JP2012142965A - Television receiver, and television receiving method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable emergency warning broadcast to be received automatically in a retransmission system.SOLUTION: A transmission side for IP retransmission detects a start-up signal for emergency warning broadcast from a transmission control signal included in a digital broadcast signal, and broadcasts a start-up packet for emergency warning broadcast based on the start-up signal for emergency warning broadcast which is detected by a detection circuit to an IP network. A gateway device has an address memory storing an address of a receiving device for IP retransmission connected via a network channel, and when receiving the start-up packet for emergency warning broadcast which is broadcasted from an accommodation station receiving IP packets from an IP retransmitting device, transmits the start-up packet to the receiving device for IP retransmission. When receiving the start-up packet from the gateway device, a television receiver makes a demultiplexing unit select from a content stream a packet required for decoding the emergency warning broadcast. Thereby, the emergency warning broadcast can be received automatically even in the IP retransmission.

Description

  The present invention relates to an IP retransmission apparatus, an IP retransmission method, a gateway apparatus, a television receiver, and a television reception method suitable for a retransmission system that receives and retransmits a digital broadcast.

  In recent years, digital broadcasting that transmits and receives digitally has been started. In Japanese digital broadcasting, the ISDB-T system is adopted. In the ISDB-T system, signal processing such as error correction coding, interleave coding, digital modulation, and the like is performed on TS (transport stream) defined by the Moving Picture Expert Group (MPEG) 2 standard. (Orthogonal Frequency Division Multiplexing) modulated and output.

  The MPEG system reduces the redundancy in the time direction by taking the difference between frames of the moving image signal, and further reduces the redundancy in the frequency direction by performing orthogonal transform processing such as discrete cosine transform (DCT). Highly efficient compression is possible. The OFDM scheme has an advantage that the delay interference characteristic in the multipath propagation path, which is an essential transmission condition in terrestrial television broadcasting, can be improved by transmitting a wide area signal with a large number of carriers orthogonal to each other.

  In the ISDB-T system, in the frequency domain, 108 symbols of OFDM symbols are used as one block, and 1, 2, and 4 blocks constitute one segment according to the mode. That is, the number of carriers in one segment is 108, 216, or 432. In the ISDB-T system, transmission is performed in a band for 13 segments. Further, in the ISDB-T system, one frame is composed of 204 OFDM symbols in the time domain. Then, TS transmission and energy diffusion processing are performed in units of frames. Further, in the ISDB-T system, hierarchical transmission in which a plurality of layers having different transmission characteristics are simultaneously transmitted is possible. Each layer includes one or a plurality of OFDM segments, and parameters such as a carrier modulation scheme, an inner code coding rate, and a time interleave length can be designated for each layer.

  Information on such layers and frame synchronization signals are transmitted by transmission control signals (TMCC: Transmission and Multiplexing Configuration Control). TMCC is inserted for each block of each symbol. That is, one carrier of each block is allocated for TMCC, and 1-bit TMCC information by BPSK modulation is included in one symbol. Accordingly, 204-bit TMCC information is transmitted for each frame in each block.

  One bit of the 204-bit TMCC information in the OFDM frame is an emergency warning broadcast activation flag. The receiver of the digital broadcast has a function of automatically receiving and displaying the emergency alert broadcast by extracting the emergency alert broadcast activation flag from the TMCC information. The receiver for emergency alert broadcasting is described in detail in Patent Document 1.

  By the way, in recent years, digital broadcast program distribution using the Internet protocol (IP) has been studied. IP re-transmission, in which a digital broadcast is once received by an IP re-transmission apparatus and transmitted via the Internet using an IP packet, is about to be implemented. In IP retransmission, received digital broadcasts are converted into IP packets and transmitted to the Internet by multicast.

  However, in IP retransmission, a transport stream after OFDM demodulation is transmitted. Since the TMCC information is information necessary only at the time of OFDM demodulation, the TMCC information is not included in the data stream retransmitted by IP. For this reason, in the IP retransmission, the function of automatically receiving the emergency alert broadcast cannot be set in the receiver.

  As an apparatus that enables automatic reception of such emergency broadcasts, a device disclosed in Patent Document 1 is known. However, the apparatus disclosed in Patent Document 1 requires both broadcast and communication paths, and only one of them does not function sufficiently. In addition, registration and management of user terminals that receive emergency information broadcasts are necessary, and the broadcaster or the like is forced to make new investments in facilities and management for emergency broadcasts. In addition, there is a disadvantage that it cannot be sent to a terminal that is not registered.

JP 2003-348034 A

  As described above, in the conventional IP retransmission system, there is a problem that it is not possible to provide an emergency alarm broadcast automatic reception function without requiring both broadcast and communication routes.

  The present invention provides an IP retransmission apparatus, an IP retransmission method, a gateway apparatus, and a television receiver that can automatically receive an emergency alert broadcast without requiring both broadcast and communication routes. With the goal.

  The television receiver according to the present invention includes a demodulating unit that demodulates a plurality of received digital broadcast signals by a plurality of demodulators and outputs a plurality of transport streams of a plurality of contents, and a plurality of transformers of the plurality of contents. A first IP circuit that packetizes a port stream into IP packets and transmits the IP packets to an IP network, and information that is extracted from transmission control signals included in each of the plurality of digital broadcast signals and combined into one IP packet An IP packet from an IP retransmitting device comprising a second IP circuit that broadcasts an emergency alert broadcast start packet for starting an emergency alert broadcast to the IP network. A receiving means for receiving and a power supply according to the emergency alarm broadcast start packet included in the IP packet received by the receiving means. It is obtained and means for turning on the circuit.

1 is a block diagram showing an IP retransmission apparatus, a gateway apparatus, and a television receiver according to a first embodiment of the present invention. The block diagram which shows the specific structure of the edge router 21 in FIG. The block diagram which shows the specific structure of the gateway apparatus 31 in the household device 30 in FIG. The block diagram which shows the specific structure of the television receiver 32 in the household device 30 in FIG. The block diagram which shows the 2nd Embodiment of this invention. FIG. 6 is a block diagram showing a specific configuration of the television receiver 33 in FIG. 5.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an IP retransmission apparatus, a gateway apparatus, and a television receiver according to the first embodiment of the present invention.

  In the present embodiment, as shown in FIG. 1, the IP retransmission system uses an IP network 40 for data transmission between the IP retransmission apparatus 10 that retransmits broadcast content and the accommodating station 20. And re-transmission is possible.

  The IP retransmission apparatus 10 receives a digital broadcast from a digital broadcast station using an antenna (not shown). The IP retransmission apparatus 10 has a plurality of retransmission units 11 corresponding to each channel in digital broadcasting. Each retransmission unit 11 has the same configuration as each other, and includes a digital broadcast demodulator 12, a TTS circuit 13, and an IP circuit 14.

  The digital broadcast demodulator 12 in each retransmission unit 11 demodulates the received digital broadcast. That is, each digital broadcast demodulator 12 selects a predetermined channel from an OFDM signal received by an antenna (not shown) by a tuner and performs quadrature detection to obtain a baseband OFDM signal. Each digital broadcast demodulator 12 removes the guard interval from the baseband OFDM signal and converts the time domain OFDM signal into a frequency domain OFDM symbol by FFT (Fast Fourier Transform) processing.

  Each digital broadcast demodulator 12 restores the original data from the OFDM symbol. For example, each subcarrier of the OFDM symbol is modulated by a modulation scheme such as PSK modulation or QAM modulation, and each digital broadcast demodulator 12 restores the original data by demodulation processing corresponding to these modulation schemes. Further, each digital broadcast demodulator 12 performs reverse processing of inner coding processing and outer coding processing, which are error correction processing performed on the transmission side, on the demodulated signal, and performs transmission on the OFDM signal. Restore the port stream.

  The TTS converting circuit 13 converts the transport stream from the digital broadcast demodulator 12 into a TTS (transport stream with a time stamp) in which a 32-bit time stamp is added. This time stamp is generated by counting a predetermined clock by a counter (not shown), and a unique value is assigned to each TS within the period range of the counter. The data stream (TTS data) converted to TTS is given to the IP conversion circuit 14.

  The TTS circuit 13 is not essential, and the transport stream from the digital broadcast demodulator 12 can be given to the IP circuit 14. Further, it may have a function of converting (transcoding) the video / audio codec in the transport stream.

  The IP circuit 14 packetizes the TTS every predetermined number and transmits the packets in multicast. Here, it is assumed that data to be multicast is IP packetized using RTP. The IP packet includes a source address and a multicast address.

  Also, the TMCC detection circuit 12a of each digital broadcast demodulator 12 detects the TMCC inserted for each OFDM frame in order to restore the broadcast stream of the broadcast signal from the OFDM signal. In the present embodiment, the TMCC detection circuit 12a of each digital broadcast demodulator 12 extracts an emergency warning broadcast activation signal in the TMCC and outputs it to the IP circuit 15.

  The IP circuit 15 packetizes the emergency warning broadcast start signal and multicasts it. Here, it is assumed that data to be multicast is transmitted using RTP. The IP packet includes a source address and a multicast address. Note that the IP circuit 15 transmits a packet (hereinafter referred to as an emergency alert broadcast start packet) only when the emergency alert broadcast start signal in the TMCC indicates that an emergency alert broadcast is being performed. It is like that.

  Also, a dedicated multicast address may be added to the emergency alert broadcast start packet, and the IP circuit 15 can be shared with the IP circuit 14. Further, the transmission rate of the IP circuit 15 may be a sufficiently low rate of about several pps.

  Transmission data from the IP circuits 14 and 15 is transmitted to the IP network 40 by multicast. The IP network 40 is a network capable of communication using an IP protocol such as the Internet. Data from the IP retransmission apparatus 10 that performs retransmission is transferred to the edge router 21 in the accommodating station 20 via the IP network 40.

  The accommodation station 20 is connected to a plurality of in-home devices 30 via an access line 25. The in-home device 30 includes a gateway device 31 and a television receiver 32. In FIG. 1, only one in-home device 30 is shown for simplification of the drawing, but the configuration of each in-home device 30 is the same. The television receiver 32 is an IP retransmission trust receiving device.

  The television receiver 32 of the in-home device 30 can generate a CH reception request (multicast participation request) to the edge router 21. The edge router 21 relays communication packets from the IP network 40 to the home device 30. That is, the edge router 21 has a function of selectively transferring the multicast data from the retransmission unit 11 to the television receiver 30 that has issued the CH reception request.

  FIG. 2 is a block diagram showing a specific configuration of the edge router 21 in FIG. In FIG. 2, an input / output port 51 inputs / outputs packets to / from the IP network 40. A packet input through the input / output port 51 is supplied to the routing processing unit 52 and the emergency warning broadcast activation signal detection unit 553. The routing processing unit 52 is controlled by the control unit 54, attaches a designated destination to each packet from the input / output port 51, and outputs the packet to the input / output port 53. The input / output port 53 inputs / outputs a packet to / from the access line 25.

  The input / output port 53 outputs a packet from the access line 25 to the packet determination unit 56. When the input packet is a CH reception request, the packet determination unit 56 detects the address of the in-home device 30 that has issued the CH reception request and outputs the detected address to the control unit 54.

  The control unit 54 controls the routing processing unit 52 so as to transfer the packet of the channel specified by the CH reception request to the in-home device 30 that has issued the CH reception request. Thereby, the packet of the designated channel is transmitted to the in-home device 30 that has issued the CH reception request.

  In the present embodiment, the emergency alert broadcast activation signal detector 55 detects the emergency alert broadcast activation packet from the IP circuit 15 out of each packet transferred via the IP network 40, and the emergency alert broadcast. When the activation packet is detected, a detection signal is output to the control unit 54. When a detection signal indicating that an emergency alert broadcast is being performed is input from the emergency alert broadcast activation signal detection unit 55, the control unit 54 transmits a control signal for multicasting an emergency alert broadcast activation packet. The data is output to the routing processing unit 52. As a result, the routing processing unit 52 attaches a multicast address to the emergency alert broadcast start packet and sends it to the access line 25 via the input / output port 53.

  Note that the edge router 21 may transmit an emergency alert broadcast start packet to the gateway devices 31 of all house devices 30 accommodated therein, or all gateway devices 31 that have transmitted a CH reception request in the past. An emergency warning broadcast start packet may be transmitted to

  FIG. 3 is a block diagram showing a specific configuration of the gateway device 31 in the home device 30 in FIG. The input / output port 61 inputs and outputs packets to and from the access line 25. A packet input via the input / output port 61 is supplied to the protocol conversion unit 62 and the control unit 64. The protocol conversion unit 62 is controlled by the control unit 64 to convert each packet from the input / output port 61 into a protocol corresponding to the network line 35 of the in-home device 30, and attaches an address designated by the control unit 64. Output to the input / output port 63. The input / output port 63 inputs / outputs a packet to / from the network line 35 in the home device 30.

  Also, the protocol conversion unit 62 is controlled by the control unit 64 to convert each packet from the input / output port 63 into a protocol corresponding to the access line 25, and attaches an address designated by the control unit 64 to the input / output. Output to port 61. As a result, a CH reception request from the input / output port 63 can be sent to the edge router 21.

  Although FIG. 1 shows an example in which only the television receiver 32 is connected to the network line 35, one or more network-compatible devices can be connected to the network line 35. A device connected to the network line 35 is configured such that a MAC address is read by the control unit 64. The control unit 64 gives the MAC address of each device to the MAC address memory 65 for storage.

  In the present embodiment, the magic packet generator 66 generates an activation packet (hereinafter also referred to as a magic packet) for activating the television receiver 32. As the magic packet, a general mechanism such as Wake on LAN may be used, or a system-dedicated packet may be used. When the packet from the input port 63 is an emergency alert broadcast activation packet, the control unit 64 gives the magic packet from the magic packet generation unit 66 to the protocol conversion unit 62. Further, the control unit 64 reads out the transmission destination of the magic packet from the MAC address memory 65 and gives it to the protocol conversion unit 62. As a result, the protocol conversion unit 62 transmits the magic packet to the designated destination stored in the MAC address memory 65.

  When there is only one television receiver or the like that can receive the emergency alert broadcast on the network line 35, the control unit 64 designates the MAC address of this device as a magic packet transmission destination. Further, when there are a plurality of television receivers or the like capable of receiving the emergency alert broadcast on the network line 35, the transmission destination of the magic packet may be all television receivers or an input device (not shown) The MAC address of a predetermined television receiver may be registered in the MAC address memory 65 in advance. The MAC address registered in the MAC address memory 65 may be automatically acquired using the DHCP protocol, the MAC address of the device that has issued the CH reception request may be automatically acquired, or manually set. May be. Further, only the MAC address of the device that is the transmission target of the magic packet may be registered in the MAC address memory 65.

  By registering a device that transmits a magic packet in the MAC address memory 65, the magic packet can be transmitted only to the specified device, and adverse effects on devices other than the specified device due to the magic packet can be avoided. it can.

  FIG. 4 is a block diagram showing a specific configuration of the television receiver 32 in the home device 30 in FIG. The television receiver 32 has a power supply circuit 75. The power supply circuit 75 includes a main power supply unit and a sub power supply unit (not shown), and the sub power supply unit is in an on state even when the main power supply unit that supplies power related to display is off (at standby). The power supply voltage can be supplied to the unit 71 and the magic packet determination unit 74.

  The communication unit 71 inputs and outputs packets with the network line 35. A packet input via the communication unit 71 is supplied to the demultiplexing unit 72 and the magic packet determination unit 74. The transport stream supplied to the demultiplexing unit 72 corresponds to a multi program (channel), and a packet of a desired program can be selected from a plurality of programs transmitted in a time division manner at the time of decoding. It can be done. For this selection, a PID, which is an ID for packet identification, is added to the header of the transport (TS) packet.

  A PMT (Program Map Table) including table information in which a list of PIDs of video, audio, etc. constituting a program is described in order to obtain information on PID of transport packets such as video, audio, etc. constituting a desired program Packets are also multiplexed. In order to extract a packet of a desired program, the demultiplexing unit 72 first obtains table information called PAT (Program Association Table) identified by PID = 0 from the transport stream. The PAT describes the PID of the PMT corresponding to the program number, and the demultiplexing unit 72 refers to this table information to know the PID of the PMT corresponding to the desired program, and obtains the PMT. The demultiplexing unit 72 extracts video data and audio data packets of a desired program with reference to the table information of the PMT, and outputs them to the AV decoder 73.

  When the packet from the communication unit 71 includes a magic packet, the magic packet determination unit 74 controls the power supply circuit 75 to turn on the main power supply unit. An emergency alert information descriptor is provided in the PMT packet supplied to the demultiplexing unit 72. When the magic packet determination unit 74 detects a magic packet, the demultiplexing unit 72 is made to refer to the emergency alert information descriptor. The demultiplexing unit 72 refers to the emergency alert information descriptor, extracts the emergency alert broadcast packet, and outputs the packet to the AV decoder 73. That is, after receiving the magic packet, the television receiver 32 performs an operation at the time of “emergency warning broadcast” defined in the ARIB standard.

  The AV decoder 73 decodes the stream separated from the demultiplexing unit 72 and outputs a video signal and an audio signal. By supplying these video and audio signals to a monitor (not shown), it is possible to display the designated content.

Next, the operation of the embodiment configured as described above will be described.
It is assumed that the in-home device 30 is in a standby state where no digital broadcast signal is received. Even in this state, IP broadcast retransmission of the digital broadcast is performed up to the edge router 21 that distributes the broadcast. That is, the digital broadcast demodulator 12 of each retransmission unit 11 of the IP retransmission apparatus 10 receives a predetermined channel by the tuner, and the TTS circuit 13 adds a 32-bit time stamp to each TS packet of the data stream. . The IP circuit 14 converts the TTS data into an IP packet, adds a multicast address to the IP network 40, and transmits it. In this way, each content of the digital broadcast is retransmitted by IP.

  In the present embodiment, the TMCC detection circuit 12a of each digital broadcast demodulator 12 extracts an emergency warning broadcast activation signal from the TMCC information used for demodulating the digital broadcast signal and outputs it to the IP circuit 15. When the emergency warning broadcast start signal indicating that the emergency warning broadcast is being performed is detected by the TMCC detection circuit 12a, the IP circuit 15 sends the emergency warning broadcast start packet to the IP network 40 by multicast. Multicast data from each retransmission unit 11 and multicast data from the IP circuit 15 are supplied to the edge router 21 of the accommodating station 20 via the IP network 40.

  In the present embodiment, the edge router 21 distributes the multicast data from the retransmitting unit 11 to each in-home device 30 in response to a CH reception request from each accommodated in-home device 30 and also issues an emergency alert. The broadcast start packet is transmitted to each in-home device 30 by multicast.

  Now, it is assumed that a CH reception request is generated by the television receiver 32 of a predetermined in-home device 30. This CH reception request is transmitted from the gateway device 31 to the edge router 21 via the access line 25. When receiving the CH reception request, the edge router 21 transmits the transport stream of the designated channel via the access line 25 with the address of the gateway device 31 that issued the CH reception request as the destination. The gateway device 31 that has issued the CH reception request receives the transport stream addressed to the own device, and outputs the received transport stream to the television receiver 32. In this way, the television receiver 32 can view the content of the channel for which the CH reception request is made.

  Here, it is assumed that the edge router 21 receives the emergency alert broadcast activation packet. The edge router 21 distributes the emergency alert broadcast activation packet to the in-home device 30 accommodated via the access line 25 by multicast.

  When the gateway device 31 of each in-home device 30 receives the emergency alert broadcast start packet, the gateway device 31 receives the magic packet from the magic packet generation unit 66 as a device having a MAC address registered in the MAC address memory 65 (TV in FIG. 1). To the John receiver 32).

  When the magic packet determination unit 74 of the television receiver 32 determines that the packet received by the communication unit 71 is a magic packet, it instructs the power supply circuit 75 to turn on the main power supply unit. Thereby, at the time of emergency warning broadcasting, the main power supply unit is automatically turned on by the power supply circuit 75 regardless of whether the main power supply unit of the television receiver 32 is on or off. Further, the magic packet determination unit 74 gives an instruction to the demultiplexing unit 72 to refer to the emergency alert information descriptor in the PMT.

  The demultiplexing unit 72 refers to the emergency alert information descriptor and extracts an emergency alert broadcast packet. The demultiplexing unit 72 outputs the extracted emergency alert broadcast packet to the AV decoder 73. The AV decoder 73 decodes the emergency alert broadcast stream separated from the demultiplexing unit 72 and outputs a video signal and an audio signal. In this way, the emergency alert broadcast can be viewed on the display screen of a monitor (not shown). In other words, regardless of whether the television receiver 32 is turned on or off and the channel being selected, when the emergency alert broadcast is performed, the emergency alert broadcast is displayed on the television receiver 32.

  As described above, in the present embodiment, on the IP retransmission transmission side, the emergency alert broadcast activation signal is extracted from the TMCC, and the emergency alert broadcast activation packet is transmitted with the dedicated multicast address added. Further, the emergency alert broadcast start packet is transmitted by multicast to each in-home device by the edge router. Upon receipt of the emergency alert broadcast activation packet, the in-home device generates a magic packet to turn on the television receiver and selectively decode the emergency alert broadcast stream. Thereby, the emergency alert broadcast can be automatically received and displayed even in the IP retransmission.

  In the above-described embodiment, the example of the reception start of the emergency alert broadcast has been described. However, it can be similarly defined when the emergency alert broadcast is stopped. As described above, the IP circuit 15 in FIG. 1 transmits an emergency alert broadcast start packet only when an emergency alert is being performed. Therefore, when the emergency alert broadcast is stopped, the transmission of the emergency alert broadcast start packet is also stopped. In other words, when the emergency alert broadcast is stopped, the emergency router broadcast activation packet is not transmitted from the edge router 21.

  Therefore, when the magic packet generation unit 66 of the gateway device 31 also generates a magic packet (end packet) for stopping the reception of the emergency alert broadcast, and the received emergency alert broadcast start packet is no longer received. Then, the control unit 64 causes the television receiver 32 to transmit a magic packet for stopping the emergency warning broadcast. When the television receiver 32 receives the emergency alert broadcast stop magic packet, the demultiplexer 72 may select the content stream before the emergency alert broadcast is received. If the main power supply is off before receiving the emergency warning broadcast, the main power supply may be turned off by controlling the power supply circuit 75 by receiving the emergency warning broadcast stop magic packet.

  In addition, when emergency alert broadcasting stops, the content of the PMT emergency alert information descriptor also changes. Therefore, the television receiver 32 may control the demultiplexing unit 72 and the power supply circuit 75 according to the contents of the emergency alert information descriptor of the PMT so as to return to the state before the emergency alert broadcast.

  According to the present invention, in the IP retransmission system, there is an effect that it is possible to automatically receive an emergency alert broadcast without requiring both broadcast and communication routes.

FIG. 5 is a block diagram showing a second embodiment of the present invention. In FIG. 5, the same components as those of FIG.
In the embodiment described above, the emergency alert broadcast can be received by the television receiver 32 by transmitting the emergency alert broadcast start packet to the in-home device 30. On the other hand, in the present embodiment, the emergency alert broadcast can be received by inserting the emergency alert broadcast reception activation information into the content stream.

  5, the IP retransmission apparatus 10 is different from the first embodiment in that an IP circuit 16 is employed instead of the IP circuit 14 of the retransmission unit 11 in FIG. The in-home device 30 is different from the first embodiment in that a television receiver 33 is adopted instead of the television receiver 32.

  Similar to the IP circuit 14, the IP circuit 16 converts the data from the TTS circuit 13 into an IP packet, adds a multicast address, and sends the packet to the IP network 40. Further, the IP circuit 16 receives an emergency warning broadcast start signal, and when the emergency warning broadcast start signal indicates that the emergency warning broadcast is being performed, an emergency warning is displayed in the extension header of the RTP packet. Broadcast reception activation information is inserted. Therefore, when emergency alert broadcasting is performed, emergency alert broadcast reception activation information is included in the RTP extension header in the stream of each channel.

  In addition, the IP device 16 can include not only emergency alert broadcast reception activation information but also information on which digital broadcast demodulator 12 is detected (referred to herein as a channel identifier) in the RTP extension header. When a plurality of detections are made, all of the detections may be entered. In this case, the RTP extension header in the stream of each channel includes two pieces of information of emergency alert broadcast reception activation information and information (channel identifier) indicating which digital broadcast demodulator (channel) is used. It will be. Note that the information included in the RTP extension header may be only the channel identifier.

FIG. 6 is a block diagram showing a specific configuration of the television receiver 33 in FIG. In FIG. 6, the same components as those in FIG.
On the other hand, the television receiver 33 in the home device 30 includes a demultiplexing unit 76 instead of the demultiplexing unit 72, a communication unit 77 instead of the communication unit 71, and a packet determination unit 78 instead of the magic packet determination unit 74. The adopted point is different from the television receiver 32 of FIG. In the television receiver 33, when the packet determination unit 78 detects that a magic packet has been received, the main power supply unit of the power supply circuit 75 is turned on.

  First, an operation when the RTP extension header sent from the IP device 16 includes emergency alert broadcast reception activation information and a channel identifier or only a channel identifier will be described. When the packet determination unit 78 detects that the RTP extension header from the communication unit 77 includes emergency alert broadcast reception activation information and a channel identifier or only a channel identifier,

The communication unit 77 is instructed to receive a stream corresponding to the channel identifier, and the demultiplexing unit 76 is instructed to refer to the emergency alert information descriptor of the PMT. The demultiplexing unit 76 refers to the emergency alert information descriptor, extracts the emergency alert broadcast packet, and outputs the extracted emergency alert broadcast packet to the AV decoder 73.

  When a plurality of channel identifiers are included in the RTP extension header, if there is a channel identifier corresponding to the stream currently received by the television receiver 33, the stream need not be changed.

  In addition, when a plurality of channel identifiers are included in the RTP extension header, the aria_code included in the emergency alert information descriptor of the PMT referred to by the demultiplexing unit 76 is the regional code set in the television receiver 33. If not, the channel identifier can be changed to display an emergency alert broadcast corresponding to the area code.

  Next, the operation when only the emergency alert broadcast reception activation information is included in the RTP extension header will be described. When the packet determination unit 78 detects that the emergency alert broadcast reception activation information is included in the RTP extension header from the communication unit 77, the packet determination unit 78 instructs the demultiplexing unit 76 to refer to the emergency alert information descriptor of the PMT. . The demultiplexing unit 76 refers to the emergency alert information descriptor, extracts the emergency alert broadcast packet, and outputs the extracted emergency alert broadcast packet to the AV decoder 73.

  In either case, the information contained in the RTP extension header is displayed before the emergency alert broadcast is displayed, since the emergency alert broadcast is being performed on the screen of the television receiver 33, and the user is notified by changing the information. It is also possible to make a selection when there are a plurality of warning alerts or to change to emergency alert broadcasting by user operation.

  In the embodiment configured as described above, the emergency warning broadcast activation packet is transmitted from the IP circuit 15 on the retransmission side, and the power supply circuit 75 is transmitted by the magic packet based on the emergency warning broadcast activation packet on the reception side. Turning on the main power supply unit is the same as in the first embodiment.

  In the present embodiment, in order to receive the emergency alert broadcast, the IP transmitter 10 inserts emergency alert broadcast reception activation information and a channel identifier into the RTP extension header in the IP transmission device 16. These pieces of information are transmitted to the IP network 40 together with the TTS data stream, and the television receiver 33 refers to the emergency alert information descriptor of the PMT by extracting the information from the RTP extension header. As a result, it is possible to automatically receive emergency alert broadcasts without requiring both broadcast and communication routes. Further, by adding a channel identifier, automatic reception is possible even when emergency alert broadcasting is performed only on a specific stream.

  When the emergency alert broadcast is stopped, the emergency alert broadcast reception activation information or the channel identifier is not detected from the RTP extension header. Therefore, the packet determination unit 78 may select the content stream before the emergency alert broadcast is received. If the main power supply is off before receiving the emergency alert broadcast, the main power supply may be turned off by controlling the power supply circuit 75.

  Also in the present embodiment, when emergency warning broadcasting is stopped, the demultiplexing unit 76 and the power supply circuit 75 are controlled according to the contents of the emergency warning information descriptor of the PMT to return to the state before the emergency warning broadcasting. You can make it.

  As described above, in this embodiment, in addition to the same effect as that of the first embodiment, an effect can be obtained even when emergency alert broadcasting is performed only on a specific stream.

The invention described in the scope of claims attached to the application for the original application is appended below.
[1]
Demodulation means for demodulating the received digital broadcast signal and outputting a content stream;
A first IP circuit for packetizing the content stream into an IP packet and transmitting the packet to an IP network;
An emergency warning broadcast activation signal detection circuit for detecting an emergency warning broadcast activation signal from a transmission control signal included in the digital broadcast signal;
A second IP circuit that broadcasts an emergency alert broadcast start packet, which is an IP packet based on the emergency alert broadcast start signal detected by the emergency alert broadcast start signal detection circuit, to the IP network. An IP retransmission apparatus.
[2]
The IP retransmission apparatus according to [1], wherein the second IP circuit can be shared with the first IP circuit.
[3]
The IP circuit performs packetization after inserting emergency alert broadcast reception activation information into the header of the content stream based on the emergency alert broadcast activation signal detected by the emergency alert broadcast activation signal detection circuit. The IP retransmission apparatus according to [1], which is characterized.
[4]
An address memory for storing the address of the IP retransmission trust receiving device connected via the network line;
When receiving the emergency alert broadcast activation packet broadcast from the accommodating station that receives the IP packet from the IP retransmission apparatus according to [1], the activation packet is transmitted to the IP retransmission credit receiving device. A gateway device, comprising: an activation packet transmission means.
[5]
When the reception of the emergency alert broadcast start packet from the accommodating station that receives the IP packet from the IP retransmission apparatus according to [1] stops, the emergency retransmission broadcast receiving device receives the emergency alert broadcast. [4] The gateway device according to [4], further comprising an end packet transmitting unit that transmits an end packet for stopping.
[6]
A demultiplexing unit that receives the content stream from a receiving station that receives an IP packet from the IP retransmission apparatus according to [1] and selects a packet for decoding the desired content;
When the activation packet is received from the gateway device according to [4], the demultiplexing unit includes a determination unit that selects a packet necessary for decoding the emergency alert broadcast from the content stream. Television receiver.
[7]
The television reception as set forth in [6], comprising a power supply circuit for turning on power necessary for receiving the emergency alert broadcast when the activation packet is received from the gateway device as set forth in [4]. Machine.
[8]
A demodulation procedure for demodulating the received digital broadcast signal and outputting a content stream;
A first IP conversion procedure for packetizing the content stream into IP packets and transmitting them to an IP network;
A detection procedure for detecting an emergency warning broadcast activation signal from a transmission control signal included in the digital broadcast signal;
And a second IP protocol that broadcasts an emergency alert broadcast start packet, which is an IP packet based on the emergency alert broadcast start signal detected by the detection procedure, to the IP network. Resend method.
[9]
Furthermore, a channel information detection circuit for detecting channel information indicating in which channel the emergency alert broadcast activation signal detection circuit has detected the emergency alert broadcast activation signal,
The IP retransmission apparatus according to [1], wherein the first IP circuit transmits the RTP extension header in the content stream including the channel information to the IP network.
[10]
The IP retransmitting device according to [9], wherein the first IP converting circuit transmits the RTP extension header in the content stream to the IP network including the emergency alert broadcast reception activation information.

  DESCRIPTION OF SYMBOLS 10 ... IP retransmission apparatus, 11 ... Retransmission part, 12 ... Digital broadcast demodulator, 13 ... TTS circuit, 14 ... IP circuit, 15 ... IP circuit, 16 ... IP circuit, 20 ... Accommodating station, 21 ... Edge router, 25 ... Access line, 30 ... In-home device 31 ... Gateway device, 32 ... Television receiver, 35 ... Network line, 40 ... IP network, 51 ... I / O port, 52 ... Routing processor, 53 ... On Output port 54... Control unit 55... Emergency warning broadcast activation signal detection unit 56. Packet determination unit 61. Input / output port 62. Protocol conversion unit 63 ... Input / output port 64. MAC address memory, 66 ... magic packet generation unit, 71 ... communication unit, 72 ... demultiplexing unit, 73 ... AV decoder, 74 ... magic packet determination unit, 75 ... power supply circuit, 6 ... demultiplexing unit, 77 ... communication unit, 78 ... packet determining unit.

Claims (2)

Demodulating means for demodulating a plurality of received digital broadcast signals by a plurality of demodulators and outputting a plurality of transport streams of a plurality of contents, and packetizing the plurality of transport streams of the plurality of contents into IP packets A first IP circuit for transmission to a network and a transmission control signal included in each of the plurality of digital broadcast signals, each of which is information packetized into one IP packet and used for emergency alert broadcasting Receiving means for receiving an IP packet from an IP retransmission apparatus comprising a second IP circuit that broadcasts an emergency alert broadcast activation packet to the IP network;
A television receiver comprising: means for turning on a power supply circuit in response to the emergency alert broadcast start packet included in the IP packet received by the receiving means. Demodulating means for demodulating a plurality of received digital broadcast signals by a plurality of demodulators and outputting a plurality of transport streams of a plurality of contents, and packetizing the plurality of transport streams of the plurality of contents into IP packets A first IP circuit for transmission to a network and a transmission control signal included in each of the plurality of digital broadcast signals, each of which is information packetized into one IP packet and used for emergency alert broadcasting Receiving the IP packet from the IP retransmitting device including the second IP circuit that broadcasts the emergency alert broadcast start packet for starting to the IP network,
A television receiving method of turning on a power circuit in accordance with the emergency alert broadcast start packet included in the IP packet received by the receiving means.

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