUTE session and a second ROUTE session. The first ROUTE session may include the HD service and the second ROUTE session may include additional information for the UHD service. The HD service may be transmitted through the first ROUTE session and the UHD service may be transmitted through the first and second ROUTE sessions. 
     Service layer signaling information may be present per service. For example, service layer signaling information for the HD service can be present in the first ROUTE session for the HD service. In addition, service layer signaling information for the UHD service can be present in the second ROUTE session for the UHD service. The service layer signaling information for the HD service, present in the first ROUTE session, may be used as service layer signaling information for the UHD service. Here, the service layer signaling information may include at least one of an LSID and an SSC (an SMT, an MDP and/or a CMT). 
     The first ROUTE session can be specified by a combination of a source IP address sip-hd, a destination IP address ip-hd and a destination port number udp-hd. In addition, the first ROUTE session can be transmitted through a first DP dp-1 and a second DP dp-2. Furthermore, the first ROUTE session can include a first transport session tsi-0, a second transport session tsi-a and a third transport session tsi-v-b. The first transport session tsi-0 can include an LSID and a signaling table. For example, the signaling table can indicate an SSC. The SSC may include an SMT, an MPD and/or a CMT. The second transport session tsi-a may include an audio component. For example, the audio component can include at least one audio segment. The third transport session tsi-v-b may include a base video component. For example, the base video component can include at least one base video segment. For example, the base video component is a video component for providing the HD service. 
     The second ROUTE session can be specified by a combination of a source IP address sip-uhd, a destination IP address ip-uhd and a destination port number udp-uhd. In addition, the second ROUTE session can be transmitted through a third DP dp-3 and a fourth DP dp-4. Furthermore, the second ROUTE session can include a fourth transport session tsi-0 and a fifth transport session tsi-v-e. The fourth transport session tsi-0 can include an LSID and a signaling table. For example, the signaling table can indicate an SSC. The SSC may include an SMT, an MPD and/or a CMT. The fifth transport session tsi-v-e may include an enhancement video component. For example, the enhancement video component can include at least one enhancement video segment. For example, the enhancement video component is a video component and/or additional information for providing the UHD service. 
     A description will be given of the FIC. 
     The FIC may be referred to as a service list table (SLT). The SLT is a signaling information table that builds a basic service list and provides bootstrap information of service layer signaling (SLS). 
     The FIC may include a service_id attribute, a device_capa_code attribute, an SSC_src_IP_address attribute, an SSC_dst_IP_address attribute, an SSC_dst_UDP_Port attribute, an SSC tsi attribute and/or an SSC DP id attribute. 
     The service_id attribute is an identifier for identifying a service. 
     The device_capa_code attribute specifies device capability and/or capability group necessary for decoding and/or meaningful reproduction of content for the service. The device_capa_code attribute may be included in the FIC or SLS. Capability category may include a download protocol, an FEC algorithm, a wrapper/archive format, a compression algorithm, a media type and/or an Internet link. 
     For example, the device_capa_code attribute can indicate FLUTE protocol and/or HTTP with respect to the download Protocol. As to the FEC algorithm, the device_capa_code attribute can indicate a compact no-code FEC scheme and/or a Raptor algorithm. As to the wrapper/archive format, the device_capa_code attribute can indicate a DECE CFF container general format, a ZIP format, a DECE CFF container format, a DECE CFF container format, a DECE CFF container format, an ISO Base Media File Format for AAC audio, an ATSC compliant MPEG-2 transport stream, an MP4 constrained container format and/or a W3C Web Apps Package. As to the compression algorithm, the device_capa_code attribute can indicate a DEFLATE algorithm, As to the media type, the device_capa_code attribute can indicate AVC standard definition video, AVC high definition video, AC-3 audio, E-AC-3 audio, MP3 audio, Browser Profile A (A/105), Atom per RFC 4287, AVC mobile video, HE AAC v2 mobile audio, HE AAC v2 level 4 audio, DTS-HD audio, CFF-TT, CEA-708 captions, HE AAC v2 with MPEG Surround, HE AAC v2 Level 6 audio, Frame-compatible 3D video (Side-by-Side), Frame-compatible 3D video (Top-and-Bottom), ATSC 3.0 HEVC Video 1 (e.g. HD video), ATSC 3.0 HEVC Video 2 (e.g. UHD video), ATSC 3.0 SHVC Video 1, ATSC 3.0 HDR Video 1, ATSC 3.0 Wide Color Gamut Video 1, ATSC 3.0 Coded Audio 1 (e.g. 5.1. channel surround audio), ATSC 3.0 Coded Audio 2 (e.g. Immersive/3D Audio) and/or Dialog level adjustment. As to the Internet link, the device_capa_code attribute can indicate a downward rate 56,000 bps or better, a downward rate 512,000 bps or better, a downward rate 2,000,000 bps or better and/or a downward rate 10,000,000 bps or better. 
     The SSC_src_IP_address attribute can indicate a source address of packets carrying SLS for the corresponding service. 
     The SSC_dst IP_address attribute can indicate a destination address of the packets carrying the SLS for the corresponding service. 
     The SSC_dst_UDP_Port attribute can indicate a port number corresponding to the packets carrying the SLS for the corresponding service. 
     The SSC_tsi attribute is an identifier for identifying a transport session through which the SLS for the corresponding service is transmitted. However, the SSC_tsi attribute may have a fixed value of “0”. When the SSC_tsi attribute is “0”, the FIC may not include the SSC_tsi attribute. 
     The SSC_DP_id attribute specifies the identifier of a data pipe (or a physical layer pipe) through which the SLS for the corresponding service is transmitted. 
     The FIC may include a first service element for the HD service and a second service element for the UHD service. 
     The first service element may include a service_id attribute having a value of “sid-hd”, a device_capa_code attribute having a value of “0x01”, an SSC_src_IP_address attribute having a value of “sip-hd”, an SSC_dst_IP_address attribute having a value of “ip-hd”, an SSC_dst_UDP_Port attribute having a value of “udp-hd”, an SSC_tsi attribute having a value of “tsi-0” and/or an SSC_DP_id attribute having a value of “dp-1”. Here, the service_id attribute having a value of “sid-hd” can indicate the HD service. The device_capa_code attribute having a value of “0x01” can indicate that capability information corresponds to the HD service. A combination of the SSC_src_IP_address attribute having a value of “sip-hd”, the SSC_dst IP_address attribute having a value of “ip-hd” and the SSC_dst UDP_Port attribute having a value of “udp-hd” can indicate the first ROUTE session. The SSC_tsi attribute having a value of “tsi-0” and the SSC_DP_id attribute having a value of “dp-1” can indicate a path through which the SLS (e.g. LSID and SSC) for the HD service is transmitted. 
     The second service element may include a service_id attribute having a value of “sid-uhd”, a device_capa_code attribute having a value of “0x02”, an SSC_src_IP_address attribute having a value of “sip-uhd”, an SSC_dst IP_address attribute having a value of “ip-uhd”, an SSC_dst_UDP_Port attribute having a value of “udp-uhd”, an SSC_tsi attribute having a value of “tsi-0” and/or an SSC DP_id attribute having a value of “dp-3”. Here, the service_id attribute having a value of “sid-uhd” can indicate the UHD service. The device_capa_code attribute having a value of “0x02” can indicate that capability information corresponds to the UHD service. A combination of the SSC_src_IP_address attribute having a value of “sip-uhd”, the SSC_dst IP_address attribute having a value of “ip-uhd” and the SSC_dst_UDP_Port attribute having a value of “udp-uhd” can indicate the second ROUTE session. The SSC_tsi attribute having a value of “tsi-0” and the SSC_DP_id attribute having a value of “dp-3” can indicate a path through which the SLS (e.g. LSID and SSC) for the UHD service is transmitted. 
     A description will be given of the SMT. 
     The SMT may include attributes (ID, name, category, etc.) of a service and information about a path through which the service can be acquired. For example, the information about the path through which the service can be acquired may include bootstrap information of a ROUTE session for the service and/or SLS transmission path information. 
     The SMT may include first service map information for the HD service and second service map information for the UHD service. 
     Each of the first service map information and the second service map information may include at least one ROUTE session element containing a service_id attribute for identifying the corresponding service, bootstrap information and SLS transmission path information of the ROUTE session for the service. The ROUTE session element may include an srcIPaddr attribute, a destIPaddr attribute, a destUDPPort attribute and/or an LSID DP attribute. A combination of the srcIPaddr attribute, the destIPaddr attribute and/or the destUDPPort attribute may be referred to as ROUTE session bootstrap information. The LSID_DP attribute may be referred to as SLS transmission path information. 
     The srcIPaddr attribute indicates a source address of packets carrying SLS for the corresponding service. 
     The destIPaddr attribute indicates a destination address of the packets carrying the SLS for the corresponding service. 
     The destUDPPort attribute indicates a port number corresponding to the packets carrying the SLS for the service. 
     The LSID_DP attribute indicates the identifier of a data pipe (or a physical layer pipe) through which the SLS for the service is transmitted. 
     The first service map information may include at least one of a service_id element that specifies the HD service and a first ROUTE session element containing bootstrap information and SLS transmission path information of the first ROUTE session for the HD service. For example, the service_id element for the HD service can have a value of “sid-hd”. The srcIPaddr attribute, the destIPaddr attribute and the destUDPPort attribute of the first ROUTE session for the HD service can respectively have values of “sip-hd”, “ip-hd” and “udp-hd”. The LSID_DP attribute of the first ROUTE session for the HD service can have a value of “dp-1”. 
     The second service map information may include at least one of a service_id element that specifies the UHD service, a first ROUTE session element containing bootstrap information of the first ROUTE session for the UHD service and SLS transmission path information, and a second ROUTE session element containing bootstrap information and SLS transmission path information of the second ROUTE session for the UHD service. For example, the service_id element for the UHD service can have a value of “sid-uhd”. The srcIPaddr attribute, the destIPaddr attribute and the destUDPPort attribute of the first ROUTE session for the UHD service can respectively have values of “sip-hd”, “ip-hd” and “udp-hd”. The LSID_DP attribute of the first ROUTE session for the UHD service can have a value of “dp-1”. In addition, the srcIPaddr attribute, the destIPaddr attribute and the destUDPPort attribute of the second ROUTE session for the UHD service can respectively have values of “sip-uhd”, “ip-uhd” and “udp-uhd”. The LSID DP attribute of the second ROUTE session for the UHD service can have a value of “dp-3”. 
     A description will be given of the MDP. 
     The MDP may include resource identifiers for individual media components of linear/streaming services. In addition, the MDP may include the context of identified resources. For example, the resource identifiers are information for identifying representation associated with components for services. 
     The MPD may include at least one period element containing information about consecutive time periods that constitute media presentation. Each period element may include at least one of a perId attribute for identifying a period and at least one representation element containing information about a component. Each representation element may include a reptnId attribute for identifying representation associated with a component for a service. In addition, each representation element may include a dependencyId attribute that indicates at least one complementary representation on which the corresponding representation depends in decoding and/or presentation processes. 
     For example, the representation element can include a first representation element containing information about an audio component, a second representation element containing information about a base video component for the HD service and/or a third representation element containing information about an enhancement video component for the UHD service. The third representation element depends on the second representation for the UHD service. The reptnID attribute in the first representation element may have a value of “com-a”, the reptnID attribute in the second representation element may have a value of “com-v-b”, and the reptnID attribute in the third representation element may have a value of “com-v-e”. In addition, the third representation element may include a dependencyId attribute, and the dependencyId attribute may indicate “com-v-b”. 
     A description will be given of the CMT. 
     The CMT may include information about a transport path of component data for a service. For example, the transport path information may be information for identifying a DP (or PLP) through which the component data for the service is transmitted. 
     The CMT may include first component map information for the HD service and second component map information for the UHD service. 
     Each of the first component map information and the second component map information can include a service_id attribute for specifying a service, a perID attribute for specifying a period and/or at least one Comp element containing information about a transport path of a component. For example, the Comp element can include a reptnId attribute that identifies representation associated with a component for the corresponding service and/or a datapipeID attribute that indicates a DP through which the component for the service is transmitted. The datapipeID attribute may be referred to as transport path information of the component. 
     The first component map information can include the service_id attribute for specifying a service, a perID attribute for specifying a period, a first Comp element containing information about a transport path of an audio component for the HD service and/or a second Comp element containing information about a transport path of a base video component for the HD service. For example, the service_id attribute can have a value of “sid-hd” and the perID attribute can have a value of “per-1”. In addition, the reptnId attribute and the datapipeID attribute included in the first Comp element for the HD service can respectively have values of “com-a” and “dp-2”. The reptnId attribute and the datapipeID attribute included in the second Comp element for the HD service can respectively have values of “com-v-b” and “dp-2”. 
     The second component map information can include the service_id attribute for specifying a service, a perID attribute for specifying a period, a first Comp element containing information about a transport path of an audio component for the UHD service, a second Comp element containing information about a transport path of a base video component for the UHD service and/or a third Comp element containing information about a transport path of an enhancement video component for the UHD service. For example, the service_id attribute can have a value of “sid-uhd” and the perID attribute can have a value of “per-1”. In addition, the reptnId attribute and the datapipeID attribute included in the first Comp element for the UHD service can respectively have values of “com-a” and “dp-2”. The reptnId attribute and the datapipeID attribute included in the second Comp element for the UHD service can respectively have values of “com-v-b” and “dp-2”. The reptnId attribute and the datapipeID attribute included in the third Comp element for the UHD service can respectively have values of “com-v-e” and “dp-4”. 
     A description will be given of the LSID. 
     The LSID may be referred to as a service-based transport session instance description (S-TSID). The S-TSID may include session description information for at least one transport session through which at least one content component of a service is transmitted. For example, the LSID can include information that specifies a transport session through which a component for a service is transmitted. 
     The LSID may include a first LSID for the HD service and a second LSID for the UHD service. 
     The first LSID may be included in the first ROUTE session. The first LSID may include at least one TransportSession element that carries a component. Each TransportSession element may include a SourceFlow element that provides information about a source flow included in a transport session. The SourceFlow element may include an ApplicationIdentifier element containing additional information mapped to a service (or application service) transmitted through the transport session. For example, the ApplicationIdentifier element can include a representation ID of DASH content and/or adaptation set parameters of DASH media representation. The representation ID is associated with a component for the service and may be referred to as a reptnID attribute. The ApplicationIdentifier element may be referred to as a ContentInfo element. 
     The first LSID may include a first TransportSession element carrying an audio component and/or a second TransportSession element carrying a base video component. For example, a tsi attribute can have a value of “tsi-a” and the reptnID attribute can have a value of “com-a” in the first TransportSession element. In addition, the tsi attribute can have a value of “tsi-v-b” and the reptnID attribute can have a value of “com-v-b” in the second TransportSession element. 
     The second LSID may include a third TransportSession element carrying an enhancement video component. For example, the tsi attribute can have a value of “tsi-v-e” and the reptnID attribute can have a value of “com-v-e” in the third TransportSession element. 
     In the figure, each ROUTE session includes a single LSID (transport session information) and two LSIDs are present. However, the present invention is not limited thereto. For example, each service can include a single LSID (transport session information). In this case, a single LSID can include information about at least one transport session through which at least one component included in at least one ROUTE session for a specific service is transmitted. For example, a single LSID can include all of the first TransportSession element, second TransportSession element and third TransportSession element for the UHD service. 
     Referring to the figure, a single frequency according to an embodiment of the present invention may include the HD service and the UHD service including the same content. 
     For example, when the device_capa_code attribute has a value of “0x00”, device capability can indicate a standard definition (SD) service. When the device_capa_code attribute has a value of “0x01”, device capability can indicate the HD service. When the device_capa_code attribute has a value of “0x02”, device capability can indicate the UHD service. 
     A device which cannot reproduce the UHD service, such as a mobile device, can configure a channel map, excluding channels corresponding to the UHD service, on the basis of the device_capa_code attribute. 
     A fixed device such as TV can reproduce both the HD service and the UHD service, and thus the fixed device can configure a channel map including all channels corresponding to the HD service and the UHD service. 
       FIG. 140  illustrates a channel map configuration method according to an embodiment of the present invention. 
     When the same content is provided in various service formats in the future broadcast network, a method for identifying the content can be provided according to an embodiment of the present invention. To identify the content, an FIC according to an embodiment of the present invention may include a service_channel_number attribute in the FIC loop. The service_channel_number attribute can indicate a channel number corresponding to a service. The broadcast reception apparatus may receive the FIC and configure a channel map, excluding channels (or services) carrying the same content, on the basis of the service_channel_number attribute of the FIC. 
     A broadcast signal having a specific frequency may include signaling information. For example, the signaling information can include the FIC and/or SLS. The FIC may be referred to as an SLT. The FIC may be included in an IP/UDP packet and transmitted. The structure of the broadcast signal, the FIC and/or the SLS according to the present embodiment may correspond to or include the corresponding ones described above. 
     The FIC according to an embodiment of the present invention can include the service channel number attribute that indicates a channel number of a service in an element. The service_channel_number attribute may include a majorChannelNo attribute that indicates a major channel number of the service and/or a minorChannelNo attribute that indicates a minor channel number of the service. 
     The FIC may include a first service element for the HD service and a second service element for the UHD service. For example, the HD service and the UHD service can provide the same content. The first service element may include a service_channel_number attribute having a value of “cnum-x”, and the second service element may include a service_channel_number attribute having a value of “cnum-x”. The service_channel_number attribute of the first service element and the service channel number attribute of the second service element can have the same value of “cnum-x”. 
     Referring to the figure, a frequency according to an embodiment of the present invention may include the HD service and UHD service containing the same content. 
     For example, when the same content is transmitted in service formats such as the HD service and/or the UHD service, the service_channel_number attributes of the respective services can have the same value. 
     An apparatus capable of performing UHD reproduction can select only UHD channels to configure a channel map on the basis of the service_channel_number attribute, instead of redundantly configuring HD channel (service) information and/or UHD channel (service) information, which carry the same content. 
       FIG. 141  is a diagram illustrating an FIC according to an embodiment of the present invention. 
     The contents related to an FIC according to an embodiment of the present invention may include all of the contents related to the aforementioned FIC. In addition, although information included in the FIC is expressed as fields in an embodiment of the present invention, the FIC may be in XML format. The information included in the FIC may be indicated as an attribute in a field. 
     The FIC according to an embodiment of the present invention may include at least one of an SCD_exist flag field, an SCD Bbpstream_id field, a bbpstream_id field, and/or an SSC_basicservice_flag field. 
     The SCD_exist_flag field may indicate whether a service configuration description (SCD) is transmitted (or present). The SCD may include a large amount of various additional signaling information which is not included in the FIC. For example, if a value of the SCD_exist_flag field is “True”, the signaling information may include the SCD. 
     The SCD_Bbpstream_id field indicates an ID of a DP (or a PLP) through which the SCD is transmitted. 
     The bbpstream_id field indicates an ID of a DP (or a PLP) through which service signaling channel (SSC) bootstrap information of a corresponding service is transmitted. 
     The SSC_basicservice flag field may indicate whether signaling information of a basic level is transmitted through an SSC. For example, if types of descriptions or types of tables used in service signaling are different, the SSC_basicservice_flag field may indicate whether signaling information of a basic level is transmitted through the SSC. In addition, the SSC_basicservice_flag may indicate whether signaling information of a basic level related to an audio component and/or a video component is transmitted through an additional signaling channel and/or signaling table. 
     The SCD_exist flag field and/or the SCD_Bbpstreamd_id field may be included in physical layer signaling information. In this case, the SCD_exist flag field may indicate whether the SCD is present in the current frame. The SCD_Bbpstream_id field may indicate a DP (or a PLP) and/or a frame through which and/or in which the SCD is transmitted. 
     A broadcast transmission device may generate signaling information using a controller. For example, the signaling information may include at least one of the SCD_exist flag field, the SCD Bbpstream_id field, the bbpstream_id field, and/or the SSC_basicservice_flag field. 
     A broadcast reception device may acquire the FIC and/or the SCD included in the signaling information, using a controller. The broadcast reception device may then receive a service based on the FIC and/or the SCD. 
       FIG. 142  is a diagram illustrating an FIC according to an embodiment of the present invention. 
     The contents related to an FIC according to an embodiment of the present invention may include all of the contents related to the aforementioned FIC. In addition, although information included in the FIC is expressed as fields in an embodiment of the present invention, the FIC may be in XML format. The information included in the FIC may be indicated as an attribute in a field. 
     The FIC according to an embodiment of the present invention may include a Provider id field. 
     The Provider_id field represents a unique ID of a provider that transmits a corresponding service. For example, the Provider_id field may indicate from which provider a corresponding service is transmitted. 
     A broadcast transmission device may generate signaling information using a controller. For example, the signaling information may include the above-described Provider_id field. 
     A broadcast reception device may acquire an FIC and/or SCD included in the signaling information, using a controller. The broadcast reception device may then receive a service based on the FIC and/or the SCD and identify a provider of the service. 
       FIG. 143  is a diagram illustrating an FIC according to an embodiment of the present invention. 
     The contents related to an FIC according to an embodiment of the present invention may include all of the contents related to the aforementioned FIC. In addition, although information included in the FIC is expressed as fields in an embodiment of the present invention, the FIC may be in XML format. The information included in the FIC may be indicated as an attribute in a field. 
     The FIC according to an embodiment of the present invention may include a Provider_Group_id field. 
     The Provider_Group_id field may represent an ID of a group to which a provider that transmits a corresponding service belongs. 
     A broadcast transmission device may generate signaling information using a controller. For example, the signaling information may include the above-described Provider_Group_id field. 
     A broadcast reception device may acquire an FIC and/or SCD included in the signaling information, using a controller. The broadcast reception device may then receive a service based on the FIC and/or the SCD and identify a group of a provider of the service. 
     For example, the broadcast reception device may distinguish between services received from provider groups, based on the Provider_Group_id field. That is, the broadcast reception device may judge by which provider an ESG including a guide for services is provided by mapping a service in which the Provider_Group_id field and a Service_category field correspond to an ESG. 
       FIG. 144  is a diagram illustrating an FIC according to an embodiment of the present invention. 
     The contents related to an FIC according to an embodiment of the present invention may include all of the contents related to the aforementioned FIC. In addition, although information included in the FIC is expressed as fields in an embodiment of the present invention, the FIC may be in XML format. The information included in the FIC may be indicated as an attribute in a field. 
     The FIC according to an embodiment of the present invention may include a Num_providers field and/or at least one provider loop. 
     The Num_providers field may represent the number of providers (or broadcasters) that use a corresponding frequency. 
     Each provider loop may include a Provider_id field, at least one service loop, a Num_provider_level_descriptor field, and/or at least one Provider_level_descriptor field. 
     The Provider_id field indicates a unique ID of a provider that transmits a corresponding service. For example, the Provider_id field is a unique ID allocated to each provider (or each broadcaster). 
     The service loop may include an attribute related to a service. Details of the service loop are as described previously. 
     The Num_provider_level_descriptor field may indicate the number of descriptors capable of being transmitted with respect to each provider. 
     The Provider_level_descriptor field may indicate a descriptor capable of being transmitted with respect to each provider. 
     A broadcast transmission device may generate signaling information using a controller. For example, the signaling information may include the above-described at least one Provider id field. 
     A broadcast reception device may acquire an FIC and/or SCD included in the signaling information, using a controller. The broadcast reception device may then receive a service based on the FIC and/or the SCD and identify a provider of the service. 
       FIG. 145  is a diagram illustrating an FIC according to an embodiment of the present invention. 
     The FIC according to an embodiment of the present invention may include at least one of an FIC_protocol version field, a broadcast_stream_id field, an SCD_exist_flag field, an SCD_DP_ID field, a Num_providers field, a provider_id field, a num_services field, a service_id field, a service_data_version field, a service_channel_number field, a service_category field, a short_service_name length field, a short_service_name field, a service_status field, a service_distribution field, an sp_indicator field, an IP_version_flag field, an SSC_source_IP_address_flag field, an SSC_source_IP_address field, an SSC_destination IP_address field, an SSC_destination_UDP_port field, an SSC_TSI field, an SSC_DP_IID field, an SSC_basicserviceflag field, a num_Provider_level_descriptors field, a Provider_level_descriptor( ) field, a num_FIC_level_descriptors field, and/or an FIC_level_descriptor( ) field. The information included in an FIC according to an embodiment of the present invention may include all of the information included in the aforementioned FIC. 
     The FIC according to an embodiment of the present invention may further include capability information (or a min_capability_code field) indicating capabilities and/or a capability group of a device, needed for decoding and/or meaningful reproduction of content for a service. 
     For example, the min_capability_code field may indicate a minimum capability code supported by a corresponding service. As an example, in a service capable of performing UD/HD scalable coding, the min_capability_code field may have a value indicating HD. 
     A broadcast reception device may receive the FIC and configure (or generate) a differentiated channel map suitable for device capabilities based on the capability information (or the min_capability_code field) of the FIC. In addition, the broadcast reception device may acquire at least one component for a service based on the capability information (or the min_capability_code field) of the FIC. Thereafter, the broadcast reception device may decode the at least one component for the service. 
       FIG. 146  is a diagram illustrating an FIC according to an embodiment of the present invention. 
     A broadcast signal having a specific frequency may include signaling information. For example, the broadcast signal may be identified by “BCStreamID1”. The signaling information may include an FIC and/or SLS. The FIC may be referred to as an SLT. The FIC may be included in an IP/UDP packet before being transmitted. 
     The broadcast signal may include a first ROUTE session. The first ROUTE session may include at least one service. For example, an ID of the service may have a value of “SrvcID1”. The service may include at least one component for an HD service and/or a UHD service. A component for the HD service may be transmitted through a specific transport session of the first ROUTE session. Additional information for the UHD service may be transmitted through another transport session of the first ROUTE session. 
     For a service, SLS information may be present. For example, for the HD service and/or the UHD service, SLS information for the HD service and/or the UHD service may be present in the first ROUTE session. In this case, the SLS information may include at least one of an LSID and an SSC (an SMT, an MDP, and/or a CMT). 
     The first ROUTE session may be identified by a combination of a source IP address (sIPAdrs1), a destination IP address (IPAdrs1), and a destination port number (Port1). In addition, the first ROUTE session may be transmitted through a first DP (DP_ID1), a second DP (DP_ID2), and/or a third DP (DP_ID3). The first ROUTE session may include a first transport session (tsi-0), a second transport session (tsi-s), a third transport session (tsi-a), a fourth transport session (tsi-v), and/or a fifth transport session (tsi-ev). The first transport session (tsi-0) may include an LSID and/or at least one LSID fragment. The second transport session (tsi-s) may include a signaling table and/or at least one SSC fragment. For example, the signaling table may indicate an SSC. The SSC may include at least one of an SMT, an MPD, and/or a CMT. The third transport session (tsi-a) may include an audio component. For example, the audio component may include at least one audio segment. The fourth transport session (tsi-v) may include a base video component. The base video component may include, for example, at least one base video segment. For example, the base video component is a video component for providing an HD service. The fifth transport session (tsi-ev) may include an enhancement video component. The enhancement video component may include, for example, at least one enhancement video segment. For example, the enhancement video component is a video component and/or additional information, for providing a UHD service. 
     Hereinafter, an FIC will be described. 
     The FIC may be referred to as an SLT. The contents related to an FIC according to an embodiment of the present invention may include all of the contents related to the aforementioned FIC. 
     The FIC may include an ID element having a value of “BCStreamID1” and/or a first service element. 
     The first service element may include a serviceId attribute having a value of “SrvcID1”, a min_capability_code attribute having a value of “HD”, and/or an SSC_Bootstrap element. The SSC_Bootstrap element may include at least one of an SSC_src_IP_address attribute having a value of “sIPAdrs1”, an SSC_dst IP_address attribute having a value of “IPAdrs1”, an SSC_dst_UDP_Port attribute having a value of “Port1”, an SSC_tsi attribute having a value of “tsi-s”, and/or an SSC DP id attribute having a value of “DP_id1”. Here, the min_capability_code attribute having a value of “HD” may indicate that a minimum capability code supported by a service is “HD”. That is, if the service can support both “HD” and “UHD”, the min_capability_code attribute may have a value of “HD”. 
       FIG. 147  is a diagram illustrating an SSC according to an embodiment of the present invention. 
     Hereinafter, an SMT will be described. 
     Referring to (a) of the drawing, the SMT may include information about attributes (an ID, a name, a category, etc.) of a service and information about a path through which a service can be acquired. The contents related to an SMT according to an embodiment of the present invention may include all of the contents related to the aforementioned SMT. 
     The SMT may include at least one of a serviceID attribute identifying a service, a ServiceName attribute identifying a name of a service, a Capability attribute indicating capabilities of a device supporting a service, and/or a ROUTEsession element including bootstrap information of a ROUTE session for a service. 
     For example, the Capability attribute may have values of “HD” and ‘UHD”. That is, the Capability attribute may indicate that both HD and UHD are supported. 
     Hereinafter, an MPD will be described. 
     The MPD may include resource IDs for individual media components of a linear/streaming service. The contents related to an MPD according to an embodiment of the present invention may include all of the contents related to the aforementioned MPD. 
     The MPD may include a Period element. The Period element may include a first AdaptationSet element including information about at least one audio component and a second AdaptationSet element including information about at least one video component. The first AdaptationSet element may include a first Representation element including information about an audio component. The second AdaptationSet element may include a second Representation element including information about a base video component and a third Representation element including information about an enhancement video component. 
     A value of a reptnID attribute in the first Representation element may be “Representationid-a”, a value of a reptnID attribute in the second Representation element may be “Representationid-v”, and a value of a reptnID attribute in the third Representation element may be “Representationid-ev”. The third Representation element may include a dependencyId attribute and a value of the dependencyId attribute may indicate “Representationid-v”. 
     Hereinafter, a CMT will be described. 
     The CMT may include transmission path information of component data for a service. The contents related to a CMT according to an embodiment of the present invention may include all of the contents related to the aforementioned CMT. 
     The CMT may include first component map information for a first service. The first component map information may include at least one of a service_id attribute identifying a service, a perID attribute identifying a period, a first Comp element (or a BCComponent element) including transmission path information of an audio component for the first service, a second Comp element (or a BCComponent(HD) element) including transmission path information of a base video component for the first service, and/or a third Comp element (or a BCComponent(UD) element) including transmission path information of an enhancement video component for the first service. 
     For example, a value of a reptnID attribute in the first Comp element for the first service may be “RepresentationID-a” and a value of a datapipeID attribute in the first Comp element may be “DP_ID1”. A value of a reptnID attribute in the second Comp element for the first service may be “RepresentationID-v” and a value of a datapipeID attribute in the second Comp element may be “DP_ID2”. A value of a reptnID attribute in the third Comp element for the first service may be “RepresentationID-ev” and a value of a datapipeID attribute in the third Comp element may be “DP_ID3”. 
     Hereinafter, an LSID will be described. 
     The LSID may be referred to as a service-based transport session instance description (S-TSID). The contents related to an LSID according to an embodiment of the present invention may include all of the contents related to the aforementioned LSID. 
     The LSID may be included in a first ROUTE session. The LSID may include a first TransportSession element transmitting an audio component, a second TransportSession element transmitting a base video component, and/or a third TransportSession element transmitting an enhancement video component. For example, a value of a tsi attribute in the first TransportSession element may be “tsi-a” and a value of a reptnID attribute in the first TransportSession element may be “RepresentationID-a”. A value of a tsi attribute in the second TransportSession element may be “tsi-v” and a value of a reptnID attribute in the second TransportSession element may be “RepresentationID-v”. In addition, a value of a tsi attribute in the third TransportSession element may be “tsi-ev” and a value of a reptnID attribute in the third TransportSession element may be “RepresentationID-ev”. 
       FIG. 148  is a flowchart illustrating a broadcast transmission method according to an embodiment of the present invention. 
     A broadcast transmission device according to an embodiment of the present invention may include a controller and/or a transmitting unit. The controller may generate the above-described service data and/or the above-described signaling information. The transmitting unit may transmit a broadcast signal including the service data and/or the signaling information. 
     The broadcast transmission device may generate and/or encode service data for at least one service which provides the same content, using the controller (CS1480100). 
     For example, the service data may include an audio component, a base video component, and/or an enhancement video component. 
     The broadcast transmission device may generate and/or encode signaling information for the service, using the controller (CS1480200). 
     For example, the signaling information may include first signaling information (or SLS) for acquisition of a service and second signaling information (or FIC) including bootstrap information for a service. The first signaling information (or SLS) may include at least one of an SMT, an MPD, a CMT, and/or an LSID. The second signaling information (or FIC) may further include capability information (e.g., a min_capability_code field and a device_capa_code attribute) indicating capabilities and/or a capability group of a device, needed for decoding and/or meaningful reproduction of content for a service. For example, the min_capability_code field may indicate a minimum capability code supported by a corresponding service. For example, in a service capable of performing UD/HD scalable coding, the min_capability_code field may have a value indicating HD. The FIC may include channel information (or a service_channel_number attribute) indicating a channel number of at least one service that provides the same content. The signaling information may further include a flag information (an SSC_basicservice_flag field) indicating whether the second signaling information (FIC and/or SCD) is present and/or ID information (an SCD_Bbpstream_id field) indicating an ID of a DP (or a PLP) through which the second signaling information (FIC and/or SCD) is transmitted. 
     The broadcast transmission device may generate a broadcast signal including the service data and the signaling information, using the controller. 
     In addition, the broadcast transmission device may transmit the broadcast signal including the service data and the signaling information, using the transmitting unit (CS1480300). 
       FIG. 149  is a flowchart illustrating a broadcast reception method according to an embodiment of the present invention. 
     A broadcast reception device according to an embodiment of the present invention may include a broadcast interface, a broadband interface, and/or a controller. The broadcast interface, the broadband interface, and/or the controller according to an embodiment of the present invention may include all of the above description. 
     For example, the broadcast interface may receive a broadcast signal through a broadcast network. The broadcast interface may include a physical layer module and a physical layer IP frame module. Alternatively, the broadcast interface may include at least one of a tuner and a physical frame parser. 
     For example, the broadband interface may transmit and/or receive data through an Internet network. The broadband interface may include an Internet access control module. 
     For example, the controller may include at least one of the above-described signaling decoder, database, service signaling manager, alert signaling manager, service guide manager, App signaling manager, targeting signaling manager, streaming media engine, non-real time file processor, component synchronizer, targeting processor, App processor, alerting processor, A/V processor, redistribution module, service/content acquisition controller, and/or companion screen interface. The companion screen interface may include at least one of a data sharing unit and/or a device manger. The contents regarding elements included in the controller according to an embodiment of the present invention may include all of the contents regarding the aforementioned elements having the same name or similar names. 
     In addition, the controller may include at least one of the above-described physical layer controller, link layer frame parser (or link layer frame processor), IP/UDP datagram filter, App layer transmission client, timing controller, system clock, DTV control engine, user input receiver, signaling parser, channel map database, HTTP access client, HTTP access cache, DASH client, ISO BMFF parser, media decoder, and file database. The contents regarding elements included in the controller according to an embodiment of the present invention may include all of the contents regarding the aforementioned elements having the same name or similar names. 
     The broadcast reception device may receive a broadcast signal including service data and signaling information, for at least one service that provides the same content, using the broadcast interface and/or the broadband interface (CS1490100). 
     The service data may include an audio component, a base video component, and/or an enhancement video component. The signaling information may include first signaling information (or SLS) for acquisition of a service and second signaling information (or FIC) including bootstrap information for a service. The first signaling information (or SLS) may include at least one of an SMT, an MPD, a CMT, and/or an LSID. The second signaling information (or FIC) may further include capability information (e.g., a min_capability_code field and a device_capa_code attribute) indicating capabilities and/or a capability group of a device, needed for decoding and/or meaningful reproduction of content for a service. For example, the min_capability_code field may indicate a minimum capability code supported by a corresponding service. For example, in a service capable of performing UD/HD scalable coding, the min_capability_code field may have a value indicating HD. The FIC may include channel information (or a service_channel_number attribute) indicating a channel number of at least one service that provides the same content. The signaling information may further include flag information (an SSC_basicservice_flag field) indicating whether the second signaling information (FIC and/or SCD) is present and/or ID information (an SCD Bbpstream_id field) indicating an ID of a DP (or a PLP) through which the second signaling information (FIC and/or SCD) is transmitted. 
     For example, if a user selects a first service (SrvcID  1 ), the broadcast reception device may acquire a minimum capability code field based on the FIC. The broadcast reception device may also acquire a minimum capability code field for at least one service based on the FIC. The first service according to an embodiment of the present invention may be a service capable of supporting both UD and HD and, in this case, a minimum capability code may indicate HD. 
     In addition, the broadcast reception device may acquire the second signaling information (or FIC) from the broadcast signal, using the controller. For example, if flag information indicating whether the second signaling information (FIC and/or SCD) is present denotes “True”, the broadcast reception device may acquire the second signaling information from the broadcast signal based on the flag information. 
     The broadcast reception device may acquire service attributes and/or bootstrap information of the first signaling information (or service layer signaling information; SLS), from the second signaling information (or FIC). For example, the second signaling information (or FIC) may include at least one of a service_id attribute, a device_capa_code attribute, an SSC_src_IP address attribute, an SSC_dst_IP address attribute, an SSC_dst_UDP_Port attribute, an SSC_tsi attribute, and/or an SSC_DP_id attribute. 
     The broadcast reception device may filter the service based on the signaling information, using the controller (CS1490200). 
     For example, the second signaling information (or FIC) may include capability information needed for service decoding and the broadcast reception device may filter the service capable of performing decoding and/or presentation based on the capability information. Plural services may be filtered and acquired first signaling information may be information for acquisition of all filtered services. 
     The broadcast reception device may primarily store service attributes for the filtered service and/or bootstrap information of the SLS in a channel map. 
     The broadcast reception device may acquire the first signaling information (or SLS) for the filtered service based on the second signaling information (or FIC), using the controller (CS1490300). 
     For example, the broadcast reception device may acquire the bootstrap information of the first signaling information (or SLS) for the filtered service from the second signaling information (or FIC) and acquire the first signaling information (SLS) based on the bootstrap information of the first signaling information (or SLS). For example, the first signaling information (or SLS) may include at least one of an SMT, an MPD, a CMT, and/or an LSID. The broadcast reception device may determine which representations are transmitted through a broadcast network, based on the first signaling information (or SLS). 
     The broadcast reception device may secondarily store information included in the acquired first signaling information for the filtered service in the channel map (CS1490400). 
     For example, information included in the first signaling information (or SLS) may include attributes (e.g., an ID, a name, a category, etc.) of a service, path information for acquiring the service, and/or information related to the service. The path information for acquiring the service may include at least one of information (reptnID attribute) identifying representation related to a component for the service, information (datapipeID attribute) identifying a DP (or a PLP) through which component data for the service is transmitted, and/or information (tsi attribute) identifying a transport session through which a component for the service is transmitted. 
     If a plurality of services has been filtered, the broadcast reception device may select one of the plural services based on channel information, using the controller. 
     The broadcast reception device may acquire the service data based on the channel map, using the controller. 
     The broadcast reception device may decode the service data, using the controller. 
     Upon receiving and/or acquiring a base video component of a base layer, the broadcast reception device according to an embodiment of the present invention may decode and then generate an HD related component. 
     To decode and/or generate a UHD related component, the broadcast reception device should decode all of a base video component of a base layer and an enhancement video component of an enhancement layer. 
     If the broadcast reception device can support only up to SD, the broadcast reception device may not reproduce the first service. 
     If the broadcast reception device can support up to HD, the broadcast reception device may receive more detailed information related to the service based on an SSC. The broadcast reception device may acquire all capability information of the service from the SSC. The broadcast reception device may be aware of dependency relationship between representations (i.e., a base/enhanced layer), resolution of representation (a width/height attribute of representation), and the like through information in the MPD (e.g., Representation/@dependencyID). Capability information of the SMT according to an embodiment of the present invention may include information about two capabilities of HD/UD. If the broadcast reception device cannot support UD, the broadcast reception device may receive and/or decode a component corresponding to HD. 
     If the broadcast reception device is capable of supporting UD, the broadcast reception device may receive and/or decode a component corresponding to UD after performing the above-described scenario. 
       FIG. 150  is a diagram illustrating a handover situation to another frequency while a receiver moves, according to an embodiment of the present invention. 
     When a receiver that is receiving a specific service moves, a handover operation to another frequency to seamlessly receive the same service may be needed. Many situations in which the receiver moves may be present and, especially, may correspond to the case in which the receiver is a mobile device. 
     A plurality of transmitters that provides a specific service may be present in areas. When a receiver leaves an area covered by a specific transmitter and moves to an area covered by another transmitter, information or an operation for seamless handover may be additionally needed. In this case, an MFN situation is assumed. In addition, a situation is assumed in which the same service is provided in each area through different frequencies. 
     In an embodiment illustrated in the drawing, the receiver may leave an area covered by a transmitter A and move to an area covered by a transmitter B. In this case, it is assumed that the receiver has watched a service X. The transmitter A may transmit the service X through frequency 10 and the transmitter B may transmit the same service X through frequency 20. To continuously reproduce the service X, the receiver may require information for tuning to a proper frequency. 
       FIG. 151  is a diagram illustrating an information transmission method for seamless handover according to an embodiment of the present invention. 
     For seamless handover, a receiver may require proper information as described above. The information may be transmitted through the above-described link layer signaling (LLS), low level signaling (LLS), a service list table (SLT), a service signaling channel (SSC), or service level signaling (SLS). In this case, the information for seamless handover may be referred to as a cell information description (CID). 
     In an embodiment illustrated in the drawing, the CID is transmitted through link layer signaling. 
     In the embodiment illustrated in the drawing, service data may be transmitted through a broadcast stream. The broadcast stream may be identified by a broadcast stream ID. The broadcast stream may be identified by area and frequency information, as abstraction of an RF channel defined as a center frequency value of a specific bandwidth. The broadcast stream may include a plurality of PLPs. A PLP may be referred to as a DP. In this embodiment, the service data is transmitted through the broadcast stream identified by BSID=1. 
     The above-described transport sessions, i.e., ROUTE/MMTP sessions may be transmitted through a plurality of PLPs (PLP ID=1, 2, 3). A transport session, for example, a ROUTE session may be identified by IP and UDP information (IP address 1 and UDP port number  1 ) and may include a plurality of LCT sessions. Each LCT session may transmit audio/video segments which are the service data. As described above, SLS may be transmitted through a specific LCT session (e.g., an LCT session having tsi=0). In the embodiment illustrated in the drawing, the LCT session is represented as SCS fragments (tsi=s). In the illustrated embodiment, an LSID is used and the LSID is transmitted to another LCT session. However, the LSID may be replaced with the above-described S-TSID according to an embodiment and the S-TSID may be included in SLS before being transmitted. In addition, while an FIC is used and the FIC is transmitted through an additional channel other than a PLP, low level signaling and the SLT may be used instead of the FIC and low level signaling may be transmitted through a well-known IP/UDP. 
     In this embodiment, the CID is transmitted through link layer signaling (t 1151010 ). When a neighboring transmitter transmits all services, which are transmitted through a current frequency, through another frequency, information related to the frequency may be gathered in one CID. 
     In this case, link layer signaling may include CID information. Link layer signaling is information which the receiver can acquire faster than information such as the SLT and SLS and may cause the CID to be rapidly acquired by the receiver. Even when a neighboring transmitter transmits only some services through different frequencies, the CID may be transmitted through link layer signaling. In this case, the CID may include handover information for each service. For example, when 5 services are transmitted through one frequency, if the neighboring transmitter is transmitting only two of the five services through another frequency, the CID may provide handover information for the two services. Since handover information for the other three services is not needed, the CID may not include related information or may include information about transmitters that are transmitting services through the same frequency. 
     Details of the handover information for seamless handover and the CID information will be described later. 
       FIG. 152  is a diagram illustrating an information transmission method for seamless handover according to another embodiment of the present invention. 
     As described above, the information for seamless handover may be included in SLS before being transmitted (t 152010 ). An LCT session through which SLS is transmitted may be referred to as a service signaling channel (SSC). 
     SLS may be performed for a corresponding service with respect to each service as described above. If CID information is included in SLS before being transmitted, a corresponding CID may include handover information about a service that SLS signals. 
     For example, if SLS signals service #1, the CID included in SLS before being transmitted may include information about neighboring transmitters that transmit service #1 through the same or different frequency. Therefore, a receiver that is moving may seamlessly reproduce service #1 through the CID information. 
     In this case, the meaning that the CID is included in SLS before being transmitted may indicate that the CID such as a USBD, an S-TSID, or an MPD is included in SLS according to an embodiment. According to an embodiment, the meaning may indicate that the USBD, S-TSID, or MPD included in SLS are extended to include the CID information. In addition, according to an embodiment, the meaning may indicate that the CID is distributed in the USBD, S-TSID, or MPD included in SLS and then is transmitted. According to an embodiment, the meaning may indicate that the receiver can calculate information corresponding to the CID using information corresponding to SLS. 
     Although not shown, the CID information may be transmitted through low level signaling or an SLT. If the CID information is transmitted through the low level signaling or the SLT, the CID may be transmitted through a well-known IP/UDP for the SLT etc. The CID may include handover information for services described by the SLT or services transmitted through a corresponding broadcast stream. 
       FIG. 153  is a diagram illustrating information for seamless handover according to an embodiment of the present invention. 
     As described above, information for handover may be referred to as a CID. The CID may provide information such as the location and signal strength of a transmitter so that handover can be performed to transmit the same service that a neighbor transmitter is transmitting. The CID may be differently configured according to an embodiment and may include either information about home cell transmitters or information about cells for each service, which will be described below. The home cell transmitters may mean other transmitters that are transmitting a plurality of the same broadcast services using the same frequency as a current frequency through which the same broadcast services are transmitted. The information about cells for each service may mean information about other neighboring transmitters that are transmitting a specific service using a frequency different from a current frequency through which the specific service is transmitted. 
     The CID may include a part indicating information about the CID, a part indicating information about home cell transmitters, and a part indicating information about neighboring transmitters that transmit a corresponding service. According to an embodiment, any one part may be omitted/changed and new information may be added. For example, when the home cell transmitters are not present, only the information about neighboring transmitters for each service may be included. Zero or more home cell transmitters and neighboring transmitters may be present. 
     The CID may include @majorProtocolVersion, @minorProtocolVersion, and/or @broadcst_stream_id. 
     @majorProtocolVersion and @minorProtocolVersion may indicate major protocol version information and minor protocol version information of a corresponding CID, respectively. 
     @broadcast_stream_id may be an ID of a broadcast stream corresponding to the CID. The broadcast stream corresponding to the CID may be a broadcast stream that transmits the CID or may be simply any broadcast stream described by the CID. 
     The CID may include a plurality of Home_cell_transmitters elements. The Home_cell_transmtiters may correspond to the above-described information about the home cell transmitters. Each Home_cell_transmitters element may include information such as @latitude, @longitude, @AERP, @relative_pattern_dept, and/or @null_positions. 
     @latitude may include latitude information of a corresponding home cell transmitter. The latitude information may be indicated with accuracy indicating up to the ten-thousandths place of a degree. The latitude information may be denoted as a conventional method for a positive/negative latitude value. 
     @longitude may indicate longitude information of the home cell transmitter. The longitude information may be indicated with accuracy indicating up to the ten-thousandths place of a degree. The longitude information may be denoted as a conventional method for a positive/negative longitude value. 
     @AERP is a theoretical measurement value of an effective RF power of a corresponding home cell transmitter and is an abbreviation of average effective radiated power. @AERP may be expressed in dBk and may be adjusted according to height of antenna center of radiation. 
     @relative_pattern_dept may indicate depth of the largest null value of an azimuth pattern of an antenna. This value may be denoted by a multiple of 8 dB and may be indicated by rounding down to the next low multiple value. Values lager than 24 dB may be rounded down to 24 dB. In the case of 00, this may mean that there is no corresponding data. 
     @null_positions may indicate ordinal directions when an azimuth pattern of an antenna is 8 dB or a value lower than a peak AERP and may be indicated by zeros of corresponding bit positions. A northern sector may be denoted in msb. Subsequent bits may be indicated in clockwise. Therefore, northeast (NE) may be indicated by the next immediate msb value. This method may proceed up to northwest (NW). NW may be indicated by lsb. If a value of this field is 1111 1111, this means that there is no corresponding data. 
     The CID may further include a plurality of Service elements. A Service element may correspond to the above-described cell information for each service. The Service elements may include information about neighboring receivers that transmit the service through another frequency. Zero or more neighboring transmitters may be present per service. 
     The Service element may include @service_id and/or @globalUniqueSeriveId. @service_id and/or @globalUniqueSeriveId may include a service ID and a globally unique service of a corresponding service, respectively. 
     The Service element may further include Cell elements. Each Cell element may include information about a neighboring transmitter. 
     Each Cell element may include @latitude, @longitude, @AERP, @relative_pattern_dept, and/or @null_positions. Each field may indicate latitude/longitude information about a corresponding cell, i.e., a neighboring transmitter, AERP information, relative pattern depth information, null position information, etc. Details of the field are identical to the above description. In this case, information about a neighboring transmitter that is transmitting a corresponding service through another frequency is used instead of the information about the home cell transmitter. 
     Each Cell element may further include information about @frequency, @preamble, @broadcast_stream_id, @DP_id, @provider_id, and @service_id. 
     @frequency may indicate information about another frequency through which a neighboring transmitter is transmitting a corresponding service. Specifically, @frequency may indicate center frequency information of bandwidth in which a corresponding service is being transmitted. 
     @preamble may indicate information about a preamble symbol for another frequency through which a corresponding service is transmitted. The preamble symbol may indicate bootstrap information of a signal frame, L 1  information, preamble information, or P 1  information. 
     @broadcast_stream_id may indicate an ID of a broadcast stream through which a neighboring transmitter is transmitting a corresponding service. 
     @DP_id may indicate an ID of a PLP or a DP through which a neighboring transmitter transmits a corresponding service. This field may indicate ID information of a PLP through which SLT information of a corresponding service is transmitted according to an embodiment. In addition, this field may indicate ID information of a PLP through which SLS information of a corresponding service is transmitted according to an embodiment. This field may indicate information of a PLP through which service data of a corresponding service is transmitted according to an embodiment. This field may include multiple fields per service according to an embodiment. 
     @provider_id may indicate ID information of a service provider of a service that a corresponding neighboring transmitter is transmitting. 
     @service_id may indicate a service ID of a service that a corresponding neighboring transmitter is transmitting. @service_id may have the same ID value or a different ID value with respect to the same service that a home cell transmitter is transmitting. If @service_id has the same ID value, a value of this field may have the same value as a Service@service_id field. 
       FIG. 154  is a diagram illustrating low level signaling information according to an embodiment of the present invention. 
     The low level signaling information may include signaling information serving to connect a physical layer to a higher layer than a layer through which low level signaling is transmitted. A receiver may efficiently search for broadcast services/content that the receiver desires to receive within a broadcast signal transmitted by the physical layer, using the low level signaling information. 
     The low level signaling information may include a fast information channel (FIC). The FIC may be called by other names and may be referred to as, for example, a service list table (SLT). 
     An embodiment of the present invention proposes a method for defining a minimum capability profile of each service and adding signaling information about the minimum capability profile to the FIC, thereby efficiently performing service scan and/or service rendering of a receiver. 
     Referring to (a) of the drawing, the FIC may include FIC_protocol_version information, Broadcast_stream_id information, SCD_exist_flag information, DP_id information, an FIC_level_descriptor( ) element, num_services information, provider_id information, service_id information, service data version information, service channel number information, service_category information, short_service_name_length information, short_service_name information, service_status information, sp_indicatoer information, IP_version_flag information, SSC_src_IP_addr_flag information, min_capability_profile information, SSC_src_IP_addr information, SSC_dst IP addr information, SSC_dst_port information, SSC_TSI information, SSC_DP_id information, and/or SSC basicservice information. 
     The FIC_protocol_version information identifies a version of a protocol of an FIC signaling structure. 
     The Broadcast_stream_id information is information identifying a broadcast stream. 
     The SCD_exist_flag information may indicate whether a service configuration description (SCD) is transmitted (or present) or not. The SCD may include service level signaling information. 
     The DP_id information is information identifying a datapipe (or a PLP) that carries low level signaling information and/or service level signaling information. 
     The FIC_level_descriptor( ) element may include a descriptor of an FIC level. 
     The num_services information represents the number of broadcast services that can be scanned by an FIC. 
     The provider_id information is information identifying a provider providing a broadcast service. 
     The service_id information is information identifying a broadcast service. 
     The service_data_version information is information representing a version of a service signaling channel (SSC or service level signaling). 
     The service_channel_number information represents a channel number of a service. 
     The service_category information identifies a category of a service. For example, the service_category information may indicate whether a broadcast service is an A/V service, an audio service, an ESG service, and/or a non-real-time (NRT) service. 
     The short_service_name_length information represents the length of information indicating a short service name of a service. 
     The short_service_name information represents a short service name of a service. 
     The service_status information represents a status of a service. For example, service_status information may indicate whether a service is in an active state, an inactive state, a show state, and/or a hidden state. 
     The sp_indicatoer information is information indicating whether service protection is applied to a service. 
     The IP_version_flag information represents IP version information used for an IP packet related to a service. The IP_version_flag information may indicate that IP version information is IPv4 or IPv6 according to a true or false value of the IP_version_flag information. 
     The SSC_src_IP_addr_flag information is information identifying whether information representing a source IP address of a service signaling channel is present. 
     The min_capability_profile information is information representing minimum capabilities of a receiver, needed to perform service rendering. The min_capability_profile information identifies minimum capabilities that a receiver should have for broadcast service rendering. The min_capability_profile information represents a minimum capability profile required for presentation of a corresponding service. For this profile, a range of a profile value may be defined in association with the service_category information of an FIC. 
     The SSC_src_IP_addr information is information representing an IP address of a source transmitting a service signaling channel. 
     The SSC_dst IP_addr information is information representing an IP address of a destination for a service signaling channel. 
     The SSC_dst_port information is information indicating a UDP port number of a destination for a service signaling channel. 
     The SSC_TSI information is information identifying a transport session that carries data of a service signaling channel. 
     The SSC_DP_id information is information identifying a datapipe that carries data of a service signaling channel. 
     The SSC_basicservice information is information identifying whether a broadcast service is a basic service. The SSC_basicservice information is transmitted together with audio, video, or caption data through the same ROUTE session as a ROUTE session that transmits service signaling and is information identifying whether all data is transmitted through a datapipe that carries service signaling. 
     Referring to (b) of the drawing, if a service identified by the service_category information is a linear service, whether minimum capabilities needed in a receiver for service rendering are high definition (HD) processing capabilities or ultra high definition (UHD) processing capabilities may be identified by the min_capability_profile information. For example, if a category of a service indicated by the service_category information is a linear service and a value of the min_capability_profile information denotes ‘xl’, this indicates that only a device capable of rendering at least UHD is capable of adding the corresponding service to a channel map through broadcast scan using an FIC. That is, if a service incapable of being supported by the receiver is provided, the service is not included in the channel map so that a user may not select the service that the user cannot view. Therefore, efficiency increases during channel selection. 
     If a service identified by the service_category information is an application (App) service, whether minimum capabilities needed in the receiver for service rendering should have capabilities capable of performing download through a broadband network or should have capabilities capable of performing download without using a broadband network may be identified by the min_capability_profile information. 
       FIG. 155  is a diagram illustrating a procedure of presenting a service in a receiver, using an FIC, according to an embodiment of the present invention. 
     Referring to (a) of the drawing, the receiver may acquire an FIC transmitted through a specific area in a broadcast signal. 
     The receiver may parse service_category information in the FIC and identify that a service identified by service_id information is an App service. 
     The receiver checks a most significant bit (MSB) of a value of min_capability_profile information in the FIC. 
     If an MSB of the min_capability_profile information is ‘1’, the receiver may recognize that components included in the App service are not transmitted through a broadband network. This indicates that the components included in the App service are transmitted through a broadcast network. Therefore, a receiver incapable of downloading the components through the broadcast network may recognize that rendering for the App serving cannot be performed. Consequently, only a receiver capable of downloading the components through the broadcast network may include the App service in a channel map and the receiver incapable of downloading the components through the broadcast network may not include the App service in the channel map. 
     In an embodiment of the present invention, even when only the min_capability_profile information of the FIC is acquired, the receiver does not register a service that is not supported by the receiver in the channel map so that a malfunction probability of the service can be reduced. 
     Referring to (b) of the drawing, a USD may include a CapabilityDescription element. The CapabilityDescription element may include information about capabilities needed in the receiver, for rendering of each service. In this example, the information in the CapabilityDescription element may indicate that the receiver should be capable of receiving a component of a specific service through the broadcast network without through the broadband network. 
       FIG. 156  is a diagram illustrating low level signaling information according to another embodiment of the present invention. 
     Another embodiment of the present invention proposes a method for defining a minimum capability profile of each service and adding signaling information about the minimum capability profile to an FIC, thereby efficiently performing service scan and/or service rendering of a receiver. 
     Referring to (a) of the drawing, the FIC may include FIC_protocol_version information, Broadcast_stream_id information, SCD_exist_flag information, DP_id information, an FIC_level_descriptor( ) element, num_services information, provider_id information, service_id information, service data version information, service channel number information, service_category information, short_service_name_length information, short_service_name information, service_status information, sp_indicatoer information, IP_version_flag information, SSC_src_IP_addr_flag information, min_capability_profile information, SSC_src_IP_addr information, SSC_dst IP_addr information, SSC_dst_port information, SSC_TSI information, SSC_DP_id information, and/or SSC basicservice information. 
     For a description of each element or information, refer to the aforementioned description. 
     In this embodiment, 10 bits may be allocated to min_capability_profile information. In this case, the min_capability_profile information may support expansion of capabilities related information that is to be added later. 
     Referring to (b) of the drawing, the structure of the min_capability_profile information is shown. 
     For example, if a category of a service identified by service_category information is a linear service, 4 bits among bits allocated to the min_capability_profile information may be defined as a video capability profile identifying capabilities needed to process video and the other 4 bits may be defined as an audio capability profile identifying capabilities needed to process audio. 
     For example, if a category of a service identified by service_category information is an App service, 2 bits among the bits applied to the min_capability_profile information may be defined as a capability profile demanded in a receiver in relation to a download protocol used to download the App service. 
       FIG. 157  is a diagram illustrating low level signaling information according to another embodiment of the present invention. 
     Another embodiment of the present invention proposes a method for defining a minimum capability profile of each service and adding signaling information about the minimum capability profile to an FIC, thereby efficiently performing service scan and/or service rendering of a receiver. 
     Referring to (a) of the drawing, the FIC may include FIC_protocol_version information, Broadcast_stream_id information, SCD_exist_flag information, DP_id information, an FIC_level_descriptor( ) element, num_services information, provider_id information, service_id information, service data version information, service channel number information, service_category information, short_service_name_length information, short_service_name information, service_status information, sp_indicatoer information, IP_version_flag information, SSC_src_IP_addr_flag information, num_capability_profile information, capability_type information, capability_profile information, SSC_src_IP_addr information, SSC_dst_IP_addr information, SSC_dst_port information, SSC_TSI information, SSC_DP_id information, and/or SSC basicservice information. 
     For a description of each element or information, refer to the above description. 
     The num_capability_profile information represents the number of minimum capability information that can be included in the FIC. The num_capability_profile information represents the number of minimum capability profiles defined in the FIC. Up to 4 minimum capability profiles may be included in the FIC. 
     The capability_type information is information indicating which type of component a value of capability_profile information is associated with. 
     The capability_profile information represents a minimum capability profile of a receiver, needed to present a service. The capability_profile information is information identifying minimum capabilities needed in the receiver for service rendering. 
     Referring to (b) of the drawing, a component indicated by corresponding information according to a value of the capability_type information is illustrated. For example, if the value of the capability_type information is ‘00’, this may indicate that a component to which a minimum capability profile is applied is a video component. If the value of the capability_type information is ‘01’, this may indicate that a component to which the minimum capability profile is applied is an audio component. If the value of the capability_type information is ‘10’, this may indicate that a component to which the minimum capability profile is applied is an App component. 
       FIG. 158  is a diagram illustrating low level signaling information according to another embodiment of the present invention. 
     Another embodiment of the present invention proposes a method for defining a minimum capability profile of each service and adding signaling information about the minimum capability profile to an FIC, thereby efficiently performing service scan and/or service rendering of a receiver. 
     Referring to (a) of the drawing, the FIC may include FIC_protocol_version information, Broadcast_stream_id information, SCD_exist_flag information, DP_id information, min_capability_profile information, an FIC_level_descriptor( ) element, num_services information, provider_id information, service_id information, service_data_version information, service_channel_number information, service_category information, short_service_name length information, short_service_name information, service_status information, sp_indicatoer information, IP_version_flag information, SSC_src_IP_addr_flag information, SSC_src_IP_addr information, SSC_dst IP_addr information, SSC_dst_port information, SSC_TSI information, SSC_DP_id information, and/or SSC basicservice information. 
     For a description of each element or information, refer to the above description. 
     The min_capability_profile information represents a minimum capability profile of a channel defined by the FIC. 8 bits may be allocated to the min_capability_profile information. A component type of a capability profile corresponding to the minimum capability profile may be defined by a combination of respective bits included in the 8 bits. 
     Referring to (b) of the drawing, combinations of bits allocated to the min_capability_profile information and information indicated by the combinations are shown. 
     Among 8 bits, two MSBs represent a type of a component to which a capability profile is applied. For example, if a value of the two bits is ‘00’, this may indicate that a component to which the minimum capability profile is applied is a video component. If the value of the two bits is ‘01’, this may indicate that a component to which the minimum capability profile is applied is an audio component. If the value of the two bits is ‘10’, this may indicate that a component to which the minimum capability profile is applied is an App component. 
     Among the 8 bits, two bits may be allocated to identify the minimum capability profile applied to the video component. For example, if a value of the two bits is ‘00’, this indicates that an HD video channel is provided and that a receiver requires capabilities of processing HD video. In addition, if the value of the two bits is ‘01’, this indicates that a UHD video channel is provided and that a receiver requires capabilities of processing UHD video. 
     Among the 8 bits, two bits may be allocated to identify the minimum capability profile applied to the audio component. For example, if a value of the two bits is ‘00’, this indicates that an audio component of a type applied in an existing broadcast system (e.g., an ATSC 1.0 broadcast system) is provided and that the receiver requires capabilities of processing an audio component of a type provided in the existing broadcast system. In addition, if the value of the two bits is ‘01’, this indicates that an audio component of a type applied to a next-generation broadcast system (e.g., an ATSC 3.0 broadcast system) is provided and that the receiver requires capabilities of processing an audio component of a type provided in the next-generation broadcast system. 
     Among the 8 bits, two bits may be allocated to identify the minimum capability profile applied to the App component. For example, if a value of the two bits is ‘00’, this indicates that the App component is provided to a broadband network and that the receiver requires capabilities of processing download through the broadband network in order to process the App component. In addition, if the value of the two bits is ‘01’, this indicates that the App component is not provided to the broadband network and that the receiver requires capabilities of processing download through a network (e.g., a broadcast network) other than the broadband network in order to process the App component. 
       FIG. 159  is a diagram illustrating a procedure of presenting a service in a receiver, using an FIC, according to another embodiment of the present invention. 
     Referring to (a) of the drawing, the receiver may acquire the FIC transmitted through a specific area in a broadcast signal. 
     The receiver acquires channel_capacity_profile information (which may include min_capabilityprofile information, num_capabilityprofile information, capability_type information, and/or capability_profile information) in the FIC. 
     The receiver may identify a type of a component to which a capability profile is applied, using partial bits of the min_capability_profile information or using the capability_type information in the FIC. 
     The receiver may identify a minimum capability profile applied to each component type, using partial bits of the min_capability_profile information or using the capability_profile information in the FIC. 
     According to the present invention, the receiver may be aware of capabilities needed in the receiver in order to present each channel, using information of an FIC level. Capabilities of a channel level described in the FIC may be described as capabilities that are capable of being commonly applied to all channels and is not frequently changed. 
     Referring to (b) of the drawing, a CapabilityDescription element that can be included in a USD is shown. The CapabilityDescription element included in the USD may include information (service level capabilities) related to capabilities at a service level. In a procedure in which the receiver acquires a service, capabilities of each program (or event) may be described through service level signaling and information related to capabilities at the service level may have priority over information related to capabilities described in the FIC. The information related to capabilities may include the above-described min_capability_profile information, num_capability_profile information, capability_type information, and/or capability_profile information. 
       FIG. 160  is a flowchart illustrating a method for generating and processing a broadcast signal according to an embodiment of the present invention. 
     A transmitter encodes broadcast data for one or more broadcast services (JS 160010 ). 
     The transmitter encodes first level signaling information including information describing attributes of the one or more broadcast services (JS 160020 ). 
     The transmitter encodes second level signaling information including information for scanning the one or more broadcast services (JS 160030 ). 
     The transmitter generates a broadcast signal including the first level signaling information and the second level signaling information (JS 160040 ). 
     According to an embodiment, the second level signaling information may include first capability information identifying capabilities needed to decode one or more pieces of broadcast content for the one or more broadcast services. 
       FIG. 161  is a diagram illustrating a broadcast system according to an embodiment of the present invention. 
     The broadcast system according to an embodiment of the present invention may include a broadcast transmitter J 161100  and/or a broadcast receiver J 161200 . 
     The broadcast transmitter J 161100  may include a broadcast data encoder, J 161110 , a signaling encoder J 161120 , and/or a broadcast signal generator J 161130 . 
     The broadcast receiver J 161200  may include a broadcast signal receiving unit J 161210 , a processor J 161220 , and/or a display unit J 161230 . 
     The broadcast data encoder J 161110  encodes broadcast data for one or more broadcast services. 
     The signaling encoder J 161120  encodes first level signaling information including information describing attributes of the one or more broadcast services and/or second level signaling information including information for scanning the one or more broadcast services. 
     The broadcast signal generator J 161130  generates a broadcast signal including the broadcast data, the first level signaling information, and the second level signaling information. 
     According to an embodiment of the present invention, the second level signaling information may include first capability information identifying capabilities needed to decode one or more pieces of broadcast content for the one or more broadcast services. 
     The broadcast signal receiving unit J 161210  receives the broadcast data for the one or more broadcast services, the first level signaling information including the information describing attributes of the one or more broadcast services, and the second level signaling information including the information for scanning the one or more broadcast services. The second level signaling information may include the first capability information identifying capabilities needed to decode one or more pieces of broadcast content for the one or more broadcast services. 
     The processor J 161220  performs a control function to present the broadcast services by acquiring the broadcast services using the second level signaling information and the first level signaling information. 
     The display unit J 161230  displays broadcast services/content. 
       FIG. 162  illustrates a protocol stack of the broadcast system according to another embodiment of the present invention. 
     As described above, the broadcast system according to the present invention can transmit broadcast data using two or more transport protocols. For service data delivery through a broadcast network, a method for transmitting service data formatted into MPUs according to the MMT protocol and/or a method for transmitting service data formatted into DASH segments through the ROUTE protocol may be present. 
     Service signaling data for data delivered through ROUTE/MMT may be transmitted through ROUTE/MMT. NRT components for a service can be delivered only through ROUTE. According to an embodiment, NRT components may be delivered only through MMT. This has been described above. 
     Service data which has been processed according to ROUTE or MMT may be processed into IP packets through the UDP/IP layer. The IP packets may be encapsulated into link layer packets in the link layer (not shown). The link layer packets may be processed into a broadcast signal through the aforementioned physical processing (encoding, interleaving, etc.) in the physical layer. The broadcast signal may be transmitted through a broadcast network. 
     In the case of a hybrid service, at least one component of the service may be delivered through a broadband network. When service data is delivered through the broadband network, the service data can be delivered in the form of a DASH segment. For delivery through a broadband network, the service data may be processed according to HTTP/TCP/IP protocols. The processed data may be delivered through the broadband network. 
     An SLT including information for service list generation may be delivered. The SLT may include bootstrap information for accessing SLS of each service. Here, the bootstrap information may provide information necessary for rapid scan and acquisition of broadcast services. 
     The SLT may be processed according to UDP/IP and delivered in the form of an IP packet. In this case, the SLT may be delivered through a specific IP stream and processed into link layer packets. Then, the SLT may be delivered through a PLP. That is, the SLT can be delivered through a PLP instead of being delivered through a dedicated channel in a signal frame. According to an embodiment, the SLT may be delivered through an FIC. In this case, the corresponding signal frame may have a dedicated channel such as the FIC. The SLT may be delivered through the FIC to locate SLS with respect to each service. 
     As described above, the broadcast system according to the present invention can transmit broadcast data using two or more transport protocols. In this case, the SLT can indicate a transport protocol by which service data delivered through a broadcast network is transmitted. 
     Specifically, the SLT can indicate a transport protocol through which SLS with respect to each service is transmitted. According to an embodiment, the SLT may indicate a transport protocol through which service data/service components of each service are transmitted. To this end, the SLT may include protocol information. The protocol information may indicate a transport protocol according to the value thereof. For example, when the protocol information has a value of 0x01, this indicates that the ROUTE protocol is used. When the protocol information has a value of 0x002, this indicates that the MMT protocol is used. When the protocol information has values of 0x03 to 0xFF, the protocol may be reserved for future use. 
     The protocol information may be located in various forms in the SLT. For each protocol, the SLT may provide a list of services delivered according to the corresponding protocol in an embodiment. For each service, the SLT may describe which protocol is used to deliver the corresponding service according to an embodiment. A detailed embodiment will be described later. 
     According to an embodiment, the PLP ID information in the LST and SLS may be deleted. In this case, the aforementioned LMT, which is link layer signaling, may be used. That is, the LMT can describe IP streams, which are delivered through a PLP, for the PLP, and bootstrapping information of the SLT can locate SLS using IP/UDP information only. In this case, a reception system can recognize IP streams of a PLP, through which the SLS is delivered, using PLP-IP stream mapping information of the LMT and information (IP/UDP information) for identifying IP streams indicated by the SLT. In this embodiment, the SLS may also include information for specifying IP streams. When the receiver uses the SLS, the receiver may use information of the LMT if a PLP needs to be identified. 
       FIG. 163  illustrates an SLT according to another embodiment of the present invention. 
     The illustrated SLT may have a form extended from the aforementioned SLT and an extended FIC payload. Fields of the SLT, for example, FIC_protocol_version information, broadcast_stream_id information and partition_id information have been described above. 
     The illustrated SLT may provide a list of services, which are delivered through a protocol, for the protocol. The illustrated SLT may include a num_protocol_stack field at the SLT level (FIC level). The num_protocol_stack field can indicate the number of transport protocols used to deliver services described by the SLT. For example, when only the ROUTE protocol is used, the num_protocol_stack field can indicate that one transport protocol is used. When a certain service is transmitted according to the ROUTE protocol and other services are transmitted according to the MMT protocol, the num_protocol_stack field can indicate that two transport protocols are used. 
     The illustrated SLT may include a for loop containing information about each protocol according to the number indicated by the num_protocol_stack field. The information about each protocol may include a for loop containing a protocol_stack_type field, a num_services field and information about each service, a num_protocol_stack_level_descriptors field and/or protocol_stack_level_descriptor( ). 
     The protocol_stack_type field indicates the corresponding transport protocol For example, this field can indicate whether the corresponding transport protocol is the ROUTE protocol or the MMT protocol. 
     The num_services field indicates the number of services delivered by the corresponding protocol. For example, this field can indicate the number of services having SLS delivered through ROUTE. The num_services field may be followed by a for loop including information about each service on the basis of the value indicated by the num_services field. 
     The information about each service may be detailed information about services delivered according to the corresponding protocol. The SLT may include service_id information, partition_id information and IP_version_flag information for each service delivered according to the corresponding protocol. The information included in the SLT has been described above. 
     Information about services delivered according to the corresponding protocol includes bootstrap information about SLS of the services. The bootstrap information may include an SLS_source_IP_address, an SLS_destination_IP_address, an SLS_destination_UDP_port and/or an SLS_DP_ID. This information may respectively indicate a source IP address, a destination IP address and a destination UDP port number of a transport session through which the SLS is delivered. The SLS_DP_ID identifies the PLP ID corresponding to a PLP through which the SLS is delivered. The SLS_DP_ID may be omitted according to an embodiment. 
     Indication of the destination IP address of the bootstrap information may depend on the transport protocol through which the corresponding service is delivered. For example, when the corresponding service (or SLS of the corresponding service) is delivered according to the ROUTE protocol, the bootstrap information can indicate a ROUTE session through which the SLS of the corresponding service is delivered. When the corresponding service is delivered according to the MMT protocol, the bootstrap information can indicate an MMT session through which the SLS of the corresponding service is delivered. 
     As described above, SLS of a specific service can be delivered through a dedicated channel of a ROUTE/MMTP session through which the SLS is delivered. When the SLS is delivered through the ROUTE session, the SLS can be delivered through an LCT session specified by tsi=0 of the ROUTE session. When the SLS is delivered through the MMTP session, the SLS can be delivered through an MMTP packet flow specified by id=00 of the MMTP session. 
     According to an embodiment, SLS may be delivered through a channel other than a dedicated channel of a transport session. In this case, the bootstrap information needs to indicate a channel of a ROUTE/MMTP session through which the SLS is delivered. To this end, the SLT may further include an SLS_TSI field. When the corresponding service is delivered according to ROUTE, the SLS_TSI field can indicates an LCT channel in a ROUTE session through which the SLS is delivered. Here, the SLS_TSI field may have a value in the form of tsi. When the corresponding service is delivered according to MMT, the SLS_TSI field can indicate an MMTP packet flow in an MMTP session through which the SLS is delivered. In this case, the SLS_TSI field may have a value in the form of packet_id. The SLS_TSI field may be omitted according to an embodiment. 
     That is, meaning of the bootstrap information of SLS of a specific service may depend on the aforementioned protocol information (protocol_stack_type field). Meaning of the bootstrap information may depend on a transport protocol used to deliver the specific service. 
     The SLT may include a num_protocol_stack_level_descriptors field and/or protocol_stack_level_descriptor( ) at the protocol stack level. 
     The num_protocol_stack_level_descriptors field indicates the number of descriptors defined at the protocol stack level. Descriptors (protocol_stack_level_descriptor( )) can be included in the SLT on the basis of the value of this field. Such descriptors can provide common information for the corresponding protocol. 
     In addition, the SLT may include a num_FIC_level_descriptors field and/or FIC_level_descriptor( ) at the SLT level. 
     The num_FIC_level_descriptors field indicates the number of descriptors defined at the SLT level. Descriptors (FIC_level_descriptorO) can be included in the SLT on the basis of the value of this field. Such descriptors can provide common information for all services described by the SLT. 
       FIG. 164  illustrates an SLT according to another embodiment of the present invention. 
     The SLT according to the present embodiment may have a form extended from the aforementioned SLT and an extended FIC payload. Fields of the SLT have been described above. 
     For each service, the SLT according to the present embodiment may provide information on a transport protocol used to transmit the corresponding service. Specifically, the SLT can indicate whether a transport protocol used to deliver SLS of the corresponding service is the ROUTE protocol or the MMT protocol. 
     The SLT according to the present embodiment may include a num_protocol_stack field per service. This field indicates the number of transport protocols that can be used to deliver the corresponding service. For example, this field can indicate that the corresponding service is delivered only through ROUTE when the value thereof is 1 and indicate that the corresponding service is delivered through ROUTE and MMT when the value thereof is 2. 
     The SLT may describe information on as many protocols as the number indicated by the num_protocol_stack field. Information on each protocol may include information for locating SLS of the corresponding service when the SLS is delivered through ROUTE. In addition, the information on each protocol may include information for locating the SLS of the corresponding service when the SLS is delivered through MMT. 
     A protocol_stack_type field indicates a transport protocol used to deliver the SLS of the corresponding service. As described above, the protocol_stack_type field can indicate the ROUTE or the MMT protocol according to the value thereof. 
     An SLS_source_IP_address, an SLS_destination_IP_address and an SLS_destination_UDP_port respectively indicate the source ID address, destination IP address and destination UDP port number of a transport session through which the SLS of the corresponding service is delivered. An SLS_DP_ID identifies the PLP ID of a PLP through which the SLS is delivered. The SLS_DP_ID may be omitted according to an embodiment. 
     Indication of the destination IP address may depend on the transport protocol through which the corresponding service is delivered, similarly to the aforementioned embodiment. For example, when the corresponding service (or SLS of the corresponding service) is delivered according to the ROUTE protocol, bootstrap information can indicate a ROUTE session through which the SLS of the corresponding service is delivered. If the corresponding service is delivered according to the MMT protocol, the bootstrap information can indicate an MMT session through which the SLS of the corresponding service is delivered. 
     When the SLS of the corresponding service is delivered through a dedicated channel of a ROUTE/MMT session, as described above, additional tsi information or packet_id information may not be needed. When there is no dedicated channel, however, an SLS_TSI field may be added. The SLS_TSI field may indicate an LCT channel or an MMTP packet flow through which the SLS is delivered, similarly to the aforementioned embodiment. 
     The illustrated SLT may include as many protocol_stacklevel_descriptors( ) as the number indicated by a num_protocol_stack_level_descriptor. The protocol_stack_level_descriptor( ) may include common information for the corresponding protocol. 
     The illustrated SLT may include as many service_level_descriptors( ) as the number indicated by a num_service_level_descriptor. The service_level_descriptor( ) may include common information for the corresponding service. 
     The illustrated SLT may include as many SLT level descriptors (FIC_level_descirptorso) as the number indicated by a num_FIC_level_descriptor. The SLT level descriptor has been described above. 
     According to an embodiment, one service may be delivered using two or more transport protocols simultaneously. A certain service component, from among a plurality of service components included in one service, may be delivered through the ROUTE protocol and other service components may be delivered through the MMT protocol. Here, a service component delivered through the ROUTE protocol may be an NRT service component. 
     When one service is delivered through two or more transport protocols simultaneously, SLS of the corresponding service may be delivered according to the MMT protocol. That is, the aforementioned bootstrap information (IP/UDP information) can locate the SLS delivered through an MMT session. In this case, the SLS delivered through the MMT session may include information necessary to access service components delivered through MMT sessions. 
     Here, the SLS delivered through the MMT session may additionally include information about service components delivered through ROUTE sessions. The information about service components delivered through ROUTE sessions may correspond to the aforementioned atsc:routeComponent. As described above, atsc:routeComponent may include IP/UDP information, PLP information and URI information for acquiring an S-TSID. Accordingly, the receiver can acquire the S-TSID. Here, the S-TSID may provide transport session description information about service components delivered according to the ROUTE protocol. The S-TSID has been described above. 
       FIG. 165  illustrates an SLT according to another embodiment of the present invention. 
     The SLT according to the present embodiment is extended such that the SLT includes information about LSID. The LSID according to the present embodiment may differ from the aforementioned LSID. 
     The aforementioned LSID may describe an LCT channel included in a ROUTE session and service components delivered through the LCT channel by being included in the ROUTE session. In addition, the aforementioned S-TSID is service-based signaling information and can describe information about all LCT channels carrying service components of a specific service. Accordingly, the LSID and the S-TSID may not be used together since the LSID is information about each ROUTE session. According to an embodiment, both the LSID and the S-TSID may be used. 
     The LSID according to the present embodiment is service-based signaling information and may include transport path information about ROUTE sessions and LCT channels through which service components of all services described by the SLT are delivered. The S-TSID may include transport path information about service components of one service, as described above. That is, the LSID according to the present embodiment can be regarded as a set of the aforementioned S-TSIDs. This LSID in a new format may not be used when SLS of each service provides S-TSID. 
     The SLT according to the present embodiment may further include information for acquiring the aforementioned LSID in the new format. The illustrated SLT may further include LSID_exist_flag, LSID_PLP_ID and/or LSID_version fields. Other fields have been described. 
     The LSID_exist_flag field may indicate whether the LSID is present in a corresponding broadcast stream. This field has a value “true” or “false”. When this field is “true”, the SLT can include the LSID PLP ID field and/or the LSID version field. 
     The LSID_PLP_ID field indicates the ID of a PLP through which the LSID is delivered. When the LSID is delivered through a transport session, IP/UDP information for identifying the transport session may be added. When the LSID is delivered through a dedicated channel of a signal frame, the LSID_PLP_ID field may be omitted. 
     The LSID_version field indicates the version of the delivered LSID. When the information of the LSID is changed, the LSID has a new version number. 
       FIG. 166  illustrates LSID according to another embodiment of the present invention. 
     The illustrated LSID may correspond to the aforementioned LSID in the new format. The illustrated LSID may have a structure similar to the aforementioned S-TSID. However, since the LSID according to the present embodiment includes transport session description information about a plurality of services, a service element for each service may be added to the LSID. 
     The illustrated LSID may include @bsid and/or a service element. The @bsid field may include information for identifying broadcast streams carrying services described by the LSID. The service element may be an element including transport path description about each service. 
     The service element may include @svcID, @version, @validFrom, @expires and/or a plurality of RS elements. 
     @svcID indicates the service ID of the corresponding service. @version, @validFrom and @expires may respectively correspond to @version, @validFrom and @expires fields in the aforementioned transport session instance description (LSID). 
     Each of The RS elements may be an element containing information about a ROUTE session through which a service component of the corresponding service is transmitted. The RS element may correspond to the RS element of the aforementioned S-TSID. 
     @bsid indicates the ID of a broadcast stream carrying the corresponding service. This field may be omitted. When this field is omitted, this field may be considered to have the same value as the aforementioned @bsid. 
     @sIpAddr, @dIpAddr and @dport fields may respectively indicate the source IP address, the destination IP address and the destination UDP port number of the corresponding ROUTE session. 
     @plpID indicates the ID of a PLP through which the corresponding ROUTE session is delivered. This field may be omitted. When @plpID is omitted, this field may be considered to have the same value as @LSID_PLP_ID included in an SLT. 
     The RS element may include a plurality of LS elements. Each LS element may include information about an LCT channel carrying a service component of the corresponding service. 
     The LS element may include @tsi, @PLPID, @bw, @startTime, @endTime, an srcFlow and/or an RprFlow element. 
     @tsi may indicate the session ID of the corresponding LCT channel. Service components of the corresponding service can be collected using this information. 
     @PLPID may indicate the ID of a PLP through which the corresponding LCT channel is delivered. @PLPID may be omitted. When @PLPID is omitted, @PLPID may be considered to have the same value as @PLPID which is a lower element of the RS element. 
     @bw may indicate a maximum bandwidth of the corresponding LCT channel. 
     @startTime may indicate the start time of the corresponding LCT channel. 
     @endTime may indicate the end time of the corresponding LCT channel. 
     The SrcFlow element may describe a source flow of ROUTE. The RprFlow element may describe a repair flow of ROUTE. The srcFlow and RprFlow elements will be described later. 
     As described above, the LSID according to the present embodiment can provide transport session description information about service components included in a plurality of services. Accordingly, the LSID according to the present embodiment can have a structure similar to the aforementioned S-TSID. 
       FIG. 167  illustrates description of a source flow/repair flow according to another embodiment of the present invention. 
     The illustrated source flow element may include @nrt, @minBuffSize, @appID, EFDT, Payload and/or FECParams. Fields may be added/changed/deleted according to embodiments. 
     @nrt may be the same as @realtime of the aforementioned source flow element. @minBuffSize may be the same as @minBufferSize of the aforementioned source flow element. @appID may be the same as the ApplicationIdentifier element of the aforementioned source flow element. 
     The EFDT element may correspond to the aforementioned EFDT of the broadcast system. The EFDT may include @idref, @version, @maxExpiresDelta, @maxTransportSize, @fileTemplate and/or FDTParameters. 
     @idref, @version, @maxExpiresDelta, @maxTransportSize and @fileTemplate may respectively correspond to attributes or elements of the aforementioned EFDT element, which have the same names. 
     The FDTParameters may include parameters about the file URL or file template of the EFDT body. This element may include any parameter defined in FLUTE FDT. 
     The Payload element may correspond to the PayloadFormat element of the aforementioned source flow element. The Payload element may further include @codePoint, @formatID, @frag, @order and/or @srcFecPayloadID. 
     @codePoint may correspond to @codePoint of the aforementioned source flow element. @formatID may correspond to @deliveryObjectFormat of the aforementioned source flow element. @frag may correspond to @fragmentation of the aforementioned source flow element. @order may correspond to @deliveryOrder of the aforementioned source flow element. @srcFecPayloadID may correspond to @sourceFecPayloadID of the aforementioned source flow element. 
     The FECParams may correspond to the FECParameter element of the aforementioned source flow element. 
     The RprFlow element may include information about a repair flow. The repair flow may provide protection of delivery objects of one or more source flows. The repair flow may include parameter information about an FEC and information (ProtectedObject) about a protected delivery object. 
     The illustrated source flow/repair flow elements and the source flow/repair flow elements according to the aforementioned embodiment may be applied as the source flow/repair flow elements of the S-TSID. 
       FIG. 168  is a signaling flow diagram according to another embodiment of the present invention. 
     The present embodiment shows delivery of transport sessions through PLPs. In the present embodiment, PLS is physical layer signaling which has been described above. While it is assumed that an FIC is used in the present embodiment, the FIC may not be used as described above and an SLT may be delivered through a specific IP stream. Information of the SLT delivered through the specific IP stream can be preferentially acquired. 
     Here, the SLT may be the aforementioned SLT having information about LSID. Whether the LSID is present in the corresponding broadcast stream can be checked using LSID_flag information of the SLT. In addition, a PLP through which the LSID is delivered can be identified using LSID_PLP_ID information of the SLT. 
     The receiver can obtain transport session description information about each service upon acquisition of the LSID. The receiver can be aware of an LCT channel of a ROUTE session through which each service is delivered using the transport session description information. 
     A path through which SLS of a specific service is delivered may be located using bootstrap information in the SLT. In the present embodiment, LCT channels through which SLS is delivered are represented as TSI SLS1 and TSI SLS3. The SLS includes an SMT and MPD in the present embodiment. The SLS may include USBD and MPD and the SMT may not be used according to embodiments. 
     When the illustrated LSID is used, S-TSID may not be used. In this case, SLS of an LCT channel may not include S-TSID. According to an embodiment, the SLS of the LCT channel may provide transport session description information about the corresponding service by including S-TSID. In this case, the illustrated LSID may not be used. According to an embodiment, the illustrated LSID and S-TSID may be simultaneously used. In this case, the LSID and S-TSID may have overlapping information. 
       FIG. 169  is a flowchart illustrating a method for transmitting a broadcast signal according to an embodiment of the present invention. 
     The method for transmitting a broadcast signal according to an embodiment of the present invention may include the steps of generating service data and service signaling information, generating a service list table, processing service components, the service signaling information and the service list table into transport packets, generating link layer packets and/or generating a broadcast signal by physical-layer-processing the link layer packets and transmitting the broadcast signal. 
     Specifically, a first module of a transmitter may generate service data of a broadcast service and service signaling information for signaling the service data. Here, the service data may include first service components delivered according to the MMT (MPEG Media Transport) protocol and second service components delivered according to the ROUTE (Real-Time Object Delivery over Unidirectional Transport) protocol. When it is assumed that NRT service components are delivered according to ROUTE, as described above, service components of one service can be delivered using a plurality of transport protocols. The broadcast service may further include service components delivered through broadband networks. Here, the service signaling information can refer to SLS. 
     A second module of the transmitter may generate a service list table. The service list table may correspond to the aforementioned SLT. The SLT may include bootstrap information for identifying a transport session through which the SLS is delivered. The transport session may be a ROUTE session or an MMTP session. The bootstrap information may refer to the IP address and the UDP port number of the ROUTE session or the MMTP session. The first module and the second module may correspond to a service provider and manage generation of services. 
     A third module of the transmitter may process the service signaling information and/or the service list table into transport packets. This step may be a step of encapsulating service component data, the SLS and the SLT into IP packets by processing the service component data, the SLS and the SLT according to UDP/IP in order to deliver the service data through a broadcast network. Here, the transport packets may be IP packets. It is assumed that an FIC is not used and the SLT is encapsulated into an IP packet and delivered through a PLP. The third module may be a hardware module which manages a UDP/IP layer. 
     A fourth module of the transmitter may output at least one link layer packet by link-layer-processing the transport packets. Here, the transport packets may be IP packets. Link layer processing has been described above. The fourth module may perform operation corresponding to the link layer. The fourth module may perform header compression/overhead reduction and packet encapsulation. 
     A fifth module of the transmitter may physical-layer-process the at least one link layer packet. The fifth module may manage operation of the physical layer. The fifth module may process the at least one link layer packet into BB packets and perform encoding, bit interleaving and constellation mapping on the BB packets. Subsequently, the fifth module may perform time interleaving, frame building and frequency interleaving and then modulation according to OFDM. In addition, the fifth module may transmit a broadcast signal including physical-layer-processed data. Here, the fourth module may be included in the fifth module. The fourth and fifth modules may be replaced by a single integrated module. The fifth module may include a plurality of internal blocks. The fourth module may be included in one of blocks of the fifth module. 
     In a method for transmitting a broadcast signal according to another embodiment of the present invention, the service list table may further include protocol information about the broadcast service. The protocol information may indicate a transport protocol used to deliver the service signaling information of the broadcast service. The protocol information may correspond to the aforementioned @slsProtocolType or protocol_stack_type. 
     In a method for transmitting a broadcast signal according to another embodiment of the present invention, the bootstrap information may include IP/UDP information on a transport session through which the service signaling information is delivered. The IP/UDP information specifies an MMTP session or a ROUTE session through which the service signaling information is delivered according to the protocol information. The IP/UDP information may refer to the source IP address, the destination IP address and the destination UDP port number of the transport session through which the SLS is delivered. Indication of the destination IP address or the like may depend on the protocol information, as described above. The transport session indicated by the UP/UDP information may be a ROUTE session or an MMTP session through which the SLS is delivered. When the SLS is delivered through the MMTP session, streaming data can be delivered according to the MMTP protocol. Here, NRT data may be additionally delivered through the ROUTE protocol. 
     In a method for transmitting a broadcast signal according to another embodiment of the present invention, the service signaling information may be delivered according to the MMTP protocol. Here, the service signaling information may include transport session description information about MMTP sessions through which the first service components of the broadcast service are delivered. It is assumed that SLS is delivered through an MMTP session. The SLS delivered through the MMTP session may include USBD and/or an MMT signaling message. The MMT signaling message, particularly, an MPT message may include information necessary to access service components delivered through MMTP sessions. The MPT message may serve as the S-TSID of ROUTE. The service components delivered through the MMTP sessions may be called the first service components as described above. 
     In a method for transmitting a broadcast signal according to another embodiment of the present invention, the service signaling information may further include information for identifying an MMTP session through which S-TSID (Service-based Transport Session Instance Description) is delivered. As described above, SLS delivered through an MMTP session may include USBD. The USBD may include information for acquiring the S-TSID through an element such as routeComponent. The S-TSID may include transport session description information about ROUTE sessions through which the second service components of the broadcast service are delivered. The S-TSID may include information (tsi) for acquiring service components (second service components) delivered through ROUTE sessions. Here, the S-TSID can be delivered through an MMTP session. 
     In a method for transmitting a broadcast signal according to another embodiment of the present invention, the S-TSID may include a plurality of ROUTE session elements. The ROUTE session elements may refer to the aforementioned RS elements. Each ROUTE session element may include IP/UDP information for identifying the corresponding ROUTE session and a plurality of LCT channel elements. The IP/UDP information may refer to the source IP address, the destination IP address and the destination UDP port number of the corresponding ROUTE session. The LCT channel elements may refer to the aforementioned LS elements. The LCT channel elements may include transport channel identifier information on LCT channels through which the second service components of the broadcast service are delivered. The transport channel identifier information may refer to the aforementioned tsi information. 
     In a method for transmitting a broadcast signal according to another embodiment of the present invention, the second service components may be NRT (Non Real Time) service components included in the broadcast service. When a single broadcast service is delivered through a broadcast network using the ROUTE protocol and the MMT protocol simultaneously, as described above, NRT service components may be delivered according to the ROUTE protocol and streaming service components may be delivered according to the MMT protocol. 
     A description will be given of a method for receiving a broadcast signal according to an embodiment of the present invention. This is not shown in the figures. 
     The method for receiving a broadcast signal according to an embodiment of the present invention may include a step in which a first module of a receiver receives a broadcast signal, a step in which a second module of the receiver outputs link layer packets by physical-layer-processing the broadcast signal, a step in which a third module of the receiver outputs transport packets by link-layer-processing the link layer packets, a step in which a fourth module of the receiver acquires an SLT and accesses SLS and/or a step in which a fifth module of the receiver acquires service data delivered through a broadcast network using the SLS. Here, physical layer processing and link layer processing may be reverse processes of those of the transmitter. The SLS may be delivered through an MMTP session. The SLS may have information for acquiring service components delivered through MMTP sessions. In addition, the SLS may include information necessary to acquire S-TSID. NRT service components delivered according to ROUTE may be acquired using the S-TSID. 
     Methods for receiving a broadcast signal according to embodiments of the present invention may correspond to the methods for transmitting a broadcast signal according to the aforementioned embodiments of the present invention. The methods for receiving a broadcast signal may be performed by hardware modules corresponding to the modules (e.g. the first to fifth modules of the transmitter) used in the methods for transmitting a broadcast signal. Embodiments of methods for receiving a broadcast signal may correspond to the aforementioned embodiments of the methods for transmitting a broadcast signal. 
     The aforementioned steps may be omitted according to embodiments or replaced by other steps which perform similar/identical operations. 
       FIG. 170  is a block diagram of an apparatus for transmitting a broadcast signal according to an embodiment of the present invention. 
     The apparatus for transmitting a broadcast signal according to an embodiment of the present invention may include the aforementioned first, second, third, fourth and/or fifth modules of the transmitter. Blocks and modules of the apparatus have been described above. 
     The apparatus for transmitting a broadcast signal and internal modules/blocks thereof according to an embodiment of the present invention may perform the methods for transmitting a broadcast signal according to the aforementioned embodiments of the present invention. 
     A description will be given of an apparatus for receiving a broadcast signal according to an embodiment of the present invention. The apparatus is not shown in the figures. 
     The apparatus for receiving a broadcast signal according to an embodiment of the present invention may include the aforementioned first, second, third, fourth and/or fifth modules of the receiver. Blocks and modules of the apparatus have been described. 
     The apparatus for receiving a broadcast signal and internal modules/blocks thereof according to an embodiment of the present invention may perform the methods for receiving a broadcast signal according to the aforementioned embodiments of the present invention. 
     The internal blocks/modules of the aforementioned apparatus may be processors which execute consecutive processes stored in a memory and may be hardware elements located inside/outside of the apparatus according to embodiments. 
     The aforementioned modules may be omitted or replaced by other modules which perform similar/identical operations according to embodiments. 
     Modules or units may be processors executing consecutive processes stored in a memory (or a storage unit). The steps described in the aforementioned embodiments can be performed by hardware/processors. Modules/blocks/units described in the above embodiments can operate as hardware/processors. The methods proposed by the present invention can be executed as code. Such code can be written on a processor-readable storage medium and thus can be read by a processor provided by an apparatus. 
     While the embodiments have been described with reference to respective drawings for convenience, embodiments may be combined to implement a new embodiment. In addition, designing a computer-readable recording medium which stores programs for implementing the aforementioned embodiments is within the scope of the present invention. 
     The apparatus and method according to the present invention are not limited to the configurations and methods of the above-described embodiments and all or some of the embodiments may be selectively combined to obtain various modifications. 
     The methods proposed by the present invention may be implemented as processor-readable code stored in a processor-readable recording medium included in a network device. The processor-readable recording medium includes all kinds of recording media storing data readable by a processor. Examples of the processor-readable recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device and the like, and implementation as carrier waves such as transmission over the Internet. In addition, the processor-readable recording medium may be distributed to computer systems connected through a network, stored and executed as code readable in a distributed manner. 
     Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Such modifications should not be individually understood from the technical spirit or prospect of the present invention. 
     Both apparatus and method inventions are mentioned in this specification and descriptions of both the apparatus and method inventions may be complementarily applied to each other. 
     Those skilled in the art will appreciate that the present invention may be carried out in other specific ways than those set forth herein without departing from the spirit and essential characteristics of the present invention. Therefore, the scope of the invention should be determined by the appended claims and their legal equivalents, not by the above description, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein. 
     In the specification, both the apparatus invention and the method invention are mentioned and description of both the apparatus invention and the method invention can be applied complementarily. 
     Various embodiments have been described in the best mode for carrying out the invention. 
     The present invention is applied to broadcast signal providing fields. 
     Various equivalent modifications are possible within the spirit and scope of the present invention, as those skilled in the relevant art will recognize and appreciate. Accordingly, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.