JP2006254363A - Information transmission apparatus and method, information receiving apparatus and method, and program providing medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology capable of bringing a particular program into a simply unviewable state for a prescribed time in a transmission/reception system using a transmodulation system (modulation conversion system) to retransmit a program by satellite broadcast to a cable television. <P>SOLUTION: A QAM modulation circuit 32F modulates a digital broadcast signal demodulated by a QPSK demodulation circuit 32B after a PSI (Program Specific Information) conversion circuit 32D rewrites a program map table (PMT: Program Map Table) of one of program specific information items in the digital broadcast signal. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an information transmission apparatus, an information transmission method, an information reception apparatus, an information reception method, and a program providing medium, and in particular, an information transmission apparatus and information transmission for redistributing a digital satellite broadcast signal via a cable television network. The present invention relates to a method, an information receiving apparatus, an information receiving method, and a program providing medium.

  Recently, so-called cable TV has begun to spread as multi-channel media even in areas other than difficult viewing areas. FIG. 16 illustrates an example of a cable television receiver. The data receiving unit 71 extracts a receiver control signal from the cable television signal transmitted from the cable television station and supplies the signal to the host processor 72. This cable TV signal is an analog broadcast wave. The host processor 72 controls the entire receiver based on the receiver control signal and the viewer's channel selection operation. The reception tuner 73 extracts the signal of the program selected by the viewer from the cable TV signal and outputs it to the descrambler 74. The descrambler 74 uses the synchronization signal supplied from the AM detection circuit 77 to release the scramble of the program signal and outputs it to the video detection circuit 75 and the AM detection circuit 77. The video detection circuit 75 extracts and demodulates the video signal from the program signal, and outputs the remainder of the program signal to the FM detection circuit 76. The FM detection circuit 76 demodulates the audio signal.

  As described above, information (video signal, audio signal, and control signal) is transmitted as an analog signal in cable television. Accordingly, since the information cannot be compressed and multiplexed, the number of channels (programs) that can be supplied on the cable television is about 60 channels.

  By the way, in digital multi-channel satellite broadcasting (for example, SKYPerfecTV! (Trademark)), which is now in widespread use, broadcasting of 100 channels or more has been realized. Channelization is desired.

  Now, in order to realize further multi-channeling in cable television, it is conceivable to compress and multiplex video by digitizing all signals in the cable television station. It is difficult to realize this, considering the capital investment and running cost. So, for example, SKYPerfecTV! A method of realizing further multi-channel in cable television by redistributing digital multi-channel satellite broadcasting such as (trademark) can be considered.

  Here, the digital multi-channel satellite broadcasting system will be described with reference to FIG. The transmission unit 111 of the satellite broadcast service provider 101 scrambles the MPEG-compressed program information supplied from the program provider, and provides electronic program guide information (EPG: Electoric Program Guide), viewer management information, and the like And transmitted to the communication satellite 102 as a linearly polarized CS wave. This CS wave is received by the CS antenna 181 via the communication satellite 102 and supplied to the receiver 182. The receiver 182 extracts predetermined program information from the CS wave and outputs it to the television receiver 106. The viewer management unit 112 issues an IC card 160 to the viewer. The key management unit 113 of the viewer management unit 112 manages a viewable program corresponding to the IC card 160. The viewing information processing unit 114 calculates a viewing fee based on the viewing information notified from the receiver 82 and notifies the customer management unit 115 of it. The customer management unit 115 charges the viewer for a viewing fee.

  FIG. 18 shows a detailed configuration of the receiver 182. The reception tuner 192 of the satellite front end unit 191 extracts a broadcast wave including a transport stream (TS) including a predetermined program from the CS wave, and outputs the broadcast wave to the QPSK demodulation circuit 193. The QPSK demodulation circuit 193 demodulates the input broadcast wave by QPSK and outputs it to the error correction circuit 194. The error correction circuit 194 corrects TS error information obtained by demodulating the broadcast wave and outputs the corrected error information to the transport unit 155. The descrambler 156 of the transport unit 155 uses the descramble information recorded on the IC card 160 issued by the satellite broadcast service provider 101 to the TS scrambled by the transmission unit 111 of the satellite broadcast service provider 101. The data is decoded (descrambled) using the data and output to the demultiplexer 157.

  The demultiplexer 157 extracts predetermined program information based on multiplexed program specification information (PSI: Program Specific Information) and supplies the extracted information to the MPEG decoder unit 158. The MPEG decoder unit 158 performs MPEG decompression on the input program, generates a video signal and an audio signal, and outputs them to the television receiver 106.

  The host processor 159 controls the entire receiver 182 in response to the viewer's operation, and records the received pay program information (program viewing information) on the IC card 160. Further, the host processor 159 reads the descrambling information recorded on the IC card 160 and supplies it to the descrambler 156. Further, the host processor 159 controls the communication unit 161 to notify the viewing information management unit 114 of the program viewing information recorded on the IC card 160 periodically. The viewing information management unit 114 calculates a viewing fee based on the input viewing information and notifies the customer management unit 115 of the fee.

  By the way, in order to distribute digital multi-channel satellite broadcast signals to the cable television network, the cable television station 103 receives the digital multi-channel satellite broadcast signals, separates the multiplexed signals, and multiplexes them again. Processing is required and the equipment is very expensive. Also, when digital multi-channel satellite broadcast signals are retransmitted to a cable station or a hearing facility using a modulation conversion method, at least the frequency information and program information in the network information are necessary for the cable station It needs to be converted to one that matches the re-transmission contents in the hearing facility.

  Therefore, when a program broadcast in digital satellite broadcasting is distributed to a cable television network using a modulation conversion method, only network information (NIT: Network Information Table) is retransmitted from the digital broadcasting signal from the satellite transmission line. By replacing with information adapted to the wired transmission path, programs to be retransmitted and programs not to be retransmitted are controlled in the local area (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 11-5729

  By the way, when a satellite broadcast program is retransmitted by cable television, it may not be possible to retransmit the program during the time period when a similar program is transmitted by terrestrial broadcasting due to the problem of the right processing of the program.

  Conventionally, in the case of analog broadcasting, cable television stations have dealt with such problems by replacing them with other programs.

  However, as described above, by replacing only the network information (Network Information Table = NIT) from the digital broadcast signal from the satellite transmission path with information adapted to the retransmitted wired transmission path, it is possible to re-transmit in the local area. Controlling a program to be transmitted and a program not to be retransmitted is difficult, for example, to prevent a retransmitted program from being viewed by all receivers in the local area for a certain period of time.

  In the method of deleting the presence of a program for a certain period of time by rewriting the NIT, even if the channel number is directly designated by a remote controller or the like, the receiver determines that there is no designated program and cannot receive it. Since it is not displayed in the program guide table such as EPG, the viewer can recognize only “the program does not exist”.

  In addition, during the viewing restriction time, receiver operations such as viewing reservation and recording reservation for the program cannot be performed. For example, even if an attempt is made to make a recording reservation for recording the program after the viewing time limit has been canceled, the operation cannot be performed.

  Furthermore, if the program that you want to restrict viewing is being received by the receiver, once the NIT information is not re-acquired by the receiver, such as channel switching or EPG display, it will continue to be viewed as it is even if it is restricted. It becomes possible.

  The purpose of the above viewing restriction is not to “eliminate the presence of a program”, but to “make the viewing impossible, that is, put it in a sleep state”, although the program exists, but the conventional processing satisfies the above requirement. Not.

  In view of the above-described conventional problems, an object of the present invention is to provide a transmission / reception system that retransmits a satellite broadcast program to a cable television using a transmodulation method (modulation conversion method) for a certain period of time. The purpose is to make it possible to put the program into a resting state in which the program cannot be viewed easily.

  Other objects of the present invention and specific advantages obtained by the present invention will become more apparent from the description of embodiments described below.

  The present invention is an information transmitting apparatus in a transmission / reception system that converts a digital broadcast signal from a satellite transmission line into a wired signal by a transmodulator and distributes the signal to the wired transmission line, and receives the digital satellite broadcast signal. Receiving means, demodulating means for demodulating the signal received by the receiving means, and modulating means for modulating the signal demodulated by the demodulating means, wherein the modulating means is included in the digital broadcast signal demodulated by the demodulating means. It has a function of rewriting a program map table (PMT) which is one of program specification information (PSI).

  The present invention also relates to an information transmission method in a transmission / reception system in which a digital broadcast signal from a satellite transmission path is converted into a wired signal by a transmodulator and distributed to the wired transmission path. A receiving step for receiving, a demodulating step for demodulating the signal received by the receiving step, and a modulating step for modulating the signal demodulated by the demodulating step, wherein in the modulating step, the digital broadcast demodulated by the demodulating step It is characterized by rewriting a program map table (PMT) which is one of program specification information (PSI) in a signal.

  The present invention also provides a control program for controlling the operation of an information transmitting apparatus in a transmission / reception system that converts a digital broadcast signal from a satellite transmission path into a wired signal by a transmodulator and distributes the signal to the wired transmission path. A program providing medium, wherein the control program includes a receiving step for receiving a digital satellite broadcast signal, a demodulating step for demodulating the signal received by the receiving step, and a modulating step for modulating the signal demodulated by the demodulating step. In the modulation step, a program map table (PMT) that is one of program specification information (PSI: Program Specific Information) in the digital broadcast signal demodulated in the demodulation step is rewritten. Processing is executed.

  Further, the present invention rewrites a program map table (PMT) that is one of program specification information (PSI: Program Specific Information) in a digital broadcast signal for a digital broadcast signal from a satellite transmission path. An information receiving apparatus in a transmission / reception system for converting to a wired signal by a transmodulator having a function of restricting viewing and distributing the signal to a wired transmission path, receiving means for receiving a digital satellite broadcast signal, and And a demodulating means for demodulating the signal received by the receiving means, wherein the demodulating means has a function of prohibiting the display of a viewing-restricted program.

  Further, the present invention rewrites a program map table (PMT) that is one of program specification information (PSI: Program Specific Information) in a digital broadcast signal for a digital broadcast signal from a satellite transmission path. An information receiving method in a transmission / reception system for converting to a wired signal by a transmodulator having a function of restricting viewing and distributing the signal to a wired transmission path, wherein the receiving step receives a digital satellite broadcast signal, and A demodulating step for demodulating the signal received in the receiving step, wherein the display of the program whose viewing is restricted is prohibited in the demodulating step.

  Furthermore, the present invention rewrites a program map table (PMT) that is one of program specification information (PSI: Program Specific Information) in a digital broadcast signal for a digital broadcast signal from a satellite transmission path. A program providing medium for providing a control program for controlling the operation of an information receiving apparatus in a transmission / reception system that converts a wired signal by a transmodulator having a function of restricting viewing and distributes the signal to a wired transmission line, The control program includes a receiving step for receiving a digital satellite broadcast signal and a demodulating step for demodulating the signal received in the receiving step, and prohibiting display of a program whose viewing is restricted in the demodulating step. It is characterized by.

  In the present invention, in a transmission / reception system that distributes a digital broadcast signal from a satellite transmission line to a wired transmission line such as a cable television by a transmodulation method, it is possible to easily restrict viewing of a specific program for a certain period of time. . As a result, due to a problem in rights processing related to program viewing, in a specific local area where the program is being retransmitted, it is connected to the retransmission network in the local area for a certain period of time when the program corresponding to the problem is not desired to be viewed. It becomes possible to make it impossible to view with all receivers.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Needless to say, the present invention is not limited to the following examples, and can be arbitrarily changed without departing from the gist of the present invention.

  The present invention is applied to, for example, a cable transmission system 100 configured as shown in FIG.

  In this specification, the term “system” means an overall apparatus constituted by a plurality of apparatuses and means.

In this cable transmission system 100, a cable television station 3 receives a digital broadcast signal or the like transmitted from a satellite broadcast service provider 1 via a communication satellite 2, and a viewer receives from the cable television station 3 via a cable television network 4. Distribution is made to the receiver 6 at the home 5.
The digital broadcast signal transmitted from the satellite broadcast service provider 1 via the communication satellite 2 can be directly received and viewed by the receiver 8 of the viewer's house 7.

  In this cable transmission system, the satellite broadcasting service provider 1 scrambles the MPEG-compressed program information supplied from the program supplier, and provides electronic program guide information (EPG: Electoric Program Guide) and viewers. It is multiplexed with service information such as management information and transmitted to the communication satellite 2 as a linearly polarized CS wave.

  The cable television station 3 temporarily receives the digital broadcast transmitted by the radio wave transmitted from the communication satellite 2 by the transmodulator 30 which is a re-transmission device, and is included in the digital broadcast signal received using the control PC of the device. Network Information Table (NIT) and Program Map Table (PMT), which are part of Program Specific Information (PSI), are adapted to re-transmission over wired systems. The data is rewritten and distributed to the receiver 6 of the viewer's house 5 via the cable television network 4.

  Then, the receiver 6 of the viewer's home 5 receives the digital broadcast signal retransmitted from the transmodulator 30, and in accordance with the NIT in the received signal, the video of the program being retransmitted for viewing by the viewer.・ Demodulate and output audio. Here, when the PMT is rewritten, the receiver 6 of the viewer's house 5 temporarily does not output the video / audio even if the program is being retransmitted for viewing by the viewer. Viewing is not possible simultaneously on all receivers, not just the specific receiver in the local area where the retransmission is being performed.

  Here, the digital broadcast signal transmitted from the communication satellite 2 will be described. In this embodiment, the digital broadcasting signal corresponds to a DVB (Digital Video Broadcasting) system. FIG. 2B shows the frame structure of digital broadcast data in the DVB system. One frame is composed of eight MPEG2 transport packets (see FIG. 2A). In this case, the synchronization byte (= 47H) in the packet is used, and the synchronization byte is inverted (= B8H) once in 8 packets to obtain frame synchronization. An error correction code according to Reed-Solomon (204, 188) is added to each MPEG2 transport packet (MPEG2TS packet). The digital broadcast data shown in FIG. 2 (B) is modulated by QPSK (Quadrature Phase Shift Keying), and then converted into a frequency band used in the uplink of the communication satellite and transmitted from the communication satellite 2 Broadcast signal.

  FIG. 3 shows the packet structure of an MPEG2 transport packet, and the first 4 bytes of 188 bytes form a packet header. A packet identifier (PID: Packet Identification) indicating an attribute of an individual stream (data string) of the packet is arranged in the packet header. In the payload (data part) of the MPEG2 transport packet, a PES (Packetized Elementary Stream) packet whose packet configuration is shown in FIG. 4 is subdivided and arranged, and program specification information defined in the MPEG2 system is further provided. Tables such as Program Association Table (PAT), Program Map Table (PMT), Network Information Table (NIT) as Program Specific Information (PSI) Types are also arranged by section format.

  Here, PSI is information necessary for realizing a simple channel selection operation and program selection. PAT indicates the PID of the PMT that transmits the information of the packets constituting the program for each program number (16 bits), and FIG. 5 shows the table structure of the PAT. As the PID of the PAT itself, PID = “0x0000” is fixedly assigned.

  The main contents will be described. The table ID indicates the type of table, and is “0x00” (hexadecimal notation) in the PAT. TS ID identifies a stream (multiplexed encoded data), and corresponds to a transponder in the case of a satellite. The version number is added every time the contents of the table are updated. The current next indicator is used for identification when the old and new versions are transmitted simultaneously. The program number identifies each channel. The network PID indicates the PID of the NIT when the program number is “0x0000”. The program map PID indicates the PID of the PMT.

  The PMT indicates, for each program number, the PID of a packet in which a stream of video, audio, additional data, etc. constituting the program is transmitted. The PID of the PMT itself is specified by the PAT as described above. FIG. 6 shows a table structure of the PMT. The main contents not overlapping with PAT will be described. The table ID indicates the type of table and is “0x02” in the PMT. The PCR PID indicates the PID of a packet including a clock (PCR: Program Clock Reference) that serves as a reference for decoding. The stream type indicates the type of signal transmitted in the stream, such as video, audio, and additional data.

  The NIT indicates physical information on the transmission path, that is, in the satellite, the orbit of the satellite, the polarization, the frequency for each transponder, and the like. The PID of the NIT itself is specified by the PAT as described above. FIG. 7 shows the NIT table structure. Main contents not overlapping with PAT and PMT will be described. The table ID indicates the type of the table. The network is “0x40” and the other networks are “0x41”. The network ID identifies the network. In the case of a satellite, it corresponds to an individual satellite.

  When the satellite digital multi-channel broadcast signal is retransmitted on the cable television by the modulation conversion method, the NIT is rewritten. Here, a descriptor that is included in the NIT and needs to be rewritten will be described.

  First, the satellite delivery system descriptor in the satellite NIT will be described. This descriptor is used as the first descriptor repeated according to the TS (Transport Stream) descriptor length, and is paired with the TS ID.

  FIG. 8 shows the structure of the satellite delivery system descriptor. The descriptor tag is defined by DVB and indicates the type of descriptor. In this descriptor, “0x43” is set. The frequency indicates a transmission frequency for each stream (here, transponder). The orbit / west longitude / east longitude flag / polarization indicates the orbit and polarization of the satellite. The modulation / symbol rate / inner error correction coding rate indicates a specification related to the transmission method.

  At the time of re-transmission at the cable television station, the satellite delivery system descriptor is replaced with a cable delivery descriptor as shown in FIG. In the descriptor, it is “0x44”. The frequency indicates a transmission frequency for each physical channel in the cable television to be retransmitted. The modulation / symbol rate / inner error correction coding rate indicates a specification related to the transmission method. This descriptor has the same total length for the satellite and the cable and can be simply replaced.

  Next, the service list descriptor will be described. This descriptor is used as the second and subsequent descriptors that are repeated according to the TS descriptor length, and indicates the ID of the service (channel) multiplexed in the stream (here, transponder). That is, a plurality of service list descriptors are attached to one TSID.

  FIG. 10 shows the structure of the service list descriptor. The descriptor tag is defined by DVB and indicates the type of descriptor. In this descriptor, “0x41” is set. The service ID identifies a service. Usually, the service matches the channel that the viewer selects. The service type indicates the contents of the service such as video, audio, and data.

  At the time of re-transmission at a cable TV station, if the program for all transponders from the satellite is serviced within the cable, the information of this descriptor remains as it is, but it is re-transmitted when only the signal of a specific transponder is serviced The service ID of the program included in the transponder not to be deleted is deleted. In this case, dummy data is added to the information that has been deleted and reduced, so that the total length of the service list descriptor is the same as that of the satellite system, and can be simply replaced.

  The MPEG2 system stipulates that the transmission of the PSI table is segmented in a format called section. For example, the NIT is sectioned every 4 kbytes, and each section is configured in the format shown in FIG. NITs divided into a plurality of sections are related by section numbers. The total number of sections is described as the last section number in the table, and a series of NIT data until the section number matches the last section number.

  Next, a specific configuration example of the transmodulator 30 of the cable television station 3 in the cable transmission system shown in FIG. 1 will be described with reference to FIG.

  The transmodulator 30 shown in FIG. 11 extracts a plurality of signal processing units 32-1 to 32-N that perform modulation conversion by extracting a TS (Transport Stream) for each channel from a CS wave received via the CS antenna 31. (N is the number of channels included in the CS wave) and a signal mixer 33 that mixes and outputs TS (Transport Stream) of each channel modulated and converted by each signal processing unit 32-1 to 32-N. Consists of.

  The channel described above is a single propagation wave including a plurality of programs multiplexed by one transponder, unlike a channel (broadcast station) in the terrestrial wave. FIG. 12 shows an example of the state of the CS wave input to the transmodulator 30. That is, the CS wave H polarization includes TS1, TS3, and TS5, and the CS wave V polarization includes TS2, TS4, and TS6.

  Each of the signal processing units 32-1 to 32-N includes a tuner 32A that extracts a TS for each channel from a CS wave received via the CS antenna 31, a QPSK demodulation circuit 32B that QPSK-demodulates the extracted TS by the tuner 32A, An ECC decoder 32C that performs error correction processing on the TS demodulated by the QPSK demodulator circuit 32B, and the TS that has been error-corrected by the ECC decoder 32C, are network information (NIT: Part of Program Specific Information). Network Information Table) and Program Map Table (PMT: Program Map Table) are rewritten so as to be suitable for re-transmission in a wired system, and the error correction code is in the TS whose PSI has been rewritten by the PSI conversion circuit 32D ECC encoder 33E and ECC encoder 3 The QAM modulation circuit 32F that QAM modulates the TS to which the error correction code is added by 2E, the frequency conversion circuit 32G that converts the carrier frequency of the TS modulated by the QAM modulation circuit 32F into the frequency of a predetermined channel, etc. Via the control unit 32I. An operation unit 32J and a display unit 32K are connected to the control unit 32I.

  In the PSI conversion circuit 32D of each of the signal processing units 32-1 to 32-N, in order to make the receiver 6 unable to view a specific program for a certain period among the retransmitted programs, Only during the period when it is desired to make it impossible, the PMT relating to the program that is made impossible to view is rewritten as follows.

  1. The program number (program_number (= service_id)) or elementary PID (elementary_PID) in the PMT is invalidated (all “1”, etc.).

  By invalidating the information for specifying the program to be viewed at the receiver in the PMT, the processing at the receiver is not performed and the viewing is disabled. After the PMT information is rewritten by the transmodulator, the PMT version information is changed.

  2. The upper 2 bits of the system management ID (system_management_ID) in the system management descriptor (system_management_descriptor) whose data structure is transmitted in PMT is set to a value other than “0 (= broadcast)”. In addition, when an IC card for canceling conditional access is used in a broadcasting system that employs the conditional access system, the system / management ID (system_management_ID) array of the IC card has been rewritten. It is assumed that the upper 2 bits of the management ID (system_management_ID) are not included. After the PMT information is rewritten by the transmodulator 30, the version information of the PMT is changed.

  Here, the system management ID (system_management_ID) in the system management descriptor (system_management_descriptor) includes a broadcasting flag (broadcasting_flag) indicating the type of broadcasting / non-broadcasting, and the system management ID (system_management_ID) By setting the upper 2 bits of the value to a value other than “0 (= broadcast)”, the processing in the receiver 6 is not performed, and viewing is disabled.

  At the end of the period when it is desired to make a specific program unviewable, the PMT is returned to the original state. After the PMT information is rewritten to the original state by the transmodulator 30, the version information of the PMT is changed.

  Also, the PMT_ID described in the PAT information is rewritten to delete the PMT_ID indicating the packet number (PID) in which the PMT information corresponding to the program to be paused is described, and the PMT_ID deleted at the same time is deleted. The PMT information itself transmitted in the packet it has may be deleted (not transmitted). When rewriting PAT, the version number is changed. Thereby, when the version number of the PAT is changed, the receiver confirms the PMT information, thereby recognizing the corresponding program as a paused state in response to the change of the PMT, that is, the deletion state. .

  Then, the signal mixer 33 mixes and outputs TS (Transport Stream) of each channel modulated and converted by each signal processing unit 32-1 to 32 -N.

  Next, a specific configuration example of the receiver 6 in the cable transmission system 100 illustrated in FIG. 1 will be described with reference to FIG.

  The receiver 6 shown in FIG. 14 includes a cable front end unit 61 and a transport unit 62 whose operations are controlled by a control unit 60, an MPEG decoding unit 63 connected to the transport unit 62, a data buffer memory 64, and an IC. From a card interface (I / F) unit 65, a key input unit 67 connected to the control unit 60, an IR signal receiving unit 68, various memories such as EEPROM 69A, SRAM 69B, ROM 69C, OSD circuit 70, MODEM 71, display unit 72, etc. Become.

  The reception tuner 61A of the cable front end unit 61 extracts a broadcast wave including a predetermined program from the mixed wave and outputs it to the QAM demodulation circuit 61B. The QAM demodulation circuit 61B QAM-demodulates the broadcast wave and outputs it to the error correction circuit 61C. The error correction circuit 61 </ b> C corrects the error information of the TS obtained by demodulating the broadcast wave and outputs it to the transport unit 62.

  The descrambler 62A of the transport unit 62 decodes (descrambles) the scramble applied to the TS using the descramble information recorded on the IC card 66 issued by the satellite broadcasting service provider 1. Output to the multiplexer 62B. The demultiplexer 62B extracts predetermined program information from the TS in which a plurality of program information is multiplexed and supplies the extracted program information to the MPEG decoding unit 63.

  The MPEG decoding unit 63 performs MPEG decompression on the input program information and outputs a video signal from the video processing unit 63A, and outputs an audio signal from the audio processing unit 63B. An on-screen display signal supplied from the OSD circuit 70 controlled by the control unit 60 can be added to the video signal from the video processing unit 63B by the addition circuit 73.

  The control unit 60 controls the entire receiver 6 based on the viewer's channel selection operation, and records the received pay program information (program viewing information) on the IC card 60. Further, the control unit 60 reads the descrambling information recorded on the IC card 66 and supplies it to the descrambler 6-5. In addition, the control unit 60 periodically notifies the satellite broadcast service provider 1 of the program viewing information recorded on the IC card 60 from the MODEM 71 via the public telephone line.

  Next, the program reception process of the receiver 5 will be described with reference to the flowchart of FIG.

  The control unit of the receiver 5 first acquires the NIT from the TS received via the cable front end unit 61 and updates the content of the NIT (step S1).

  Next, the control unit 60 searches the program list, selects a program (step S2), and determines whether the TS is addressed to itself (step S3). If the TS is not addressed to itself, the transmission channel is moved (step S4). If the TS is addressed to itself, a PAT is received (step S5), and further a PMT is received (step S6).

  Next, the control unit 60 determines whether or not the system management ID included in the received PMT indicates non-broadcasting (step S7).

  If the system management ID included in the received PMT does not indicate non-broadcasting, an ECM is received (step S8), and it is determined whether or not the program is a viewing-permitted program (step S9). If it is a program, it receives an elementary storm (step S10), decodes and outputs video and audio (step S11).

  If the program is not a viewing-permitted program, the viewer is notified by the OSD display that viewing is not possible (step S11).

  Further, if the system management ID included in the received PMT indicates non-broadcasting, an exception process is performed (step S7).

  The receiver 6 checks the version information of the PMT every time the PMT is transmitted in the digital broadcast signal, and when the version changes, the receiver 6 performs a process for newly reacquiring the PMT. During the period in which the PMT is being rewritten, information such as video / audio of the program corresponding to the rewritten PMT is not processed from the received PMT information, so that the viewer cannot view the program.

  Here, the computer program for performing the above-described processes can be provided to the user via a network providing medium such as the Internet or a digital satellite in addition to a providing medium made of an information recording medium such as a magnetic disk or a CD-ROM.

It is a conceptual diagram which shows the structure of the cable transmission system to which this invention is applied. It is a figure which shows the frame structure of an MPEG2 transport packet and a DVB system. It is a figure which shows the packet structure of an MPEG2 transport packet. It is a figure which shows the packet structure of a PES packet. It is a figure which shows the table structure of a program association table (PAT). It is a figure which shows the table structure of a program map table (PMT). It is a figure which shows the table structure of a network information table (NIT). It is a figure which shows the structure of the satellite delivery system descriptor in NIT. It is a figure which shows the structure of the cable delivery system descriptor in NIT. It is a figure which shows the structure of the service list descriptor in NIT. It is a block diagram which shows the structural example of the transmodulator of the cable television station in the said cable transmission system. It is a figure explaining the linearly polarized wave of CS wave. It is a figure which shows the data structure of the system management descriptor (system_management_descriptor) transmitted by PMT. It is a block diagram which shows the specific structural example of the receiver in the said cable transmission system. It is a flowchart which shows the program reception process of the said receiver. It is a block diagram which shows an example of a structure of the conventional cable television receiver. It is a conceptual diagram which shows the structure of a digital multichannel satellite broadcasting system. It is a block diagram which shows an example of a structure of the receiver in the said digital multichannel satellite broadcasting system.

Explanation of symbols

1 satellite broadcasting service provider, 2 communication satellite, 3 cable TV station, 4 cable TV network, 6 receiver, 30 transmodulator, 31 CS antenna, 32-1 to 32-N signal processing unit, 32A tuner, 32B QPSK demodulation circuit 32C ECC decoder, 32D PSI conversion circuit, 33E ECC encoder, 32F QAM modulation circuit, 32G frequency conversion circuit, 32H interface 32H, 32I control unit, 32J operation unit, 32K display unit, 33 signal mixer, 60 control unit, 61 Cable front end unit, 61A reception tuner, 61B QAM demodulation circuit, 61C error correction circuit, 62 transport unit, 62A descrambler, 62B demultiplexer, 63 MPEG decoding unit, 64 data buffer memory, 65 IC card interface Face (I / F) unit, 66 IC card, 67 a key input unit, 68 IR signal receiving unit, 69A EEPROM, 69B SRAM, 70 OSD circuit, 71 MODEM, 72 display unit, 100 a cable transmission system

Claims (6)

An information transmission device in a transmission / reception system that converts a digital broadcast signal from a satellite transmission line into a wired signal by a transmodulator and distributes the signal to the wired transmission line,
Receiving means for receiving a digital satellite broadcast signal;
Demodulation means for demodulating the signal received by the receiving means;
Modulation means for modulating the signal demodulated by the demodulation means,
The modulation means has a function of rewriting a program map table (PMT) which is one of program specification information (PSI: Program Specific Information) in the digital broadcast signal demodulated by the demodulation means. A characteristic information transmission apparatus. An information transmission method in a transmission / reception system that converts a digital broadcast signal from a satellite transmission line into a wired signal by a transmodulator and distributes the signal to the wired transmission line,
A receiving step of receiving a digital satellite broadcast signal;
A demodulation step for demodulating the signal received by the reception step;
A modulation step for modulating the signal demodulated in the demodulation step,
In the modulation step, a program map table (PMT) that is one of program specification information (PSI) in the digital broadcast signal demodulated in the demodulation step is rewritten. Information transmission method. A program providing medium for providing a control program for controlling an operation of an information transmitting apparatus in a transmission / reception system that converts a digital broadcast signal from a satellite transmission path into a wired signal by a transmodulator and distributes the signal to the wired transmission path. .
The control program is
A receiving step of receiving a digital satellite broadcast signal;
A demodulation step for demodulating the signal received by the reception step;
A modulation step for modulating the signal demodulated in the demodulation step,
In the modulation step, a process of rewriting a program map table (PMT) which is one of program specification information (PSI: Program Specific Information) in the digital broadcast signal demodulated in the demodulation step is executed. A program providing medium characterized by the above. Limit viewing of digital broadcast signals from satellite transmission channels by rewriting the Program Map Table (PMT), which is one of Program Specific Information (PSI) in the digital broadcast signal An information receiving device in a transmission / reception system that converts a wired signal by a transmodulator having a function and distributes the signal to a wired transmission line,
Receiving means for receiving a digital satellite broadcast signal;
Demodulating means for demodulating the signal received by the receiving means,
The demodulator has a function of prohibiting display of a program whose viewing is restricted. Limit viewing of digital broadcast signals from satellite transmission channels by rewriting the Program Map Table (PMT), which is one of Program Specific Information (PSI) in the digital broadcast signal An information receiving method in a transmission / reception system for converting into a wired signal by a transmodulator having a function and distributing it to a wired transmission line,
A receiving step of receiving a digital satellite broadcast signal;
A demodulation step of demodulating the signal received in the reception step,
An information receiving method characterized in that, in the demodulation step, display of a program whose viewing is restricted is prohibited. Limit viewing of digital broadcast signals from satellite transmission channels by rewriting the Program Map Table (PMT), which is one of Program Specific Information (PSI) in the digital broadcast signal A program providing medium for providing a control program for controlling an operation of an information receiving apparatus in a transmission / reception system that converts a wired signal by a transmodulator having a function and distributes the signal to a wired transmission line.
The control program is
A receiving step of receiving a digital satellite broadcast signal;
A demodulation step of demodulating the signal received in the reception step,
A program providing medium characterized in that, in the demodulation step, display of a program whose viewing is restricted is prohibited.

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