Abstract:
An Ethernet-MOST gateway apparatus for exchanging data between a MOST network transferring multimedia data within a vehicle and a packet network for a computer and Internet communications. The Ethernet-MOS gateway apparatus including: an Ethernet frame interface unit connected with a packet network to transmit and receive an Ethernet frame, and converting the Ethernet frame into a MOST frame; a MOST frame interface unit connected with a MOST network to transmit and receive the MOST frame, and converting the MOST frame into the Ethernet frame; and a switch fabric connecting the Ethernet frame interface unit and the MOST frame interface unit.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the priority of Korean Patent Application No. 10-2009-0128750 filed on Dec. 22, 2009, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to an Ethernet-MOST (Media Oriented System Transport) gateway apparatus and, more particularly, to an Ethernet-MOST gateway apparatus for exchanging data between a MOST network transferring multimedia data within a vehicle and a packet network for a computer and Internet communication. 
         [0004]    2. Description of the Related Art 
         [0005]    MOST (Media Oriented System Transport) is a communications standard for data transmission between various vehicle-based multimedia devices (e.g., a vehicle audio visual (AV) system, a navigation system, a digital versatile disc (DVD) player, a changer, an amplifier, and the like). In general, it establishes a ring-type network so as to transmit large quantities of multimedia information such as voice, video, and the like, through optical fibers at a wide bandwidth according to a high speed transmission scheme. 
         [0006]    Packet networks are commonly employed for a LAN (Local Area Network), a WAN (Wide area network), and the like, owing to the development of high-tech equipment such as a hub, a switch, a router, and the like, as well as various types of multimedia services such as a digital broadcast, a video call, VoD (Video on Demand), IPTV (Internet Protocol Television), and the like, in concert with the explosive increase in Internet users and existing data services. 
         [0007]    In the past, vehicles were merely transportation systems carrying human beings, things or objects from place to place; however, some contemporary vehicles are classified as infotainment (information+entertainment) systems, having information and entertainment functions in addition to their existing transportation functionality. Thus, a MOST network supporting a vehicle multimedia service must use packet network data providing general data services and novel multimedia services in order to support such Infotainment. 
         [0008]    However, a MOST frame for transferring data in the MOST network and an Ethernet frame for transferring data in the packet network are of different frame types, so information cannot be transferred between these frames without being converted. Also, an improper use of MOST frame synchronization and asynchronization intervals makes it impossible to effectively transfer the multimedia services from the packet network thereto. 
         [0009]    Therefore, a gateway connecting the MOST frame of the MOST network and the Ethernet frame of the packet network is required. 
       SUMMARY OF THE INVENTION 
       [0010]    An aspect of the present invention provides an Ethernet-MOST (Media Oriented System Transport) gateway apparatus capable of effectively converting a frame for a data transfer between a MOST network and a packet network, and a method for processing a frame thereof. 
         [0011]    According to an aspect of the present invention, there is provided an Ethernet-MOS gateway apparatus including: an Ethernet frame interface unit connected with a packet network so as to transmit and receive an Ethernet frame, and converting the Ethernet frame into a MOST frame; a MOST frame interface unit connected with a MOST network to transmit and receive the MOST frame, and converting the MOST frame into the Ethernet frame; and a switch fabric connecting the Ethernet frame interface unit and the MOST frame interface unit. 
         [0012]    The Ethernet frame interface unit may include: a physical layer and MAC layer processing unit performing physical layer and MAC layer processing on the Ethernet frame; an Ethernet frame parser parsing the Ethernet frame; and an Ethernet frame processor converting the Ethernet frame which has been parsed by the Ethernet frame parser into the MOST frame when the Ethernet frame is to be transmitted to the MOST network. 
         [0013]    The Ethernet frame processor may fragment data included in the parsed Ethernet frame, according to the length of the MOST frame, generate one or more MOST frames, each including the fragmented data, and output the same. 
         [0014]    The Ethernet frame processor may additionally have a function of analyzing Ethernet type information included in the Ethernet frame and determining whether to use an SDA (Synchronous Data Area) or an ADA (Asynchronous Data Area) of the MOST frame. 
         [0015]    Each of the MOST frames may include: a preamble area in which information for the synchronization of the MOST frame is stored; an SDA in which synchronous data is stored; an ADA in which asynchronous data is stored; a BD (Boundary Descriptor) area in which information for discriminating the SDA and the ADA is stored; a CC (Control Channel) area in which command, status, and diagnosis information for controlling the MOST network is stored; an FC (Frame Control) area in which information for controlling the MOST frame is stored; and a PB (Parity Bit) area in which information for detecting a MOST frame error is stored, wherein one of the SDA and the ADA stores data fragmented by the Ethernet frame processor. 
         [0016]    The MOST frame interface unit may include: a MOST physical layer processing unit performing physical layer processing on the MOST frame; a framer framing the MOST frame to be transmitted to or received from the MOST network; a MOST frame parser parsing the MOST frame; and a MOST frame processor converting the MOST frame which has been parsed by the MOST frame parser into an Ethernet frame when the MOST frame is to be transmitted to the packet network. 
         [0017]    The MOST frame processor may generate one or more Ethernet frames by using one or more units of synchronous data and asynchronous data included in the parsed MOST frame, and output the same. 
         [0018]    Each of one or more of the Ethernet frames may include: a preamble area in which information for the synchronization of the Ethernet frame is stored; an SFD (Start Frame Delimiter) area in which information indicating a start of the Ethernet frame is stored; a DA (Destination Address) area in which information indicating the address of a destination is stored; an SA (Source Address) area in which information indicating the address of a source is stored; an Ethernet type (E-type) area in which information indicating that the parsed MOST frame is a frame having synchronous data or asynchronous data is stored; a data area in which the synchronous data or the asynchronous data of the parsed MOST frame is stored; and an FCS (Frame Check Sequence) area in which information for detecting an Ethernet frame error is stored. 
         [0019]    If necessary, dummy information for adjusting the size of a minimum Ethernet frame may be additionally stored in the data area. 
         [0020]    According to another aspect of the present invention, there is provided a method for processing a frame of an Ethernet-MOST gateway apparatus, including: receiving and parsing an Ethernet frame; determining a network to which the Ethernet frame is to be transmitted; when the Ethernet frame is to be transmitted to a MOST network, fragmenting data included in the Ethernet frame such that the fragmented data fits the length of a MOST frame; and generating one or more MOST frames, each of the one or more MOST frames including the fragmented data, and outputting the same. 
         [0021]    The method may further include: analyzing Ethernet type information included in the Ethernet frame to determine whether to use an SDA (Synchronous Data Area) or an ADA (Asynchronous Data Area) of the MOST frame. 
         [0022]    Each of the MOST frames may include: a preamble area in which information for the synchronization of the MOST frame is stored; an SDA in which synchronous data is stored; an ADA in which asynchronous data is stored; a BD (Boundary Descriptor) area in which information for discriminating the SDA and the ADA is stored; a CC (Control Channel) area in which command, status, and diagnosis information for controlling the MOST network is stored; an FC (Frame Control) area in which information for controlling the MOST frame is stored; and a PB (Parity Bit) area in which information for detecting a MOST frame error is stored, wherein one of the SDA and the ADA stores data fragmented by the Ethernet frame processor, instead of the synchronous data or the asynchronous data. 
         [0023]    According to another aspect of the present invention, there is provided a method for processing a frame of an Ethernet-MOST gateway apparatus, including: receiving and parsing a MOST frame; determining a network to which the MOST frame is to be transmitted; and when the MOST frame is to be transmitted to a packet network, generating one or more Ethernet frames by using one or more units of synchronous data and asynchronous data included in the MOST frame, and outputting the same. 
         [0024]    The generating and outputting of one or more Ethernet frames may include: generating one or more Ethernet frames by using one or more units of synchronous data and asynchronous data included in the MOST frame; and setting an E-type A or port information (UDP (User Datagram Protocol)) in the Ethernet frame which has been generated by using the synchronous data included in the MOST frame and setting an E-type B or port information (TCP (Transmission Control Protocol)) in the Ethernet frame which has been generated by using the asynchronous data included in the MOST frame. 
         [0025]    Each of one or more of the Ethernet frames may include: a preamble area in which information for the synchronization of the Ethernet frame is stored; an SFD (Start Frame Delimiter) area in which information indicating a start of the Ethernet frame is stored; a DA (Destination Address) area in which information indicating the address of a destination is stored; an SA (Source Address) area in which information indicating the address of a source is stored; an Ethernet type (E-type) area in which information indicating that the parsed MOST frame is a frame having synchronous data or asynchronous data is stored; a data area in which the synchronous data or the asynchronous data of the parsed MOST frame is stored; and an FCS (Frame Check Sequence) area in which information for detecting an Ethernet frame error is stored. 
         [0026]    The generating and outputting of one or more Ethernet frames may include: additionally storing dummy information for adjusting the size of a minimum Ethernet frame in the data area. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]    The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
           [0028]      FIG. 1  is a schematic block diagram of an Ethernet-MOST gateway apparatus according to an exemplary embodiment of the present invention; 
           [0029]      FIG. 2  illustrates the structure of a general Ethernet frame and that of a MOST frame; 
           [0030]      FIG. 3  is a flow chart illustrating the process of a method for processing a frame of the Ethernet-MOST gateway apparatus according to an exemplary embodiment of the present invention; 
           [0031]      FIG. 4  illustrates the process of receiving an Ethernet frame by the Ethernet-MOST gateway apparatus from a packet network and generating a MOST frame to be transmitted to a MOST network according to an exemplary embodiment of the present invention; 
           [0032]      FIG. 5  is a flow chart illustrating the process of a method for processing a frame of the Ethernet-MOST gateway apparatus according to an exemplary embodiment of the present invention; and 
           [0033]      FIG. 6  illustrates the process of receiving a MOST frame by the Ethernet-MOST gateway apparatus from the MOST network and generating an Ethernet frame to be transmitted to the packet network according to another exemplary embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0034]    Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In describing the present invention, if a detailed explanation for a related known function or construction is considered to unnecessarily divert the gist of the present invention, such explanation will be omitted but would be understood by those skilled in the art. 
         [0035]    In the drawings, the shapes and dimensions may be exaggerated for clarity, and the same reference numerals will be used throughout to designate the same or like components. 
         [0036]    It will be understood that unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising,” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. 
         [0037]      FIG. 1  is a schematic block diagram of an Ethernet-MOST gateway apparatus according to an exemplary embodiment of the present invention. 
         [0038]    With reference to  FIG. 1 , the Ethernet-MOST gateway apparatus according to an exemplary embodiment of the present invention includes an Ethernet frame interface unit  100  connected with a packet network to transmit and receive an Ethernet frame and converting an Ethernet frame into a MOST frame, a MOST frame interface unit  110  connected with a MOST network to transmit and receive a MOST frame and converting a MOST frame into an Ethernet frame, and a switch fabric  120  connecting the Ethernet frame interface unit  100  and the MOST frame interface unit  110 , namely, the packet network and the MOST network. 
         [0039]    The Ethernet frame interface unit  100  includes an Ethernet physical layer processing unit  101  for transmitting and receiving an Ethernet frame through a plurality of transmission/reception ports (namely, performing physical layer processing on the Ethernet frame), an Ethernet MAC layer processing unit  102  for transmitting and receiving the Ethernet frame to and from the packet network through the Ethernet physical layer processing unit  101  (namely, performing MAC layer processing on the Ethernet frame), an Ethernet frame parser  103  for parsing the Ethernet frame, and an Ethernet frame processor  104  converting the Ethernet frame, which has been parsed by the Ethernet frame parser  103 , into a MOST frame when the Ethernet frame is to be transferred to the MOST frame. 
         [0040]    The MOST frame interface unit  110  includes a MOST physical layer processing unit  111  for transmitting and receiving a MOST frame through a plurality of transmission/reception ports (namely, performing physical layer processing on the MOST frame), a framer  112  for transmitting and receiving the MOST frame to and from the MOST network through the MOST physical layer processing unit  111  (namely, performing MAC layer processing on the Ethernet frame), a MOST frame parser  113  for parsing the MOST frame, and a MOST frame processor  114  for converting the MOST frame, which has been parsed by the MOST frame parser  113 , in to an Ethernet frame, when the MOST frame is to be transferred to the packet network. 
         [0041]      FIG. 2  illustrates the structure of a general Ethernet frame and that of a MOST frame. 
         [0042]    First, with reference to  FIG. 2(   a ), an Ethernet frame  200  according to an exemplary embodiment of the present invention includes a preamble area  201  in which preamble information for the synchronization of an Ethernet frame is stored, an SFD (Start Frame Delimiter) area  202  in which information indicating a start of the Ethernet frame is stored, a DA (Destination Address) area  203  in which information indicating the address of a destination is stored, an SA (Source Address) area  204  in which information indicating the address of a source is stored, an Ethernet type (E-type) area  205  in which information regarding the type of the Ethernet frame is stored, a data area  206  in which data desired to be transmitted is stored, and an FCS (Frame Check Sequence) area  207  in which information for detecting an Ethernet frame error is stored. 
         [0043]    With reference to  FIG. 2(   b ), a MOST frame  210  includes a preamble area  211  in which preamble information for the synchronization of a MOST frame is stored, a BD (Boundary Descriptor) area  212  in which information for discriminating an SDA (Synchronous Data Area) and an ADA (Asynchronous Data Area) in the MOST frame is stored, an SDA  213  in which synchronous data desired to be transmitted is stored, an ADA  214  in which asynchronous data desired to be transmitted is stored, a CC (Control Channel) area  215  in which command, status, and diagnosis information for controlling a MOST network is stored, an FC (Frame Control) area  216  in which information for controlling the MOST frame is stored, and a PB (Parity Bit) area  217  in which information for detecting a MOST frame error is stored. 
         [0044]      FIG. 3  is a flow chart illustrating the process of a method for processing a frame of the Ethernet-MOST gateway apparatus according to an exemplary embodiment of the present invention. For example, a case in which an Ethernet frame of the packet network is transmitted to the MOST network will be described with reference to  FIG. 3 . 
         [0045]    First, in an Ethernet frame reception step S 11 , the Ethernet physical layer processing unit  101  and the Ethernet MAC layer processing unit  102  of the Ethernet frame interface unit  100  receive an Ethernet frame. 
         [0046]    In an Ethernet frame analysis step S 12 , the Ethernet frame parser  103  of the Ethernet frame interface unit  100  extracts information from the received Ethernet frame. 
         [0047]    In a network determining step S 13 , the Ethernet frame processor  104  of the Ethernet frame interface unit  100  determines which network the received Ethernet frame is to be transmitted to. Also, in the network determining step S 13 , the decision as to whether to transmit data by using the SDA  213  or by using the ADA  214  of the MOST frame  210  is determined by analyzing the Ethernet type information and port number (TCP/UDP (Transmission Control Protocol/User Datagram Protocol)) information. 
         [0048]    In a packet fragmentation step S 14 , when the received Ethernet frame is to be transmitted to the MOST network, the Ethernet frame processor  104  of the Ethernet frame interface unit  100  fragments data of the received Ethernet frame such that it fits the length of the MOST frame. 
         [0049]    In a MOST frame generation step S 15 , when the received Ethernet frame is a synchronous data-stored frame, the Ethernet frame processor  104  of the Ethernet frame interface unit  100  transmits each of the units of data fragmented in the packet fragmentation step S 14  by using the SDA  213  of the MOST frame. Meanwhile, when the received Ethernet frame is an asynchronous data-stored frame, the Ethernet frame processor  104  of the Ethernet frame interface unit  100  transmits each of the units of data fragmented in the packet fragmentation step S 14  by using the ADA  214 . 
         [0050]      FIG. 4  illustrates the process of the Ethernet-MOST gateway apparatus receiving an Ethernet frame from the packet network and generating a MOST frame to be transmitted to the MOST network according to an exemplary embodiment of the present invention. 
         [0051]    In  FIG. 4 , it is assumed that the Ethernet frame  200  is transmitted to the MOST network and is a frame in which asynchronous data is stored, for the sake of brevity. 
         [0052]    First, because the amount of data that can be transmitted by the MOST frame is limited, data  206  of the Ethernet frame  200 , received from the packet network, is fragmented into units of data Data 1   401 , Data 2   402 , Data 3   403 , and Data 4   404 . 
         [0053]    The Ethernet-MOST gateway apparatus inserts the fragmented units of data Data 1   401 , Data 2   402 , Data 3   403 , and Data 4   404  into the ADA  214  of the MOST frame  210  in order to generate a first MOST frame  410 , a second MOST frame  420 , a third MOST frame  430 , and a fourth MOST frame  440 , and transmits them to the MOST network. 
         [0054]    The first MOST frame  410  includes the preamble area  211 , the BD area  212 , the SDA  213 , the Data 1  area  401 , the CC area  215 , the FC area  216 , and the PB area  217 . The second MOST frame  420  includes the preamble area  211 , the BD area  212 , the SDA  213 , the Data 2  area  402 , the CC area  215 , the FC area  216 , and the PB area  217 . The third MOST frame  430  includes the preamble area  211 , the BD area  212 , the SDA  213 , the Data 3  area  403 , the CC area  215 , the FC area  216 , and the PB area  217 . The fourth MOST frame  440  includes the preamble area  211 , the BD area  212 , the SDA  213 , the Data 4  area  404 , the CC area  215 , the FC area  216 , and the PB area  217 . 
         [0055]      FIG. 5  is a flow chart illustrating the process of a method for processing a frame of the Ethernet-MOST gateway apparatus according to an exemplary embodiment of the present invention. For example, a case in which a MOST frame of the MOST network is transmitted to the packet network will be described. 
         [0056]    First, in a MOST frame reception step S 21 , the Ethernet physical layer processing unit  111  and the framer  112  of the MOST frame interface unit  110  receive the MOST frame. 
         [0057]    In a MOST frame analysis step S 22 , the MOST frame parser  113  of the MOST frame interface unit  110  extracts information of the received MOST frame. 
         [0058]    In a network determining step S 23 , the MOST frame processor  114  of the MOST frame interface unit  110  determines to which network the received MOST frame is to be transmitted. 
         [0059]    An Ethernet frame generation step S 24 , the MOST frame processor  114  of the MOST frame interface unit  110  transmits SDA  213  data of the received MOST frame  210  by using Data  206  of the Ethernet frame  200 . Also, the MOST frame processor  114  of the MOST frame interface unit  110  transmits ADA  214  of the received MOST frame  210  by using Data  206  of the Ethernet frame  200 . In addition, in the Ethernet frame generation step S 24 , in the case of a synchronous frame, a corresponding E-type A or port information (UDP) unit of data is additionally set and transmitted, and in case of an asynchronous frame, a corresponding E-type B or port information (TCP) unit of data is additionally set and transmitted. 
         [0060]      FIG. 6  illustrates the process of the Ethernet-MOST gateway apparatus receiving a MOST frame from the MOST network and generating an Ethernet frame to be transmitted to the packet network according to another exemplary embodiment of the present invention. 
         [0061]    In  FIG. 6 , it is assumed that a MOST frame received from the MOST network is transmitted to the packet network and both asynchronous data units and synchronous data units exist in the frame, for the sake of brevity. 
         [0062]    The Ethernet-MOST gateway apparatus generates first and second Ethernet frames  610  and  620  by using the synchronous data Data 1  and asynchronous data Data 2  stored in the SDA  213  and ADA  214  of the received MOST frame  210 . 
         [0063]    If the synchronous units of data Data 1   213  and asynchronous data Data 2   214  are too small to satisfy a minimum Ethernet size, a first padding unit of dummy information  612  (Padding 1 ) and a second padding unit of dummy information  622  (Padding 2 ) may be inserted, respectively, in order to satisfy the minimum Ethernet size. 
         [0064]    Also, in order to signify that the frame is the Ethernet frame including the asynchronous data in the packet network, E-type  611 , an exclusive Ethernet-type, may be used, and in order to signify that the frame is the Ethernet frame including the synchronous data, E-type B  621 , an exclusive Ethernet-type, may be used. 
         [0065]    Namely, the Ethernet-MOST gateway apparatus according to an exemplary embodiment of the present invention receives the MOST frame  210  including the synchronous data Data 1  and the asynchronous data Data 2 , generates two Ethernet frames  610  and  620 , and outputs the generated Ethernet frames  610  and  620  to the packet network. 
         [0066]    The first Ethernet frame  610  includes the preamble area  201 , the SFD area  202 , the DA area  203 , the SA  204 , the E-type area  611 , the Data 1  area  213 , the Padding 1  area  612 , the FCS area  207 . The second Ethernet frame  620  includes the preamble area  201 , the SFD area  202 , the DA area  203 , the SA  204 , the E-type area  611 , the Data 1  area  213 , the Padding 2  area  622 , the FCS area  207 . 
         [0067]    As set forth above, according to exemplary embodiments of the invention, the Ethernet-MOST gateway apparatus is able to convert an Ethernet frame transmitting data in a packet network into a MOST frame transmitting data in a MOST network, infotainment can be supported by using various types of asynchronous and synchronous data. Also, when the MOST frame transmitting data in the MOST network is converted into the Ethernet frame transmitting data in the packet network, synchronous data and asynchronous data are discriminately marked by using E-type or port number information, thus making it possible to process data while maintaining its characteristics. 
         [0068]    While the present invention has been shown and described in connection with the exemplary embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.