Source: https://patents.google.com/patent/US20100260286A1/en
Timestamp: 2019-04-24 17:10:06+00:00

Document:
A digital broadcasting system and a data processing method are disclosed. A receiving system of the digital broadcasting system includes a baseband processor, a management processor, and a presentation processor. The baseband processor receives broadcast signals including mobile service data and main service data. Herein, the mobile service data may configure a RS frame, which includes mobile service data and table information describing channel configuration information and IP access information of an ensemble level corresponding to the RS frame. The table information is encapsulated to a UDP/IP header. The management processor processes table information from the RS frame to acquire channel configuration information and IP access information of an ensemble level, and accesses mobile service data requested to be received from the RS frame, based upon the acquired information. The presentation processor decodes the accessed mobile service data and outputs the decoded data to a display screen and/or a speaker.
This application claims the benefit of U.S. Provisional Patent Application No. 60/957,714, filed on Aug. 24, 2007, U.S. Provisional Patent Application No. 60/974,084, filed on Sep. 21, 2007, U.S. Provisional Patent Application No. 60/977,379, filed on Oct. 4, 2007, U.S. Provisional Patent Application No. 61/044,504 filed on Apr. 13, 2008, U.S. Provisional Patent Application No. 61/076,683, filed on Jun. 29, 2008, U.S. Provisional Patent Application No. 61/076,686, filed on Jun. 29, 2008 and Korean Patent Application No. 10-2008-0082928, filed on Aug. 25, 2008, which are hereby incorporated by reference as if fully set forth herein.
The present invention relates to a digital broadcasting system and a method of processing data in a digital broadcasting system for transmitting and receiving digital broadcast signals.
Accordingly, an object of the present invention is to provide a digital broadcasting system and a data processing method that are highly resistant to channel changes and noise.
Another object of the present invention is to provide a receiving system and a data processing method that can receive and process mobile service data and access information of the respective mobile service data.
To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a receiving system includes a baseband processor, a management processor, and a presentation processor. The baseband processor receives broadcast signals including mobile service data and main service data. Herein, the mobile service data may configure a Reed-Solomon (RS) frame. The RS frame includes mobile service data and table information describing channel configuration information and IP access information of an ensemble level corresponding to the RS frame. And, the table information is encapsulated to a UDP/IP header. The management processor processes table information from the RS frame so as to acquire channel configuration information and IP access information of an ensemble level. The management processor also accesses mobile service data requested to be received from the RS frame, based upon the acquired channel configuration information and IP access information. The presentation processor decodes the accessed mobile service data and outputs the decoded mobile service data to at least one of a display screen and a speaker.
Herein, at least one data group configuring the RS frame may include a plurality of known data sequences, wherein a signaling information region may be included between a first known data sequence and a second known data sequence among the plurality of known data sequences, and wherein the signaling information region may include transmission parameter channel (TPC) signaling data and fast information channel (FIC) signaling data. The baseband processor may refer to the fast information channel (FIC) signaling data, so as to acquire slots only corresponding to a requested ensemble using a time-slicing method, thereby configuring the RS frame. Also, a target IP address and a target UDP port number included in a UDP/IP header of the table information may correspond to values pre-known by the digital broadcast receiving system.
The table information may be distinguished by an ensemble identifier included in the corresponding table information. Herein, an ensemble may include at least one virtual channel, and a virtual channel may include at least one component. The management processor may use the IP access information acquired from the table information to access mobile service information of a corresponding component from the RS frame. Furthermore, when the table information simultaneously includes IP access information of a virtual channel and IP access information for each component within a corresponding virtual channel, the management processor may refer to the IP access information for each component so as to access the mobile service data of the corresponding component. The table information may further include at least one of an ensemble level descriptor describing additional information of an ensemble level, a virtual channel descriptor describing additional information of a virtual channel level, and a component descriptor describing additional information of a component level.
According to another embodiment of the present invention, a method for processing data in a receiving system includes the steps of receiving broadcast signals including mobile service data and main service data, wherein the mobile service data may configure a Reed-Solomon (RS) frame, wherein the RS frame includes mobile service data and table information describing channel configuration information and IP access information of an ensemble level corresponding to the RS frame, and wherein the table information is encapsulated to a UDP/IP header, processing table information from the RS frame so as to acquire channel configuration information and IP access information of an ensemble level, and accessing mobile service data requested to be received from the RS frame, based upon the acquired channel configuration information and IP access information, and decoding the accessed mobile service data and outputting the decoded mobile service data to at least one of a display screen and a speaker.
Additional advantages, objects, and features of the invention may be realized and attained by the structure particularly pointed out in the written description as well as the appended drawings.
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Hereinafter, the preferred embodiment of the present invention will be described with reference to the accompanying drawings. At this time, it is to be understood that the following detailed description of the present invention illustrated in the drawings and described with reference to the drawings are exemplary and explanatory and technical spirits of the present invention and main features and operation of the present invention will not be limited by the following detailed description.
Among the terms used in the description of the present invention, main service data correspond to data that can be received by a fixed receiving system and may include audio/video (A/V) data. More specifically, the main service data may include A/V data of high definition (HD) or standard definition (SD) levels and may also include diverse data types required for data broadcasting. Also, the known data correspond to data pre-known in accordance with a pre-arranged agreement between the receiving system and the transmitting system.
Additionally, among the terms used in the present invention, “MH” corresponds to the initials of “mobile” and “handheld” and represents the opposite concept of a fixed-type system. Furthermore, the MH service data may include at least one of mobile service data and handheld service data, and will also be referred to as “mobile service data” for simplicity. Herein, the mobile service data not only correspond to MH service data but may also include any type of service data with mobile or portable characteristics. Therefore, the mobile service data according to the present invention are not limited only to the MH service data.
Furthermore, the transmitting system according to the present invention performs additional encoding on the mobile service data and inserts the data already known by the receiving system and transmitting system (e.g., known data), thereby transmitting the processed data.
FIG. 1 illustrates a block diagram showing a general structure of a receiving system according to an embodiment of the present invention. The receiving system according to the present invention includes a baseband processor 100, a management processor 200, and a presentation processor 300.
The baseband processor 100 includes an operation controller 110, a tuner 120, a demodulator 130, an equalizer 140, a known sequence detector (or known data detector) 150, a block decoder (or mobile handheld block decoder) 160, a primary Reed-Solomon (RS) frame decoder 170, a secondary RS frame decoder 180, and a signaling decoder 190.
The demodulator 130 performs self-gain control, carrier recovery, and timing recovery processes on the passband digital IF signal inputted from the tuner 120, thereby translating the IF signal to a baseband signal. Then, the demodulator 130 outputs the baseband signal to the equalizer 140 and the known sequence detector 150. The demodulator 130 uses the known data symbol sequence inputted from the known sequence detector 150 during the timing and/or carrier recovery, thereby enhancing the demodulating performance.
Meanwhile, according to the present invention, the transmitting system uses RS frames by encoding units. Herein, the RS frame may be divided into a primary RS frame and a secondary RS frame. However, according to the embodiment of the present invention, the primary RS frame and the secondary RS frame will be divided based upon the level of importance of the corresponding data.
The primary RS frame decoder 170 receives the data outputted from the block decoder 160. At this point, according to the embodiment of the present invention, the primary RS frame decoder 170 receives only the mobile service data that have been Reed-Solomon (RS)-encoded and/or cyclic redundancy check (CRC)-encoded from the block decoder 160. Herein, the primary RS frame decoder 170 receives only the mobile service data and not the main service data. The primary RS frame decoder 170 performs inverse processes of an RS frame encoder (not shown) included in the transmitting system, thereby correcting errors existing within the primary RS frame. More specifically, the primary RS frame decoder 170 forms a primary RS frame by grouping a plurality of data groups and, then, correct errors in primary RS frame units. In other words, the primary RS frame decoder 170 decodes primary RS frames, which are being transmitted for actual broadcast services.
Additionally, the secondary RS frame decoder 180 receives the data outputted from the block decoder 160. At this point, according to the embodiment of the present invention, the secondary RS frame decoder 180 receives only the mobile service data that have been RS-encoded and/or CRC-encoded from the block decoder 160. Herein, the secondary RS frame decoder 180 receives only the mobile service data and not the main service data. The secondary RS frame decoder 180 performs inverse processes of an RS frame encoder (not shown) included in the transmitting system, thereby correcting errors existing within the secondary RS frame. More specifically, the secondary RS frame decoder 180 forms a secondary RS frame by grouping a plurality of data groups and, then, correct errors in secondary RS frame units. In other words, the secondary RS frame decoder 180 decodes secondary RS frames, which are being transmitted for mobile audio service data, mobile video service data, guide data, and so on.
Finally, the FIC version number signifies the version number of an FIC carried on the corresponding physical channel.
The IP network stack 220 processes broadcast data that are being transmitted in the form of IP datagrams. More specifically, the IP network stack 220 processes data that are inputted via user datagram protocol (UDP), real-time transport protocol (RTP), real-time transport control protocol (RTCP), asynchronous layered coding/layered coding transport file delivery over unidirectional (ALC/LCT), transport (FLUTE), and so on. Herein, when the processed data correspond to streaming data, the corresponding data are outputted to the streaming handler 230. And, when the processed data correspond to data in a file format, the corresponding data are outputted to the file handler 250. Finally, when the processed data correspond to SI-associated data, the corresponding data are outputted to the SI handler 240.
FIG. 2 shows an example of dividing a data group according to the data structure of the present invention into 10 MH blocks (i.e., MH block 1 (B1) to MH block 10 (B10)). In this example, each MH block has the length of 16 segments. Referring to FIG. 2, only the RS parity data are allocated to portions of the previous 5 segments of the MH block 1 (B1) and the next 5 segments of the MH block 10 (B10). The RS parity data are excluded in regions A to D of the data group.
More specifically, when it is assumed that one data group is divided into regions A, B, C, and D, each MH block may be included in any one of region A to region D depending upon the characteristic of each MH block within the data group. Herein, the data group is divided into a plurality of regions to be used for different purposes. More specifically, a region of the main service data having no interference or a very low interference level may be considered to have a more resistant (or stronger) receiving performance as compared to regions having higher interference levels. Additionally, when using a system inserting and transmitting known data in the data group, wherein the known data are known based upon an agreement between the transmitting system and the receiving system, and when consecutively long known data are to be periodically inserted in the mobile service data, the known data having a predetermined length may be periodically inserted in the region having no interference from the main service data (i.e., a region wherein the main service data are not mixed). However, due to interference from the main service data, it is difficult to periodically insert known data and also to insert consecutively long known data to a region having interference from the main service data.
In the present invention, the signaling information area may start from the 1st segment of the 4th MH block (B4) to a portion of the 2nd segment. According to an embodiment of the present invention, the signaling information area for inserting signaling information may start from the 1st segment of the 4th MH block (B4) to a portion of the 2nd segment.
More specifically, 276(=207+69) bytes of the 4th MH block (B4) in each data group are assigned as the signaling information area. In other words, the signaling information area consists of 207 bytes of the 1st segment and the first 69 bytes of the 2nd segment of the 4th MH block (B4). The 1st segment of the 4th MH block (B4) corresponds to the 17th or 173rd segment of a VSB field.
FIG. 4 illustrates a structure of a MH frame for transmitting and receiving mobile service data according to the present invention. In the example shown in FIG. 4, one MH frame consists of 5 sub-frames, wherein each sub-frame includes 16 slots. In this case, the MH frame according to the present invention includes 5 sub-frames and 80 slots.
According to the embodiment of the present invention, a plurality of consecutive data groups is assigned to be spaced as far apart from one another as possible within the sub-frame. Thus, the system can be capable of responding promptly and effectively to any burst error that may occur within a sub-frame.
The mobile service data within one RS frame may be assigned either to all of regions A/B/C/D within the corresponding data group, or to at least one of regions A/B/C/D. In the embodiment of the present invention, the mobile service data within one RS frame may be assigned either to all of regions A/B/C/D, or to at least one of regions A/B and regions C/D. If the mobile service data are assigned to the latter case (i.e., one of regions A/B and regions C/D), the RS frame being assigned to regions A/B and the RS frame being assigned to regions C/D within the corresponding data group are different from one another. According to the embodiment of the present invention, the RS frame being assigned to regions A/B within the corresponding data group will be referred to as a “primary RS frame”, and the RS frame being assigned to regions C/D within the corresponding data group will be referred to as a “secondary RS frame”, for simplicity. Also, the primary RS frame and the secondary RS frame form (or configure) one parade. More specifically, when the mobile service data within one RS frame are assigned either to all of regions A/B/C/D within the corresponding data group, one parade transmits one RS frame. Conversely, when the mobile service data within one RS frame are assigned either to at least one of regions A/B and regions C/D, one parade may transmit up to 2 RS frames.
More specifically, the RS frame mode indicates whether a parade transmits one RS frame, or whether the parade transmits two RS frames. Such RS frame mode is transmitted as the above-described TPC data.
As described in the assignment of data groups, the parades are also assigned to be spaced as far apart from one another as possible within the sub-frame. Thus, the system can be capable of responding promptly and effectively to any burst error that may occur within a sub-frame.
Furthermore, the method of assigning parades may be identically applied to all MH frames or differently applied to each MH frame. According to the embodiment of the present invention, the parades may be assigned differently for each MH frame and identically for all sub-frames within an MH frame. More specifically, the MH frame structure may vary by MH frame units. Thus, an ensemble rate may be adjusted on a more frequent and flexible basis.
FIG. 9 illustrates an example of multiple data groups of a single parade being assigned (or allocated) to an MH frame. More specifically, FIG. 9 illustrates an example of a plurality of data groups included in a single parade, wherein the number of data groups included in a sub-frame is equal to ‘3’, being allocated to an MH frame.
Referring to FIG. 9, 3 data groups are sequentially assigned to a sub-frame at a cycle period of 4 slots. Accordingly, when this process is equally performed in the 5 sub-frames included in the corresponding MH frame, 15 data groups are assigned to a single MH frame. Herein, the 15 data groups correspond to data groups included in a parade. Therefore, since one sub-frame is configured of 4 VSB frame, and since 3 data groups are included in a sub-frame, the data group of the corresponding parade is not assigned to one of the 4 VSB frames within a sub-frame.
Basically, the method of assigning data groups corresponding to multiple parades is very similar to the method of assigning data groups corresponding to a single parade. In other words, data groups included in other parades that are to be assigned to an MH frame are also respectively assigned according to a cycle period of 4 slots.
At this point, data groups of a different parade may be sequentially assigned to the respective slots in a circular method. Herein, the data groups are assigned to slots starting from the ones to which data groups of the previous parade have not yet been assigned.
Also, when the 2nd parade includes 2 data groups for each sub-frame, the positions of each data groups within the sub-frames may be obtained by substituting values ‘3’ and ‘4’ for i in Equation 1. More specifically, the data groups of the 2nd parade (Parade #1) are sequentially assigned to the 2nd and 12th slots (Slot #1 and Slot #11) within the sub-frame.
FIG. 11 illustrates an example of expanding the assignment process of 3 parades, shown in FIGS. 10, to 5 sub-frames within an MH frame.
FIG. 12 illustrates a data transmission structure according to an embodiment of the present invention, wherein signaling data are included in a data group so as to be transmitted.
As described above, an MH frame is divided into 5 sub-frames. Data groups corresponding to a plurality of parades co-exist in each sub-frame. Herein, the data groups corresponding to each parade are grouped by MH frame units, thereby configuring a single parade.
The FIC body defined in an MH transport (M1) identifies the physical location of each the data stream for each virtual channel and provides very high level descriptions of each virtual channel.
The FIC_seg_number field is a 4-bit field. Herein, when a single FIC body is divided into a plurality of FIC segments and transmitted, the FIC_seg_number field indicates the number of the corresponding FIC segment.
Finally, the FIC_last_seg_number field is also a 4-bit field. The FIC_last_seg_number field indicates the number of the last FIC segment within the corresponding FIC body.
The current_next_indicator field is a 1-bit field. The current_next_indicator field acts as an indicator identifying whether the corresponding FIC data carry MH ensemble configuration information of an MH frame including the current FIC segment, or whether the corresponding FIC data carry MH ensemble configuration information of a next MH frame.
A third region of the FIC segment payload a channel loop region, which includes a channel_type field, a channel_activity field, a CA_indicator field, a stand_alone_service_indicator field, a major_channel_num field, and a minor_channel_num field.
The channel_type field is a 5-bit field indicating a service type of the corresponding virtual channel. For example, the channel_type field may indicates an audio/video channel, an audio/video and data channel, an audio-only channel, a data-only channel, a file download channel, an ESG delivery channel, a notification channel, and so on.
FIG. 17 illustrates an exemplary bit stream syntax structure of a service map table (hereinafter referred to as “SMT”) section according to the present invention. According to the embodiment of the present invention, the SMT section is configured in an MPEG-2 private section format. However, this will not limit the scope and spirit of the present invention. The SMT section according to the embodiment of the present invention includes description information for each virtual channel within a single MH ensemble. And, additional information may further be included in each descriptor area. In the description of the present invention, the section will be referred to as a “transmission unit” for simplicity. More specifically, a single SMT is divided into a plurality of SMT transmission units (e.g., SMT sections) so as to be transmitted in section units.
According to an embodiment of the present invention, an SMT section provides signaling information on a single ensemble. In this case, the SMT section is included in an RS frame transmitting the corresponding ensemble, thereby being transmitted. More specifically, the SMT section provides channel information, service identification information, IP access information, and so on, for each virtual channel within the corresponding ensemble. The SMT section may also provide IP access information for each IP stream component included in a single virtual channel.
According to the embodiment of the present invention, if IP access information of a virtual channel and IP access information for each IP stream component included in a virtual channel are simultaneously provided to the SMT section, a priority level is assigned to the IP access information for each IP stream component. In other words, in order to access the corresponding IP stream component, the IP access information of a virtual channel is ignored (or disregarded), and the IP access information of a corresponding IP stream component is used. In order to describe the above-mentioned information, the SMT section includes at least one field and is transmitted from the transmitting system to the receiving system.
Meanwhile, when the SMT is encapsulated to IP datagrams, and when it is determined that the corresponding MH TP includes an SMT section based upon the header in each of the inputted MH TP, the MH TP handler 213 outputs the SMT section to the IP network stack 220. Accordingly, the IP network stack 220 performs IP and UDP processes on the inputted SMT section and, then, outputs the processed SMT section to the SI handler 240. The SI handler 240 parses the inputted SMT section and controls the system so that the parsed SI data can be stored in the storage unit 290.
A table_id field corresponds to an 8-bit unsigned integer number, which indicates the type of table section. The table_id field allows the corresponding table to be defined as the service map table (SMT).
An ensemble_id field is an 8-bit unsigned integer field, which corresponds to an ID value associated to the corresponding MH ensemble. Herein, the ensemble_id field may be assigned with a value ranging from range ‘0x00’ to ‘0x3F’. It is preferable that the value of the ensemble_id field is derived from the parade_id of the TPC data, which is carried from the baseband processor of MH physical layer subsystem. When the corresponding MH ensemble is transmitted through (or carried over) the primary RS frame, a value of ‘0’ may be used for the most significant bit (MSB), and the remaining 7 bits are used as the parade_id value of the associated MH parade (i.e., for the least significant 7 bits). Alternatively, when the corresponding MH ensemble is transmitted through (or carried over) the secondary RS frame, a value of ‘1’ may be used for the most significant bit (MSB).
A num_channels field is an 8-bit field, which specifies the number of virtual channels in the corresponding SMT section.
A major_channel_num field corresponds to an 8-bit field, which represents the major channel number associated with the corresponding virtual channel. Herein, the major_channel_num field may be assigned with a value ranging from ‘0x00’ to ‘0xFF’.
A minor_channel_num field corresponds to an 8-bit field, which represents the minor channel number associated with the corresponding virtual channel. Herein, the minor_channel_num field may be assigned with a value ranging from ‘0x00’ to ‘0xFF’.
A short_channel_name field indicates the short name of the virtual channel.
A service_id field is a 16-bit unsigned integer number (or value), which identifies the virtual channel service.
A service_type field is a 6-bit enumerated type field, which designates the type of service carried in the corresponding virtual channel as defined in Table 2 below.
A virtual_channel_activity field is a 2-bit enumerated field identifying the activity status of the corresponding virtual channel. When the most significant bit (MSB) of the virtual_channel_activity field is ‘1’, the virtual channel is active, and when the most significant bit (MSB) of the virtual_channel_activity field is ‘0’, the virtual channel is inactive. Also, when the least significant bit (LSB) of the virtual_channel_activity field is ‘1’, the virtual channel is hidden (when set to 1), and when the least significant bit (LSB) of the virtual_channel_activity field is ‘0’, the virtual channel is not hidden.
A num_components field is a 5-bit field, which specifies the number of IP stream components in the corresponding virtual channel.
An IP_version_flag field corresponds to a 1-bit indicator. More specifically, when the value of the IP_version_flag field is set to ‘1’, this indicates that a source_IP_address field, a virtual_channel_target_IP_address field, and a component_target_IP_address field are IPv6 addresses. Alternatively, when the value of the IP_version_flag field is set to ‘0’, this indicates that the source_IP_address field, the virtual_channel_target_IP_address field, and the component_target_IP_address field are IPv4.
A source_IP_address_flag field is a 1-bit Boolean flag, which indicates, when set, that a source IP address of the corresponding virtual channel exist for a specific multicast source.
A virtual_channel_target_IP_address_flag field is a 1-bit Boolean flag, which indicates, when set, that the corresponding IP stream component is delivered through IP datagrams with target IP addresses different from the virtual_channel_target_IP_address. Therefore, when the flag is set, the receiving system (or receiver) uses the component_target_IP_address as the target_IP_address in order to access the corresponding IP stream component. Accordingly, the receiving system (or receiver) may ignore the virtual_channel_target_IP_address field included in the num_channels loop.
The virtual_channel_target_IP_address field also corresponds to a 32-bit or 128-bit field. Herein, the virtual_channel_target_IP_address field will be significant (or present), when the value of the virtual_channel_target_IP_address_flag field is set to ‘1’. However, when the value of the virtual_channel_target_IP_address_flag field is set to ‘0’, the virtual_channel_target_IP_address field will become insignificant (or absent). More specifically, when the virtual_channel_target_IP_address_flag field value is set to ‘1’, and when the IP_version_flag field value is set to ‘0’, the virtual_channel_target_IP_address field indicates a 32-bit target IPv4 address associated to the corresponding virtual channel. Alternatively, when the virtual_channel_target_IP_address_flag field value is set to ‘1’, and when the IP_version_flag field value is set to ‘1’, the virtual_channel_target_IP_address field indicates a 64-bit target IPv6 address associated to the corresponding virtual channel. If the virtual_channel_target_IP_address field is insignificant (or absent), the component_target_IP_address field within the num channels loop should become significant (or present). And, in order to enable the receiving system to access the IP stream component, the component_target_IP_address field should be used.
Herein, an RTP_payload_type field, which is assigned with 7 bits, identifies the encoding format of the component based upon Table 3 shown below. When the IP stream component is not encapsulated to RTP, the RTP_payload_type field shall be ignored (or deprecated).
Table 3 below shows an example of an RTP payload type.
A component_target_IP_address_flag field is a 1-bit Boolean flag, which indicates, when set, that the corresponding IP stream component is delivered through IP datagrams with target IP addresses different from the virtual_channel_target_IP_address. Furthermore, when the component_target_IP_address_flag is set, the receiving system (or receiver) uses a component_target_IP_address field as the target IP address for accessing the corresponding IP stream component. Accordingly, the receiving system (or receiver) will ignore the virtual_channel_target_IP_address field included in the num_channels loop.
A port_num_count field is a 6-bit field, which indicates the number of UDP ports associated with the corresponding IP stream component. A target UDP port number value starts from the target_UDP_port_num field value and increases (or is incremented) by 1. For the RTP stream, the target UDP port number should start from the target_UDP_port_num field value and shall increase (or be incremented) by 2. This is to incorporate RTCP streams associated with the RTP streams.
A target_UDP_port_num field is a 16-bit unsigned integer field, which represents the target UDP port number for the corresponding IP stream component. When used for RTP streams, the value of the target_UDP_port_num field shall correspond to an even number. And, the next higher value shall represent the target UDP port number of the associated RTCP stream.
A component_level_descriptor( )represents zero or more descriptors providing additional information on the corresponding IP stream component.
A virtual_channel_level_descriptor( ) represents zero or more descriptors providing additional information for the corresponding virtual channel.
An ensemble_level_descriptor( ) represents zero or more descriptors providing additional information for the MH ensemble, which is described by the corresponding SMT.
A descriptor_tag field is an 8-bit unsigned integer having a TBD value, which indicates that the corresponding descriptor is the MH_audio_descriptor( ).
A descriptor_length field is also an 8-bit unsigned integer, which indicates the length (in bytes) of the portion immediately following the descriptor_length field up to the end of the MH_audio_descriptor( ).
A channel_configuration field corresponds to an 8-bit field indicating the number and configuration of audio channels. The values ranging from ‘1’ to ‘6’ respectively indicate the number and configuration of audio channels as given for “Default bit stream index number” in Table 42 of ISO/IEC 13818-7:2006. All other values indicate that the number and configuration of audio channels are undefined.
A sample_rate_code field is a 3-bit field, which indicates the sample rate of the encoded audio data. Herein, the indication may correspond to one specific sample rate, or may correspond to a set of values that include the sample rate of the encoded audio data as defined in Table A3.3 of ATSC A/52B.
A bit_rate_code field corresponds to a 6-bit field. Herein, among the 6 bits, the lower 5 bits indicate a nominal bit rate. More specifically, when the most significant bit (MSB) is ‘0’, the corresponding bit rate is exact. On the other hand, when the most significant bit (MSB) is ‘0’, the bit rate corresponds to an upper limit as defined in Table A3.4 of ATSC A/53B.
An ISO—639_language_code field is a 24-bit (i.e., 3-byte) field indicating the language used for the audio stream component, in conformance with ISO 639.2/B [x]. When a specific language is not present in the corresponding audio stream component, the value of each byte will be set to ‘0x00’.
The MH_RTP_payload_type_descriptor( ) specifies the RTP payload type. Yet, the MH_RTP_payload_type_descriptor( ) exists only when the dynamic value of the RTP_payload_type field within the num_components loop of the SMT is in the range of ‘96’ to ‘127’. The MH_RTP_payload_type_descriptor( ) is used as a component_level_descriptor of the SMT.
A descriptor_tag field corresponds to an 8-bit unsigned integer having the value TBD, which identifies the current descriptor as the MH_RTP_payload_type_descriptor( ).
A descriptor_length field also corresponds to an 8-bit unsigned integer, which indicates the length (in bytes) of the portion immediately following the descriptor_length field up to the end of the MH_RTP_payload_type_descriptor( ).
An RTP_payload_type field corresponds to a 7-bit field, which identifies the encoding format of the IP stream component. Herein, the dynamic value of the RTP_payload_type field is in the range of ‘96’ to ‘127’.
A MIME_type_length field specifies the length (in bytes) of a MIME_type_field.
A descriptor_tag field corresponds to an 8-bit unsigned integer having the value TBD, which identifies the current descriptor as the MH_current_event_descriptor( ).
A descriptor_length field also corresponds to an 8-bit unsigned integer, which indicates the length (in bytes) of the portion immediately following the descriptor_length field up to the end of the MH_current_event_descriptor( ).
A current_event_start_time field corresponds to a 32-bit unsigned integer quantity. The current_event_start_time field represents the start time of the current event and, more specifically, as the number of GPS seconds since 00:00:00 UTC, Jan. 6, 1980.
A current_event_duration field corresponds to a 24-bit field. Herein, the current_event_duration field indicates the duration of the current event in hours, minutes, and seconds (wherein the format is in 6 digits, 4-bit BCD=24 bits).
A title_length field specifies the length (in bytes) of a title_text field. Herein, the value ‘0’ indicates that there are no titles existing for the corresponding event.
The optional MH_next_event_descriptor( ) shall be used as the virtual_channel_level_descriptor( ) within the SMT. Herein, the MH_next_event_descriptor( ) provides basic information on the next event (e.g., the start time, duration, and title of the next event, etc.), which is transmitted via the respective virtual channel.
The fields included in the MH_next_event_descriptor( ) will now be described in detail.
A descriptor_tag field corresponds to an 8-bit unsigned integer having the value TBD, which identifies the current descriptor as the MH_next_event_descriptor( ).
A descriptor_length field also corresponds to an 8-bit unsigned integer, which indicates the length (in bytes) of the portion immediately following the descriptor_length field up to the end of the MH_next_event_descriptor( ).
A next_event_start_time field corresponds to a 32-bit unsigned integer quantity. The next_event_start_time field represents the start time of the next event and, more specifically, as the number of GPS seconds since 00:00:00 UTC, Jan. 6, 1980.
A next_event_duration field corresponds to a 24-bit field. Herein, the next_event_duration field indicates the duration of the next event in hours, minutes, and seconds (wherein the format is in 6 digits, 4-bit BCD=24 bits).
The MH_system_time_descriptor( ) shall be used as the ensemble_level_descriptor( ) within the SMT. Herein, the MH_system_time_descriptor( ) provides information on current time and date. The MH_system_time_descriptor( ) also provides information on the time zone in which the transmitting system (or transmitter) transmitting the corresponding broadcast stream is located, while taking into consideration the mobile/portable characteristics of the MH service data.
A descriptor_tag field corresponds to an 8-bit unsigned integer having the value TBD, which identifies the current descriptor as the MH_system_time_descriptor( ).
A descriptor_length field also corresponds to an 8-bit unsigned integer, which indicates the length (in bytes) of the portion immediately following the descriptor_length field up to the end of the MH_system_time_descriptor( ).
A system_time field corresponds to a 32-bit unsigned integer quantity. The system_time field represents the current system time and, more specifically, as the number of GPS seconds since 00:00:00 UTC, Jan. 6, 1980.
A GPS_UTC_offset field corresponds to an 8-bit unsigned integer, which defines the current offset in whole seconds between GPS and UTC time standards. In order to convert GPS time to UTC time, the GPS_UTC_offset is subtracted from GPS time. Whenever the International Bureau of Weights and Measures decides that the current offset is too far in error, an additional leap second may be added (or subtracted). Accordingly, the GPS_UTC_offset field value will reflect the change.
A time_zone_offset_polarity field is a 1-bit field, which indicates whether the time of the time zone, in which the broadcast station is located, exceeds (or leads or is faster) or falls behind (or lags or is slower) than the UTC time. When the value of the time_zone_offset_polarity field is equal to ‘0’, this indicates that the time on the current time zone exceeds the UTC time. Therefore, a time_zone_offset field value is added to the UTC time value. Conversely, when the value of the time_zone_offset_polarity field is equal to ‘1’, this indicates that the time on the current time zone falls behind the UTC time. Therefore, the time_zone_offset field value is subtracted from the UTC time value.
The time_zone_offset field is a 31-bit unsigned integer quantity. More specifically, the time_zone_offset field represents, in GPS seconds, the time offset of the time zone in which the broadcast station is located, when compared to the UTC time.
A daylight_savings field corresponds to a 16-bit field providing information on the Summer Time (i.e., the Daylight Savings Time).
A time_zone field corresponds to a (5×8)-bit field indicating the time zone, in which the transmitting system (or transmitter) transmitting the corresponding broadcast stream is located.
According to the present invention, the SMT is encapsulated to UDP/IP, while including a target IP address and a target UDP port number within the IP datagram. More specifically, the SMT is first segmented into a predetermined number of sections, then encapsulated to a UDP header, and finally encapsulated to an IP header.
As described above, the digital broadcasting system and the data processing method have the following advantages. For service acquisition, the present invention uses FIC data, which are transmitted through a separate fast information channel (FIC) apart from an RS frame data channel. Also, after tuning to a requested (or desired) ensemble, the present invention processes the service map table (SMT) included in an RS frame of the corresponding ensemble. Thus, the present invention may access the mobile service data of a requested (or desired) IP stream component from the RS frame based upon the processed SMT information.
The SMT includes mapping information for virtual channels and IP access information and also information required for the acquisition of IP stream components of each virtual channel in field and descriptor formats. At this point, the SMT is divided (or segmented) into the respective transmission units (e.g., section units), thereby transmitted. Herein, each SMT section may be used for parsing. The SMT section includes virtual channel information of an ensemble through which the corresponding SMT section is transmitted. And, each SMT section is distinguished by a respective ensemble identifier and a respective section number.
Furthermore, each SMT section is encapsulated to UDP/IP. Herein, since the IP address and the UDP port number use well-known values, the digital broadcast receiving system may be able to receive the corresponding SMT section without any additional or separate IP access information. More specifically, by using an SMT that is transmitted via well-known IP address and UDP port number, the present invention may be able to acquire access information of an IP-based virtual channel, thereby receiving the corresponding virtual channel service.
accessing to IP datagrams of the mobile service data in the ensemble according to mobile service acquisition information of at least one mobile service included in the extracted SMT.
17. The method of claim 16, wherein the first channel information and the second channel information are positioned between a first known data sequence and a second known data sequence of the plurality of known data sequences.
18. The method of claim 16, wherein at least two of the plurality of known data sequences are spaced 16 segments apart and have different lengths.
19. The method of claim 16, wherein the SMT includes the ensemble identifier identifying the ensemble.
20. The method of claim 19, wherein the SMT is differentiated by utilizing a table identifier and the ensemble identifier included therein.
21. The method of claim 16, wherein the SMT is encapsulated with a UDP header and an IP header.
a second handler for accessing to IP datagrams of the mobile service data in the ensemble according to mobile service acquisition information of at least one mobile service included in the extracted SMT.
23. The broadcast receiver of claim 22, wherein the first channel information and the second channel information are positioned between a first known data sequence and a second known data sequence of the plurality of known data sequences.
24. The broadcast receiver of claim 22, wherein at least two of the plurality of known data sequences are spaced 16 segments apart and have different lengths.
25. The broadcast receiver of claim 22, wherein the SMT includes the ensemble identifier identifying the ensemble.
26. The broadcast receiver of claim 25, wherein the SMT is differentiated by utilizing a table identifier and the ensemble identifier included therein.
27. The broadcast receiver of claim 22, wherein the SMT is encapsulated with a UDP header and an IP header.
wherein the ensemble includes a service map table (SMT) having mobile service acquisition information of at least one mobile service, and wherein Internet protocol (IP) datagrams carrying the SMT have a well-known target IP address and a well-known target user datagram protocol (UDP) port number.
29. The method of claim 28, wherein the first channel information and the second channel information are positioned between a first known data sequence and a second known data sequence of the plurality of known data sequences.
30. The method of claim 28, wherein at least two of the plurality of known data sequences are spaced 16 segments apart and have different lengths.
31. The method of claim 28, wherein the SMT includes an ensemble identifier identifying the ensemble.
32. The method of claim 31, wherein the SMT is differentiated by utilizing a table identifier and the ensemble identifier included therein.
33. The method of claim 28, wherein the SMT is encapsulated with a UDP header and an IP header.
35. The broadcast transmitter of claim 34, wherein the first channel information and the second channel information are positioned between a first known data sequence and a second known data sequence of the plurality of known data sequences.
36. The broadcast transmitter of claim 34, wherein at least two of the plurality of known data sequences are spaced 16 segments apart and have different lengths.
37. The broadcast transmitter of claim 34, wherein the SMT includes an ensemble identifier identifying the ensemble.
38. The broadcast transmitter of claim 37, wherein the SMT is differentiated by utilizing a table identifier and the ensemble identifier included therein.
39. The broadcast transmitter of claim 34, wherein the SMT is encapsulated with a UDP header and an IP header.

References: Application No. 60
 Application No. 60
 Application No. 60
 Application No. 61
 Application No. 61
 Application No. 61
 Application No. 10