JP5049151B2 - Receiver and transmission system - Google Patents

Description

  The present invention relates to a receiving apparatus and a transmission system used for digital broadcasting, and in particular, selects a signal to be demodulated based on information for specifying a multicast group, and selects an IP (Internet Protocol) packet from the demodulated signal. It is about technology.

  2. Description of the Related Art Conventionally, there is a satellite broadcasting system that includes a transmission device that packetizes content and transmits broadcast waves of MPEG-2 TS (Transport Stream) by time division multiplexing, and a reception device that receives broadcast waves via a broadcast satellite. It is known (see Patent Document 1). For example, Patent Document 1 discloses a technique in which a user who operates a receiving apparatus interactively performs tuning (tuning) for viewing content.

  In order to select a channel, control information included in the MPEG-2 TS transmitted / received between the transmission device and the reception device is used. This control information is standardized (see Non-Patent Document 1). For example, according to the description on page 31 attached to Part 1 of Non-Patent Document 1, when a channel selection operation is performed by the user, the receiving device refers to a network information table (NIT) included in the control information. The carrier frequency of the TS including the content desired by the user is acquired and switched to the carrier frequency to be demodulated. In this way, tuning using control information is performed.

  By the way, a new advanced BS digital broadcast transmission system has been proposed as a digital broadcast system using BS frequencies that can be used from 2011 (see Non-Patent Document 2). By using this new advanced BS digital broadcasting transmission system, research and development for realization of not only a television broadcasting service but also a content downloading service has been promoted. The content download service by advanced BS digital broadcasting acquires content to be viewed by a user from a broadcast wave according to the operation of the terminal device by the user, and stores it in the terminal device.

  In general, as a content download service, a service for downloading from a server via the Internet is known. In order to share with this service, a mechanism for transmitting and receiving IP packets as TLV (Type Length Value) is being studied in the content download service using advanced BS digital broadcasting (see Non-Patent Document 3). Details of the TLV will be described later.

Japanese Patent No. 3382569 ARIB STD-B. 32, “Video Coding, Audio Coding and Multiplexing Methods in Digital Broadcasting” Hashimoto, Suzuki, Suji, Tanaka, Kimura, Masamoto et al., “Transmission system of advanced BS digital broadcasting”, IEICE, Technical Report SAT2007-10, pp13-18, June 2007 Aoki, Nishimura, Aoki, Kimura, et al., “A Study on IP Packet Transmission Method in Advanced BS Digital Broadcasting”, Video Information Media Society, 2007 Winter Conference 3-3, Dec. 2007

  Channel selection in the satellite broadcasting system is performed by the user selecting a content that the user wants to view from a plurality of contents broadcast at that time by designating a channel. Specifically, PSI (Program Specific Information) defined by MPEG-2 Systems and ARIB STD-B. Control information of SI (Service Information) defined in 10 “Program arrangement information used for digital broadcasting” is used. When the service ID is designated in accordance with the user's channel designation, the receiving device acquires the video and audio ES (Elementary Stream) PID (Packet IDentifier) constituting the service, and the ES indicated by the PID is acquired. Receive.

  On the other hand, in multicast distribution or on-demand distribution of content in a communication network such as the Internet using IP, a terminal device operated by a user is a URI (Uniform Resource Identifier) for specifying content, that is, a content distribution source. A source address and a group address which is a multicast group are selected, a server indicated by the nearest router or URI is requested to transmit an IP packet, and a series of transmitted IP packets is received. Thereby, the terminal device can acquire a desired content.

  In the content download service using the advanced BS digital broadcasting described above, MPEG-2 Systems or ARIB STD-B. The content is transmitted as MPEG-2 TS by using the PSI / SI specified in the standard No. 10. In addition to this transmission method, as described in Non-Patent Document 3, there is a method of transmitting content by multiplexing IP packets as TLVs on a transmission path.

  A receiving device used for advanced BS digital broadcasting extracts an IP packet from a TLV multiplexed on a transmission path, and outputs the IP packet to an application inside or outside the receiving device. Therefore, when the application is connected to both the advanced BS receiver and the Internet communication network by a network such as a home network, the application can receive an IP packet transmitted via the Internet communication network, It becomes possible to receive IP packets transmitted via the transmission path of advanced BS digital broadcasting.

  However, there is a difference between a mechanism for receiving content via an Internet communication network and a mechanism for receiving content via a transmission path for advanced BS digital broadcasting. For this reason, when an application requests distribution of content, it is necessary to distinguish whether the content is distributed via the Internet communication network or the content distribution via the advanced BS digital broadcast transmission path. . Further, when content is received via a transmission path of advanced BS digital broadcasting, the advanced BS receiving apparatus needs to specify an IP packet including the content selected by the application. The application performs distribution request processing suitable for each application, and the advanced BS receiving apparatus needs to perform channel selection processing that matches the distribution request.

  Therefore, the present invention has been made to solve such a problem, and the purpose of the present invention is to receive content distribution without requiring the content requester to distinguish between the Internet communication network and the digital broadcast transmission path. To provide a receiving apparatus and a transmission system capable of processing a distribution request from a request source.

  In order to achieve the above object, a transmission system having the following configuration is proposed as a simple example of the present invention. A transmission device is a service for identifying a destination address for identifying an IP packet including content, a source address, or a combination of a destination address and a source address, and a content download service performed using the IP packet. An address map table that associates IDs is created and transmitted to the transmission path of advanced BS digital broadcasting. Here, the address map table may be transmitted via an advanced BS digital transmission path, or may be transmitted via an Internet communication network. The receiving device receives the address map table and, based on information such as the destination address included in the distribution request for downloading the content, the carrier frequency and the like necessary for selecting a signal to which the IP packet is transmitted Identify information and select the signal to demodulate.

That is, the receiving apparatus according to claim 1 of the present invention is a TLV (Type Length Value) including an MPEG-2 TS including information of a television broadcast service and a content IP packet distributed for each multicast group by the content download service. In a receiving device that receives a broadcast wave of a digital broadcast via a digital broadcast transmission path, the receiver includes a demodulation unit, a classification unit, and a packet adapter, and the demodulation unit receives the broadcast wave signal at a designated carrier frequency. selected, demodulates the signal, the classification unit, on the basis of the demodulated TMCC signal, classifying and the MPEG-2 TS and TLV, the packet adapter, the classified TLV by the classifying unit , IP packet for content data, identifying the content download service Control TLV composed of an address map table including a service ID for identifying and an IP address for identifying a multicast group, and a control TLV composed of a Network Information Table (NIT) including a service ID and a carrier frequency A type classification unit for classifying into a group, an address map table in a control TLV that receives a distribution request including an IP address for specifying a multicast group from a request source that receives the content download service, and is classified by the type classification unit A multicast management unit that identifies a service ID from an IP address included in the distribution request, and a NIT in the TLV for control classified by the type classification unit. For the data classified by the type classification unit, a front-end control unit that identifies the carrier frequency from the service ID that has been specified, and specifies the identified carrier frequency as the carrier frequency of the signal selected by the demodulation unit A packet filter unit that selects an IP packet having an IP address included in the distribution request received by the multicast management unit from among the IP packets, and transmits the selected IP packet as an IP packet of content corresponding to the distribution request; It is characterized by having .

According to a second aspect of the present invention, in the receiving device according to the first aspect, the IP address for specifying the multicast group is a source address and a destination group address to which the content is multicast-delivered. It is characterized by that.

According to a third aspect of the present invention, there is provided the receiving device according to the first aspect, wherein the IP address for specifying the multicast group is a destination group address to which the content is multicast distributed. And

According to a fourth aspect of the present invention, in the reception device according to the first aspect, the packet adapter includes the type classification unit, the multicast management unit, the front-end control unit, and the packet filter unit. , correspondence to said delivery request including the CID which associates the IP address for identifying the multicast group (Context IDentification), received from the requester to receive the content download service, IP address for identifying the multicast group The carrier frequency is identified from the IP address included in the distribution request using the table including the CID and the carrier frequency to which the contents of the multicast group are distributed, and the identified carrier frequency is selected by the demodulator Be done The IP packet having the IP address included in the distribution request is selected from the IP packets of the TLV specified as the carrier frequency of the signal and demodulated at the specified carrier frequency, and the selected IP packet is It transmits to the said request origin as an IP packet of the content with respect to a request, It is characterized by the above-mentioned.

The transmission system according to claim 5 of the present invention transmits an MPEG-2 TS broadcast wave including information of a television broadcast service, and also transmits a broadcast wave including IP packets of content distributed to each multicast group by the content download service. a transmitting device for transmitting, receiving the broadcast waves via the transmission path of the digital broadcast from the transmitting device, characterized by comprising a receiving device according to any one of claims 1 to 4 .

  As described above, according to the present invention, content download based on IP address information for specifying a multicast group, such as a source address of an IP packet, a destination address, or a combination of a source address and a destination address It is possible to distinguish between broadcast wave signals to be serviced. As a result, the content requester makes the distribution request without distinguishing between the communication network of the Internet and the transmission path of the digital broadcast by making the distribution request the data including the IP address information for specifying the multicast group. You can request and receive content distribution.

The best mode for carrying out the present invention will be described below in detail with reference to the drawings.
[Transmission system]
First, the transmission system will be described. FIG. 1 is a diagram illustrating a configuration of a transmission system according to an embodiment of the present invention. This transmission system is a satellite broadcasting system, which includes a transmission device 400 that transmits broadcast waves, a broadcast satellite 500 that amplifies and transmits the broadcast waves transmitted from the transmission device 400, and a broadcast transmitted from the broadcast satellite 500. An advanced BS receiving apparatus 200 that receives waves, a terminal apparatus that includes applications 301 to 303 that make content distribution requests and the like, and a server 306 that is connected to the Internet 305 are configured. The advanced BS receiving device 200, the terminal device, and the Internet 305 are connected by a home network 304, and the home network 304 and the server 306 are connected by the Internet 305.

  The transmission device 400 generates an MPEG-2 TS including information for realizing a television broadcast service and a TLV including content for realizing a content download service, and transmits the TLV as a broadcast wave. When transmitting broadcast waves, the transmission device 400 stores IP packets of contents distributed by multicast in the TLV. The NIT is stored in the control TLV, and the address map table is stored in the control TLV. The TLV, NIT, and address map table will be described later.

  Applications 301 to 303 are processing means provided in the terminal device, and receive and store list information of contents distributed by multicast from the advanced BS receiving apparatus 200 and the Internet 305. When a user who operates the terminal device requests a desired content, a distribution request is generated and transmitted based on the content list, and the requested content is received. Further, when requesting the stop of the distribution while receiving the distribution of the content, a distribution stop request is transmitted.

  Specifically, the applications 301 to 303 receive content list information including a content name, an ID, a content transmission source address, a multicast group address as a content destination, and the like. When there is a content distribution request by a user operation, the applications 301 to 303 obtain information related to the content specified by the user operation from the content list information, a transmission source IP address (hereinafter referred to as a transmission source address), A distribution request to which information such as a multicast group address is added is transmitted. When there is a content distribution stop request by a user operation, the applications 301 to 303 transmit a distribution stop request to which information such as a transmission source address and a multicast group address of the content being distributed is added.

  Here, there are ASM (Any Source Multicast) and SSM (Source Specific Multicast) as multicast systems. ASM is a system for identifying a series of IP packets that are multicast-distributed only by a group address that is a destination of an IP packet regardless of a source address. SSM is a method for identifying a series of IP packets that are multicast-distributed by a combination of a source address and a group address that is a destination of the IP packet. In the present embodiment, the applications 301 to 303 generate a distribution request or a distribution stop request including only a group address or a combination of a transmission source address and a group address in accordance with each multicast mechanism, and a content distribution request Or a delivery stop request. As a delivery request and delivery stop request method, IGMPv2 (specified in RFC2236), IGMPv3 (specified in RFC2710), MLDv1 (specified in RFC2710), or MLDv2 (RFC3810). Is used according to the IP version and multicast method.

  The distribution request or distribution stop request transmitted by the applications 301 to 303 is transmitted to the advanced BS receiving apparatus 200 and the Internet 305 via the home network 304.

  The advanced BS receiving apparatus 200 receives a plurality of time-division multiplexed contents from the transmitting apparatus 400 that is a content transmission source via the broadcasting satellite 500, and receives a content distribution request from the applications 301 to 303. The IP packet constituting the content is selected and transmitted to the requesting applications 301 to 303. When receiving a content distribution stop request, the transmission of the IP packet for the content is stopped. If there is no content corresponding to the received distribution request or distribution stop request, these requests are ignored. Whether there is content corresponding to the received distribution request or distribution stop request is determined based on information such as a source address and a multicast group address added to the request.

  The server 306 is a transmission source of content transmitted through the communication network of the Internet 305. When receiving a content distribution request from the applications 301 to 303, the router connected to the Internet 305 performs multicast processing and transmits the content to the requesting applications 301 to 303. When receiving a content distribution stop request, the transmission of the IP packet for the content is stopped. If there is no content corresponding to the received distribution request or distribution stop request, these requests are ignored. Whether there is content corresponding to the received distribution request or distribution stop request is determined based on information such as a source address and a multicast group address added to the request. Since multicast control is a known technique, description thereof is omitted here.

  The Internet 305 includes a communication network in which various content providers are freely connected, and a communication network in which transmission quality is guaranteed although the connected content providers are limited.

[Advanced BS receiver]
Next, the advanced BS receiving apparatus 200 will be described. FIG. 2 is a diagram showing a configuration of the advanced BS receiving apparatus 200 shown in FIG. The advanced BS receiving apparatus 200 includes a BS-IF demodulation unit 201, an error correction unit 202, a stream classification unit 203, an AV decoder 204, and a packet adapter 100.

  The BS-IF demodulation unit 201 inputs a BS-IF signal via an antenna and demodulates the BS-IF signal. Thereby, video, audio, data content, or IP packet can be taken out. Here, prior to the demodulation of the BS-IF signal, the BS-IF demodulation unit 201 needs to select the BS-IF signal to be demodulated. In this embodiment, in order to simplify the description, it is assumed that the BS-IF signal is selected only by the carrier frequency.

  Here, there are two types of methods for selecting a signal to be demodulated. The first method is to select a signal to be demodulated based on PSI / SI transmitted by MPEG-2 TS. In the second method, the carrier frequency is specified by the packet adapter 100 shown in FIG. 2, and only the BS-IF signal of the specified carrier frequency is demodulated. Since the first method is a known technique, the description thereof is omitted here. As an example of the first method, the receiving apparatus inputs a service ID using a channel button provided in the remote controller, selects a carrier wave on which video and audio included in the service are multiplexed, and demodulates the carrier wave. Thus, the content desired by the user is acquired. Since the first method is a known technique, detailed description thereof is omitted here. For details, see ARIB STD-B. 32 See the description of FIG. 1-2 (a) on page 31.

  The error correction unit 202 receives the signal demodulated by the BS-IF demodulation unit 201 and performs error correction processing. Thereby, the slot can be taken out. A slot is a physical transmission unit. In advanced BS digital broadcasting, a slot is modulated and transmitted in units of frames.

  FIG. 3 is a diagram illustrating the relationship among frames, streams, slots, and TLVs. In FIG. 3, TLV is composed of IP packets, and “A, B, C,..., H” indicate a multicast group of IP packets stored in the TLV. “Control” indicates a TLV composed of control information. The slot is composed of a plurality of TLVs. The stream is composed of byte strings transmitted in a plurality of slots identified by stream IDs. The frame is composed of a plurality of slots.

  The byte string may be composed only of TLV or may be composed only of MPEG-2 TS packets. FIG. 3 shows an example composed of only TLV. In the frame transmitted at the carrier frequency f1, the first, second, and third slots from the top are streams with a stream ID of 0x0101. IP packets belonging to multicast groups A, B, C, and D are transmitted as TLVs by a stream having a stream ID of 0x0101.

  Which stream the MPEG-2 TS is multiplexed or the TLV is multiplexed is indicated in a TMCC (Transmission and Multiplexing Configuration Control) signal. The TMCC signal is a transmission multiplex control signal in digital broadcasting, such as the modulation method of the signal transmitted by the broadcast wave and the type of information to be multiplexed (in the advanced BS broadcasting, the type of MPEG-2 TS packet or TLV). Used for identification.

  Returning to FIG. 2, the stream classification unit (DEMUX) 203 inputs the signal that has been subjected to the error correction processing by the error correction unit 202, extracts the TMCC signal, and stores the MPEG-2 TS based on the TMCC signal. And the stream storing the TLV. Then, the MPEG-2 TS is extracted from the stream storing the MPEG-2 TS and output to the AV decoder 204, and the TLV is extracted from the stream storing the TLV and output to the packet adapter 100.

  FIG. 4 is a diagram illustrating the configuration of the TLV. The TLV includes a field for storing a version “01” of the TLV, an undefined field, a type field for storing a type of data in a value field to be described later, a length field for storing the length of the value field, and , An IP packet, a NIT, an address map table, etc., and a value field that stores actual data of control information.

  Returning to FIG. 2, the AV decoder 204 receives the MPEG-2 TS from the stream classification unit 203, and processes the MPEG-2 TS multiplexed with video, audio, data content, or PSI / SI. Note that the processing of the AV decoder 204 is the same as that of an existing digital broadcast receiving apparatus and is a known technique, and thus the description thereof is omitted here.

  The packet adapter 100 receives the TLV from the stream classification unit 203, receives a content distribution request or distribution stop request from the applications 301 to 303 via the home network 304, and sets a carrier frequency for selecting a BS-IF signal. It outputs to BS-IF demodulation section 201 and transmits an IP packet of content corresponding to the distribution request. Further, the packet adapter 100 stops the transmission of the IP packet according to the distribution stop request.

[Packet adapter]
Next, the packet adapter 100 will be described. FIG. 5 is a diagram showing a configuration of the packet adapter 100 shown in FIG. The packet adapter 100 includes a multicast management unit 101, a front-end control unit 102, a packet filter unit 103, an IP header restoration unit 104, a type classification unit 105, and an input / output interface 106, and has the following two functions.
(1) A TLV is input from the stream classification unit 203, and necessary IP packets are transmitted.
(2) A carrier wave signal for selecting a signal to be demodulated in the BS-IF demodulator 201 in order to receive a content distribution request and a distribution stop request from the applications 301 to 303 and transmit an IP packet of the requested content Is output.

  The type classification unit 105 classifies the input TLVs according to the types constituting the TLV, and outputs the data stored in the value field constituting the TLV for each type. The TLV type indicates “IP packet whose header is not compressed”, “IP packet whose header is compressed”, “control”, and “NULL”.

  The type classification unit 105 does not perform output processing when the type is “NULL”. When the type is “IP packet whose header is not compressed”, the data stored in the value field is output to the packet filter unit 103 as an IP packet. When the type is “IP packet with compressed header”, the data stored in the value field is output to the IP header restoring unit 104. When the type is “control”, when the NIT is stored for the data stored in the value field (see FIG. 6), the NIT is output to the front-end control unit 102. On the other hand, when the address map table is stored for the data stored in the value field (see FIG. 7), the address map table is output to the multicast management unit 101.

  The IP header restoration unit 104 receives data of the type “IP packet with compressed header” from the type classification unit 105, restores the header of the packet with compressed header information, and sends it to the packet filter unit 103 as an IP packet. Output. Since there are various known techniques for restoring the header, detailed description is omitted here. Although not a known technique, the header may be restored based on a CID (Context IDentification) stored in the compressed header information. The CID will be described later.

  The packet filter unit 103 receives an IP packet from the IP header restoration unit 104 and the type classification unit 105, inputs an IP address from the multicast management unit 101, selects only the IP packet specified by the IP address, and inputs / outputs an interface It outputs to 106. In this case, the packet filter unit 103 determines whether or not the input IP address corresponds to the source address and the destination address stored in the header of the input IP packet. Is output.

  The input / output interface 106 is a modular terminal, and transmits and receives IP packets to and from the home network 304.

  The multicast management unit 101 inputs an address map table from the type classification unit 105, and inputs a content distribution request or a distribution stop request from the applications 301 to 303 via the home network 304 and the input / output interface 106. The multicast management unit 101 determines whether the IP packet of the content requested for distribution is multicast based on the input distribution request or distribution stop request and the input address map table. If it is determined that it is not multicast, the request is ignored. On the other hand, if it is determined that multicasting is performed, the service ID is specified based on the distribution request and the address map table, and is output to the front end control unit 102, and the IP address corresponding to the IP packet requested for distribution is specified. And output to the packet filter unit 103. In addition, the multicast management unit 101 refers to the input distribution stop request, the address map table, and the already input distribution request, identifies the IP address corresponding to the IP packet requested to stop distribution, and outputs it to the packet filter unit 103 To do.

  The front-end control unit 102 inputs the NIT from the type classification unit 105, inputs the service ID from the multicast management unit 101, and provides a service list descriptor and a satellite distribution system descriptor that configure the NIT (details will be described later). Then, the carrier frequency of the signal to be demodulated is specified, and the carrier frequency is output to the BS-IF demodulator 201.

[Delivery request processing flow]
Next, the distribution request processing flow will be described. FIG. 8 is a diagram showing a distribution request processing flow from when an application 301 to 303 transmits a distribution request to when an IP packet of desired content is received.

  The multicast management unit 101 of the packet adapter 100 in the advanced BS receiver 200 uses the above-described IGMP or MLD to indicate an IP packet indicating a content distribution request (destination group address in the case of ASM, or source address in the case of SSM). And a join message including the destination group address) from the applications 301 to 303 (step S801). The multicast management unit 101 recognizes that an IP packet indicating a distribution request has been input, and identifies a multicast group for which distribution has been requested. In the case of ASM, the group address described in the IP packet indicating the distribution request is extracted, and in the case of SSM, the source address and group address described in the packet indicating the distribution request are extracted. The multicast management unit 101 refers to the address map table and identifies the service ID to which the requested multicast group IP packet is transmitted.

  FIG. 9 is a diagram illustrating an example of an address map table. This address map table is a table indicating multicast groups belonging to a certain service ID. In FIG. 9, the source address range is indicated by src_addr and src_mask. src_mask is information indicating how many bits are identified from the head of the IP address described as src_addr. In the example in which src_addr is 202.214.202.0 and src_mask is 24, this means that the first 24 bits from src_addr are identified as the source address. Therefore, in this example, it means an address in the range of 202.214.202.0 to 202.214.202.255. Similarly, the destination address range is indicated by dst_addr and dst_mask. dst_mask is information indicating how many bits from the beginning of the IP address described as dst_addr are identified. In the example in which dst_addr is 239.192.0.1 and dst_mask is 32, the destination address has no width and means only one address of 239.192.0.1 in order to identify 32 bits from the beginning of dst_addr.

  As described above, in the example of FIG. 9, since the IP version ip_ver is 4, the IP address is IPv4, the source address is 202.214.202.0 to 202.214.202.255, and the destination address is 239.192.0.1. This means that the packet is transmitted as service ID 0x0001. The same applies to IPv6. In the example of the address map table shown in FIG. 9, the source address 202.214.202.2 and the destination address 239.192.0.1 are group A, the source address 202.214.202.4 and the destination address 239.192.0.1 are group B, and the source address 202.214.202.10. And destination address 239.192.0.2 as group C, source address 202.214.202.14 and destination address 239.192.0.2 as group D, source address 2001: c90: 7000 :: 9876 and destination address ff38: 1234 :: 5678 as group E, If source address 2001: c90: 7000 :: 9876 and destination address ff38: 1234 :: 8765 are group F, groups A and B have service ID 0x0001, groups C and D have service ID 0x0002, and group E has It can be seen that the service ID is 0x0003, and the service ID of group F is 0x0004.

  Although not explicitly shown in FIG. 9, there is an example in which a multicast group is distinguished only by a destination address with respect to an arbitrary source address. In this case, it can be identified by an address map table in which src_mask is set to 0. . The address map table includes information for configuring each service transmitted in the same network as the network (the advanced BS network) to which the address map table is transmitted, that is, the IP packet transmitted in the same network. Stores multicast group information.

  The multicast management unit 101 refers to the address map table to identify which service ID is used to transmit the IP packet of the multicast group that is the target of the distribution request (step S802). The service ID specified in this way is output to the front end control unit 102 (step S803). In addition, the multicast management unit 101 transmits an IP packet having an IP address (a group address that is a destination in the case of ASM, a source address and a group address that is a destination in the case of SSM) as a distribution request target. Then, the packet filter unit 103 is controlled (step S804).

  The front-end control unit 102 refers to the NIT and specifies which carrier frequency is used to transmit the service ID input from the multicast management unit 101 and which stream ID is transmitted (steps S805 and S806). . Then, the front end control unit 102 outputs the carrier frequency to the BS-IF demodulation unit 201 to perform tuning control (step S807).

  The NIT is composed of a satellite distribution system descriptor, a system management descriptor, and a service list descriptor. The satellite distribution system descriptor is a descriptor indicating physical conditions of the satellite transmission path. The system management descriptor is a descriptor used for identifying broadcast and non-broadcast. The service list descriptor is a descriptor indicating a list of service IDs transmitted with a certain stream ID. For details, see ARIB STD-B. See 32.

  FIG. 10 is a diagram illustrating an example of the NIT. In FIG. 10, the transmission parameter is a satellite distribution system descriptor, the type is a system management descriptor, and the stream ID and service ID are service list descriptors. A stream with a stream ID of 0x0101 is transmitted by a carrier wave signal having a frequency of f1, and the stream includes both a service ID of type 0x0001 and a service ID of 0x0002.

  BS-IF demodulation section 201 receives the carrier frequency from front end control section 102 and starts demodulating the signal at the carrier frequency. Thereby, the packet adapter 100 can input the TLV belonging to the specified stream ID. Specifically, the packet filter unit 103 inputs the IP packet multiplexed in the slot with the specified stream ID (step S808). The packet filter unit 103 causes the multicast management unit 101 to transmit an IP packet having a predetermined IP address (a destination group address in the case of ASM, a transmission source address and a destination group address in the case of SSM). Since it is controlled, an IP packet that is a target of a distribution request from the applications 301 to 303 is selected and transmitted via the input / output interface 106 (step S809).

[Delivery stop request processing flow]
Next, a distribution stop request process flow will be described. FIG. 11 is a diagram illustrating a distribution stop request processing flow from when the application 301 to 303 transmits a distribution stop request to when the distribution of the IP packet of the desired content is stopped.

  The multicast management unit 101 of the packet adapter 100 in the advanced BS receiving apparatus 200 uses the above-described IGMP or MLD to indicate an IP packet indicating a content distribution stop request (destination group address in the case of ASM, transmission source in the case of SSM) (Leave message including the address and the destination group address) is received from the applications 301 to 303 (step S1101).

  The multicast management unit 101 recognizes that an IP packet indicating a distribution stop request has been input, and receives an IP address (a group address in the case of ASM, a source address and a destination address in the case of SSM) that is the target of the distribution stop request. The packet filter unit 103 is controlled so as to stop transmission of the IP packet (step S1102). As a result, as shown in step S808, the packet filter unit 103 inputs the IP packet multiplexed in the slot of the identified stream ID (step S1103), but the multicast management unit 101 uses the predetermined IP address ( Since it is controlled not to send an IP packet having a destination group address in the case of ASM and a source address and a destination group address in the case of SSM, it is a target of a distribution stop request from the applications 301 to 303 The transmission of the IP packet to be stopped is stopped.

  The present invention has been described with reference to the embodiment. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the technical idea thereof. For example, in the above-described embodiment, an IP address for specifying a multicast group (a group address that is a destination in the case of ASM, a source address and a group address that is a destination in the case of SSM) is serviced using an address map table. In association with the ID, one service ID is configured to include a plurality of multicast groups. However, the present invention is not limited to such a configuration, and a multicast group of IP packets may be associated one-to-one with a PID that specifies an ES in MPEG-2 Systems. FIG. 12 shows an example in which the elements constituting the service identified by the service ID are IP packets of two multicast groups in addition to the video, audio and data streams of the MPEG-2 TS packet.

  With such a configuration, the advanced BS receiving apparatus 200 can process information transmitted in IP packets while reproducing and displaying video and audio transmitted in MPEG-2 TS packets. In this case, in the address map table, PID or component_tag is associated with information for specifying the multicast group instead of the service ID. FIG. 13 shows an example of an address map table for associating PIDs with multicast groups of IP packets. FIG. 14 shows an example of an address map table that associates component_tag with a multicast group of an IP packet. By associating a multicast group of an IP packet with a PID or component_tag using an address map table, the packet is transmitted as an IP packet as one of the components described in the existing PAT (Program Association Table) and PMT (Program Map Table). Information may be included.

  Specifically, the multicast management unit 101 of the packet adapter 100 in the advanced BS receiving apparatus 200 inputs the address map table shown in FIG. 13 or FIG. 14 from the type classification unit 105, identifies the PID or component_tag, and Output to the control unit 102. The front end control unit 102 inputs NIT, PAT, and PMT from the type classification unit 105, inputs PID or component_tag from the front end control unit 102, specifies a service ID from PID or component_tag using the PAT and PMT, The carrier frequency is identified from the service ID using NIT, and the carrier frequency is output to BS-IF demodulation section 201.

  In the embodiment, a multicast group is used as information for specifying an IP packet. However, the present invention is not limited to multicast distribution, and a series of IP packets may be specified by the destination address of the IP packet, the source address, or a combination of the destination address and the source address. Further, as described in an unpublished patent application (Japanese Patent Application No. 2007-304333) filed by the same applicant as the present application, a series of IP packets are specified by a CID indicating a flow of IP packets. May be. FIG. 15 shows an example of an address map table for associating service IDs with CIDs. As shown in FIG. 15, CID is used in the address map table in place of all the information of ip_ver, src_addr, src_mask, dst_addr, and dst_mask shown in FIG. The multicast management unit 101 of the packet adapter 100 in the advanced BS receiving apparatus 200 receives the distribution request with the CID added instead of the IP address, and identifies the service ID from the CID using the address map table shown in FIG. be able to.

  Here, the CID will be described. Generally, RFC2508 (Compressing IP / UDP / RTP Headers for Low-Speed Serial Links), RFC3095 (Robust Header Compression (ROHC): Framework and four profiles: RTP, UDP, ESP, and uncompressed) Etc. are known. These header compression techniques are performed using the property that IP packet header information belonging to the same flow is exactly the same, or that a lot of predictable information is included. In the specific example described in the unpublished patent application (Japanese Patent Application No. 2007-304333), instead of transmitting an IP packet including all the header information, an IP packet including all the header information and the CID (hereinafter, referred to as “IP packet”). The full-header IP packet is transmitted intermittently, and the CID is included as the other IP packet, but only a part of the header information is included (in IPv4, only a part is included, but in IPv6, the header information is It is transmitted with a compressed header (not included at all). By transmitting a full header IP packet, header information using the CID as a key can be shared between the device that transmits the IP packet and the device that receives the IP packet. When receiving a full header IP packet, the device that receives the IP packet (advanced BS receiving device 200) generates a CID table that enables association between the CID and the header information. When an IP packet to which a compressed header including a CID is added is received, the header information is restored by referring to the CID table. In this way, header information of all IP packets can be restored. Therefore, the overhead during transmission can be reduced by using the CID.

  Moreover, in the said embodiment, although existing IGMP or MLD was used as control of the delivery request and the delivery stop request | requirement transmitted from the applications 301-303, this invention is not limited to this. For example, a series of IP packets to be transmitted by the advanced BS receiving apparatus 200 based on a source address, a destination address, a combination of a source address and a destination address, or an arbitrary combination of a source port number or a destination port number. Alternatively, control for specifying a series of IP packets to be stopped may be performed.

  Further, in the above-described embodiment, an example in which the transmission device 400 multiplexes the address map table with the TLV transmitted through the transmission path of the advanced BS digital broadcasting and transmits the multiplexed information to the advanced BS reception device 200 has been described. However, the present invention is not limited to this, and the address map table may be transmitted to the advanced BS receiving apparatus 200 via the Internet 305 and the home network 304.

  Furthermore, in the above-described embodiment, the advanced BS receiving apparatus 200 used for advanced BS digital broadcasting and the applications 301 to 303 have been described as being connected via the home network 304. However, the applications 301 to 303 are advanced BS digital. When the advanced BS receiving apparatus 200 used for broadcasting exists in the same casing, the connection does not need to go through the home network 304. In this case, the exchange of information between the advanced BS digital broadcasting and the applications 301 to 303 does not have to be in the IP packet format, and the information transmitted by the IP packet in the embodiment is transmitted in a different format. May be.

It is a figure which shows the structure of the transmission system by embodiment of this invention. It is a figure which shows the structure of the advanced BS receiver by embodiment of this invention. It is a figure which shows the relationship between a frame, a stream, a slot, and TLV. It is a figure which shows the structure of TLV. It is a figure which shows the structure of a packet adapter. It is a figure which shows the structure of TLV for control containing NIT. It is a figure which shows the structure of TLV for control containing an address map table. It is a figure which shows a delivery request processing flow. It is a figure which shows the example of an address map table. It is a figure which shows the example of NIT. It is a figure which shows a delivery stop request | requirement processing flow. It is a figure which shows the example in the case of using a multicast group in association with PID and combining with ES. It is a figure which shows the example of another address map table. It is a figure which shows the example of another address map table. It is a figure which shows the example of another address map table.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transmission system 100 Packet adapter 101 Multicast management part 102 Front end control part 103 Packet filter part 104 IP header decompression part 105 Type classification part 106 Input / output interface 200 Advanced BS receiver 201 BS-IF demodulation part 202 Error correction part 203 Stream classification Unit 204 AV decoders 301 to 303 Application 304 Home network 305 Internet 306 Server

Claims (5)

Broadcast waves of MPEG-2 TS including information of the television broadcast service and TLV (Type Length Value) including content IP packets distributed for each multicast group by the content download service are transmitted via a digital broadcast transmission path. In the receiving device for receiving,
A demodulation unit, a classification unit, and a packet adapter;
The demodulator selects the signal of the broadcast wave by the specified carrier frequency, demodulates the signal,
The classification unit, on the basis of the demodulated TMCC signal, classifying and the MPEG-2 TS and TLV,
The packet adapter is
The TLV classified by the classification unit is used for control including an IP packet for content data, an address map table including a service ID for identifying the content download service and an IP address for specifying a multicast group. Type classification unit for classifying into TLV for control composed of TLV and NIT (Network Information Table) including service ID and carrier frequency,
A distribution request including an IP address for specifying a multicast group is received from a request source that receives the content download service, and the distribution request is transmitted using an address map table in a control TLV classified by the type classification unit. A multicast management unit for identifying a service ID from an IP address included in
A signal selected from the service ID specified by the multicast management unit using the NIT in the control TLV classified by the type classifying unit, and the specified carrier frequency selected by the demodulation unit A front-end control unit that is designated as a carrier frequency, and
Among IP packets for data classified by the type classification unit, an IP packet having an IP address included in the distribution request received by the multicast management unit is selected, and the selected IP packet is selected for the distribution request. A receiving apparatus comprising a packet filter unit that transmits an IP packet of content . The receiving device according to claim 1,
The IP address for specifying the multicast group is a transmission source address to which content is distributed by multicast and a destination group address . The receiving device according to claim 1,
The receiving apparatus according to claim 1, wherein the IP address for specifying the multicast group is a group address that is a destination to which the content is multicast . The receiving device according to claim 1,
The packet adapter is
Instead of comprising the type classification unit, the multicast management unit, the front end control unit and the packet filter unit,
Receiving a distribution request including a CID (Context IDentification) associated with an IP address for specifying the multicast group from a request source that receives the content download service;
Identifying a carrier frequency from an IP address included in the distribution request, using a table including a CID associated with an IP address for identifying a multicast group and a carrier frequency to which the contents of the multicast group are distributed; Specify the identified carrier frequency as the carrier frequency of the signal selected by the demodulator,
Of the TLV IP packets demodulated at the designated carrier frequency, an IP packet having an IP address included in the distribution request is selected, and the selected IP packet is selected as the content IP packet for the distribution request. A receiving apparatus that transmits to a request source . A transmitter for transmitting an MPEG-2 TS broadcast wave including information on a television broadcast service and transmitting a broadcast wave including an IP packet of content distributed to each multicast group by the content download service;
5. A transmission system comprising: the receiving device according to claim 1 that receives the broadcast wave from the transmitting device via a digital broadcast transmission path.

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