JP2020010199A - IP retransmission device, SI server, edge router, receiver, IP retransmission method, and transmission facility - Google Patents

Abstract

To provide an IP retransmission device that allows each receiver to efficiently obtain SI information for all channels.SOLUTION: An IP retransmission device is used in an IP retransmission system that re-transmits a multi-channel digital broadcast signal received from an antenna to a plurality of receivers via an IP multicast network. The IP retransmission device takes out SI information from the digital broadcast signal, stores the SI information in a packet in which an SI identification value is given to part of header information, and transmits the packet together with or separately from a broadcast stream to the IP multicast network.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an IP retransmission device, an SI server, an edge router, a receiver, an IP retransmission method, and a transmission facility.

  2. Description of the Related Art Conventionally, technology for transmitting contents using MMTP (MPEG Media Transport Protocol) packets has been developed. For example, Non-Patent Document 1 discloses a broadcasting system using the MMT method. In this broadcasting system, an MMT packet including program information such as audio information and video information is stored in a payload of an IP (Internet Protocol) packet. The IP packet is stored in the payload of a TLV (Type Length Value) packet.

  Also, so-called IP retransmission for transmitting a digital broadcast signal transmitted from a broadcast facility operated by a broadcaster to a receiver of a subscriber via a transmission facility operated by an IP retransmission service provider and an IP multicast network. Services are beginning to spread. Non-Patent Document 2 discloses an operation rule for an IP retransmission service of BS digital broadcasting.

ARIB STD-B32 Version 3.4, "Video Coding, Audio Coding and Multiplexing in Digital Broadcasting," The Radio Wave Industry Association, September 30, 2015 IPTVFJ STD-0009 version 1.3, "BS Digital Broadcasting IP Retransmission Operational Rules", IPTV Forum, September 13, 2017

  A digital broadcast signal transmitted from a broadcast facility includes SI (Service Information) information such as an electronic program guide (EPG) in addition to video information and audio information. Although the SI information is included in the digital broadcast signal for each of a plurality of channels, in order for the receiver to acquire the SI information of all the channels, the digital broadcast signals of each channel are acquired sequentially, and the It is necessary to extract SI information from. With the increase in the number of broadcast channels in recent years, it takes time to acquire SI information. In particular, in the IP retransmission service, an edge router transmits a specific digital broadcast signal in response to a request from a receiver from digital broadcast signals of all channels obtained from an IP multicast network. If each receiver attempts to acquire SI information of all channels, it must extract SI information from digital broadcast signals of all channels. Usually, since the digital broadcast signal and the SI information are transmitted in the same stream, there is a problem that the processing load on each receiver increases.

  The present invention has been made in view of such a problem, and an IP retransmission device, an SI server, an edge router, a receiver, and an IP retransmission that enable each receiver to efficiently acquire SI information of a plurality of channels. It is intended to provide a method and a transmission facility.

  In order to solve the above-described problem, an IP retransmission apparatus according to one embodiment includes an IP retransmission system that retransmits digital broadcast signals of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network. An IP retransmitting device used in the above, extracts SI information from a digital broadcast signal, stores the SI information in a packet in which an SI identification value is added to a part of header information, and stores the packet together with a broadcast stream, or It is transmitted to an IP multicast network separately from the broadcast stream.

  Similarly, an IP retransmission method according to one embodiment is an IP retransmission method for retransmitting a digital broadcast signal of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network. The SI information is extracted from the signal, the SI information is stored in a packet in which an SI identification value is added to a part of the header information, and the packet is transmitted to the IP multicast network together with the broadcast stream or separately from the broadcast stream.

  An SI server according to an embodiment is an SI server used in an IP retransmission system that retransmits a digital broadcast signal of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network. It stores the SI information extracted from the signal and makes a single multicast packet of a plurality of channels in which an SI identification value is added to a part of the header information, and sends it to the IP multicast network.

  An edge router according to one embodiment is an edge router used together with an IP retransmitting device that retransmits a digital broadcast signal of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network. A packet in which SI information extracted from a signal is stored and an SI identification value is added to a part of header information is received via an IP multicast network, and a packet of a channel requested by each receiver is transmitted to each receiver. I do.

  An edge router according to another embodiment is an edge router used together with an IP retransmitting device that retransmits digital broadcast signals of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network. It stores the SI information extracted from the broadcast signal and receives, via the IP multicast network, aggregated SI information that is a single multicast packet of a plurality of channels in which an SI identification value is given to a part of the header information. The aggregated SI information is transmitted to each receiver in response to a request from the receiver.

  A receiver according to one embodiment is a receiver used in an IP retransmission system for retransmitting a digital broadcast signal of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network, and A packet in which the SI information extracted from the signal is stored and a part of the header information is added with the SI identification value is received via the IP multicast network, and the packet is extracted from the TLV packet based on the SI identification value.

  A receiver according to another embodiment is a receiver used in an IP retransmission system for retransmitting digital broadcast signals of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network, Through the IP multicast network, it stores the SI information extracted from the broadcast signal and receives the aggregated SI information that is a single multicast packet of a plurality of channels in which a part of the header information is provided with the SI identification value.

  A transmission facility according to one embodiment is a transmission facility used in an IP retransmission system for retransmitting digital broadcast signals of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network, wherein A receiving device that receives a plurality of channels of digital broadcast signals from an antenna to create a TLV packet, extracts SI information from the TLV packet, and stores the SI information in a packet in which an SI identification value is added to a part of the header information And an IP retransmission device for transmitting the packet to the IP multicast network together with the broadcast stream or separately from the broadcast stream. Further, a transmission facility according to another embodiment is a transmission facility used in an IP retransmission system for retransmitting digital broadcast signals of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network. , An antenna, a receiving device that receives a digital broadcast signal of a plurality of channels from the antenna to generate a TLV packet, extracts SI information from the TLV packet, and outputs a SI having a SI identification value to a part of header information. An IP retransmitting device that stores information, and an SI server that converts a packet of a plurality of channels into a single multicast and sends the packet to an IP multicast network.

  According to the IP retransmission device, the SI server, the edge router, the receiver, the IP retransmission method, and the transmission equipment according to the present invention, each receiver can efficiently acquire SI information of a plurality of channels.

FIG. 1 is a diagram schematically illustrating a configuration of an IP retransmission system 1 according to an embodiment. FIG. 2 is a diagram showing the data structure of the divided TLV packet and the IP packet. FIG. 3 is a diagram showing a sequence up to viewing by the receiver 5 in the IP retransmission system 1. FIG. 4 is a diagram showing a sequence until the receiver 5 acquires the SI-dedicated IP packet. FIG. 5 is a diagram conceptually illustrating a method in which the receiver 5 acquires the SI-dedicated IP packet. FIG. 6 is a flowchart illustrating an IP retransmission method realized by the IP retransmission system 1 according to the embodiment. FIG. 7 is a flowchart illustrating an IP retransmission method realized by the IP retransmission system 1 according to one embodiment. FIG. 8 is a diagram showing an improvement sequence. FIG. 9 is a diagram showing another improvement sequence. FIG. 10 is a diagram showing the internal configuration of the SI server for realizing the sequence shown in FIG.

[Description of Embodiment of the Present Invention]
First, the contents of the embodiment of the present invention will be listed and described. An IP retransmission device according to one embodiment is an IP retransmission device used in an IP retransmission system that retransmits digital broadcast signals of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network. Extracting the SI information from the digital broadcast signal, storing the SI information in a packet in which an SI identification value is given as a part of the header information, and transmitting the packet to an IP multicast network together with the broadcast stream or separately from the broadcast stream. Send out.

  Similarly, an IP retransmission method according to one embodiment is an IP retransmission method for retransmitting a digital broadcast signal of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network. The SI information is extracted from the signal, the SI information is stored in a packet in which an SI identification value is added to a part of the header information, and the packet is transmitted to the IP multicast network together with the broadcast stream or separately from the broadcast stream.

  In these IP retransmission devices and IP retransmission methods, SI information is extracted from a digital broadcast signal, and the SI information is stored in a packet in which an SI identification value is added to a part of header information. Part of the header information is, for example, a packet ID. Then, this packet is transmitted to the IP multicast network together with the broadcast stream. Alternatively, this packet is sent to the IP multicast network separately from the broadcast stream. This allows each receiver to easily select and extract the packet including the SI information from the broadcast stream. Therefore, each receiver can efficiently acquire the SI information of a plurality of channels, and the processing load on each receiver can be reduced.

  An SI server according to an embodiment is an SI server used in an IP retransmission system that retransmits a digital broadcast signal of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network. It stores the SI information extracted from the signal and makes a single multicast packet of a plurality of channels in which an SI identification value is added to a part of the header information, and sends it to the IP multicast network. According to the SI server, each receiver can easily select and extract a packet including the SI information in distinction from the broadcast stream. Therefore, each receiver can efficiently acquire the SI information of a plurality of channels, and the processing load on each receiver can be reduced. In addition, by making a single multicast packet of a plurality of channels to which the SI identification value is assigned, the amount of communication data between the edge router and the receiver can be reduced, and an access request from each receiver to the edge router ( The number of join requests) can be reduced, and the processing load on the edge router can be reduced.

  An edge router according to one embodiment is an edge router used together with an IP retransmitting device that retransmits a digital broadcast signal of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network. A packet in which SI information extracted from a signal is stored and an SI identification value is added to a part of header information is received via an IP multicast network, and a packet of a channel requested by each receiver is transmitted to each receiver. I do. An edge router according to another embodiment is an edge router used with an IP retransmitting device that retransmits digital broadcast signals of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network. Receiving, via an IP multicast network, aggregated SI information obtained by storing SI information extracted from a digital broadcast signal and unicasting a plurality of channels of packets in which an SI identification value is added to a part of header information into a single multicast, The aggregated SI information is transmitted to each receiver in response to a request from each receiver. According to these edge routers, each receiver can easily select and extract a packet including SI information from a broadcast stream. Therefore, each receiver can efficiently acquire the SI information of a plurality of channels, and the processing load on each receiver can be reduced. Also, in the case where a packet of a plurality of channels to which the SI identification value is assigned is converted into a single multicast, the amount of communication data between the edge router and the receiver can be reduced, and an access request (join) from each receiver to the edge router can be made. Requests) and the processing load on the edge router can be reduced.

  A receiver according to one embodiment is a receiver used in an IP retransmission system for retransmitting a digital broadcast signal of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network, and A packet in which the SI information extracted from the signal is stored and a part of the header information is added with the SI identification value is received via the IP multicast network, and the packet is extracted from the TLV packet based on the SI identification value. Further, a receiver according to another embodiment is a receiver used in an IP retransmission system for retransmitting digital broadcast signals of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network. Through the IP multicast network, it stores the SI information extracted from the digital broadcast signal, and receives, via the IP multicast network, aggregated SI information obtained by making a single multicast packet of a plurality of channels in which an SI identification value is added to a part of the header information. According to these receivers, a packet including SI information can be easily selected and extracted while distinguishing it from a broadcast stream. Therefore, each receiver can efficiently acquire the SI information of a plurality of channels, and the processing load on each receiver can be reduced. Also, in the case where a packet of a plurality of channels to which the SI identification value is assigned is converted into a single multicast, the amount of communication data between the edge router and the receiver can be reduced, and an access request (join) from each receiver to the edge router can be made. Requests) and the processing load on the edge router can be reduced.

  A transmission facility according to one embodiment is a transmission facility used in an IP retransmission system for retransmitting digital broadcast signals of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network, wherein A receiving device that receives a plurality of channels of digital broadcast signals from an antenna to create a TLV packet, extracts SI information from the TLV packet, and stores the SI information in a packet in which an SI identification value is added to a part of the header information And an IP retransmission device for transmitting the packet to the IP multicast network together with the broadcast stream or separately from the broadcast stream. Further, a transmission facility according to another embodiment is a transmission facility used in an IP retransmission system for retransmitting digital broadcast signals of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network. , An antenna, a receiving device that receives a digital broadcast signal of a plurality of channels from the antenna to generate a TLV packet, extracts SI information from the TLV packet, and outputs a SI having a SI identification value to a part of header information. An IP retransmitting device that stores information, and an SI server that converts a packet of a plurality of channels into a single multicast and sends the packet to an IP multicast network. According to these transmission facilities, each receiver can easily select and extract a packet including the SI information from the broadcast stream. Therefore, each receiver can efficiently acquire the SI information of a plurality of channels, and the processing load on each receiver can be reduced. In addition, by making a single multicast packet of a plurality of channels to which the SI identification value is assigned, the amount of communication data between the edge router and the receiver can be reduced, and an access request from each receiver to the edge router ( The number of join requests) can be reduced, and the processing load on the edge router can be reduced.

[Details of Embodiment of the Present Invention]
Specific examples of an IP retransmission device, an SI server, an edge router, a receiver, an IP retransmission method, and a transmission facility according to an embodiment of the present invention will be described below with reference to the drawings. It should be noted that the present invention is not limited to these examples, but is indicated by the appended claims, and is intended to include all modifications within the meaning and scope equivalent to the appended claims. In the following description, the same elements will be denoted by the same reference symbols in the description of the drawings, without redundant description.

  FIG. 1 is a diagram schematically illustrating a configuration of an IP retransmission system 1 according to an embodiment. As shown in FIG. 1, the IP retransmission system 1 of the present embodiment includes a transmission facility 2, an IP multicast network 3, an edge router 4, and a plurality of receivers 5. The transmission equipment 2 is equipment owned by the IP retransmission service provider, and is connected to the antenna 6 via a communication line. The antenna 6 receives digital broadcast waves such as advanced broadband satellite digital broadcast (advanced BS digital broadcast) or terrestrial digital broadcast. The digital broadcast wave received by the antenna 6 includes N channels (N is an integer of 2 or more) of digital broadcast signals. The digital broadcast signal of each channel includes SI information such as an electronic program guide (EPG) in addition to video information and audio information.

  The transmission facility 2 has N receiving devices 21, N IP retransmitting devices 22, an SI server 23, and a multiplexing router 24. The N receiving devices 21 are connected to the antenna 6 via a communication line. Each receiving device 21 receives a digital broadcast signal of a channel allocated to itself from the antenna 6, and generates and outputs a TLV (Type Length Value) packet including broadcast data (video information and audio information). The TLV packet is a packet including a header and a payload, and the length of the payload is variable. The header includes information indicating the length of the payload in addition to the channel information. The payload stores broadcast data, SI information, and the like.

  Each of the N IP retransmitting devices 22 is connected to each of the N receiving devices 21 via wiring. Each IP retransmitting device 22 receives a TLV packet from the corresponding receiving device 21, and converts the TLV packet into an IPTV signal system (split TLV, time stamp addition, IPv6 multicast). Specifically, first, each IP retransmission device 22 deletes a null packet from the TLV packet output from the reception device 21. A null packet is a TLV packet with no payload. Next, each IP retransmitting device 22 stores broadcast data, SI information, and the like in fixed-length divided TLV packets by dividing or combining broadcast data, SI information, and the like included in the payload of the TLV packet. The divided TLV packet has, for example, an MPEG2-TS format, and is also referred to as a TS (Transport Stream) packet. The size of the divided TLV packet is, for example, 188 bytes. The specific configuration of the divided TLV packet is described in JCTEA STD-002-6.0 Volume 1, Part 5 of the first volume. Next, each IP retransmission device 22 converts the divided TLV packet into a TTS (Timestamped Transport Stream) by adding time information (time stamp) to each of the divided TLV packets.

  Each IP retransmission device 22 transmits the TTS-divided TLV packet to the IP multicast network 3 as a broadcast stream. Each IP retransmission device 22 of the present embodiment stores a plurality of TTS-divided TLV packets in the payload of one IP packet. The number of divided TLV packets stored in one IP packet is predetermined, and is, for example, seven. Each IP retransmission device 22 transmits an IP packet as a broadcast stream to the IP multicast network 3 via the multiplexing router 24. When the multiplexing router 24 is not provided, each IP retransmitting device 22 may directly transmit an IP packet to the IP multicast network 3. The multiplexing router 24 multiplexes a plurality of IP packets.

  FIG. 2 is a diagram showing the data structure of the divided TLV packet and the IP packet. As shown in FIG. 2, one IP packet 30 includes a header section 31 and a payload section 32 following the header section 31. The header section 31 includes an IP header 31a, a UDP (User Datagram Protocol) header 31b, and an RTP (Real-time Transport Protocol) header 31c. The payload section 32 includes a predetermined number of divided TLV packets 33. Each time stamp 34 is added to the head of the corresponding divided TLV packet 33. The size of the time stamp 34 is, for example, 4 bytes. When the size of the divided TLV packet 33 is 188 bytes, the size of the TTS-converted packet including the time stamp 34 and the divided TLV packet 33 is 192 bytes. Usually, since the maximum packet size (MTU) of Ethernet (registered trademark) is 1500 bytes, seven TTS-converted packets are stored in the payload section 32 and the IP packet 30 is transmitted as an IPv6 multicast signal as shown in FIG. .

  Each divided TLV packet 33 includes a header section 35 and a payload section 36 following the header section 35. The size of the header section 35 is, for example, 3 bytes. In one example, the header section 35 includes a synchronization byte 35a (8 bits), a transport error indicator 35b (1 bit), a TLV packet start indicator 35c (1 bit), a "0" bit 35d (1 bit), and a packet ID 35e. (13 bits). The payload section 36 contains 185 × 8 bits of broadcast data or SI information.

  Further, each IP retransmitting device 22 extracts only predetermined SI information (for example, EPG) from the TLV packet received from the receiving device 21, and stores the SI information in a packet different from the above-described divided TLV packet. Hereinafter, this packet is referred to as an SI information packet. Each IP retransmitting device 22 assigns an SI identification value to a part of the header information of this packet, distinguishes it from the divided TLV packet 33, and sets it as an SI dedicated multicast. Then, each IP retransmission device 22 sends this packet to the IP multicast network 3 together with the broadcast stream (divided TLV packet 33). Alternatively, each IP retransmission device 22 may transmit this packet to the IP multicast network 3 separately from the broadcast stream (divided TLV packet 33). In one example, the format of this packet is the same as that of the divided TLV packet 33. Then, the predetermined SI information is stored in the payload section 36. For example, the packet ID 35e is used as the header information for giving the SI identification value. For example, in CATV, the value of the packet ID 35e is "0x002D" indicating that the packet is a divided TLV packet ("" Japan Cable Television Engineers Association Standard JCTEA STD-002-6.1 Digital Cable Broadcasting Multiplexer First Edition) Fifth division section 6.1 Divided TLV packet "). By assigning an SI identification value different from" 0x002D "to the packet ID 35e, the SI information packet and the divided TLV packet 33 can be easily distinguished. it can. Note that the SI identification value may be different for each channel. In that case, it is possible to easily determine which channel the SI information is based on the header information.

  Specific examples of the predetermined SI information include, for example, a TLV network information table (actual table), an MH event information table (p / f actual table), an MH event information table (scheduled actual table), an MH broadcast information table, and an MH service description. Table (actual table).

  The SI server 23 multiplexes the SI information packets of a plurality of channels and transmits them by a single multicast. Specifically, the SI server 23 receives the SI information packet of each channel from each of the N IP retransmitting devices 22. At this time, the SI server 23 may select and extract the SI information packet from the divided TLV packets 33 output from each IP retransmitting device 22 by a filter operation based on the SI identification value. The SI server 23 collectively holds the at least N SI information packets thus received from each IP retransmission device 22. The SI server 23 collectively stores SI information packets of a plurality of channels in one or a plurality of SI-dedicated IP packets. The format of the SI-dedicated IP packet is the same as that of the IP packet 30 shown in FIG. The SI server 23 sends out the SI-dedicated IP packet to the IP multicast network 3 in a single multicast flow.

  The edge router 4 is interposed between the IP multicast network 3 and a plurality of receivers 5. The edge router 4 receives all the divided TLV packets and SI information packets via the IP multicast network 3. The edge router 4 transmits a broadcast stream of a channel corresponding to the multicast address included in the join request from each receiver 5 or an SI information packet (SI) of a channel corresponding to the multicast address included in the join request from each receiver 5. When the SI information is aggregated by the server 23, it passes the SI-dedicated IP packet) and sends it to the receiver 5.

  The receiver 5 is connected to the IP multicast network 3 via the edge router 4. The receiver 5 selects and extracts (filters) an SI information packet from a broadcast stream (divided TLV packet) received from the IP multicast network 3 based on the SI identification value. Alternatively, the receiver 5 receives the SI-dedicated IP packet from the IP multicast network 3, and selects and extracts (filters) the SI information of the desired channel based on the SI identification value set for each channel.

  FIG. 3 shows a sequence up to viewing by the receiver 5 in the IP retransmission system 1. In the figure, A, B,..., X are channel numbers. The digital broadcast signal of each channel is sent to the edge router 4 (arrows Aa to Ax in the figure). The receiver 5 acquires the IP address of the DNS from the edge router 4, acquires the address of the tuning control information server from the DNS, and then acquires and holds the tuning control information of all the channels from the tuning control information server. . Thereafter, the receiver issues a join request to the multicast address corresponding to the channel to be viewed, receives the digital broadcast signal of the channel from the edge router, and views (arrow Ba in the figure). When stopping viewing, the receiver makes a release request to the multicast address corresponding to the channel.

  FIG. 4 shows a sequence until the receiver 5 acquires the SI dedicated IP packet. FIG. 5 conceptually shows a method in which the receiver 5 acquires an SI-dedicated IP packet. As shown in FIGS. 4 and 5, when the SI information is aggregated by the SI server 23, the SI server 23 converts the divided TLV packets (arrows Aa to Ax) storing the digital broadcast signals into the SI information packets (arrows Aa to Ax). Arrows Da to Dx in FIG. 5 are selected and extracted (filtered) based on the SI identification value. The SI server 23 sends these SI information packets to the edge router 4 as single IP multicast packets (arrow D) by single multicast. As described above, the edge router 4 sends an SI-dedicated IP packet to each receiver 5 in response to a join request from each receiver 5 for the multicast.

  As illustrated in FIG. 5, in the receiver 5, the tuning of the SI-only multicast (that is, the SI-only IP packet) is performed by acquiring the tuning control information from the tuning control information server 41. The receiver 5 determines the SI identification value included in the packet by any of the following methods, and extracts the SI information packet of each channel. The first method is to specify the SI identification value of each channel from the channel selection control information. The second method is to register the SI identification value of each channel in the receiver 5 in advance.

  6 and 7 are flowcharts illustrating an IP retransmission method realized by the IP retransmission system 1 according to the present embodiment. FIG. 6 shows a case where the SI information packet is stored in the SI dedicated IP packet for each channel. FIG. 7 shows a case where the SI information packet is stored in the IP packet regardless of the channel. Referring to FIGS. 6 and 7, first, in step S1, predetermined SI information is extracted from a TLV packet of a digital broadcast signal included in a broadcast stream of each channel. Next, in step S2, SI information is stored in an SI information packet in which an SI identification value is added to a part (for example, a packet ID) of the header information, and is used as an SI dedicated multicast. The SI identification value may be different for each channel. Then, in the example shown in FIG. 6, the SI information packet is stored in the SI-dedicated IP packet for each SI identification value (that is, for each channel) (step S3A). In the example shown in FIG. 7, the SI information packet is stored in the SI dedicated IP packet regardless of the channel (step S3B). Thereafter, the IP packet dedicated to the SI is transmitted to the IP multicast network 3 together with the broadcast stream (divided TLV packet) as a single multicast. Alternatively, the SI information packet is transmitted as a single multicast to the IP multicast network 3 separately from the broadcast stream (divided TLV packet) (step S4).

  The effects obtained by the above-described IP retransmission system 1, IP retransmission device 22, receiver 5, and IP retransmission method of the present embodiment will be described together with the problems of the conventional IP retransmission system. In the receiver, SI information such as EPG is acquired in order to display EPG of all channels while acquiring a certain channel, and acquire latest EPG information for the purpose of recording a back program, and the like. Is required. For this reason, the receiver continuously obtains a digital broadcast signal of a certain channel (for example, A channel) (arrow Ba in FIG. 3), and receives another channel (B channel, C channel,..., X channel). An IP retransmission stream is acquired, and SI information is extracted from the stream (arrows Bb to Bx in FIG. 3). In such a system, if the SI information exists only in the broadcast stream of each channel, all receivers access the IP retransmission stream of all channels held by the edge router. Therefore, when the number of channels increases, the access network becomes congested, and the load on the receiver and the edge router increases.

  FIG. 8 shows an improved sequence for solving the above problem. In the sequence shown in FIG. 8, an SI server is provided between the IP retransmission device and the edge router, the SI server extracts SI information from the IP retransmission stream of all channels, and outputs an IP flow ( The destination / source IP address and port number) are changed and transmitted to the edge router. Each receiver continuously obtains an IP retransmission stream of a certain channel (for example, A channel) (arrow Ba in the drawing), and receives another channel (B channel, C channel,..., X channel). Access (join / leave) the multicast to acquire SI information (arrows Cb to Cx in the figure). However, in this method, it is necessary to repeat access for each channel in order to collect SI information of all channels, and the load on the edge router increases when the number of receivers increases.

  FIG. 9 shows another improved sequence for solving the above problem. In the sequence shown in FIG. 9, the SI server provided between the IP retransmission device and the edge router collects the SI information of all the channels into one and transmits the SI information to the edge router as a SI-dedicated multicast. The receiver accesses the SI dedicated multicast as needed. According to such a sequence, necessary SI information can be efficiently acquired even if the receiver does not access the IP retransmission streams of all channels of the edge router. Therefore, the load on the edge router is reduced. However, this sequence also has the following problem. FIG. 10 shows an internal configuration of the SI server for realizing the sequence shown in FIG. The SI server 100 includes an SI information collection unit 101, an SI information globalization processing unit 102, and an SI information retransmission unit 103. The SI information collection unit 101 extracts and holds SI information from the IP retransmission streams of all channels. The SI information globalization processing unit 102 receives the SI information of all channels from the SI information collection unit 101, and compiles the SI information of all channels as SI dedicated packets. The SI information retransmission unit 103 receives the SI-dedicated packet from the SI information globalization processing unit 102, and transmits it as an SI-dedicated multicast to the edge router via the IP multicast network.

  Since the SI information has a large data size, it is transmitted after being divided into a plurality of packets. However, if it conforms to the broadcasting standard, the packets of each channel cannot be simply mixed. Therefore, in the sequence shown in FIG. 9, as shown in FIG. 10, after collecting the SI information of all the channels and performing the globalization process (the process of collecting and reconstructing the channel information of all the stations) Therefore, it is necessary to repacketize the packet. However, for example, since the EPG information is transmitted at a period of several tens of seconds, it takes time to acquire the EPG information of all the channels, and there is a possibility that the whole localization processing is delayed. As a result, the display of the latest EPG information is delayed in the receiver, which may hinder program reservation. Therefore, it is difficult to use this sequence practically.

  In view of the above problems, the IP retransmitting device 22 of the present embodiment extracts SI information from a digital broadcast signal (TLV packet) and converts the SI information into a packet in which an SI identification value is added to a part of the header information. Store. Then, this packet is transmitted to the IP multicast network 3 together with the broadcast stream. Alternatively, this packet may be sent to the IP multicast network 3 separately from the broadcast stream. Thereby, each receiver 5 can easily select and extract a packet including the predetermined SI information from the broadcast stream. Therefore, each receiver 5 can efficiently acquire the SI information of all channels. In addition, this makes it possible to reduce the time required for acquiring the SI information and reduce the delay of the timing of acquiring the SI information with respect to the broadcast stream (video and audio). It should be noted that a packet containing predetermined SI information (SI-dedicated multicast) is an auxiliary signal and is not a transmission of a broadcast stream, and that packets transmitted in the present system are only divided TLV packets. It is not necessary to identify the divided TLV packet using the packet ID. Therefore, there is no problem even if the SI identification value is set to the packet ID and the SI identification value is made different for each channel as in the present embodiment.

  In addition, the SI server 23 of the present embodiment stores the SI information extracted from the digital broadcast signal (TLV packet) and converts a packet of a plurality of channels in which an SI identification value is added to a part of the header information into a single multicast. To the IP multicast network 3. According to the SI server 23, each receiver 5 can easily select and extract a packet including the SI information from the broadcast stream. Therefore, each receiver 5 can efficiently acquire the SI information of all channels. In addition, by making a single multicast packet of a plurality of channels to which the SI identification value is assigned, the amount of communication data between the edge router 4 and the receiver 5 can be reduced, and the receiver 5 for the edge router 4 can receive the communication data. , The number of access requests (join requests) can be reduced, and the processing load on the edge router 4 can be reduced.

  Further, the edge router 4 of the present embodiment stores the SI information extracted from the digital broadcast signal (TLV packet) and transmits the packet in which the SI identification value is added to a part of the header information via the IP multicast network 3. Upon receiving, the packet of the channel requested by each receiver 5 is transmitted to each receiver 5. Alternatively, the edge router 4 stores the SI information extracted from the digital broadcast signal (TLV packet) and combines the packets of a plurality of channels in which a part of the header information is provided with the SI identification value into a single multicast into an aggregated SI. The information is received via the IP multicast network 3, and the aggregated SI information is transmitted to each receiver 5 in response to a request from each receiver 5. According to the edge router 4, each receiver 5 can easily select and extract a packet including the SI information while distinguishing the packet from the TLV packet. Therefore, each receiver 5 can efficiently acquire the SI information of all channels. Also, in the case where a single multicast packet of a plurality of channels to which the SI identification value is assigned is made, the amount of communication data between the edge router 4 and the receiver 5 can be reduced, and at the same time, the amount of data transmitted from each receiver 5 to the edge router 4 can be reduced. The number of access requests (join requests) can be reduced, and the processing load on the edge router 4 can be reduced.

  Further, the receiver 5 of the present embodiment stores the SI information extracted from the digital broadcast signal (TLV packet) and transmits the packet having the SI identification value added to a part of the header information via the IP multicast network 3. The packet is received and extracted from the broadcast stream based on the SI identification value. Alternatively, the receiver 5 stores the SI information extracted from the digital broadcast signal (TLV packet) and combines the packets of a plurality of channels in which a part of the header information is given an SI identification value into a single multicast to form an aggregated SI. Information is received via the IP multicast network 3. According to the receiver 5, the packet including the SI information can be easily selected and extracted while distinguishing it from the broadcast stream. Therefore, each receiver 5 can efficiently acquire the SI information of all channels. Also, in the case where a single multicast packet of a plurality of channels to which the SI identification value is assigned is made, the amount of communication data between the edge router 4 and the receiver 5 can be reduced, and at the same time, the amount of data transmitted from each receiver 5 to the edge router 4 can be reduced. The number of access requests (join requests) can be reduced, and the processing load on the edge router 4 can be reduced.

  Further, the transmission equipment 2 of the present embodiment includes an antenna 6, a receiving device 21 that receives a digital broadcast signal of a plurality of channels from the antenna 6 and creates a TLV packet, extracts SI information from the TLV packet, An IP retransmitting device 22 that stores SI information in a packet to which a SI identification value is partially given and sends the packet to the IP multicast network 3 together with a broadcast stream. Alternatively, the transmitting equipment 2 includes the antenna 6, a receiving device 21 that receives digital broadcast signals of a plurality of channels from the antenna 6 and creates a TLV packet, and extracts SI information from the TLV packet, and outputs the SI information as part of the header information. It includes an IP retransmitting device 22 that stores SI information in a packet to which an identification value has been added, and an SI server 23 that converts a packet of a plurality of channels into a single multicast and sends it to the IP multicast network 3. According to the transmission equipment 2, each receiver 5 can easily select and extract a packet including the SI information from the broadcast stream. Therefore, each receiver 5 can efficiently acquire the SI information of all channels. Also, in the case where a single multicast packet of a plurality of channels to which the SI identification value is assigned is made, the amount of communication data between the edge router 4 and the receiver 5 can be reduced, and at the same time, the amount of data transmitted from each receiver 5 to the edge router 4 can be reduced. The number of access requests (join requests) can be reduced, and the processing load on the edge router 4 can be reduced.

  The IP retransmission device, the SI server, the edge router, the receiver, the IP retransmission method, and the transmission equipment according to the present invention are not limited to the above-described embodiment, and various other modifications are possible. For example, in the above-described embodiment, the packet ID is used as the header information for giving the SI identification value, but the SI identification value may be given to other header information. In the above-described embodiment, EPG information is illustrated as an example of the predetermined SI information. However, the predetermined SI information stored in the divided TLV packet to which the SI identification value is added in the present invention is limited to the EPG information. I can't. In the above-described embodiment, the same type of packet as the divided TLV packet is used for the SI-dedicated multicast. However, the format of the packet used for the SI-dedicated multicast may be different from that of the divided TLV packet.

  DESCRIPTION OF SYMBOLS 1 ... IP retransmission system, 2 ... Transmission equipment, 3 ... IP multicast network, 4 ... Edge router, 5 ... Receiver, 6 ... Antenna, 21 ... Reception device, 22 ... IP retransmission device, 23 ... SI server, 24 ... Multiplexing router, 30 ... IP packet, 31 ... Header part, 31a ... IP header, 31b ... UDP header, 31c ... RTP header, 32 ... Payload part, 33 ... Division TLV packet, 34 ... Time stamp, 35 ... Header part , 35a: synchronization byte, 35b: transport error indicator, 35c: TLV packet start indicator, 35d: "0" bit, 35e: packet ID, 36: payload section, 41: channel selection control information server.

Claims (9)

An IP retransmission device used in an IP retransmission system for retransmitting digital broadcast signals of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network,
Extracting the SI information from the digital broadcast signal, storing the SI information in a packet in which a part of header information is provided with an SI identification value, and storing the packet together with a broadcast stream or separately from the broadcast stream in the IP multicast network; To the IP retransmitting device. An SI server used in an IP retransmission system for retransmitting digital broadcast signals of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network,
An SI server that stores the SI information extracted from the digital broadcast signal and makes a single multicast packet of a plurality of channels in which an SI identification value is added to a part of the header information, and sends the packet to the IP multicast network. An edge router for use with an IP retransmitter for retransmitting digital broadcast signals of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network,
A packet in which SI information extracted from the digital broadcast signal is stored and a header information part of which is provided with an SI identification value is received via the IP multicast network, and the packet of the channel requested by each receiver is received. An edge router that transmits to each receiver. An edge router for use with an IP retransmitter that retransmits digital broadcast signals of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network,
Receives, via the IP multicast network, aggregated SI information that stores SI information extracted from the digital broadcast signal and that performs a single multicast of a packet of a plurality of channels in which an SI identification value is added to a part of the header information. An edge router for transmitting the aggregated SI information to each receiver in response to a request from each receiver. A receiver used in an IP retransmission system for retransmitting digital broadcast signals of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network,
A packet that stores SI information extracted from the digital broadcast signal and that has an SI identification value added to a part of header information is received via the IP multicast network, and the packet is broadcast based on the SI identification value. Extract from the receiver. A receiver used in an IP retransmission system for retransmitting digital broadcast signals of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network,
Receives, via the IP multicast network, aggregated SI information that stores SI information extracted from the digital broadcast signal and that performs a single multicast of a packet of a plurality of channels with an SI identification value added to a part of header information. ,Receiving machine. An IP retransmission method for retransmitting digital broadcast signals of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network,
Extracting the SI information from the digital broadcast signal, storing the SI information in a packet in which a part of header information is provided with an SI identification value, and storing the packet together with a broadcast stream or separately from the broadcast stream in the IP multicast network; To send to the IP retransmission method. A transmission facility used in an IP retransmission system for retransmitting digital broadcast signals of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network,
Said antenna;
A receiving device that receives a digital broadcast signal of a plurality of channels from the antenna and creates a TLV packet;
The SI information is extracted from the TLV packet, the SI information is stored in a packet in which an SI identification value is added to a part of the header information, and the packet is transmitted to the IP multicast network together with a broadcast stream or separately from the broadcast stream. An IP retransmitting device for sending;
A transmission facility comprising: A transmission facility used in an IP retransmission system for retransmitting digital broadcast signals of a plurality of channels received from an antenna to a plurality of receivers via an IP multicast network,
Said antenna;
A receiving device that receives a digital broadcast signal of a plurality of channels from the antenna and creates a TLV packet;
An IP retransmitting device that extracts SI information from the TLV packet and stores the SI information in a packet in which an SI identification value is added to a part of header information;
An SI server that converts the packets of a plurality of channels into a single multicast and sends the packet to the IP multicast network;
A transmission facility comprising:

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