JP6844505B2 - Broadcast retransmission device and broadcast retransmission method - Google Patents

Description

The present invention relates to a broadcast retransmission device and a broadcast retransmission method.

Conventionally, a technique for transmitting content using an MMTP (MPEG Media Transport Protocol) packet has been developed.

For example, Non-Patent Document 1 (ARIB STD-B32 3.4 version, "Video coding, audio coding and multiplexing method in digital broadcasting", Association of Radio Industries and Businesses, September 30, 2015) A broadcasting system using the MMT method is disclosed.

In this broadcasting system, an MMT packet containing program information such as audio information and video information is stored in the payload of the IP packet. The IP packet is stored in the payload of the TLV (Type Length Value) packet.

Further, Patent Document 1 (Japanese Unexamined Patent Publication No. 2013-175949) discloses the following techniques. That is, it is a transmission device that multiplex-transmits variable-length packets in a frame consisting of a plurality of packet placement slots for allocating TS (Transport Stream) packets and one slot for header information, and has the same size as the TS packet to be transmitted. A predetermined variable-length packet division unit that generates a third packet of packet length, divides the variable-length packet to be transmitted, and sequentially allocates the data of the divided variable-length packet to the third packet. An arrangement position for indicating a relative arrangement position in a frame for the TS packet and the third packet in order to transmit the TS packet and the third packet in a frame having a plurality of packet placement slots. A multiple frame header generation unit that generates multiple frame header information including information and start position information for indicating the start position of the variable length packet, and one slot for the multiple frame header information are arranged in one frame. The TS packet and the third packet are arranged and multiplexed for each packet arrangement slot of the one frame, and the multiplexing unit configured as a plurality of TS multiplex frames and the multiplexing signal of the plurality of TS multiplex frames are externally arranged. It is provided with a transmission unit for transmitting to.

Japanese Unexamined Patent Publication No. 2013-175949

ARIB STD-B32 3.4 version, "Video coding, audio coding and multiplexing method in digital broadcasting", Association of Radio Industries and Businesses, September 30, 2015 International Telecommunication Union Radiocommunication Sector, "Recommunication ITU-R BT.1869", March 2010, [online], [Search on October 12, 2017], Internet <URL: http: // www. itu. int / dms_pubrec / itu-r / rec / bt / R-REC-BT. 1869-0-201003-I! !! PDF-E. pdf> "JCTEA STD-002-6.1 Digital Cable Television Broadcasting Multiplexer", Japan CATV Technology Association, February 13, 2017

For example, when an IP retransmission service for transmitting an advanced broadband satellite digital broadcast to a subscriber's home via an IP (Internet Protocol) TV transmission network is performed, a broadcast wave including an MMT packet is received and the received MMT packet is IP. A configuration is conceivable in which the packet is stored and retransmitted to the in-home device at the subscriber's home. An excellent technique for performing such retransmission is desired.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to perform excellent data processing in a configuration in which a broadcast wave including program information is received and retransmitted to another device. It is to provide a possible broadcast retransmission device and broadcast retransmission method.

(1) In order to solve the above problems, the broadcast retransmission device according to a certain aspect of the present invention is a broadcast retransmission device used for advanced broadband satellite digital broadcasting, and one or more TLVs included in the broadcast wave. A TLV division unit that performs division processing to generate a plurality of TS packets in which packet data is divided and stored, and an IP packet containing a predetermined number of the TS packets divided by the TLV division unit are generated and transmitted. The TLV division unit does not store a part or all of the TLV null packet in the TS packet when the TLV packet is a TLV null packet having a predetermined length or more in the division process. When the null data processing is performed, the IP conversion unit performs null data processing, and when the null data processing is performed, one or a plurality of TS packets which are null packets are added to the TS packet divided by the TLV division unit before the null data processing. In addition, the predetermined number of IP packets is generated and transmitted.

(4) In order to solve the above problems, the broadcast retransmission device according to a certain aspect of the present invention is a broadcast retransmission device used for advanced broadband satellite digital broadcasting, and acquires a stream included in a broadcast wave. The data of one or a plurality of TLV packets included in the stream acquired by the acquisition unit and the acquisition unit is divided and stored to generate a plurality of TS packets, and the generated TS packets are stored. The packet processing unit includes a packet processing unit that generates and transmits an IP packet that is an IP packet and stores a predetermined number of the TS packets, and the packet processing unit is a TLV null in which the TLV packet has a predetermined length or more in the division processing. In the case of a packet, null data processing for suppressing the storage of the TLV null packet data in the TS packet is performed, and the packet processing unit has a predetermined value of fluctuation in the delay time of the stream data in the broadcast retransmission device. As described below, one or a plurality of TS packets, which are null packets, are added to the TS packets generated prior to the null data processing to generate and transmit the IP packets having the predetermined number.

(5) In order to solve the above problems, the broadcast retransmission method according to a certain aspect of the present invention is a broadcast retransmission method in a broadcast retransmission device used for advanced broadband satellite digital broadcasting, and is included in the broadcast wave. A step of performing a division process for generating a plurality of TS packets in which the data of one or a plurality of TLV packets included in the stream is divided and stored, and a predetermined number of IP packets storing the generated TS packets. In the step of performing the division process, which includes a step of generating and transmitting an IP packet containing a TS packet, when the TLV packet is a TLV null packet having a predetermined length or more, a part of the TLV null packet or In the step of performing null data processing in which not all are stored in the TS packet and transmitting the IP packet, when the null data processing is performed, the TS packet generated by the division processing prior to the null data processing is null. One or a plurality of TS packets, which are packets, are added to generate and transmit the IP packets having the predetermined number.

(6) In order to solve the above problems, the broadcast retransmission method according to a certain aspect of the present invention is a broadcast retransmission method in a broadcast retransmission device used for advanced broadband satellite digital broadcasting, and is included in the broadcast wave. An IP that stores the generated TS packet by performing a step of acquiring a stream and a division process of generating a plurality of TS packets in which the data of one or a plurality of TLV packets included in the acquired stream is divided and stored. In the step of transmitting the IP packet, which includes a step of generating and transmitting an IP packet containing a predetermined number of the TS packets, which is a packet, in the division process, the TLV packet has a TLV of a predetermined length or more. In the case of a null packet, null data processing for suppressing the storage of the TLV null packet data in the TS packet is performed so that the fluctuation of the delay time of the stream data in the broadcast retransmission device becomes a predetermined value or less. , One or a plurality of TS packets, which are null packets, are added to the TS packets generated before the null data processing to generate the IP packets having the predetermined number.

The present invention can be realized not only as a broadcast retransmission device provided with such a characteristic processing unit, but also as a program for causing a computer to execute such a characteristic processing step. Further, the present invention can be realized as a semiconductor integrated circuit that realizes a part or all of the broadcast retransmission device, or can be realized as a system including the broadcast retransmission device.

According to the present invention, excellent data processing can be performed in a configuration in which a broadcast wave including program information is received and retransmitted to another device.

FIG. 1 is a diagram showing a configuration of a broadcast retransmission system according to an embodiment of the present invention. FIG. 2 is a diagram showing an example of a protocol stack of data transmitted by broadcast waves in the broadcast retransmission system according to the embodiment of the present invention. FIG. 3 is a diagram showing an example of a TLV packet transmitted by a broadcast wave in the broadcast retransmission system according to the embodiment of the present invention. FIG. 4 is a diagram showing another example of a protocol stack of data transmitted by a broadcast wave. FIG. 5 is a diagram showing an example of a TS packet transmitted by a broadcast wave. FIG. 6 is a diagram showing a configuration of a broadcast retransmission device in the broadcast retransmission system according to the embodiment of the present invention. FIG. 7 is a diagram showing an example of a TLV packet division method performed in the broadcast retransmission device according to the embodiment of the present invention. FIG. 8 is a diagram showing an example of the TS packet format shown in FIG. 7. FIG. 9 is a diagram showing an example of a method for processing a TLV null packet by the broadcast retransmission device according to the embodiment of the present invention. FIG. 10 is a diagram showing an example of an IP packet transmitted by the broadcast retransmission device according to the embodiment of the present invention. FIG. 11 is a flowchart defining an operation procedure when the broadcast retransmission device in the broadcast retransmission system according to the embodiment of the present invention retransmits a broadcast wave. FIG. 12 is a flowchart defining an operation procedure when the broadcast retransmission device in the broadcast retransmission system according to the embodiment of the present invention processes a TLV null packet.

First, the contents of the embodiments of the present invention will be listed and described.

(1) The broadcast retransmission device according to the embodiment of the present invention is a broadcast retransmission device used for advanced broadband satellite digital broadcasting, in which data of one or a plurality of TLV packets included in a broadcast wave is divided. It includes a TLV division unit that performs division processing for generating a plurality of stored TS packets, and an IP conversion unit that generates and transmits an IP packet that stores a predetermined number of the TS packets divided by the TLV division unit. In the division process, when the TLV packet is a TLV null packet having a predetermined length or longer, the TLV division unit performs null data processing in which a part or all of the TLV null packet is not stored in the TS packet, and the IP When the null data processing is performed, the conversion unit adds one or a plurality of TS packets, which are null packets, to the TS packets divided by the TLV division unit before the null data processing to obtain the predetermined number. The IP packet is generated and transmitted.

In this way, with the configuration that suppresses the storage of the TLV null packet data of the predetermined length or longer in the TS packet, for example, the transmission data is compared with the case where the TLV packet in the broadcast wave is transmitted as it is via a communication line such as the Internet. Since the amount can be reduced, the communication traffic on the communication line can be reduced. Further, by adding a TS packet which is a null packet and transmitting the IP packet at an early stage without waiting for the next TLV packet, the delay of stream transmission and the transmission delay time in the broadcast receiving device due to the deletion of the TLV null packet Fluctuation can be suppressed. Thereby, for example, the amount of buffer in the receiving device can be reduced. Therefore, excellent data processing can be performed in a configuration in which a broadcast wave including program information is received and retransmitted to another device.

(2) Preferably, when the data of one TLV packet is divided and stored in a plurality of TS packets, insertion of null data between the divided data is not allowed.

With such a configuration, the data of the TLV packet is divided and stored in a plurality of TS packets, and in the process in which the insertion of null data between the divided data is not allowed, the amount of transmitted data is reduced and the TLV null packet is reduced. It is possible to suppress the delay of stream transmission due to the deletion and the fluctuation of the transmission delay time in the broadcast receiving device.

(3) Preferably, in the division process, the TLV division unit is a part of the TLV null packet at the end of the TS packet in which the data of the TLV packet before the TLV null packet having a predetermined length or more is stored. Or store everything.

With such a configuration, in the process in which the data of the TLV packet is divided into a plurality of TS packets and stored, and null data is allowed to be stored at the end of the TS packet, the amount of transmission data is reduced and the TLV It is possible to suppress the delay of stream transmission due to the deletion of null packets and the fluctuation of the transmission delay time in the broadcast receiving device.

(4) The broadcast retransmission device according to the embodiment of the present invention is a broadcast retransmission device used for advanced broadband satellite digital broadcasting, and is composed of an acquisition unit that acquires a stream included in a broadcast wave and the acquisition unit. A predetermined number of IP packets containing the generated TS packets after performing a division process to generate a plurality of TS packets in which the data of one or a plurality of TLV packets included in the acquired stream is divided and stored. The packet processing unit includes a packet processing unit that generates and transmits an IP packet containing the TS packet of the above, and the packet processing unit is the TLV when the TLV packet is a TLV null packet having a predetermined length or more in the division processing. Null data processing for suppressing the storage of null packet data in the TS packet is performed, and the packet processing unit performs the null data processing so that the fluctuation of the delay time of the stream data in the broadcast retransmission device becomes equal to or less than a predetermined value. One or a plurality of TS packets, which are null packets, are added to the TS packets generated before the null data processing to generate and transmit the IP packets having the predetermined number.

In this way, with the configuration that suppresses the storage of the TLV null packet data of the predetermined length or longer in the TS packet, for example, the transmission data is compared with the case where the TLV packet in the broadcast wave is transmitted as it is via a communication line such as the Internet. Since the amount can be reduced, the communication traffic on the communication line can be reduced. Further, by adding a TS packet which is a null packet and transmitting the IP packet at an early stage without waiting for the next TLV packet, the delay of stream transmission and the transmission delay time in the broadcast receiving device due to the deletion of the TLV null packet Fluctuation can be suppressed. Thereby, for example, the amount of buffer in the receiving device can be reduced. Therefore, excellent data processing can be performed in a configuration in which a broadcast wave including program information is received and retransmitted to another device.

(5) The broadcast retransmission method according to the embodiment of the present invention is a broadcast retransmission method in a broadcast retransmission device used for advanced broadband satellite digital broadcasting, and is one or a plurality of broadcast retransmission methods included in a stream included in a broadcast wave. A step of performing a division process to generate a plurality of TS packets in which the data of the TLV packet is divided and stored, and an IP packet containing the generated TS packet and storing a predetermined number of the TS packets. In the step of performing the division process, including the step of generating and transmitting the TLV packet, when the TLV packet is a TLV null packet having a predetermined length or more, a part or all of the TLV null packet is stored in the TS packet. In the step of performing the null data processing and transmitting the IP packet, when the null data processing is performed, one or a plurality of null packets are added to the TS packet generated by the division processing prior to the null data processing. The TS packets are added to generate and transmit the IP packets having the predetermined number.

In this way, by the method of suppressing the storage of the data of the TLV null packet having a predetermined length or more in the TS packet, the transmission data is compared with the case where the TLV packet in the broadcast wave is transmitted as it is via a communication line such as the Internet. Since the amount can be reduced, the communication traffic on the communication line can be reduced. Further, by adding a TS packet which is a null packet and transmitting the IP packet at an early stage without waiting for the next TLV packet, the delay of stream transmission and the transmission delay time in the broadcast receiving device due to the deletion of the TLV null packet. Fluctuation can be suppressed. Thereby, for example, the amount of buffer in the receiving device can be reduced. Therefore, excellent data processing can be performed in a configuration in which a broadcast wave including program information is received and retransmitted to another device.

(6) The broadcast retransmission method according to the embodiment of the present invention is a broadcast retransmission method in a broadcast retransmission device used for advanced broadband satellite digital broadcasting, and includes a step of acquiring a stream included in a broadcast wave. A predetermined number of IP packets containing the generated TS packets after performing a division process to generate a plurality of TS packets in which the data of one or a plurality of TLV packets included in the acquired stream is divided and stored. In the step of transmitting the IP packet, which includes a step of generating and transmitting an IP packet containing the TS packet, when the TLV packet is a TLV null packet having a predetermined length or more in the division process, the step is described. Prior to the null data processing, the null data processing for suppressing the storage of the TLV null packet data in the TS packet is performed so that the fluctuation of the delay time of the stream data in the broadcast retransmission device becomes equal to or less than a predetermined value. One or a plurality of TS packets, which are null packets, are added to the generated TS packets to generate the IP packets having the predetermined number.

In this way, by the method of suppressing the storage of the data of the TLV null packet having a predetermined length or more in the TS packet, the transmission data is compared with the case where the TLV packet in the broadcast wave is transmitted as it is via a communication line such as the Internet. Since the amount can be reduced, the communication traffic on the communication line can be reduced. Further, by adding a TS packet which is a null packet and transmitting the IP packet at an early stage without waiting for the next TLV packet, the delay of stream transmission and the transmission delay time in the broadcast receiving device due to the deletion of the TLV null packet. Fluctuation can be suppressed. Thereby, for example, the amount of buffer in the receiving device can be reduced. Therefore, excellent data processing can be performed in a configuration in which a broadcast wave including program information is received and retransmitted to another device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals, and the description thereof will not be repeated. In addition, at least a part of the embodiments described below may be arbitrarily combined.

FIG. 1 is a diagram showing a configuration of a broadcast retransmission system according to an embodiment of the present invention.

With reference to FIG. 1, the broadcast retransmission system 301 includes a broadcast retransmission device 101 and a plurality of IP broadcast receiving devices 202.

The broadcast retransmission system 301 is not limited to the configuration including a plurality of IP broadcast receiving devices 202, and may be configured to include one IP broadcast receiving device 202.

The broadcast retransmission device 101 and the router 121 are provided in, for example, the IPTV center 251.

The ONU (Optical Network Unit) 122, STB131, TV receiver 132, and TV monitor 133 are provided in the subscriber's home. The STB 131 and the TV receiver 132 include an IP broadcast receiver 202.

For example, an external antenna 81 is connected to the broadcast retransmission device 101. The broadcast retransmission device 101 receives, for example, a broadcast wave including a stream.

The stream contains program information and the like. The program information includes, for example, audio information, video information, EPG (Electronic Program Guide) information, SI information (Service Information), subtitle information, and the like.

The audio information and the video information are compressed and encrypted according to a predetermined method, for example.

The broadcast retransmission device 101 receives, for example, a broadcast wave transmitted from a broadcast satellite for advanced broadband satellite digital broadcasting (not shown) for relaying a stream from a broadcast station via an external antenna 81.

The broadcast retransmission device 101 may, for example, receive the broadcast wave transmitted from the radio tower via the external antenna 81.

FIG. 2 is a diagram showing an example of a protocol stack of data transmitted by broadcast waves in the broadcast retransmission system according to the embodiment of the present invention. FIG. 2 shows a protocol stack using TLV packets.

With reference to FIG. 2, TLV packets are often used for transmission such as 4K UHDTV (Ultra High Definition Television) or 8K UHDTV according to standards such as 2160p or 4320p.

In the example shown in FIG. 2, the broadcast wave includes, for example, TMCC information, AC information and TLV packets.

FIG. 3 is a diagram showing an example of a TLV packet transmitted by a broadcast wave in the broadcast retransmission system according to the embodiment of the present invention. FIG. 3 shows an example of a packet having a header in which information indicating a data type is stored, Non-Patent Document 2 (International Telecommunication Union Radiocommunication Sector, “Recommunication ITU-R BT.1869”, March 2010, [ online], [Searched on October 12, 2017], Internet <URL: http: //www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.1869-0-201003- The format of the TLV packet according to the standard of I !! PDF-E. Pdf>) is shown.

The TLV packet includes a TLV header and a TLV payload. The TLV header includes a "start code" field containing a value of "01", a "future reservation" field, a "packet type" field, and a "length" field, and the lengths of these fields. Are 2 bits, 6 bits, 8 bits and 16 bits, respectively.

Values such as "0x01", "0x02", "0x03", and "0xFF" are stored in the "packet type" field. Here, the numbers starting with "0x" mean that the numbers after "0x" are represented by hexadecimal numbers.

When "0x01" is stored in the "packet type" field, the TLV packet 61 includes an IPv4 packet that is the total data length of the values stored in the "length" field in the TLV payload.

Further, when "0x02" is stored in the "packet type" field, the TLV packet 62 includes an IPv6 packet which is the total data length of the value stored in the "length" field in the TLV payload.

Further, when "0x03" is stored in the "packet type" field, the TLV packet 63 includes an IP packet which is the total data length of the value stored in the "length" field in the TLV payload. A compressed IP packet is, for example, an IP packet in which an IP header is compressed.

Further, when "0xFF" is stored in the "packet type" field, the TLV packet 64 includes null data which is the total data length of the values stored in the "length" field in the TLV payload. Hereinafter, a TLV packet containing null data in the TLV payload is also referred to as a TLV null packet.

With reference to FIG. 2 again, for example, NTP (Network Time Protocol) data for time synchronization, IP-SI data, time information, MMT packet, or data transmission method is stored in UDP (User Datagram Protocol) / IP packet. Will be done. Video information, audio information, MMT-SI data, and other information are stored in the MMT packet.

The TLV packets 61 to 63 (hereinafter, also referred to as TLV information packets) store such UDP / IP packets.

FIG. 4 is a diagram showing another example of a protocol stack of data transmitted by a broadcast wave. FIG. 4 shows a protocol stack using TS (Transport Stream) packets.

With reference to FIG. 4, TS packets are often used for transmission such as HDTV or SDTV (Standard Definition Television) according to standards such as 1080i, 720p or 480p. The TS packet may be used for transmission of 4K UHDTV, 8K UHDTV, or the like.

In the example shown in FIG. 4, the broadcast wave includes, for example, TMCC information, AC information and TS packets.

FIG. 5 is a diagram showing an example of a TS packet transmitted by a broadcast wave. FIG. 5 shows the format of the TS packet.

The TS packet includes a TS header and a TS payload. The TS header includes a "synchronous byte" field in which the value of "0x47" is stored and a field for storing "PID (Packet ID), etc.", and the lengths of these fields are, for example, 1 octet and 1 octet, respectively. It is 3 octets. The TS payload includes, for example, a "payload" field for storing all or part of the PES (Packetized Elementary Stream) or all or part of the section. The length of this field is, for example, 184 octets.

With reference to FIG. 4 again, the PCR (Program Lock Reference) data is stored in, for example, a TS packet. Further, for example, video information, audio information, subtitle information, and timeline are stored in the PES packet.

In addition, for example, PSI-SI data and a part of AIT (Application Information Table) are included in the section. Also included in the section are the rest of AIT, the app HTML and content downloads, which are transmitted in a data carousel fashion.

With reference to FIG. 1 again, the broadcast retransmission device 101 acquires program information from the broadcast wave and stores the acquired program information in an IP packet. Then, the broadcast retransmission device 101 transmits an IP packet containing program information (hereinafter, also referred to as a distribution IP packet) to each subscriber's home.

Here, the broadcast retransmission device 101, for example, sets the destination of the distribution IP packet to an IP multicast address that reaches a plurality of subscribers' homes and transmits the IP packet to the router 121.

The router 121 is, for example, an IP multicast router, and when a distribution IP packet is received from the broadcast retransmission device 101, the received distribution IP packet is transmitted to an IPTV transmission network (CDN: Content Delivery Network) which is an example of a communication line. Send to 451. In the IPTV transmission network 451 for example, distribution IP packets are transmitted according to the IP protocol. The communication line may be another communication line such as the Internet.

Further, the IPTV center 251 may be provided with an OLT (Optical Line Thermal) instead of the router 121.

The ONU 122 receives, for example, a distribution IP packet transmitted from the broadcast retransmission device 101 by a communication service of FTTH (Fiber To The Home).

More specifically, the ONU 122 is a home-side device in, for example, GPON (Gigabit Passive Optical Network) and GE-PON (Gigabit Ethernet®-PON).

When the ONU 122 receives a distribution IP packet from the IPTV transmission network 451 via an optical communication line, the ONU 122 transmits the received distribution IP packet to the STB 131 and the TV receiver 132.

When the IP broadcast receiving device 202 in the STB 131 receives the distribution IP packet from the ONU 122, it acquires program information from the received distribution IP packet, decodes audio information and video information based on the acquired program information, and then decodes the audio information and video information. The decoded audio information and video information are transmitted to the TV monitor 133.

The TV monitor 133 reproduces the program based on the audio information and the video information received from the STB 131.

Further, the IP broadcast receiving device 202 of the TV receiver 132 reproduces a program in the speaker module and the display module of its own TV receiver 132 by using the similarly decoded audio information and video information.

Here, in the broadcast wave, a TLV null packet (see FIG. 3) for adjusting the bit rate is inserted in order to make the bit rate fixed according to the transmission device of the broadcast wave. Therefore, the amount of data transmitted by the TLV packet in the broadcast wave is larger than the amount of data of the program information.

Unlike broadcast waves, the IP retransmission service cannot occupy a band, so it is required that the amount of data to be transmitted is small.

Therefore, in the broadcast retransmission system according to the embodiment of the present invention, the above problem is solved by the following configuration and operation.

FIG. 6 is a diagram showing a configuration of a broadcast retransmission device in the broadcast retransmission system according to the embodiment of the present invention.

With reference to FIG. 6, the broadcast retransmission device 101 includes a demodulation unit (acquisition unit) 11, a TLV division unit 12, an IP conversion unit 13, a high-accuracy oscillator 15, a counter 16, and an NTP packet acquisition unit 17. And a conversion unit 18. The TLV division unit 12 includes a deletion unit 21 and a TS conversion unit 22. The IP conversion unit 13 includes a TTS conversion unit 23, a blocking unit 24, an IP packetization unit 25, and an IP transmission unit 26.

The TLV division unit 12 and the IP conversion unit 13 divide and generate a plurality of TS packets in which the data of one or a plurality of TLV packets included in the stream acquired by the demodulation unit 11 is divided and stored as a packet processing unit. Processing is performed to generate and transmit an IP packet containing a predetermined number of TS packets, which is an IP packet containing the generated TS packet.

That is, the TLV division unit 12 performs a division process for generating a plurality of TS packets in which the data of one or a plurality of TLV packets included in the broadcast wave is divided and stored.

The IP conversion unit 13 generates and transmits an IP packet containing a predetermined number of TS packets divided by the TLV division unit 12. In the example shown in FIG. 6, the IP conversion unit 13 stores the TTS packet based on the TS packet in the IP packet and transmits the TTS packet.

In the broadcast retransmission device 101, the high-accuracy oscillator 15 generates, for example, a transmission-side reference clock. More specifically, the high-accuracy oscillator 15 is, for example, an oscillator that generates a high-precision clock pulse of 27 MHz synchronized with time information included in radio waves transmitted from a GPS (Global Positioning System) satellite. The high-accuracy oscillator 15 outputs the generated clock pulse to the counter 16.

The high-accuracy oscillator 15 may be configured to generate a high-precision clock pulse by using an OCXO (Oven Control Oscillator), a rubidium oscillator, or the like.

The counter 16 updates the transmitter count value according to, for example, the timing of the transmitter reference clock generated by the high-accuracy oscillator 15.

More specifically, the counter 16 counts the clock pulses from the high-accuracy oscillator 15 and holds the transmitted-side count value, which is the counted value.

The sender count can represent, for example, Coordinated Universal Time with an accuracy of 27 MHz.

The broadcast wave in the broadcast retransmission system 301 is, for example, the above-mentioned TLV null packet, a TLV program packet which is a TLV packet including program information, and time adjustment information for performing time adjustment between devices using Coordinated Universal Time. Etc., and follow the MMT method. The NTP data is an example of time adjustment information.

The demodulation unit 11 acquires a stream included in the broadcast wave. More specifically, the demodulation unit 11 receives the broadcast wave and demodulates the received broadcast wave to generate a stream including a TLV null packet, a TLV program packet, time adjustment information, and the like.

More specifically, the demodulation unit 11 receives the broadcast wave via the external antenna 81 and demodulates the received broadcast wave to generate a stream composed of a plurality of TLV packets, and the TLV division unit 12 and the demodulation unit 11 and the demodulation unit 11 generate a stream composed of a plurality of TLV packets. Output to the NTP packet acquisition unit 17. In the stream, for example, NTP data is transmitted every 33 milliseconds.

The TLV division unit 12 divides the TLV packet included in the stream received from the demodulation unit 11 to generate a plurality of fixed-length divided packets.

The NTP packet acquisition unit 17 receives a stream from the demodulation unit 11, acquires an IP packet containing NTP data (hereinafter, also referred to as an NTP packet) from the received stream, and outputs the acquired NTP packet to the conversion unit 18. ..

The conversion unit 18 adjusts the time to the counter 16 by using, for example, the NTP data included in the broadcast wave.

More specifically, the conversion unit 18 receives the NTP packet from the NTP packet acquisition unit 17, and acquires Coordinated Universal Time (UTC) in the NTP length format from the NTP data included in the received NTP packet.

The NTP length format has a 32-bit field indicating seconds and a 32-bit field indicating 1 second or less.

The conversion unit 18 holds a formula for converting Coordinated Universal Time in NTP length format into a transmission side count value (hereinafter, also referred to as a transmission side conversion formula).

The difference between the time based on the transmission side count value and Coordinated Universal Time is acceptable up to, for example, about 500 nanoseconds. Since one count of the transmission side count value corresponds to about 37 nanoseconds, even if the transmission side count value fluctuates by about 10 counts, it falls within the permissible range.

For example, when the frequency accuracy of the high-accuracy oscillator 15 is 1 ppm, it is considered that the transmitting side count value deviates by 1 count about every 37 milliseconds, so that the transmitting side count value is deviated by 10 NTP data, that is, every 330 milliseconds. By calibrating, the time based on the sender count value can be synchronized with Coordinated Universal Time with sufficient accuracy.

In this example, the conversion unit 18 converts Coordinated Universal Time into a transmission side count value using the transmission side conversion formula every time an NTP packet is received from the NTP packet acquisition unit 17, that is, every 33 milliseconds, and after conversion. The sender count value of is set in the counter 16.

In the TLV division unit 12, the deletion unit 21 deletes the TLV null packet from the stream generated by the demodulation unit 11.

More specifically, the deletion unit 21 monitors the stream received from the demodulation unit 11 and attempts to detect the start code in the TLV header (see FIG. 3).

When the deletion unit 21 detects the start code, the deletion unit 21 confirms the value stored in the packet type field after the start code.

When the value stored in the above field is 0xFF, the deletion unit 21 determines that the TLV packet including the start code is a TLV null packet, and deletes the TLV packet from the stream.

On the other hand, when the value stored in the above field is a value other than 0xFF, the deletion unit 21 determines that the TLV packet including the start code is not a TLV null packet, and outputs the TLV packet to the TS conversion unit 22. ..

FIG. 7 is a diagram showing an example of a TLV packet division method performed in the broadcast retransmission device according to the embodiment of the present invention.

In FIG. 7, a TLV packet described in Non-Patent Document 3 (“JCTEA STD-002-6.0 Digital Cable Television Broadcast Multiplexing Device”, Japan CATV Technology Association) is converted into a plurality of TS packets. The method of storing is shown.

FIG. 8 is a diagram showing an example of the TS packet format shown in FIG. 7.

With reference to FIGS. 6 to 8, the TS conversion unit 22 generates a plurality of fixed packets having a predetermined size, each including divided data of the TLV packets included in the stream. Here, the TS packet has a size of 188 bytes and is an example of a fixed packet.

More specifically, the TS conversion unit 22 has, for example, a buffer for holding unstored data.

When the TS conversion unit 22 receives the TLV packet 1 (see FIG. 7) from the deletion unit 21, for example, when the unstored data is not stored in the buffer, the TS conversion unit 22 receives, for example, from the beginning of the received TLV packet 1 to 184 bytes. Data is acquired as divided data.

The TS conversion unit 22 adds a 3-byte TS header and, if a TLV header, a 1-byte start TLV instruction to the acquired divided data, so that the divided data is stored in the payload of the TS packet. (Hereinafter, also referred to as a TLV-stored TS packet) is generated, and the generated TLV-stored TS packet is output to the TTS conversion unit 23.

Similarly, each time the TS conversion unit 22 acquires 185 bytes of data from the beginning of the remaining data of the TLV packet 1 as divided data, the TS conversion unit 22 generates a TLV storage TS packet and outputs the data to the TTS conversion unit 23.

Further, when the size of the acquired data is less than 185 bytes, the TS conversion unit 22 stores the acquired data as unstored data in the buffer.

Then, when the TS conversion unit 22 receives the subsequent TLV packet 2 (see FIG. 7) from the deletion unit 21, the unstored data is stored in the buffer, so the size obtained by subtracting the size of the unstored data from 184 bytes. Data is acquired from the beginning of the TLV packet 2.

The TS conversion unit 22 adds unstored data to the beginning of the acquired data, arranges the head TLV instruction and the data of the TLV packet 2 to generate divided data, and then discards the unstored data in the buffer.

The TS conversion unit 22 adds a TS header to the generated divided data to generate a TLV storage TS packet, and outputs the generated TLV storage TS packet to the TTS conversion unit 23.

In this way, with the configuration using TS packets, the TSoverIP recording device, measuring device, monitoring device, and the like utilized in the MPEG2-TS technical system can be used.

With reference to FIG. 6, the TTS conversion unit 23 adds, for example, transmission time information indicating the transmission timing of the TLV-stored TS packet to the TLV-stored TS packet.

Specifically, the TTS conversion unit 23 adds transmission time information indicating the transmission timing of the TLV-stored TS packet by the transmission side count value to the TLV-stored TS packet.

More specifically, when the TTS conversion unit 23 receives the TLV storage TS packet from the TS conversion unit 22, the transmission side count value is acquired from the counter 16, and the acquired transmission side count value is used as the TS of the TLV storage TS packet. Prepend it as a time stamp before the header.

Hereinafter, the TLV-stored TS packet to which the time stamp is added is also referred to as a TLV-stored TTS (Time-stopped TS) packet.

The size of the time stamp is a predetermined size, for example, 4 bytes. Therefore, the size of the TLV-stored TTS packet is a fixed length of 192 bytes.

The TTS conversion unit 23 outputs the generated TLV storage TTS packet to the blocking unit 24.

The blocking unit 24 accumulates a predetermined number of TLV-stored TTS packets received from the TTS-forming unit 23. The blocking unit 24 waits until a predetermined number of TLV-stored TTS packets are accumulated.

More specifically, for example, 1500 bytes is often used as the MTU size. In this case, if seven TLV-stored TTS packets are collectively transmitted as one IP packet, the transmission efficiency in the IPTV transmission network 451 can be improved. ..

In this example, the blocking unit 24 accumulates seven TLV-stored TTS packets and then outputs these seven TLV-stored TTS packets as one block data to the IP packetizing unit 25. Due to the configuration in which the TTS packets are stored, even if a plurality of TS packets are stored in one IP packet, the timing of each TS packet can be easily recognized on the receiving side of the IP packet.

Based on the block data, the blocking unit 24 performs FEC processing for adding an FEC (Forward Error Correction) packet for forward error correction as additional block data, for example, in accordance with the SMPTE 2022 standard (pro MPEG COP3). You may.

Upon receiving the block data from the blocking unit 24, the IP packetizing unit 25 adds, for example, an RTP (Real-time Transport Protocol) header, a UDP (User Datagram Protocol) header, and an IP header to the received block data. Generates an IP packet, that is, an IP packet for distribution.

The IP multicast address of the destination in the IP header and the destination port number in the UDP header can be set to arbitrary values by the operator. The IP packetization unit 25 outputs the generated IP packet for distribution to the IP transmission unit 26.

The IP transmission unit 26 transmits a stream from which the TLV null packet has been deleted by the deletion unit 21 to the IP broadcast receiving device 202 via the IPTV transmission network 451.

More specifically, the IP transmission unit 26 transmits the distribution IP packet received from the IP packetization unit 25 to the router 121.

Here, the TLV division unit 12 and the IP conversion unit 13 perform null data processing that suppresses the storage of the TLV null packet data in the TS packet when the TLV packet is a TLV null packet having a predetermined length or more in the division processing. Do.

Then, the TLV division unit 12 and the IP conversion unit 13 add a null packet to the TS packet generated before the null data processing so that the fluctuation of the delay time in the broadcast retransmission device 101 of the stream data becomes equal to or less than a predetermined value. A certain one or a plurality of TS packets are added to generate and transmit an IP packet having the above-mentioned predetermined number.

Specifically, when the stream received from the demodulation unit 11 does not include the TLV null packet, the broadcast retransmission device 101 divides the TLV packet by the method described with reference to FIGS. 7 and 8 and divides the TLV packet into TLV. A stored TS packet is generated, and a TLV stored TTS packet based on the stored TS packet is generated. Then, the broadcast retransmission device 101 generates a distribution IP packet in which seven TLV-stored TTS packets are stored, and transmits the IP packet to the IP broadcast receiving device 202 via the IPTV transmission network 451.

On the other hand, when the stream received from the demodulation unit 11 contains a TLV null packet, the broadcast retransmission device 101 generates a distribution IP packet by the following method in addition to the above method.

FIG. 9 is a diagram showing an example of a method for processing a TLV null packet by the broadcast retransmission device according to the embodiment of the present invention. In FIG. 9, the time axes of the input stream and the output stream are not aligned, and an image of processing focusing on the data correspondence is shown.

In the division process, the TLV division unit 12 performs null data processing in which a part or all of the TLV null packet is not stored in the TS packet when the TLV packet is a TLV null packet having a predetermined length or more. For example, the TLV division unit 12 performs null data processing in which a part or all of the data of the TLV null packet is discarded without being stored in the TS packet.

Further, for example, in the division process, the TLV division unit 12 stores a part or all of the TLV null packet at the end of the TS packet in which the data of the TLV packet before the TLV null packet having the predetermined length or more is stored. ..

Further, for example, in the division process, the TLV division unit 12 deletes the TLV null packet when the TLV packet is a TLV null packet having a length less than the predetermined length.

That is, in the broadcast retransmission system 301, when the data of one TLV packet is divided into a plurality of TS packets and stored, the insertion of null data between the divided data is not allowed, and the TS packet is not allowed. Null data is allowed to be stored at the end of.

Specifically, referring to FIG. 9, the TLV division unit 12 uses, for example, a normal TLV packet A, a TLV null packet 1, a normal TLV packet B, a TLV null packet 2, and a normal TLV packet C. It is assumed that the streams included in order are received from the demodulation unit 11. The normal TLV packet is, for example, the above-mentioned TLV information packet.

For example, the data length of a normal TLV packet is about 1.5 kbytes at the maximum, and the data length of a TLV null packet is about 5 kbytes at the maximum.

In the example shown in FIG. 9, the deletion unit 21 in the broadcast retransmission device 101 deletes the TLV null packets 1 and 2 from the stream received from the demodulation unit 11, and outputs the deleted stream to the TS conversion unit 22.

Here, since the data length of the TLV null packet 2 is larger than a predetermined threshold value, the deletion unit 21 outputs a deletion notification to the TS conversion unit 22 and the blocking unit 24.

As described above, the TS conversion unit 22 acquires 184 bytes or 185 bytes of data from the TLV packet as divided data depending on whether or not the TLV header is included, and the acquired divided data is stored in the payload. Generate a packet.

On the other hand, as described above, when the size of the data acquired from the TLV packet is less than 184 bytes or 185 bytes, the TS conversion unit 22 adds the data acquired from the subsequent TLV packet after the data. Generates divided data and generates TS packets.

In the example shown in FIG. 9, the TS conversion unit 22 receives the stream from the deletion unit 21 and generates the TS packet A1 in which the data A1 acquired from the TLV packet A is stored, and the remaining data A2 of the TLV packet A, And the TS packet (A2 + B1) in which the data B1 acquired from the TLV packet B is stored is generated, and the TS packet B2 in which the data B2 which is a part of the remaining data of the TLV packet B is stored is generated.

Next, the TS conversion unit 22 receives a deletion notification from the deletion unit 21 for the next TLV null packet 2 of the TLV packet B in a situation where the data B3, which is the remaining data of the TLV packet B, is less than 185 bytes. Therefore, TS termination processing is performed.

That is, in the division process, the TLV division unit 12 determines that the TS packet next to the TS packet is the next TS packet of the TS packet when the remaining area of the TS packet in which the data of the TLV null packet having the predetermined length or more is stored is equal to or less than the header length of the TLV null packet. A TS packet containing null data of the TLV null packet is added as.

More specifically, the TS conversion unit 22 determines the remaining data when the remaining data length of the payload of the TS packet in which the data B3 is stored is equal to or greater than a predetermined threshold value, that is, a value capable of storing data in the form of a TLV null packet. A long TLV null packet is added after the data B3 to generate divided data, and a TS packet B3 is generated. Specifically, for example, when the data length of the TLV header is 4 bytes as described above, the threshold value is 5 bytes.

On the other hand, when the remaining data length of the payload of the TS packet in which the data B3 is stored is insufficient and the data in the form of the TLV null packet cannot be saved, the TS conversion unit 22 data a part or all of the header of the TLV null packet. It is added after B3 to generate divided data, and TS packet B3 is generated. Further, the TS conversion unit 22 generates the divided data composed of the rest of the header of the TLV null packet and the null data, or only the null data, and generates the TS packet N1.

In this way, by storing the data in the form of the TLV null packet in a maximum of two TS packets, it is possible to prevent an error from occurring because the IP broadcast receiving device 202 cannot recognize the TLV null packet.

Next, the TS conversion unit 22 receives a stream from the deletion unit 21, generates a TS packet C1 in which the data C1 acquired from the TLV packet C is stored, and should store the TS packet C1 together with the remaining data C2 of the TLV packet C. Wait for the TLV packet.

When null data processing is performed, the IP conversion unit 13 adds one or a plurality of TS packets, which are null packets, to the TS packets divided by the TLV division unit 12 before the null data processing to obtain the above-mentioned predetermined number of IPs. Generate and send packets.

Specifically, the blocking unit 24 has received the TTS packet A1, the TTS packet (A2 + B1), the TTS packet B2, and the TTS packet B3 from the TTS packet 23, for example, in a situation where new block data is generated. When the TTS packet N1 is received in addition to these, the IP forced transmission process is performed because the deletion notification is received from the deletion unit 21 for the TLV null packet 2 next to the TLV packet B.

That is, the blocking unit 24 does not wait until the seven TLV-stored TTS packets are accumulated, and the TLV null packets are stored so that the total of the accumulated TLV-stored TTS packets becomes seven packets1. Alternatively, a plurality of TLV-stored TTS packets are generated. Then, the blocking unit 24 outputs seven TLV-stored TTS packets including the generated TTS packet to the IP packetizing unit 25 as one block data.

The blocking unit 24 is not limited to a configuration in which a TLV null packet is newly generated. For example, the deleting unit 21 selectively outputs a TLV packet other than the TLV null packet to the TS unit 22, and the blocking unit 24 , The TLV null packet skipped by the deletion unit 21 may be acquired from the deletion unit 21 and used.

Then, the blocking unit 24 receives the TTS packet C1 from the TTS processing unit 23, and stores the TTS packet C1 as the beginning of new block data, that is, the beginning packet stored in the next IP packet.

That is, the IP conversion unit 13 sets the data of the TLV packet after the TLV null packet having the predetermined length or more as the data of the TS packet to be stored first in the next IP packet.

FIG. 10 is a diagram showing an example of an IP packet transmitted by the broadcast retransmission device according to the embodiment of the present invention.

With reference to FIG. 10, the IP packetization unit 25 includes a TTS packet A1, a TTS packet (A2 + B1), a TTS packet B2, a TTS packet B3, and a blocking unit based on each TS packet generated by the TS packetization unit 22. The TTS packets N11 to N13 generated by 24 are stored in the payload, and an IP packet with an IP header, a UDP header, and an RTP header added is generated.

The TTS packet N11 is a packet newly created by the blocking unit 24 or created from the above-mentioned TS packet N1.

As described above, the broadcast retransmission device 101 deletes the TLV null packet having a small data length, and for the TLV null packet having a large data length, the data in the generation of the divided data by using a part of the null data including the TLV header. When the shortage of the data is supplemented, the remaining null data is deleted, and the transmission of the IP packet waits for the next normal TLV packet, the number of TTS packets stored in the IP packet is calculated as the number of TTS packets stored. By adding TTS packets, the number of IP packets is reduced to seven and IP packets are transmitted.

In this way, with the configuration of deleting the TLV null packet, for example, the amount of transmitted data can be reduced as compared with the case where the TLV packet in the broadcast wave is transmitted as it is via a communication line such as the Internet, so that communication on the communication line can be performed. Traffic can be reduced.

Further, when a TLV null packet having a large data length is deleted, a TTS packet in which the TLV null packet is stored is added, and an IP packet is transmitted at an early stage without waiting for the next normal TLV packet. It is possible to suppress the delay of stream transmission due to the deletion of packets and the fluctuation of the transmission delay time in the broadcast retransmission device 101. Thereby, for example, the amount of buffer in the IP broadcast receiving device 202, which is the device on the receiving side, can be reduced.

In addition, for TLV null packets with a small data length, the processing load is reduced, stream transmission is delayed, and broadcasting is performed by simply deleting the TTS packet containing the TLV null packet without performing TS termination processing and adding the TTS packet containing the TLV null packet. It is possible to achieve a good balance with the suppression of fluctuations in the transmission delay time in the retransmission device 101.

[Operation flow]
Each device in the broadcast retransmission system 301 includes a computer, and an arithmetic processing unit such as a CPU in the computer reads a program including a part or all of each step of the following sequence diagram or flowchart from a memory (not shown). Execute. The programs of these plurality of devices can be installed from the outside. The programs of these plurality of devices are distributed in a state of being stored in a recording medium.

FIG. 11 is a flowchart defining an operation procedure when the broadcast retransmission device in the broadcast retransmission system according to the embodiment of the present invention retransmits a broadcast wave.

With reference to FIG. 11, first, the broadcast retransmission device 101 receives the broadcast wave and acquires a variable-length TLV packet included in the received broadcast wave (step S1).

Next, the broadcast retransmission device 101 divides the acquired TLV packet to generate a plurality of fixed-length divided packets. That is, the broadcast retransmission device 101 generates a plurality of fixed-length divided packets in which the data of one or a plurality of TLV packets included in the broadcast wave is divided and stored (step S2).

Next, the broadcast retransmission device 101 generates and transmits an IP packet storing data of the TLV packet. More specifically, the broadcast retransmission device 101 generates an IP packet containing a predetermined number of generated divided packets (step S3) and transmits the IP packet to the IPTV transmission network 451 (step S4).

FIG. 12 is a flowchart defining an operation procedure when the broadcast retransmission device in the broadcast retransmission system according to the embodiment of the present invention processes a TLV null packet. FIG. 12 corresponds to a part of the detailed operation of the operations of steps S2 and S3 in the flowchart shown in FIG.

With reference to FIG. 12, first, the broadcast retransmission device 101 acquires a stream included in the broadcast wave, and acquires a TLV null packet included in the stream (step S11).

Next, when the data length of the acquired TLV null packet is equal to or less than a predetermined threshold value (YES in step S12), the broadcast retransmission device 101 simply deletes the TLV null packet until the acquisition of the next TLV packet. Wait (step S13).

By setting this threshold value to an appropriate value, it is possible to achieve a good balance between the reduction of the processing load and the delay of the stream transmission and the suppression of the fluctuation of the transmission delay time in the broadcast retransmission device 101 as described above. it can.

Next, when the broadcast retransmission device 101 acquires a normal TLV packet, it divides the acquired TLV packet into TS, that is, generates one or a plurality of TLV-stored TS packets in which the divided data is stored (). Step S14).

On the other hand, when the data length of the acquired TLV null packet is larger than a predetermined threshold value (NO in step S12), the broadcast retransmission device 101 terminates the TS packet corresponding to the data of the TLV packet immediately before the TLV null packet. The process is started (step S15).

That is, when the remaining data length of the payload of the TS packet is 5 bytes or more (NO in step S16), the broadcast retransmission device 101 can store the data in the form of a TLV null packet, and thus the TS packet. Terminated with, that is, the divided data including the TLV null packet is generated, and the TS packet is generated (step S18).

On the other hand, when the remaining data length of the payload of the TS packet is 4 bytes or less (YES in step S16), the broadcast retransmission device 101 cannot save the data in the TLV null packet format, so that the next TS packet is used. Terminate, that is, generate split data including part or all of the TLV null packet header to generate a TS packet, and consist of the rest of the TLV null packet header and null data, or consist only of null data. The divided data to be generated is generated, and a TS packet is generated (step S17).

Next, the broadcast retransmission device 101 sends out an IP packet by filling it with null data so that it becomes seven TTS packets. More specifically, the broadcast retransmission device 101 does not wait until seven TLV-stored TTS packets are accumulated, and the TLV null is formed so that the total of the plurality of TTS packets including the terminated TTS packet becomes seven packets. One or a plurality of TTS packets in which the packets are stored are generated, and the seven TTS packets are stored in the IP packet and transmitted to the IP broadcast receiving device 202 via the IPTV transmission network 451 (step S19).

Next, the broadcast retransmission device 101 stores the data of the TLV packet next to the TLV null packet at the beginning of the TS packet, that is, stores the data at the beginning of the payload of the IP packet to be transmitted next (step S20). ..

When the remaining data length of the TS packet corresponding to the data of the TLV packet immediately before the TLV null packet whose data length is larger than the predetermined threshold value is zero, the TS conversion unit 22 specifically, for example, Assuming that the remaining data length of the payload of the TS packet in which the data B3 shown in FIG. 9 is stored is zero, the TS termination process is not performed because it is not necessary. In this case, all the data of the TLV null packet is deleted.

Further, in the broadcast retransmission device according to the embodiment of the present invention, the deletion unit 21 is configured to delete the TLV null packet regardless of the data length of the TLV null packet, but the present invention is not limited to this. .. The deletion unit 21 may be configured not to delete the TLV null packet when the data length of the TLV null packet is less than a predetermined threshold value.

Further, the broadcast retransmission device according to the embodiment of the present invention is said to have a configuration including a demodulation unit 11, but the present invention is not limited to this. The demodulation unit 11 may be provided outside the broadcast retransmission device 101, and the broadcast retransmission device 101 may include an acquisition unit that acquires the stream from the external demodulation unit 11.

Further, the broadcast retransmission device according to the embodiment of the present invention is said to have a configuration in which a time stamp is added to the TLV-stored TS packet, but the present invention is not limited to this. The broadcast retransmission device 101 may be configured to include the TLV-stored TS packet in the IP packet and transmit it without adding a time stamp.

Further, the broadcast retransmission device according to the embodiment of the present invention is configured to include a pair of a high-accuracy oscillator 15 of 27 MHz and a counter 16, but the present invention is not limited to this. The broadcast retransmission device 101 may be configured to include a pair of an oscillator that generates a clock pulse having a frequency other than 27 MHz, for example, a 2 ^ n Hz VCO described in Non-Patent Document 1, and a counter. Here, "a ^ b" means y to the xth power. However, while broadcast retransmission devices equipped with a set of a 2 ^ n-hertz VCO and a corresponding counter are not widely distributed, a set of a 27-megahertz oscillator and a counter 16 is used for the MPEG2-TS system. It is modularized and widely distributed. Therefore, a configuration including a pair of a 27 MHz high-accuracy oscillator 15 and a counter 16 is preferable.

Further, in the broadcast retransmission device according to the embodiment of the present invention, the high-accuracy oscillator 15 is configured to synchronize with the time information included in the radio waves transmitted from the GPS satellites, but the present invention is not limited to this. Absent. The high-accuracy oscillator 15 may be configured to synchronize the high-accuracy oscillator 15 to 27 MHz by feeding back the difference between Coordinated Universal Time and the transmission side count value to the high-accuracy oscillator 15 using an NTP packet. .. For this feedback, for example, control of an analog PLL (Phase Locked Loop) circuit and various digital clock synthesizers is used.

By the way, for example, in the case of performing an IP retransmission service for transmitting an advanced broadband satellite digital broadcast to a subscriber's home via an IPTV transmission network, a broadcast wave including an MMT packet is received and the received MMT packet is sent to the subscriber's home. A configuration is conceivable in which the data is retransmitted to the home device. An excellent technique for performing such retransmission is desired.

On the other hand, in the broadcast retransmission device according to the embodiment of the present invention, the TLV division unit 12 divides and stores a plurality of TS packets in which data of one or a plurality of TLV packets included in the broadcast wave is divided and stored. Perform the split processing to generate. The IP conversion unit 13 generates and transmits an IP packet containing a predetermined number of TS packets divided by the TLV division unit 12. In the division process, the TLV division unit 12 performs null data processing in which a part or all of the TLV null packet is not stored in the TS packet when the TLV packet is a TLV null packet having a predetermined length or more. When null data processing is performed, the IP conversion unit 13 adds one or a plurality of TS packets, which are null packets, to the TS packets divided by the TLV division unit 12 before the null data processing to obtain the above-mentioned predetermined number of IPs. Generate and send packets.

In this way, with the configuration that suppresses the storage of the TLV null packet data of the predetermined length or longer in the TS packet, for example, the transmission data is compared with the case where the TLV packet in the broadcast wave is transmitted as it is via a communication line such as the Internet. Since the amount can be reduced, the communication traffic on the communication line can be reduced.

Further, by adding the TS packet which is a null packet and transmitting the IP packet at an early stage without waiting for the next TLV packet, the delay of stream transmission due to the deletion of the TLV null packet and the transmission in the broadcast retransmission device 101 Fluctuations in the delay time can be suppressed. Thereby, for example, the amount of buffer in the receiving device can be reduced.

Therefore, in the broadcast retransmission device according to the embodiment of the present invention, excellent data processing can be performed in a configuration in which a broadcast wave including program information is received and retransmitted to another device.

Further, in the broadcast retransmission device according to the embodiment of the present invention, when the data of one TLV packet is divided and stored in a plurality of TS packets, it is permissible to insert null data between the divided data. Not done.

With such a configuration, the data of the TLV packet is divided and stored in a plurality of TS packets, and in the process in which the insertion of null data between the divided data is not allowed, the amount of transmitted data is reduced and the TLV null packet is reduced. It is possible to suppress the delay of stream transmission due to the deletion and the fluctuation of the transmission delay time in the broadcast retransmission device 101.

Further, in the broadcast retransmission device according to the embodiment of the present invention, in the division process, the TLV division unit 12 is the end side of the TS packet in which the data of the TLV packet before the TLV null packet having the predetermined length or more is stored. Stores some or all of TLV null packets in.

With such a configuration, in the process in which the data of the TLV packet is divided into a plurality of TS packets and stored, and null data is allowed to be stored at the end of the TS packet, the amount of transmission data is reduced and the TLV It is possible to suppress the delay of stream transmission due to the deletion of null packets and the fluctuation of the transmission delay time in the broadcast retransmission device 101.

Further, in the broadcast retransmission device according to the embodiment of the present invention, the demodulation unit 11 acquires a stream included in the broadcast wave. The TLV division unit 12 and the IP conversion unit 13 divide and generate a plurality of TS packets in which the data of one or a plurality of TLV packets included in the stream acquired by the demodulation unit 11 is divided and stored as a packet processing unit. Processing is performed to generate and transmit an IP packet containing a predetermined number of TS packets, which is an IP packet containing the generated TS packet. Further, the TLV division unit 12 and the IP conversion unit 13 perform null data processing for suppressing the storage of the TLV null packet data in the TS packet when the TLV packet is a TLV null packet having a predetermined length or more in the division processing. .. Then, the TLV division unit 12 and the IP conversion unit 13 add a null packet to the TS packet generated before the null data processing so that the fluctuation of the delay time in the broadcast retransmission device 101 of the stream data becomes equal to or less than a predetermined value. A certain one or a plurality of TS packets are added to generate and transmit an IP packet having the above-mentioned predetermined number.

In this way, with the configuration that suppresses the storage of the TLV null packet data of the predetermined length or longer in the TS packet, for example, the transmission data is compared with the case where the TLV packet in the broadcast wave is transmitted as it is via a communication line such as the Internet. Since the amount can be reduced, the communication traffic on the communication line can be reduced.

Further, by adding the TS packet which is a null packet and transmitting the IP packet at an early stage without waiting for the next TLV packet, the delay of stream transmission due to the deletion of the TLV null packet and the transmission in the broadcast retransmission device 101 Fluctuations in the delay time can be suppressed. Thereby, for example, the amount of buffer in the receiving device can be reduced.

Therefore, in the broadcast retransmission device according to the embodiment of the present invention, excellent data processing can be performed in a configuration in which a broadcast wave including program information is received and retransmitted to another device.

Further, in the broadcast retransmission method according to the embodiment of the present invention, first, the data of one or a plurality of TLV packets included in the stream included in the broadcast wave is divided and stored to generate a plurality of TS packets. Perform processing. Next, an IP packet containing a predetermined number of TS packets, which is an IP packet containing the generated TS packet, is generated and transmitted. Then, when performing the division processing, if the TLV packet is a TLV null packet having a predetermined length or more, null data processing is performed in which a part or all of the TLV null packet is not stored in the TS packet. When null data processing is performed when transmitting an IP packet, one or more TS packets, which are null packets, are added to the TS packets generated by the division processing prior to the null data processing to obtain the above-mentioned predetermined number of IP packets. Generate and send.

In this way, by the method of suppressing the storage of the data of the TLV null packet having a predetermined length or more in the TS packet, the transmission data is compared with the case where the TLV packet in the broadcast wave is transmitted as it is via a communication line such as the Internet. Since the amount can be reduced, the communication traffic on the communication line can be reduced.

Further, by adding a TS packet which is a null packet and transmitting the IP packet at an early stage without waiting for the next TLV packet, the delay of stream transmission due to the deletion of the TLV null packet and the transmission in the broadcast retransmission device 101 Fluctuations in the delay time can be suppressed. Thereby, for example, the amount of buffer in the receiving device can be reduced.

Therefore, in the broadcast retransmission method according to the embodiment of the present invention, excellent data processing can be performed in a configuration in which a broadcast wave including program information is received and retransmitted to another device.

Further, in the broadcast retransmission method according to the embodiment of the present invention, first, a stream included in the broadcast wave is acquired. Next, the data of one or a plurality of TLV packets included in the acquired stream is divided and subjected to a division process to generate a plurality of TS packets stored, and a predetermined number of IP packets storing the generated TS packets. An IP packet containing the TS packet of is generated and transmitted. When transmitting an IP packet, if the TLV packet is a TLV null packet having a predetermined length or longer in the division process, a null data process for suppressing the storage of the TLV null packet data in the TS packet is performed, and the stream data is transmitted. IPs obtained by adding one or more TS packets, which are null packets, to the TS packets generated before the null data processing so that the fluctuation of the delay time in the broadcast retransmission device 101 of the above is equal to or less than the predetermined value. Generate a packet.

In this way, by the method of suppressing the storage of the data of the TLV null packet having a predetermined length or more in the TS packet, the transmission data is compared with the case where the TLV packet in the broadcast wave is transmitted as it is via a communication line such as the Internet. Since the amount can be reduced, the communication traffic on the communication line can be reduced.

Further, by adding a TS packet which is a null packet and transmitting the IP packet at an early stage without waiting for the next TLV packet, the delay of stream transmission due to the deletion of the TLV null packet and the transmission in the broadcast retransmission device 101 Fluctuations in the delay time can be suppressed. Thereby, for example, the amount of buffer in the receiving device can be reduced.

Therefore, in the broadcast retransmission method according to the embodiment of the present invention, excellent data processing can be performed in a configuration in which a broadcast wave including program information is received and retransmitted to another device.

It should be considered that the above embodiments are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

The above description includes the features described below.
[Appendix 1]
A broadcast retransmission device used for advanced broadband satellite digital broadcasting.
A TLV division unit that performs division processing to generate a plurality of TS (Transport Stream) packets in which data of one or a plurality of TLV (Type Length Value) packets included in a broadcast wave is divided and stored.
It includes an IP conversion unit that generates and transmits an IP packet that stores a predetermined number of the TS packets divided by the TLV division unit.
In the division process, when the TLV packet is a TLV null packet having a predetermined length or longer, the TLV division unit performs null data processing in which a part or all of the TLV null packet is not stored in the TS packet.
When the null data processing is performed, the IP conversion unit adds one or a plurality of TS packets, which are null packets, to the TS packets divided by the TLV division unit before the null data processing, and the predetermined number. Generate and transmit the IP packet
Null data is allowed to be stored at the end of the TS packet,
In the division process, when the TLV packet is a TLV null packet having a length less than the predetermined length, the TLV division unit deletes the TLV null packet.
In the division process, the TLV division unit is next to the TS packet when the remaining area of the TS packet in which the data of the TLV null packet having a predetermined length or more is stored is equal to or less than the header length of the TLV null packet. A TS packet containing null data of the TLV null packet is added as a TS packet, and the TS packet is added.
The IP conversion unit is a broadcast retransmission device that uses the data of the TLV packet after the TLV null packet having a predetermined length or more as the data of the TS packet to be stored first in the next IP packet.

[Appendix 2]
A broadcast retransmission device used for advanced broadband satellite digital broadcasting.
The acquisition unit that acquires the stream included in the broadcast wave,
The data of one or a plurality of TLV packets included in the stream acquired by the acquisition unit is divided and a division process for generating a plurality of stored TS packets is performed, and the generated IP packet is an IP packet containing the TS packet. It is equipped with a packet processing unit that generates and transmits an IP packet that stores a predetermined number of the TS packets.
In the division process, when the TLV packet is a TLV null packet having a predetermined length or longer, the packet processing unit performs null data processing for suppressing storage of the TLV null packet data in the TS packet.
The packet processing unit is one or a plurality of null packets in the TS packet generated prior to the null data processing so that the fluctuation of the delay time in the broadcast retransmission device of the stream data is equal to or less than a predetermined value. The TS packets of the above are added to generate and transmit the IP packets having the predetermined number.
Null data is allowed to be stored at the end of the TS packet,
In the division process, when the TLV packet is a TLV null packet having a length less than the predetermined length, the packet processing unit deletes the TLV null packet.
In the division process, when the remaining area of the TS packet in which the data of the TLV null packet having a predetermined length or more is stored is equal to or less than the header length of the TLV null packet, the packet processing unit is next to the TS packet. A TS packet containing null data of the TLV null packet is added as a TS packet, and the TS packet is added.
The packet processing unit is a broadcast retransmission device that uses the data of the TLV packet after the TLV null packet having a predetermined length or more as the data of the TS packet to be stored first in the next IP packet.

11 Demodulation section (acquisition section)
12 TLV division part 13 IP conversion part 15 High-accuracy oscillator 16 Counter 17 NTP packet acquisition part 18 Conversion part 21 Delete part 22 TS conversion part 23 TTS conversion part 24 Blocking part 25 IP packetization part 26 IP transmission part 101 Broadcast retransmission Device 202 IP broadcast receiver 301 Broadcast retransmission system

Claims (6)

A broadcast retransmission device used for advanced broadband satellite digital broadcasting.
A TLV division unit that performs division processing to generate a plurality of TS (Transport Stream) packets in which data of one or a plurality of TLV (Type Length Value) packets included in a broadcast wave is divided and stored.
It includes an IP conversion unit that generates and transmits an IP packet that stores a predetermined number of the TS packets divided by the TLV division unit.
In the division process, when the TLV packet is a TLV null packet having a predetermined length or longer, the TLV division unit performs null data processing in which a part or all of the TLV null packet is not stored in the TS packet.
When the null data processing is performed, the IP conversion unit adds one or a plurality of TS packets, which are null packets, to the TS packets divided by the TLV division unit before the null data processing, and the predetermined number. A broadcast retransmission device that generates and transmits the above-mentioned IP packet. The broadcast retransmission device according to claim 1, wherein when the data of one TLV packet is divided and stored in a plurality of TS packets, insertion of null data between the divided data is not allowed. In the division process, the TLV division unit stores a part or all of the TLV null packet at the end of the TS packet in which the data of the TLV packet before the TLV null packet having a predetermined length or longer is stored. The broadcast retransmission device according to claim 1 or 2. A broadcast retransmission device used for advanced broadband satellite digital broadcasting.
The acquisition unit that acquires the stream included in the broadcast wave,
The data of one or a plurality of TLV packets included in the stream acquired by the acquisition unit is divided and a division process for generating a plurality of stored TS packets is performed, and the generated IP packet is an IP packet containing the TS packet. It is equipped with a packet processing unit that generates and transmits an IP packet that stores a predetermined number of the TS packets.
In the division process, when the TLV packet is a TLV null packet having a predetermined length or longer, the packet processing unit performs null data processing for suppressing storage of the TLV null packet data in the TS packet.
The packet processing unit is one or a plurality of null packets in the TS packet generated prior to the null data processing so that the fluctuation of the delay time in the broadcast retransmission device of the stream data is equal to or less than a predetermined value. A broadcast retransmission device that generates and transmits the IP packets having the predetermined number by adding the TS packets of. A broadcast retransmission method in a broadcast retransmission device used for advanced broadband satellite digital broadcasting.
A step of performing a division process to generate a plurality of TS packets in which the data of one or more TLV packets included in the stream included in the broadcast wave is divided and stored, and
It includes a step of generating and transmitting an IP packet containing the generated TS packet and storing a predetermined number of the TS packets.
In the step of performing the division process, when the TLV packet is a TLV null packet having a predetermined length or more, null data processing is performed so that a part or all of the TLV null packet is not stored in the TS packet.
In the step of transmitting the IP packet, when the null data processing is performed, one or a plurality of TS packets which are null packets are added to the TS packet generated by the division processing prior to the null data processing. A broadcast retransmission method in which a predetermined number of IP packets are generated and transmitted. A broadcast retransmission method in a broadcast retransmission device used for advanced broadband satellite digital broadcasting.
Steps to get the stream contained in the broadcast wave,
A predetermined number of IP packets containing the generated TS packets after performing a division process to generate a plurality of TS packets in which the data of one or a plurality of TLV packets included in the acquired stream is divided and stored. Including the step of generating and transmitting an IP packet containing the TS packet.
In the step of transmitting the IP packet, in the division process, when the TLV packet is a TLV null packet having a predetermined length or more, a null data process for suppressing the storage of the TLV null packet data in the TS packet is performed. , One or a plurality of TS packets which are null packets are added to the TS packet generated before the null data processing so that the fluctuation of the delay time in the broadcast retransmission device of the data of the stream becomes a predetermined value or less. A broadcast retransmission method for generating the IP packets having the predetermined number.

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