JP3902075B2 - Relay device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a relay device, and more particularly, to a relay device that distributes digital broadcasting via a communication network operating with IP (Internet Protocol).
Hereinafter, in this specification, digital television broadcasting is referred to as digital broadcasting, and analog television broadcasting is referred to as analog broadcasting.
[0002]
[Prior art]
[Digital broadcasting, satellite broadcasting, terrestrial broadcasting, CATV, etc.]
In recent years, digital broadcasts related to wireless media such as satellite broadcasts and terrestrial broadcasts can be viewed by installing an antenna and a predetermined receiver, similarly to analog broadcasts related to wireless media.
[0003]
Also, digital broadcasting (for example, digital broadcasting using CATV (Cable Television), etc.) related to a wired medium as a means for complementing reception by radio waves, is similar to an analog broadcasting related to a wired medium. Can be received on a wired medium with stable transmission quality, and if a good reception point is selected, even if the radio wave environment around the viewer changes due to the construction of a new building, etc., stable TV broadcasting Can be watched.
[0004]
[Digital broadcasting, ADSL / FTTH, etc.]
In recent years, inexpensive and broadband communication services called broadband, such as ADSL (Asymmetric Digital Subscriber Line) and FTTH (Fiber To The Home), are becoming widespread, and video and audio stream distribution is performed on the Internet. Yes.
Conventionally, it has been considered to distribute digital broadcasting on the Internet.
[0005]
[Digital broadcasting and encryption]
Also, in digital broadcasting, there are cases where encryption processing is performed on broadcast content for viewing management in pay programs. In this case, the broadcaster performs cryptographic processing with relatively low strength in anticipation of difficulty in storing broadcast signals on the transmission path.
[0006]
[From analog to digital]
Therefore, in recent years, television broadcasting is shifting from analog to digital.
[0007]
[Problems to be solved by the invention]
[Problems when Digital Broadcasting is Performed by Satellite Broadcasting, Terrestrial Broadcasting, CATV, etc.] However, in recent years, installation of antennas and reception of broadcast waves by antennas are becoming difficult due to progress in urban development and the like. Therefore, in recent years, satellite broadcasting and terrestrial broadcasting have become difficult to receive even analog broadcasting, rather than digital broadcasting.
[0008]
In addition, a coaxial cable used in CATV or the like has a limited frequency band that can be used. Therefore, in recent years, in CATV and the like, due to an increase in broadcasting media, the depletion of a new usable band has become a problem even for analog broadcasting as well as digital broadcasting.
[0009]
[Problems for digital broadcasting using ADSL / FTTH]
In ADSL / FTTH, etc., a program table is provided using a Web page. In the provided program table, each program name is described in association with a multicast address that is a distribution destination of each program. Has been.
Therefore, when digital broadcasting is performed using ADSL / FTTH or the like, it is conceivable that there may be a problem with a viewing operation peculiar to television such as zapping.
[0010]
On the other hand, in digital broadcasting, information for generating an electronic program guide (EPG) (hereinafter referred to as “program arrangement information”) is transmitted at the same time together with encoded video / audio information, and viewers are sent to the viewer. The program is selected by the electronic program guide.
[0011]
However, in the conventional digital broadcasting using ADSL / FTTH or the like, only a program guide is provided by a web page, and no measures are taken for transmission of program arrangement information for generating the electronic program guide. It was.
[0012]
Therefore, there has been a difference in program selection for viewers between conventional digital broadcasting using ADSL, FTTH, and the like and digital broadcasting using satellite broadcasting, terrestrial broadcasting, CATV, or the like.
[0013]
[Problems of encryption methods used in conventional digital broadcasting]
In addition, packets can be easily stored and monitored by a commercially available personal computer or the like on a transmission path based on the Internet protocol. For this reason, in the conventional encryption method, after the packets are temporarily stored in a personal computer or the like, the broadcast content that has been encrypted is decrypted over a period of time, so that the equivalent broadcast content can be obtained. Therefore, in the conventional encryption method, there is a possibility that the broadcast content is unintentionally copied by the broadcaster.
[0014]
[Digitization failure]
As described above, since there are many problems in the conventional digital broadcasting, these problems have become a major obstacle to the transition from analog broadcasting to digital broadcasting.
[0015]
[Object of the present invention]
Therefore, in view of such circumstances, an object of the present invention is to provide a relay device that realizes digital broadcasting that is superior in stability, quality, and security compared to conventional digital broadcasting.
[0016]
[Means for Solving the Problems]
According to the present invention, the above problem is solved by the means described in the claims.
[0017]
  That is,The relay apparatus according to the present invention receives a broadcast signal in which one MPEG2 transport stream (the MPEG2 transport stream includes a mixture of MPEG2 packets related to a plurality of services) modulated to one channel. And a plurality of MPEG2 packets output from the broadcast receiver, a plurality of IP (Internet Protocol) packets (a part or all of each MPEG2 packet is stored in the payload of the IP packet, An IP header of the IP packet stores an IP multicast address as a destination address), and outputs the plurality of IP packets as an IP stream to an IP network to which a receiving apparatus is connected; In the relay apparatus comprising: the broadcast receiver The received broadcast signal includes a first network information table, and the converter replaces the first network information table with a newly defined second network information table, and the second network information table. Includes first and second descriptors associated with the MPEG2 transport stream, and the first descriptor includes a service ID that identifies each service included in the MPEG2 transport stream, and The second descriptor includes one or both of an IP multicast address and a port number of a delivery destination of the MPEG2 transport stream.
[0018]
Here, the payload refers to an information field for transmitting actual data, excluding a header portion, such as an ATM cell or a frame.
[0019]
  the aboveAccording to the invention, the relay device is installed at one end of an IP network that operates according to the Internet protocol, receives a broadcast signal, and distributes the broadcast signal to a viewer by IP multicast. Therefore,the aboveAccording to the invention, the broadcast signal can be efficiently distributed to many viewers.
[0020]
  the aboveAccording to the invention, the relay device stores each MPEG2 packet output from the broadcast receiver as it is in each IP packet. Therefore,the aboveADVANTAGE OF THE INVENTION According to invention, digital broadcasting can be distributed in IP network, maintaining the quality (for example, image quality etc.) of broadcasting in satellite broadcasting, CATV, etc.
[0024]
  the aboveAccording to the invention, the network information table (hereinafter referred to as “NIT: Network Information Table”) is replaced in the IP network. Therefore,the aboveAccording to the present invention, a receiving apparatus installed in a viewer's house or the like operates necessary for selecting a program using only the service ID of the MPEG2 transport stream related to the program, even if the program distribution condition is changed. It can be performed.
[0026]
  The above inventionTherefore, by including the service ID and the multicast address or port number in the second NIT, the corresponding multicast address and port number can be searched using the service ID as a key.
[0028]
  the aboveThe invention describes a service ID and a multicast address or port number as a descriptor in the second NIT.
  Therefore,the aboveAccording to the present invention, the NIT main body can be shared with other broadcast media, and digital broadcasting with flexibility corresponding to changes in transmission means can be realized.
[0035]
  BookinventionIn the relay deviceThe converter has encryption processing means for encrypting a part or all of each MPEG2 packet output from the broadcast receiver, and the receiving device receives a payload of an IP packet received via the IP network. And a decryption unit for decrypting a cipher related to the MPEG2 packet stored in the encryption method by a method corresponding to the encryption performed by the encryption processing unit.The
[0036]
  the aboveAccording to the present invention, since encryption having a strength different from that of distribution on a broadcast network can be applied to a broadcast signal, unauthorized copying of broadcast content due to accumulation of packets can be prevented in the IP network.
[0037]
  BookinventionIn the relay deviceThe converter has encryption processing means for encrypting a part or all of the payload of the IP packet to be output to the IP network, and the receiving device receives the payload of the IP packet received via the IP network. Characterized in that it has decryption means for decrypting the encryption according to a method corresponding to the encryption performed by the encryption processing means.The
[0038]
  the aboveAccording to the present invention, it is possible to apply encryption having a strength different from encryption in a broadcast network to a broadcast signal. Also,the aboveAccording to the invention, the entire content including the MPEG2 header can be protected from unauthorized monitoring, duplication, and the like by performing encryption processing on the IP packet.
[0039]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0040]
FIG. 9 is a diagram illustrating a configuration example of an IP broadcast distribution system using the relay device according to the embodiment of the present invention.
The broadcast center transmits broadcast radio waves to the broadcast satellite, and the broadcast satellite receives the broadcast radio waves transmitted from the broadcast center and transmits them to the relay device.
The relay device receives the broadcast radio wave transmitted from the broadcast satellite, and transmits the broadcast signal by IP multicast to the receiver at the viewer's house connected via the IP network (network in which packet communication is performed by the Internet protocol). Delivery of.
The relay device and the IP network are individually managed and operated by a distribution company, and the broadcast center is individually managed and operated by a broadcast company.
[0041]
FIG. 3 is a diagram illustrating a configuration example of a broadcast center in the IP broadcast distribution system of FIG.
The broadcast center has a function of encoding video / audio constituting a broadcast program and transmitting the encoded video / audio to a broadcast satellite.
[0042]
A video signal sent from a video source such as a TV camera or a video recorder is encoded by an MPEG2 encoder, and a plurality of packets (hereinafter referred to as “MPEG2 stream”) constituting an MPEG2 transport stream (hereinafter referred to as “MPEG2 stream”). The packet is converted to “MPEG2 packet”).
[0043]
In the MPEG2 system, a plurality of programs can be multiplexed and transmitted in one MPEG2 stream. Therefore, as shown in FIG. 3, a plurality of video sources, MPEG2 encoders, and the like can be installed in parallel at the broadcast center.
[0044]
Each packet is assigned an identifier (hereinafter referred to as “PID”) so that the MPEG2 packet of each video source can be uniquely identified from the MPEG2 stream. The MPEG2 stream output from the MPEG2 encoder is input to a content CAS (conditional reception system) processing unit.
[0045]
FIG. 4 is a diagram illustrating a configuration example of the content CAS processing unit in the broadcasting center of FIG.
The payload of each MPEG2 packet constituting the MPEG2 stream input to the content CAS processing unit is encrypted by the encryption processing unit in FIG. 4 so that viewing of the broadcast program can be limited. This encryption is performed with the key Ks managed by the first key management means.
[0046]
Based on the key Ks, information related to the program, and the like, an ECM (Entirement Control Message) is generated in the ECM generation means. The generated ECM is encrypted with the key Kw managed by the second key management means.
[0047]
Also, an EMM (Entitlement Management Message) is generated by the EMM generation unit based on the key Kw, information on the viewer who can view the program, and the like. The generated EMM is encrypted with the key Kmi possessed by each viewer managed by the third key management means.
[0048]
The encrypted MPEG2 stream, ECM, and EMM are multiplexed by the multiprocessing means shown in FIG. 4, then output from the content CAS processing unit, and input to the multiprocessing unit shown in FIG.
[0049]
The MPEG2 stream input to the multiplexing processing unit shown in FIG. 3 is multiplexed with the PSI / SI generated by the PSI / SI generating unit and input to the modulation processing unit.
Note that PSI / SI is an abbreviation of (Program Specific Information / Service Information), and is program arrangement information added to an MPEG2 stream to identify a program. PSI / SI is standardly used in digital broadcasting systems such as a program association table (PAT), a program map table (PMT), a conditional access table (CAT), and NIT.
[0050]
The MPEG2 stream input to the modulation processing unit is modulated and then transmitted from the antenna to the broadcasting satellite.
Note that the broadcast center may transmit control signals other than the MPEG2 stream main body together with the MPEG2 stream, if necessary. Also, the modulation processing unit in FIG. 3 can perform processing such as power spreading and interleaving as necessary.
[0051]
Broadcast radio waves transmitted from the broadcast center are received by the relay device via the broadcast satellite.
[0052]
FIG. 1 is a diagram illustrating a configuration example of a relay device according to an embodiment of the present invention.
Broadcast radio waves received by the antenna of the broadcast receiver are subjected to frequency selection and demodulation by a predetermined demodulation method by the frequency selection demodulator of the broadcast receiver, and become an MPEG2 stream.
[0053]
Note that the frequency selective demodulator can perform processing such as deinterleaving and power spreading in accordance with transmission conditions from the broadcasting center.
[0054]
The MPEG2 stream output from the frequency selective demodulator is input to the converter, and the packet filtering unit filters null packets.
In the packet transmission path using the Internet protocol, unlike the satellite broadcasting in which the transmission rate is constant, even if the link speed between nodes is constant, it is not necessary to make the effective transmission speed constant. Therefore, unnecessary null packets are filtered by this filtering, and the band is effectively used.
[0055]
The packet filtering unit extracts PSI / SI by filtering. The extracted PSI / SI is input to the PSI / SI analysis unit, and in principle, input to the multiprocessing unit of FIG. However, the NIT is input from the PSI / SI analysis unit to the NIT conversion unit, not the multiple processing unit.
[0056]
The receiving apparatus acquires the physical conditions of the transmission path necessary for channel selection, such as the frequency and the modulation scheme, based on the description contents of the NIT, and the NIT description scheme differs depending on the transmission scheme of the transmission path. Therefore, the description content of the NIT needs to be changed from the description method of the satellite broadcast to the description method of the IP network before being input to the multiprocessing unit.
[0057]
FIG. 10 is a diagram illustrating the structure of the NIT. In the second loop of NIT, a distribution system descriptor corresponding to the transmission medium is described.
In this embodiment, it is necessary to change the description contents of the distribution system descriptor from the description method of the satellite broadcast to the description method of the IP network.
[0058]
FIG. 11 is a diagram showing distribution system descriptors used in the IP network.
Hereinafter, this distribution system descriptor is referred to as an IP multicast distribution system descriptor.
In the content IP network, content is distributed by IP multicast. Therefore, the MPEG2 packet includes an IP multicast address and a port number so that the receiver can select a predetermined content.
[0059]
In the relay apparatus of FIG. 1, the packet output from the packet filtering unit, the PSI / SI output from the PSI / SI analysis unit, and the NIT output from the NIT conversion unit are multiplexed by the multiprocessing unit and again MPEG2 The stream is output to the IP packet processing unit.
[0060]
The MPEG2 packet input to the IP packet processing unit is given an IP header and a UDP header, and is output to the network CAS processing unit as an IP packet. The destination IP address in the IP header is a preset IP multicast address.
[0061]
The IP packet input to the network CAS processing unit is subjected to an encryption process different from the CAS performed in the broadcast center of FIG.
[0062]
FIG. 2 is a diagram illustrating a configuration example of a network CAS processing unit of the relay apparatus of FIG.
The IP packet input to the network CAS processing unit in FIG. 1 is input to the encryption processing means, and the payload is encrypted with the key Kd managed by the first key management means and input to the packet multiplexing processing means. The
[0063]
The key Kd is encrypted with the key Koi of the second key management unit in the key distribution message generation unit, and is input to the packet multiplexing processing unit as a key distribution message. Since the key Koi is different for each viewer, the key distribution message generated using this key Koi is also different for each viewer.
[0064]
The encrypted IP packet and the key distribution message input to the packet multiplex processing means are output to the IP network and distributed to the receiving device installed in the viewer's house in FIG.
[0065]
FIG. 5 is a diagram illustrating a configuration example of a receiving device in the IP broadcast distribution system of FIG.
The IP packet input to the receiving device is first input to the network CAS processing unit, and the encryption for the payload is decrypted.
[0066]
FIG. 6 is a diagram illustrating a configuration example of a network CAS processing unit in the receiving apparatus of FIG. The IP packet input to the network CAS processing unit in FIG. 5 is input to the IP packet filtering means and filtered. The filtered IP packet is input to both the key extraction unit and the decryption unit.
[0067]
The key extraction unit extracts the key Kd necessary for the CAS process from the input IP packet using the key Kpi managed by the key management unit. The key Kpi may be the same as the key Koi used in the relay device, or may be a different key by using a public key cryptosystem.
[0068]
The key Kd extracted in this way is input from the key extraction unit to the decryption unit.
The decryption means decrypts the payload of the IP packet output from the IP packet filtering means using the key Kd output from the key extraction means.
[0069]
The key Kd can be distributed by a protocol generally used on the Internet, such as http (Hyper Text Transfer Protocol) and tftp (Trivial File Transfer Protocol).
[0070]
The IP packet output from the network CAS processing unit in FIG. 5 is input to the IP packet decomposing unit. The IP packet decomposition unit extracts an MPEG2 packet mounted as a payload in the IP packet from the input IP packet, and outputs the extracted MPEG2 packet to the MPEG2 packet separation unit.
[0071]
The MPEG2 packet input to the MPEG2 packet separation unit is separated into information related to content encryption such as PSI / SI, ECM and EMM, and content parts such as encoded video and audio.
[0072]
The separated PSI / SI is input to the PSI / SI analysis unit and analyzed.
Information related to the content encryption such as the separated ECM and EMM is sent to the content CAS processing unit and used to generate a key Ks used in the broadcasting center as necessary.
[0073]
FIG. 7 is a diagram illustrating a configuration example of a content CAS processing unit in the receiving apparatus of FIG.
The EMM separated from the MPEG2 stream is input to the EMM analysis means. The EMM analysis means extracts the key Kw from the input EMM using the key Km managed by the key management means, and outputs this to the key holding means. The key holding means temporarily holds the input key Kw and outputs it to the ECM analysis means as necessary.
[0074]
The EMM separated from the MPEG2 stream is input to the ECM analysis means. The ECM analysis means extracts the key Ks from the input ECM using the key Kw output from the key holding means, and outputs it to the decryption unit in FIG. By using the key Ks, it is possible to decipher the separated encoded content such as video and audio.
[0075]
The separated content portion such as encoded video / audio is sent to the decryption unit as necessary, and decrypted using the key Ks output from the content CAS processing unit.
[0076]
The decrypted content such as video and audio is input to the display processing unit via the MPEG2 decoding unit.
Content such as video / audio input to the display processing unit is output as video / audio from a video / audio output unit such as a television screen or a speaker after necessary processing is performed.
[0077]
As described above, the receiving apparatus in FIG. 5 has two CAS processing units, a network CAS processing unit and a content CAS processing unit. Each of these CAS processing units has a different key.
[0078]
The key Kd used for decryption of the IP packet in the network CAS processing unit is managed by the content distribution company, and is distributed from the content distribution company to the receiving device at the viewer's home that has contracted for content distribution.
[0079]
Therefore, according to the present embodiment, when there is a viewer who is not contracted or not paid, the content distribution company uses the receiver K to use the key Kd used for decryption of the IP packet in the viewer's home. By not delivering to the receiving device, it is possible to refuse the delivery of the content to this viewer.
[0080]
Therefore, according to the present embodiment, it is possible to prevent unauthorized viewing of video / audio by the viewer.
[0081]
Further, the content distribution company registers the key Kpi of the viewer who has contracted for content distribution, and the key Kd used for decryption of the IP packet is encrypted with the registered key Kpi. Output to the IP network.
[0082]
Therefore, even if the viewer monitors the key Kd distributed to other viewers at the IP packet level, the key Kd is encrypted with the key Kpi as described above, and thus does not have the key Kpi. Other viewers cannot extract the key Kd from the delivered IP packet.
[0083]
Since the keys Ks, Kw, and Km used in the content CAS processing unit of FIG. 5 are also managed by the broadcasting company in the same manner as the key Kd, the broadcasting company prevents the viewer from watching the program illegally. it can.
[0084]
Therefore, according to the present embodiment, the viewer can view the program only when agreed with both the distribution company and the broadcasting company.
Therefore, according to the present embodiment, illegal viewing of a program by a viewer who does not contract with at least one of the programs can be prevented.
[0085]
In the present embodiment, encryption processing is performed on the payload of the IP packet as the network CAS. However, in the present invention, encryption processing may be performed on the payload of the MPEG2 packet. In this case, the relay device performs multiplexing processing and encryption processing between the IP packet processing units, and the receiving device performs decryption processing after IP packet decomposition.
[0086]
FIG. 8 is a diagram for explaining the program selection operation of the receiving apparatus of FIG.
When the viewer selects a program to be viewed by the viewer, the receiving device receives the PAT from the currently received MPEG2 stream. The PAT is multiplexed with the broadcast content in the MPEG2 stream, and the PAT describes the service ID of the program currently broadcast as the MPEG2 stream and the PID of the MPEG2 packet storing the PMT corresponding to the service ID. Has been.
[0087]
The receiving apparatus can determine whether or not the program selected by the viewer is included in the currently received multicast stream by searching for the service ID of the program described in the PAT.
[0088]
If the service ID selected by the viewer is not found in the PAT by the above search, the receiving apparatus receives the NIT from the currently received MPEG2 stream. The NIT is multiplexed with the broadcast content in the MPEG2 stream, like the PAT.
[0089]
FIG. 10 is a diagram showing a format of NIT.
Various descriptors are described in descriptor () in the NIT. In satellite broadcasting or the like, a distribution system descriptor that specifies a frequency, a modulation method, and the like is described in the second loop of the NIT.
[0090]
In this embodiment, an IP multicast distribution system descriptor describing an IP multicast address or the like is described instead.
[0091]
FIG. 11 is a diagram showing a format of an IP multicast distribution system descriptor.
The receiving device can detect the IP multicast address of the multicast stream to which the corresponding program is transmitted by describing the IP multicast distribution system descriptor and the service list descriptor.
[0092]
When the IP multicast address is found by searching the NIT, the receiving device starts receiving a multicast stream by transmitting an IP multicast join message. Since this PAT including the corresponding service ID is transmitted to the multicast stream, the receiving apparatus receives this and detects the PID of the PMT.
[0093]
In the PMT, video and audio PIDs constituting the corresponding service ID are described. Therefore, the receiving device can view the broadcast by performing CAS processing as necessary.
Since the receiving apparatus does not view a specific program when the power is turned on, it cannot receive program arrangement information such as NIT and PAT transmitted multiplexed with video and audio.
[0094]
Therefore, the NIT is also transmitted in a multicast stream different from the video / audio. At this time, the other multicast stream is always distributed to all receiving apparatuses as a multicast address having a destination address of 224.0.0.1.
[0095]
【The invention's effect】
As described above, according to the present invention, a viewer can view a digital broadcast via a relay device and an IP network without installing an antenna at the viewer's home. Therefore, the viewer can watch a stable TV broadcast even in an environment where radio waves are shielded in a high-rise building or in an environment where it is difficult to install an antenna in an apartment house or the like.
[0096]
According to the present invention, an IP packet in which an MPEG2 packet storing a broadcast signal is directly encapsulated is delivered to a viewer's home. Therefore, according to the present invention, it is possible to distribute digital broadcasts while maintaining broadcast quality (for example, image quality, etc.) on satellite broadcasts, CATV, and the like on the IP network.
[0097]
According to the present invention, encryption processing performed by the operator operating the IP network and the relay device is performed along with encryption processing performed by the broadcaster. Therefore, according to the present invention, it is possible to prevent viewing of a digital broadcast via the IP network by a viewer who has not signed a contract with a provider operating the IP network and the relay device.
[0098]
According to the present invention, the encryption strength can be selected according to the degree of management of the IP network. Therefore, according to the present invention, for example, by monitoring and analyzing all packets being broadcast, it is possible to prevent unauthorized viewing of broadcast programs that are originally paid.
[0099]
According to the present invention, the receiving apparatus can select a program with a service ID used in a broadcast network.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration example of a relay device according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a configuration example of a network CAS processing unit of the relay apparatus of FIG. 1;
3 is a diagram illustrating a configuration example of a broadcast center in the IP broadcast distribution system of FIG. 9;
4 is a diagram illustrating a configuration example of a content CAS processing unit in the broadcast center of FIG. 3. FIG.
5 is a diagram illustrating a configuration example of a receiving device in the IP broadcast distribution system of FIG.
6 is a diagram illustrating a configuration example of a network CAS processing unit in the receiving apparatus of FIG. 5;
7 is a diagram illustrating a configuration example of a content CAS processing unit in the receiving apparatus of FIG. 5. FIG.
8 is a diagram for explaining a program selection operation of the receiving apparatus of FIG.
FIG. 9 is a diagram illustrating a configuration example of an IP broadcast distribution system using the relay device according to the embodiment of the present invention.
FIG. 10 is a diagram illustrating a format of NIT.
FIG. 11 is a diagram showing distribution system descriptors used in the IP network.

Claims (3)

A broadcast receiver for receiving a broadcast signal in which one MPEG2 transport stream (in which one MPEG2 transport stream includes MPEG2 packets related to a plurality of services) is modulated into one channel;
A plurality of MPEG2 packets output from the broadcast receiver are converted into a plurality of IP (Internet Protocol) packets (a part or all of each MPEG2 packet is stored in the payload of the IP packet, and the IP header of the IP packet includes In which the IP multicast address is stored as the destination address), and the plurality of IP packets are output as IP streams to the IP network to which the receiving device is connected;
In the relay device with
The broadcast signal received by the broadcast receiver includes a first network information table,
The converter replaces the first network information table with a newly defined second network information table,
The second network information table includes first and second descriptors associated with the MPEG2 transport stream;
The first descriptor includes a service ID that identifies each service included in the MPEG2 transport stream,
The second descriptor includes one or both of an IP multicast address and a port number of a delivery destination of the MPEG2 transport stream.
Splicing device in you, characterized in that. The converter has encryption processing means for encrypting a part or all of each MPEG2 packet output from the broadcast receiver,
The receiving apparatus includes a decryption unit that decrypts a cipher related to the MPEG2 packet stored in a payload of an IP packet received via the IP network by a method corresponding to the encryption performed by the encryption processing unit. ,
The relay apparatus according to claim 1 . The converter includes encryption processing means for encrypting a part or all of the payload of an IP packet output to the IP network,
The receiving device includes a decryption unit that decrypts a cipher associated with a payload of an IP packet received via the IP network by a method corresponding to the encryption performed by the encryption processing unit.
The relay apparatus according to claim 1 .

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