JP2018121214A - Broadcast program receiver and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To establish resistance against a packet loss, improve reliability of a transfer system using device redundancy, and reduce a processing load of a device on the broadcast station side.SOLUTION: Broadcast program receivers 2-1, 2-2 receive IP packets from broadcast program transmitters 1-1, 1-2. A TSP processing unit 23 performs parity check on broadcast TS packets extracted from the IP packets; discards a broadcast TS packet having an error; and on the basis of a TSP counter, discards one broadcast TS packet of duplicate broadcast TS packets. Thereby, compensation for a missing broadcast TS packet is enabled using redundant data of the same duplicate broadcast TS packets. The broadcast program transmitters 1-1, 1-2 do not need to generate IP packets having the same encapsulation structure. Thereby, reliability of a transfer system can be improved by easily implementing a device redundancy structure.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a broadcast program receiving apparatus and a program for a relay station that receives a broadcast program transmitted from a broadcast station (performer) via an IP network.

  Conventionally, in order to transmit a broadcast program from a broadcast station to a relay station, a wireless line between the broadcast station and the relay station is often used. However, with the progress of broadband lines in recent years, transmission using an IP network has been considered.

  In general, when video and audio contents such as broadcast programs are transmitted using an IP network, a plurality of compressed contents (MPEG-2 TS signals) are collectively stored (encapsulated) in one IP packet. A transmission method is used. Also, since transmission of broadcast programs is important in real time, IP / UDP / RTP protocols are often used.

  The broadcast program is transmitted from the broadcast station to the relay station in the form of a “broadcast TS packet” (204 bytes) in which information for transmission control at the relay station is added to the MPEG-2 TS signal. The method of encapsulating the broadcast TS packet into an IP packet and transmitting it is the same as that for transmitting a general MPEG-2 TS packet.

  FIG. 11 is a schematic diagram showing an example of the overall configuration of a conventional transmission system when the broadcasting station and the relay station are each configured as a single unit. This transmission system includes a broadcast program transmission device 101 provided in a broadcast station, a broadcast program reception device 102 provided in a relay station, transmitters 103-1 and 103-2, a switch 104 and a transmission antenna 105. Configured.

  The broadcast program transmitting apparatus 101 receives a broadcast TS packet including a broadcast program, encapsulates a plurality of broadcast TS packets into one IP packet, and transmits the IP packet to the broadcast program receiving apparatus 102 via the IP network.

  The broadcast program receiving apparatus 102 receives the IP packet transmitted from the broadcast program transmitting apparatus 101 via the IP network, and extracts the broadcast TS packet from the IP packet. Broadcast program receiving apparatus 102 then outputs the broadcast TS packet to transmitter 103-1, and outputs the same broadcast TS packet to transmitter 103-2.

  The transmitter 103-1 receives a broadcast TS packet from the broadcast program receiving apparatus 102, generates an OFDM signal including the broadcast program from the broadcast TS packet, converts and amplifies the OFDM signal to a specific broadcast frequency, and then switches Output to the device 104. The transmitter 103-2 performs the same processing as the transmitter 103-1.

  The switch 104 receives the OFDM signal from the transmitter 103-1, and also receives the OFDM signal from the transmitter 103-2, and selects and outputs one of the OFDM signals based on a predetermined switching signal. . For example, normally, the OFDM signal input from the transmitter 103-1 is selected and output. When an abnormality of the transmitter 103-1 is detected, the OFDM signal input from the transmitter 103-1 is switched to the OFDM signal input from the transmitter 103-2, and the OFDM signal from the transmitter 103-2 is changed. Selected and output. As a result, a radio signal is transmitted from the transmission antenna 105.

  In the transmission system shown in FIG. 11, if a packet loss occurs when an IP packet is being transmitted, the IP packet that caused the packet loss cannot be complemented. In addition, when the broadcast program transmitting apparatus 101 or the broadcast program receiving apparatus 102 fails, an IP packet transmission interruption occurs.

  In a broadcast program transmission system, in order to continue broadcasting for 24 hours 365 days, it is necessary to increase the reliability of transmission by duplicating the apparatus.

  In the transmission system shown in FIG. 11, the IP / UDP / RTP protocol is used. In a transmission system using the IP / UDP / RTP protocol, packet reachability on the receiving side is not guaranteed as a protocol. For this reason, the receiving side detects the presence or absence of packet loss by referring to the sequence number stored in the RTP header included in the arrived IP packet.

  In order to compensate for packet loss, there is a technique in which the transmitting side overlaps the IP packet and transmits it as redundant data, and the receiving side supplements the IP packet (missing packet) subject to packet loss with the redundant data. The transmission system shown in FIG. 12 and FIG. 13 to be described later employs this method. Missing packets are determined based on the RTP sequence number and complemented in units of IP packets.

  Here, since the transmission side stores and transmits a plurality of broadcast TS packets in one IP packet, the redundant data needs to have the same configuration (the same encapsulation structure) as the missing packet. If the redundant data is not the same configuration as the missing packet, even if the redundant data is specified based on the RTP sequence number, the content of the broadcast TS packet is different, so the missing packet cannot be complemented and the original broadcast TS The packet cannot be reproduced.

  Therefore, in order to increase the reliability of the transmission system and to make redundant data have the same encapsulation structure as that of the missing packet, it is necessary to construct a transmission system shown in FIG. Making the redundant data into the same encapsulation structure as the missing packet means that the IP packet transmitted from the transmission side and the redundant data (IP packet thereof) are divided into a plurality of broadcast TS packets stored in the IP packet and redundant data. This means that a plurality of stored broadcast TS packets are made the same.

  FIG. 12 is a schematic diagram showing an example of the overall configuration of a conventional transmission system when two relay station devices are configured. This transmission system includes a broadcast program transmitting apparatus 101 provided in a broadcasting station, a switch 106 provided in a relay station, broadcast program receiving apparatuses 102-1 and 102-2, transmitters 103-1 and 103-2, switching And a transmission antenna 105. The broadcast program receiving apparatuses 102-1 and 102-2 are made up of two units and made redundant. Broadcast program transmitting apparatus 101 and broadcast program receiving apparatuses 102-1 and 102-2 are connected by two different IP networks, and the IP networks are made redundant. A router may be used instead of the switch 106. The same applies to FIGS. 1, 2 and 13 described later.

  The broadcast program transmitting apparatus 101 receives a broadcast TS packet including a broadcast program, and encapsulates a plurality of broadcast TS packets into one IP packet. Broadcast program transmitting apparatus 101 multicasts IP packets having the same encapsulation structure to broadcast program receiving apparatuses 102-1 and 102-2 via two IP networks. That is, the broadcast program transmitting apparatus 101 multicasts the same IP packet from two ports.

  The switch 106 receives the IP packet multicast-transmitted from the broadcast program transmitting apparatus 101 via the IP network, and transfers the IP packet to the broadcast program receiving apparatuses 102-1 and 102-2.

  The broadcast program receiving apparatus 102-1 receives the IP packet transferred from the switch 106, and outputs the broadcast TS packet extracted from the IP packet to the transmitter 103-1, similarly to FIG. Broadcast program receiving apparatus 102-2 performs the same processing as broadcast program receiving apparatus 102-1, and outputs the broadcast TS packet extracted from the IP packet to transmitter 103-2.

  Processing of the transmitters 103-1 and 103-2 and the switch 104 is the same as that in FIG. 11. As a result, a radio signal is transmitted from the transmission antenna 105.

  In the transmission system shown in FIG. 12, since the same IP packet is multicast-transmitted from the two ports of the broadcast program transmitting apparatus 101, each of the broadcast program receiving apparatuses 102-1 and 102-2 duplicates the same IP packet. Receive. For this reason, even if a packet loss of the IP packet occurs, the broadcast program receiving apparatuses 102-1 and 102-2 can complement the IP packet using redundant data. However, since there is only one broadcast program transmitting apparatus 101, if the broadcast program transmitting apparatus 101 fails, transmission of an IP packet is interrupted.

  For this reason, in the transmission system of the broadcast program, the above-described transmission interruption problem can be solved by duplicating the transmission side apparatus.

  FIG. 13 is a schematic diagram illustrating an example of the overall configuration of a conventional transmission system in the case where two broadcast station and relay station apparatuses are configured. This transmission system includes broadcast program transmitting devices 101-1 and 101-2 and a switch 106-1 provided in a broadcasting station, a switch 106-2 and a broadcast program receiving device 102-1 and 102- provided in a relay station. 2, transmitters 103-1 and 103-2, a switch 104 and a transmission antenna 105. The broadcast program transmitting apparatuses 101-1 and 101-2 and the broadcast program receiving apparatuses 102-1 and 102-2 are each made up of two units and made redundant.

  Broadcast program transmission apparatuses 101-1 and 101-2 receive broadcast TS packets including a broadcast program. Broadcast program transmitting apparatuses 101-1 and 101-2 encapsulate a plurality of broadcast TS packets into one IP packet and multicast-transmit the IP packet.

  In order to realize redundancy on the transmission side, a plurality of broadcast TS packets included in an IP packet transmitted from the broadcast program transmission apparatus 101-1 and an IP packet transmitted from the broadcast program transmission apparatus 101-2 are included. It is necessary to make the plurality of broadcast TS packets to be the same. For this reason, the broadcast program transmitting apparatuses 101-1 and 101-2 synchronize the encapsulation process by exchanging information for encapsulating the same plurality of broadcast TS packets into one IP packet. .

  The switch 106-1 receives the IP packet multicast-transmitted from the broadcast program transmitting apparatuses 101-1 and 101-2, and transfers the IP packet to the switch 106-2 via the IP network.

  The process of the switch 106-2 receives the IP packet transferred from the switch 106-1 (IP packet transmitted by multicast) and transfers the IP packet to the broadcast program receiving apparatuses 102-1 and 102-2. The processing of the broadcast program receiving apparatuses 102-1 and 102-2, the transmitters 103-1 and 103-2, and the switch 104 is the same as that in FIG. As a result, a radio signal is transmitted from the transmission antenna 105.

  In the transmission system shown in FIG. 13, broadcast program transmitting apparatuses 101-1 and 101-2 multicast IP packets having the same encapsulation structure, so that each of broadcast program receiving apparatuses 102-1 and 102-2 is the same. Receive duplicate IP packets. For this reason, even if a packet loss of the IP packet occurs, the broadcast program receiving apparatuses 102-1 and 102-2 can complement the IP packet using redundant data. In addition, since the broadcast program transmitting apparatuses 101-1 and 101-2 and the broadcast program receiving apparatuses 102-1 and 102-2 are each configured in a redundant manner, even if one apparatus fails, the other This can be supplemented by the above-mentioned apparatus, and the transmission interruption of the IP packet can be compensated.

  On the other hand, in a transmission system for transmitting a broadcast program, a technique has been proposed in which the sequence of broadcast TS packets is reproduced in time series on the receiving side (see, for example, Patent Document 1).

  This method extracts broadcast TS packets from received IP packets, stores them in a buffer, and generates them based on a TSP (Transport Stream Packet) counter included in the broadcast TS packets, modulation setting information included in the broadcast TS packets, and the like. By comparing with the TSP counter, the broadcast TS packet is read from the buffer, and the sequence of the original broadcast TS packet is reproduced.

Japanese Patent Laying-Open No. 2015-95679

  As described above, the transmission system illustrated in FIGS. 12 and 13 is configured to detect an IP packet in which packet loss has occurred based on the RTP sequence number stored in the RTP header included in the IP packet in order to cope with packet loss. Complement with redundant data. That is, redundant data that is the same IP packet as the missing IP packet is specified, and the missing IP packet is complemented using the redundant data.

  In the transmission system shown in FIG. 12, it is possible to cope with packet loss, but when the broadcast program transmitting apparatus 101 breaks down, transmission of an IP packet is interrupted.

  The transmission system shown in FIG. 13 can cope with packet loss, and further, any one of the broadcast program transmission apparatuses 101-1 and 101-2 is made redundant by the broadcast program transmission apparatuses 101-1 and 101-2. Even if one of them fails, the transmission of the IP packet is not interrupted.

  However, in the transmission system shown in FIG. 13, the broadcast program transmitting apparatuses 101-1 and 101-2 need to generate IP packets having the same encapsulation structure. In order to realize this, it is necessary to exchange information for encapsulating the same plurality of broadcast TS packets into one IP packet between the broadcast program transmitting apparatuses 101-1 and 101-2, and to synchronize them. is there. For this reason, in the conventional transmission system, there existed a problem that the process of the broadcast program transmission apparatuses 101-1 and 101-2 became complicated.

  As described above, in a transmission system for transmitting a broadcast program, it is possible to cope with packet loss, cope with transmission interruption of an IP packet, and further reduce the processing load on the broadcast program transmission apparatuses 101-1 and 101-2. Was desired.

  The technique of the above-mentioned patent document 1 is not based on the premise that the transmission side apparatus is made redundant as in the transmission system shown in FIG. 13, but pays attention to the processing load of the two transmission side apparatuses. not.

  Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide resistance to packet loss when transmitting a broadcast program from a broadcast station to a relay station via an IP network, An object of the present invention is to provide a broadcast program receiving apparatus and program capable of improving the reliability of a transmission system by redundancy and reducing the processing load on the apparatus on the broadcast station side.

  In order to solve the above-mentioned problem, the broadcast program receiving device according to claim 1 is composed of two broadcast program transmitting devices provided in a broadcast station and two broadcast program receiving devices provided in a relay station. In the broadcast program receiving device that receives a broadcast program from the two broadcast program transmitting devices via an IP network under the transmission system, each of the two broadcast program transmitting devices includes the broadcast program. When a plurality of broadcast TS packets are encapsulated together, an IP packet is generated, and the IP packet is transmitted to each of the two broadcast program receivers, each of the two broadcast program receivers A receiving unit that receives the IP packet, and the IP packet received by the receiving unit The TSP extraction unit that extracts a plurality of broadcast TS packets, and the TSP counter included in the broadcast TS packet extracted by the TSP extraction unit, the count value for each broadcast TS packet is set, and the duplicated A TSP processing unit that discards one of the broadcast TS packets and rearranges the broadcast TS packets in the order of the TSP counter, and the TSP processing unit extracts the TSP counter from the broadcast TS packet, and If the TSP counters are the same, it is determined that they are duplicated, one of the two broadcast TS packets that are duplicated is discarded and the other is output, and if the TSP counters are not identical, they are duplicated. A counter comparison unit that determines that the broadcast TS packet is not duplicated, The broadcast TS packet output by the counter comparing unit, the alignment is such that consecutive in the order of TSP counter to an alignment unit for outputting the broadcast TS packet after alignment, characterized by comprising a.

  The broadcast program receiving apparatus according to claim 2 is the broadcast program receiving apparatus according to claim 1, wherein a plurality of broadcast TS packets including the broadcast program are encapsulated by each of the two broadcast program transmitting apparatuses. An IP packet is generated, and the IP packet is transmitted from one of the two broadcast program transmitters to each of the two broadcast program receivers via the first IP network, In the case where transmission is performed from the other of the two broadcast program transmission apparatuses to each of the two broadcast program reception apparatuses via a second IP network different from the first IP network, the reception unit The IP packet transmitted from one of the two broadcast program transmission devices is Which receives via the IP network, the IP packet transmitted from the other of said two of the broadcast program transmission apparatus and received via the second IP network, it is characterized.

  The broadcast program receiving apparatus according to claim 3 is the broadcast program receiving apparatus according to claim 1 or 2, wherein the number of broadcast program receiving apparatuses provided in the relay station is one. .

  Furthermore, the program according to claim 4 causes a computer to function as the broadcast program receiving device according to any one of claims 1 to 3.

  As described above, according to the present invention, when a broadcast program is transmitted from a broadcast station to a relay station via an IP network, it is possible to provide resistance to packet loss, and the reliability of the transmission system through device redundancy. Can be increased. In addition, the processing load on the broadcasting station apparatus can be reduced.

It is the schematic which shows the example of whole structure of the 1st transmission system containing the broadcast program receiver by embodiment of this invention. It is the schematic which shows the example of a whole structure of the 2nd transmission system containing the broadcast program receiver by embodiment of this invention. It is a block diagram which shows the structural example of a broadcast program transmitter. It is a block diagram which shows the structural example of a broadcast program receiver. It is a block diagram which shows the structural example of a TSP process part. It is a figure explaining the structure of a broadcast TS packet. It is a figure explaining the structure of an IP packet. It is a flowchart which shows the process example of a broadcast program transmitter. It is a flowchart which shows the process example of a broadcast program receiver. It is a figure explaining the process example of a TSP process part. It is the schematic which shows the example of whole structure of the conventional transmission system at the time of setting the apparatus of a broadcasting station and a relay station as one each. It is the schematic which shows the example of whole structure of the conventional transmission system at the time of setting the apparatus of a relay station as 2 units | sets. It is the schematic which shows the example of whole structure of the conventional transmission system at the time of setting each two apparatuses of a broadcasting station and a relay station.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. The broadcast program receiving apparatus of the present invention receives IP packets multicast-transmitted from each of the two broadcast program transmitting apparatuses in a transmission system in which the broadcast program transmitting apparatus provided in the broadcasting station is made redundant by the structure of two. To do. Thereby, the broadcast program receiving apparatus can receive the same broadcast TS packet in duplicate. Then, the broadcast program receiving apparatus determines the lack of the broadcast TS packet based on the TSP counter included in the broadcast TS packet extracted from the IP packet, and the missing broadcast TS packet is replaced with redundant data that is a duplicate broadcast TS packet. Complement with

  Thus, each of the two broadcast program transmitting apparatuses does not need to generate and transmit an IP packet having the same encapsulation structure. That is, the broadcast program transmitting apparatus can store and transmit a plurality of broadcast TS packets in one IP packet without being aware of the same encapsulation structure, thereby reducing the processing load on the broadcast program transmitting apparatus. be able to. Also, the broadcast program receiving apparatus can supplement the missing broadcast TS packet even if the encapsulation structure of the IP packet is different. That is, it is possible to easily realize a redundant configuration of the apparatus and improve the reliability of the transmission system.

[First transmission system]
First, a configuration example of the first transmission system will be described. FIG. 1 is a schematic diagram showing an overall configuration example of a first transmission system including a broadcast program receiving device according to an embodiment of the present invention. This transmission system includes broadcast program transmitting apparatuses 1-1 and 1-2 and a switch 106-1 provided in a broadcasting station, a switch 106-2 and a broadcast program receiving apparatus 2-1 and 2- provided in a relay station. 2, transmitters 103-1 and 103-2, a switch 104 and a transmission antenna 105. Broadcast program transmitting apparatuses 1-1 and 1-2 and broadcast program receiving apparatuses 2-1 and 2-2 are connected by a one-line IP network.

  Each of the broadcast program transmitting apparatuses 1-1 and 1-2 and the broadcast program receiving apparatuses 2-1 and 2-2 is configured by two units and made redundant. The IP network between the broadcast program transmitting apparatuses 1-1 and 1-2 and the broadcast program receiving apparatuses 2-1 and 2-2 is not made redundant.

  When the conventional transmission system shown in FIG. 13 is compared with the transmission system shown in FIG. 1, both transmission systems are switches 106-1, 106-2, transmitters 103-1, 103-2, switch 104, and transmission. This is common in that the antenna 105 is provided. On the other hand, the transmission system in FIG. 1 includes broadcast program transmission apparatuses 1-1 and 1-2 different from the broadcast program transmission apparatuses 101-1 and 101-2 in FIG. 13, and receives the broadcast program shown in FIG. It differs from the apparatus 102-1 and 102-2 by the point provided with the broadcast program receivers 2-1 and 2-2 different.

  The broadcast program transmitting apparatus 1-1 receives a broadcast TS packet including a broadcast program, encapsulates a plurality of broadcast TS packets into one IP packet, and multicasts the IP packet. The IP packet multicast-transmitted by the broadcast program transmitting apparatus 1-1 is transmitted to the broadcast program receiving apparatuses 2-1 and 2-2 via the switch 106-1, the IP network, and the switch 106-2.

  The broadcast program transmission device 1-2 performs the same process as the broadcast program transmission device 1-1. The IP packet multicast-transmitted by the broadcast program transmitting apparatus 1-2 is transmitted to the broadcast program receiving apparatuses 2-1 and 2-2 via the switch 106-1, the IP network, and the switch 106-2.

  Here, a plurality of broadcast TS packets included in an IP packet multicast-transmitted by the broadcast program transmitting apparatus 1-1, and a plurality of broadcast TS packets included in an IP packet multicast-transmitted by the broadcast program transmitting apparatus 1-2. Need not be identical. In the conventional transmission system shown in FIG. 13, a plurality of broadcast TS packets included in the IP packet transmitted by the broadcast program transmitting apparatus 101-1 and an IP packet transmitted by the broadcast program transmitting apparatus 101-2. The plurality of broadcast TS packets need to be the same.

  Thus, each of the broadcast program transmitting apparatuses 1-1 and 1-2 does not need to generate IP packets having the same encapsulation structure. This eliminates the need for complicated processing to synchronize the encapsulation processing, thereby reducing the processing load compared to the conventional transmission system shown in FIG. Details of the broadcast program transmitting apparatuses 1-1 and 1-2 will be described later.

  FIG. 6 is a diagram for explaining the configuration of a broadcast TS packet. The broadcast TS packet includes an 188-byte information part, an 8-byte additional information (ISDB-T Information) part, and an 8-byte parity part. The additional information in the additional information part includes a TSP counter, and a different count value incremented from 1 to 4608 is set for each broadcast TS packet. Broadcast TS packets can be distinguished by this TSP counter.

  FIG. 7 is a diagram for explaining the configuration of an IP packet. This IP packet is composed of a 20-byte IP header, an 8-byte UDP header, a 12-byte RTP header, and a variable-length payload portion. The RTP header includes an RTP sequence number. N broadcast TS packets are stored in the variable-length payload portion. n is an integer of 1 or more.

  Returning to FIG. 1, the processing of the switch 106-2 is the same as that of the switch 106-2 shown in FIG.

  The broadcast program receiving apparatus 2-1 receives the IP packet multicast-transmitted from the broadcast program transmitting apparatuses 1-1 and 1-2 via the switch 106-1, the IP network, and the switch 106-2. That is, the broadcast program receiving device 2-1 receives the same broadcast TS packet from the broadcast program transmitting devices 1-1 and 1-2 in a state where the same broadcast TS packet is stored in IP packets that are not necessarily the same encapsulation structure. To do. In other words, the broadcast program receiving device 2-1 receives the same broadcast TS packet in duplicate.

  The broadcast program receiving device 2-1 takes out the broadcast TS packet from the IP packet, determines the lack of the broadcast TS packet based on the TSP counter included in the broadcast TS packet, and replaces the missing broadcast TS packet with the duplicate broadcast TS. Complement with redundant data that is a packet. That is, the broadcast program receiving device 2-1 discards one of the two duplicate broadcast TS packets based on the TSP counter, arranges the broadcast TS packets in order, and the broadcast TS packet from which the value of the TSP counter is missing. A null packet is inserted at the position of. The broadcast program receiving apparatus 2-1 outputs the broadcast TS packet (and null packet) to the transmitter 103-1.

  The process of the broadcast program receiving device 2-2 is the same as that of the broadcast program receiving device 2-1. Details of the broadcast program receiving apparatuses 2-1 and 2-2 will be described later.

  The processes of the transmitters 103-1, 103-2 and the switch 104 are the same as those of the transmitters 103-1, 103-2 and the switch 104 shown in FIG. As a result, a radio signal is transmitted from the transmission antenna 105.

  As described above, according to the first transmission system including the broadcast program receivers 2-1 and 2-2 according to the embodiment of the present invention, the broadcast program transmitters 1-1 and 1-2 include a plurality of broadcast TSs. The packet is encapsulated into one IP packet, and the IP packet is multicast. Thereby, the IP packet transmitted by multicast is transmitted to the broadcast program receiving apparatuses 2-1 and 2-2 via the IP network.

  Broadcast program receivers 2-1 and 2-2 receive IP packets multicast-transmitted from broadcast program transmitters 1-1 and 1-2. Then, the broadcast program receiving apparatuses 2-1 and 2-2 determine the lack of the broadcast TS packet based on the TSP counter included in the broadcast TS packet extracted from the IP packet, and complement the missing broadcast TS packet. Thereby, the broadcast program receivers 2-1 and 2-2 can receive the same broadcast TS packet in duplicate, and are the other broadcast TS packets that have received the missing broadcast TS packet in duplicate. Can be supplemented with redundant data.

  Therefore, the broadcast program transmitting apparatuses 1-1 and 1-2 need only store a plurality of input broadcast TS packets as they are in IP packets without transmitting the same encapsulation structure. That is, it is not necessary to synchronize the encapsulation process between the broadcast program transmitting apparatuses 1-1 and 1-2, and a complicated process for generating an IP packet having the same encapsulation structure is not necessary.

  As described above, when a broadcast program is transmitted from the broadcast station to the relay station via the IP network, resistance against sporadic packet loss can be provided. Further, even if any one of the broadcast program transmitting apparatuses 1-1 and 1-2 and the broadcast program receiving apparatuses 2-1 and 2-2 fails, the apparatus is made redundant, so that the reliability of the transmission system is improved. be able to. Furthermore, the processing load on the broadcast program transmitting apparatuses 1-1 and 1-2 on the broadcast station side can be reduced.

[Second transmission system]
Next, a configuration example of the second transmission system will be described. FIG. 2 is a schematic diagram showing an example of the overall configuration of the second transmission system including the broadcast program receiving device according to the embodiment of the present invention. This transmission system includes broadcast program transmitters 1-1 and 1-2 provided in a broadcast station, a switch 106 provided in a relay station, broadcast program receivers 2-1 and 2-2, and a transmitter 103-1. 103-2, a switch 104 and a transmission antenna 105. Broadcast program transmitting apparatuses 1-1 and 1-2 and broadcast program receiving apparatuses 2-1 and 2-2 are connected by two different IP networks.

  Each of the broadcast program transmitting apparatuses 1-1 and 1-2 and the broadcast program receiving apparatuses 2-1 and 2-2 is configured by two units and made redundant. The IP network between the broadcast program transmitting apparatuses 1-1 and 1-2 and the broadcast program receiving apparatuses 2-1 and 2-2 is also made redundant.

  When the first transmission system shown in FIG. 1 and the second transmission system shown in FIG. 2 are compared, both transmission systems are broadcast program transmitting apparatuses 1-1, 1-2, broadcast program receiving apparatuses 2-1, 2-2, the transmitters 103-1 and 103-2, the switch 104 and the transmission antenna 105 are common. On the other hand, the second transmission system shown in FIG. 2 transmits an IP packet using a single-line IP network in that the IP packet is transmitted using a two-line IP network. 1 transmission system.

  The processing of the broadcast program transmission apparatuses 1-1 and 1-2 is the same as that of the broadcast program transmission apparatuses 1-1 and 1-2 shown in FIG. The broadcast program transmitting apparatus 1-1 multicasts IP packets to the broadcast program receiving apparatuses 2-1 and 2-2 via the IP network and the switch 106. The broadcast program transmitting apparatus 1-2 multicasts IP packets to the broadcast program receiving apparatuses 2-1 and 2-2 via an IP network different from the IP network used by the broadcast program transmitting apparatus 1-1 and the switch 106. To do.

  The switch 106 receives the IP packet multicast-transmitted from the broadcast program transmitting apparatus 1-1, and transfers the IP packet to the broadcast program receiving apparatuses 2-1 and 2-2. Further, the switch 106 receives the IP packet multicast-transmitted from the broadcast program transmitting apparatus 1-2, and transfers the IP packet to the broadcast program receiving apparatuses 2-1 and 2-2.

  The processing of the broadcast program receivers 2-1, 2-2, transmitters 103-1, 103-2 and switch 104 is the same as the broadcast program receivers 2-1, 2-2, transmitter 103- shown in FIG. 1, 103-2 and the switch 104. As a result, a radio signal is transmitted from the transmission antenna 105.

  As described above, according to the second transmission system including the broadcast program receivers 2-1 and 2-2 according to the embodiment of the present invention, the broadcast program transmitters 1-1 and 1-2 include a plurality of broadcast TSs. The packet is encapsulated into one IP packet, and the IP packet is multicast transmitted through each IP network. Thereby, the IP packet transmitted by multicast is transmitted to the broadcast program receiving apparatuses 2-1 and 2-2 via the IP network.

  Each of the broadcast program receiving devices 2-1 and 2-2, based on the TSP counter included in the broadcast TS packet extracted from the IP packet, as in the first transmission system shown in FIG. The lack is determined, and the missing broadcast TS packet is complemented. Thereby, the broadcast program receivers 2-1 and 2-2 can receive the same broadcast TS packet in duplicate, and are the other broadcast TS packets that have received the missing broadcast TS packet in duplicate. Can be supplemented with redundant data.

  Therefore, as with the first transmission system shown in FIG. 1, the broadcast program transmitting apparatuses 1-1 and 1-2 need to generate IP packets having the same encapsulation structure when encapsulating broadcast TS packets. There is no. That is, complicated processing is not required between the broadcast program transmitting apparatuses 1-1 and 1-2. In addition, parameters can be set so that the number of capsules, error correction strength, and the like differ for each line of the IP network, and flexible transmission according to the line condition is possible.

  As described above, when a broadcast program is transmitted from the broadcast station to the relay station via the IP network, resistance against sporadic packet loss can be provided. In addition, even if one of the broadcast program transmitting apparatuses 1-1 and 1-2 and the broadcast program receiving apparatuses 2-1 and 2-2 fails, the apparatus is made redundant so that the reliability of the transmission system is improved. Can be increased. Furthermore, the processing load on the broadcast program transmitting apparatuses 1-1 and 1-2 on the broadcast station side can be reduced.

[Broadcast program transmitter 1]
Next, the broadcast program transmission apparatuses 1-1 and 1-2 (collectively referred to as the broadcast program transmission apparatus 1) shown in FIGS. 1 and 2 will be described in detail. FIG. 3 is a block diagram illustrating a configuration example of the broadcast program transmission device 1, and FIG. 8 is a flowchart illustrating a processing example of the broadcast program transmission device 1. With reference to FIG. 3, the broadcast program transmitting apparatus 1 includes a receiving unit 10, a buffer unit 11, an encapsulating unit 12, and an IP packetizing unit 13.

  Referring to FIGS. 3 and 8, receiving unit 10 receives a broadcast TS packet including a broadcast program through an ASI (Asynchronous Serial Interface), and performs a predetermined reception process on the broadcast TS packet. This is performed (step S801). Then, the receiving unit 10 stores the broadcast TS packet after reception processing in the buffer unit 11 (step S802). The buffer unit 11 stores broadcast TS packets.

  The encapsulation unit 12 reads the broadcast TS packets from the buffer unit 11, collects a predetermined number of broadcast TS packets, adds an RTP header as a unit, and performs encapsulation (step S803). Then, the encapsulation unit 12 outputs the encapsulated packet having the RTP configuration to the IP packetization unit 13.

  The IP packetizing unit 13 inputs an RTP-encapsulated packet from the encapsulating unit 12, and adds a UDP header and an IP header storing a multicast address to the destination address. Then, the IP packetization unit 13 generates an IP packet for multicast transmission having an IP / UDP / RTP configuration (step S804), and multicasts the IP packet (step S805).

  As described above, by applying the broadcast program transmission apparatus 1 shown in FIG. 3 to the broadcast program transmission apparatuses 1-1 and 1-2 shown in FIGS. 1 and 2, the broadcast program transmission apparatuses 1-1 and 1 are performed. -2 is multicast-transmitted without the synchronization of the encapsulation process between -2. That is, since the IP packet multicast-transmitted by the broadcast program transmitting apparatus 1-1 and the IP packet multicast-transmitted by the broadcast program transmitting apparatus 1-2 have different encapsulation timings, they always have the same encapsulation structure. Is not limited. Since the broadcast program transmitting apparatuses 1-1 and 1-2 do not need to be synchronized unlike the conventional ones, complicated processing is not required, and the processing load can be reduced.

  The broadcast program receivers 2-1 and 2-2 receive IP packets multicast-transmitted from the broadcast program transmitter 1-1, and receive IP packets multicast-transmitted from the broadcast program transmitter 1-2. be able to. That is, each of the broadcast program receiving devices 2-1 and 2-2 can receive the same broadcast TS packet in duplicate.

[Broadcast program receiving device 2]
Next, the broadcast program receivers 2-1 and 2-2 (collectively referred to as the broadcast program receiver 2) shown in FIGS. 1 and 2 will be described in detail. FIG. 4 is a block diagram illustrating a configuration example of the broadcast program receiving device 2, and FIG. 9 is a flowchart illustrating a processing example of the broadcast program receiving device 2. With reference to FIG. 4, the broadcast program receiving apparatus 2 includes a receiving unit 20, a TSP extracting unit 21, a buffer unit 22, a TSP processing unit 23, and a transmitting unit 24.

  Referring to FIGS. 4 and 9, receiving unit 20 receives IP packets multicast-transmitted from broadcast program transmitting apparatuses 1-1 and 1-2, and performs predetermined reception processing on the IP packets (step S901). ). Then, the reception unit 20 outputs the IP packet after the reception process to the TSP extraction unit 21.

  The IP packet received by the receiving unit 20 is an IP packet multicast-transmitted from the broadcast program transmitting apparatus 1-1 and an IP packet multicast-transmitted from the broadcast program transmitting apparatus 1-2. The encapsulation structure of these IP packets is not necessarily the same.

  The TSP extraction unit 21 receives the IP packet after reception processing from the reception unit 20, extracts a plurality of broadcast TS packets from the payload portion of the IP packet (step S902), and stores the broadcast TS packets in the buffer unit 22 (step S902). S903). The buffer unit 22 stores broadcast TS packets.

  The TSP processing unit 23 reads the broadcast TS packet from the buffer unit 22 and, after parity check, extracts the TSP counter from the additional information portion of the broadcast TS packet, and performs a duplication check on the broadcast TS packet based on the TSP counter (step). S904). Then, when the broadcast TS packet is duplicated, the TSP processing unit 23 discards one broadcast TS packet among the duplicate broadcast TS packets (step S905). Moreover, when the broadcast TS packet does not overlap, the TSP processing unit 23 determines that at least one of the two broadcast TS packets transmitted in duplicate is missing.

  The TSP processing unit 23 arranges the broadcast TS packets so as to be continuous TSP counters (step S906), determines the lack of broadcast TS packets based on the TSP counter, and inserts null packets (step S907). . Then, the TSP processing unit 23 outputs the broadcast TS packet in which the null packet is inserted to the transmission unit 24.

  Missing broadcast TS packets are when the broadcast program receiving device 2 does not receive an IP packet including the broadcast TS packet, when the broadcast TS packet is discarded by a parity check of the parity check unit 30 described later, and This occurs when the broadcast TS packet is discarded due to duplication inspection by the counter comparison unit 31 described later.

  Here, when one of the two broadcast TS packets transmitted in duplicate is lost, the other remains, so that it can be complemented by this, and there is no problem. A null packet is inserted when both of these broadcast TS packets are missing. Details of the TSP processing unit 23 will be described later.

  The transmission unit 24 receives the broadcast TS packet (and null packet) from the TSP processing unit 23, and transmits the broadcast TS packet by ASI (step S908).

  In this way, by applying the broadcast program receiving apparatus 2 shown in FIG. 4 to the broadcast program receiving apparatuses 2-1 and 2-2 shown in FIGS. 1 and 2, the broadcast program receiving apparatuses 2-1 and 2- Each of the two can receive the same broadcast TS packet in duplicate.

  Further, a missing broadcast TS packet is determined based on a TSP counter included in the broadcast TS packet, and the missing broadcast TS packet is used by using a broadcast TS packet that is not missing among the same broadcast TS packets received in duplicate. Can be complemented.

(TSP processor 23)
Next, the TSP processing unit 23 shown in FIG. 4 will be described in detail. FIG. 5 is a block diagram illustrating a configuration example of the TSP processing unit 23. The TSP processing unit 23 includes a parity check unit 30, a counter comparison unit 31, an alignment unit 32, and a null insertion unit 33.

  The parity check unit 30 reads the broadcast TS packet from the buffer unit 22, extracts the parity data from the parity part of the broadcast TS packet, and performs the parity check of the broadcast TS packet based on the parity data.

  When the parity check unit 30 determines that there is no error by the parity check, the parity check unit 30 outputs the broadcast TS packet to the counter comparison unit 31. On the other hand, when the parity check unit 30 determines that there is an error by the parity check, the parity check unit 30 discards the broadcast TS packet.

  As a result, of the broadcast TS packets included in the IP packets received from the broadcast program transmitting apparatuses 1-1 and 1-2, the broadcast TS packets determined to have an error by the parity check are discarded.

  The counter comparison unit 31 inputs a broadcast TS packet having no error due to the parity check from the parity check unit 30 and extracts a TSP counter from the additional information portion of the broadcast TS packet. Then, the counter comparison unit 31 is based on the TSP counter in the range of a predetermined number of broadcast TS packets (including the inspection target broadcast TS packets) continuously input from the parity check unit 30 for the inspection target broadcast TS packets. Thus, the duplication of broadcast TS packets is determined.

  When the TSP counters are not the same, the counter comparison unit 31 determines that the inspection target broadcast TS packets are not duplicated, and outputs the inspection target broadcast TS packets to the alignment unit 32. On the other hand, when the TSP counters are the same, the counter comparison unit 31 determines that there is an overlap in the inspection target broadcast TS packet, and discards the inspection target broadcast TS packet.

  As a result, one of the duplicate broadcast TS packets input from the parity check unit 30 is discarded, and one broadcast TS packet is output to the alignment unit 32.

  The aligning unit 32 receives the broadcast TS packet having no overlap from the counter comparison unit 31 and extracts the TSP counter from the additional information portion of the broadcast TS packet. Then, the alignment unit 32 aligns the broadcast TS packets so as to be continuous in the order of the TSP counter, and outputs the aligned broadcast TS packets to the null insertion unit 33.

  Thereby, the broadcast TS packets are rearranged in the order of the TSP counter. The broadcast TS packet output from the alignment unit 32 does not include a packet that could not be received by the broadcast program receiving apparatus 2 and a packet discarded by the parity check unit 30 or the counter comparison unit 31. Accordingly, the broadcast TS packets output from the aligning unit 32 are arranged in the order of the TSP counter, but there may be missing numbers that are not serial numbers.

  The null insertion unit 33 inputs the broadcast TS packet after the alignment from the alignment unit 32 and extracts the TSP counter from the additional information portion of the broadcast TS packet. And the null insertion part 33 determines the presence or absence of a broadcast TS packet by determining whether a TSP counter is a serial number.

  If the null insertion unit 33 determines that the TSP counter is a sequential number, the null insertion unit 33 outputs the broadcast TS packet assuming that there is no missing broadcast TS packet. On the other hand, if the null insertion unit 33 determines that the TSP counter is not a serial number, it is assumed that there is a missing broadcast TS packet. The null insertion unit 33 specifies a TSP counter with a number that is not a serial number, generates a null packet (a null packet having a broadcast TS packet configuration) in which the TSP counter is stored in the additional information portion, and omits the number of the null packet. Are inserted as broadcast TS packets (broadcast TS packets in which only the TSP counter is stored). And the null insertion part 33 outputs a broadcast TS packet.

  As a result, the null packet is inserted into a part of the series of broadcast TS packets input from the aligning unit 32 where the number is not a serial number. A series of broadcast TS packets including null packets are output from the null insertion unit 33 in the order of the TSP counter. In this way, the broadcast TS packet is restored. Therefore, continuity of broadcast TS packets can be ensured and synchronization can be maintained.

  FIG. 10 is a diagram for explaining a processing example of the TSP processing unit 23, and shows a specific TSP counter value for a broadcast TS packet discarding process, a missing determination process, and the like. In FIG. 10, arrows from left to right indicate the flow of processing in the parity check unit 30, the counter comparison unit 31, the alignment unit 32, and the null insertion unit 33 of the TSP processing unit 23, and a square frame indicates a broadcast TS. Indicates a packet.

  Numerical values (10, 11, 12, 13) within the square frame indicate the value of the TSP counter. Also, the numerical values (1, 2) in parentheses in the square frame indicate the distinction of broadcast TS packets (transmission source distinction) transmitted from the broadcast program transmission apparatuses 1-1, 1-2. 1 indicates that the transmission source is the broadcast program transmission device 1-1, and 2 indicates that the transmission source is the broadcast program transmission device 1-2.

  As shown in FIG. 10, the broadcast TS packet before the parity check in the parity check unit 30 is a packet “10 (1)” with a TSP counter value of 10 transmitted from the broadcast program transmitting apparatus 1-1, the broadcast program transmitting apparatus A packet “11 (1)” of TSP counter value 11 transmitted from 1-1,..., A packet “13 (2)” of TSP counter value 13 transmitted from the broadcast program transmitting apparatus 1-2. Suppose there is. The numerical value in “” indicates the TSP counter, and the numerical value in () indicates the transmission source. Broadcast TS packets “10 (1)”, “11 (1)”... “13 (2)” are read from the buffer unit 22 in this order.

  If there is no error in the ○ broadcast TS packet shown in FIG. 10 and there is an error in the × broadcast TS packet due to the parity check of the parity check unit 30, the × broadcast TS packet is discarded. Then, the broadcast TS packets after the parity check are “10 (1)”, “10 (2)”, “13 (1)”, and “11 (2)”.

  The counter comparison unit 31 determines that there is an overlap in the broadcast TS packets “10 (1)” and “10 (2)” having a TSP counter value of 10, and either one is discarded. As a result, the broadcast TS packet after the counter comparison is “10”, “13”, and “11” with the transmission source omitted.

  The broadcasting TS packets are arranged by the arranging unit 32 so as to be continuous in the order of the TSP counter, and the arranged broadcasting TS packets are “10”, “11”, and “13”.

  The null insertion unit 33 specifies the TSP counter value 12 with no number that is not a serial number, and generates a null packet (null packet with a broadcast TS packet configuration) “12 (null)” that stores the TSP counter value. , Inserted at the missing number. The broadcast TS packet after insertion of the null packet is “10” “11” “12 (null)” “13”.

  As described above, by applying the broadcast program receiving device 2 shown in FIG. 4 to the broadcast program receiving devices 2-1 and 2-2 shown in FIGS. -2 receives an IP packet multicast-transmitted from the broadcast program transmitter 1-1, and receives an IP packet multicast-transmitted from the broadcast program transmitter 1-2. That is, each of the broadcast program receiving apparatuses 2-1 and 2-2 receives the same broadcast TS packet in duplicate.

  The TSP processing unit 23 of the broadcast program receivers 2-1 and 2-2 extracts a plurality of broadcast TS packets from the received IP packet, performs a parity check, and discards an erroneous broadcast TS packet by the parity check. Then, the TSP processing unit 23 extracts a TSP counter from the broadcast TS packet, determines a duplicate broadcast TS packet based on the TSP counter, and discards one broadcast TS packet among the duplicate broadcast TS packets.

  As a result, the broadcast program receivers 2-1 and 2-2 can detect the missing broadcast TS packet or parity check on the IP network even if the encapsulation structure of two IP packets including the same broadcast TS packet is different. Broadcast TS packets that are lost due to discarding can be supplemented with redundant data that is other broadcast TS packets among duplicate broadcast TS packets.

  Therefore, the broadcast program transmitting apparatuses 1-1 and 1-2 do not need to generate IP packets having the same encapsulation structure when encapsulating broadcast TS packets. That is, complicated processing is not required between the broadcast program transmitting apparatuses 1-1 and 1-2.

  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 transmission system shown in FIGS. 1 and 2, the broadcast program transmitting apparatuses 1-1 and 1-2 are configured to multicast transmit IP packets to the broadcast program receiving apparatuses 2-1 and 2-2. On the other hand, the broadcast program transmitting apparatuses 1-1 and 1-2 may transmit IP packets to the broadcast program receiving apparatuses 2-1 and 2-2, respectively, instead of multicast transmission. This is effective when there is a sufficient bandwidth in the line of the IP network.

  In the transmission system shown in FIG. 1 and FIG. 2, the broadcast program receiving devices 2-1 and 2-2 are configured to be redundant by two units, but are not configured by two units but by one unit. You may make it comprise. Also in this case, the broadcast program transmitting apparatuses 1-1 and 1-2 are configured by two units to be redundant, and the broadcast program receiving apparatus 2 can receive the same broadcast TS packet repeatedly.

  Therefore, in this case as well, resistance to sporadic packet loss can be provided, and even if one of the broadcast program transmission apparatuses 1-1 and 1-2 fails, the apparatus is made redundant. The reliability of the transmission system can be increased. Furthermore, the processing load on the broadcast program transmitting apparatuses 1-1 and 1-2 on the broadcast station side can be reduced.

  The broadcast program receiving device 2 shown in FIG. 4 includes one input port that receives IP packets transmitted from the broadcast program transmitting devices 1-1 and 1-2, respectively. That is, the broadcast program receiving apparatus 2 includes a single system receiving unit 20 and a TSP extracting unit 21. On the other hand, the broadcast program receiving apparatus 2 includes an input port that receives an IP packet from the broadcast program transmitting apparatus 1-1 and an input port that receives an IP packet from the broadcast program transmitting apparatus 1-2. You may do it. In this case, the broadcast program receiving device 2 includes two systems of receiving units 20 and a TSP extracting unit 21.

  Also, as shown in FIGS. 4, 5, 9, and 10, the TSP processing unit 23 of the broadcast program receiving device 2 inserts a null packet at a location where the broadcast TS packet is missing, and a serial number TSP counter. A null insertion unit 33 is provided for outputting broadcast TS packets having. On the other hand, the TSP processing unit 23 does not necessarily need to include the null insertion unit 33. In this case, the TSP processing unit 23 outputs a broadcast TS packet in a missing state having a TSP counter that is not a serial number without inserting a null packet at a location where the broadcast TS packet is missing.

  Note that a normal computer can be used as the hardware configuration of the broadcast program receiving apparatus 2 according to the embodiment of the present invention. The broadcast program receiving apparatus 2 is configured by a computer including a CPU, a volatile storage medium such as a RAM, a non-volatile storage medium such as a ROM, an interface, and the like. Each function of the receiving unit 20, the TSP extracting unit 21, the buffer unit 22, the TSP processing unit 23, and the transmitting unit 24 included in the broadcast program receiving device 2 is realized by causing the CPU to execute a program describing these functions. Is done. These programs are stored in the storage medium and read out and executed by the CPU. These programs can also be stored and distributed in a storage medium such as a magnetic disk (floppy (registered trademark) disk, hard disk, etc.), optical disk (CD-ROM, DVD, etc.), semiconductor memory, etc. You can also send and receive.

DESCRIPTION OF SYMBOLS 1,101 Broadcast program transmission apparatus 2,102 Broadcast program reception apparatus 10, 20 Reception part 11, 22 Buffer part 12 Encapsulation part 13 IP packetization part 21 TSP extraction part 23 TSP processing part 24 Transmission part 30 Parity check part 31 Comparison unit 32 Alignment unit 33 Null insertion unit 103 Transmitter 104 Switch 105 Transmitting antenna 106 Switch

Claims (4)

An IP network is connected from the two broadcast program transmission devices under a transmission system composed of two broadcast program transmission devices provided in the broadcast station and two broadcast program reception devices provided in the relay station. In the broadcast program receiving device for receiving a broadcast program via
Each of the two broadcast program transmitting devices encapsulates a plurality of broadcast TS packets including the broadcast program, generates an IP packet, and the IP packet is sent to each of the two broadcast program receiving devices. When sent
Each of the two broadcast program receiving devices is:
A receiving unit for receiving the IP packet;
A TSP extraction unit for extracting a plurality of broadcast TS packets from the IP packet received by the reception unit;
Based on the TSP counter in which the count value for each broadcast TS packet included in the broadcast TS packet extracted by the TSP extraction unit is set, one of the duplicate broadcast TS packets is discarded, and the TSP counter A TSP processing unit that rearranges the
The TSP processing unit
The TSP counter is extracted from the broadcast TS packet, and when the TSP counter is the same for a plurality of the broadcast TS packets, it is determined that they are duplicated, and one of the two duplicate broadcast TS packets is discarded. And the other, and if the TSP counters are not the same, the counter comparison unit determines that they are not duplicated and outputs the broadcast TS packets that are not duplicated;
An alignment unit that aligns the broadcast TS packets output by the counter comparison unit so as to be continuous in the order of the TSP counter, and outputs the aligned broadcast TS packets;
A broadcast program receiving apparatus comprising: The broadcast program receiving device according to claim 1,
Each of the two broadcast program transmitters encapsulates a plurality of broadcast TS packets including the broadcast program, generates an IP packet, and the IP packet is one of the two broadcast program transmitters. To the two broadcast program receivers via the first IP network, and a second one different from the first IP network from the other of the two broadcast program transmitters. When transmitted to each of the two broadcast program receiving devices via the IP network,
The receiver is
The IP packet transmitted from one of the two broadcast program transmitters is received via the first IP network and the IP packet transmitted from the other of the two broadcast program transmitters A broadcast program receiving apparatus, wherein the packet is received via the second IP network. In the broadcast program receiver according to claim 1 or 2,
A broadcast program receiving apparatus, wherein the number of broadcast program receiving apparatuses provided in the relay station is one.   A program for causing a computer to function as the broadcast program receiving device according to any one of claims 1 to 3.

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