JP2010219996A - Transmitting-side network and broadcast system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a broadcast system for transmitting information without omission to user terminal equipment without trouble in transmission using Gigabit Ethernet at a receiving side. <P>SOLUTION: The present invention relates to a transmitting-side network for containerizing content data from a content distribution device that distributes contents. The transmitting-side network comprises: a containerization section for containerizing content data distributed from the content distribution device in such a way that the content data becomes less than or equal to prescribed bytes; a multiplexer for multiplexing the container containerized by the containerization section in a specific format for conversion into a signal form on a transmission line; and a modulator for modulating the signal multiplexed by the multiplexer for outputting onto the transmission line. A byte size of the container is limited, thereby preventing trouble in transmission using Gigabit Ethernet. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an advanced ISDB-S (Integrated Services Digital Broadcasting-Satelite), that is, a TLV (Type Length Value) transmission technology that is considered to be operated in the standard of advanced satellite broadcasting. By limiting the number of TLV containers or the number of bytes, which is a unit for transmitting content, it is possible to prevent transmission failure when Gigabit Ethernet is output.

  In a conventional broadcasting system, a transmission method using a fixed-length packet MPEG2-TS as a signal format suitable for a real-time broadcasting system is generally used. FIG. 7 shows a broadcasting system having a configuration using MPEG2-TS, which is a conventional broadcasting system. When content is transmitted from the content distributor to the end user, the content is transmitted in the order from the content distribution device 600 to the transmission side network 700, the transmission path, the reception side network 800, and the display device 900.

  The content distribution apparatus 600 encodes video, audio, and control signals thereof into an MPEG2-TS packet format and outputs the encoded signal to the transmission side network 700.

  The transmission-side network 700 includes a multiplexing unit 710 and a modulation unit 720. The multiplexing unit 710 converts the MPEG2-TS packet format signal input from the content distribution apparatus 600 into a format that matches the signal format of the transmission path. The signal is multiplexed, and the modulation unit 720 modulates the signal multiplexed by the multiplexing unit 710 to a transmission path and outputs the modulated signal.

  The receiving-side network 800 includes a demodulator 810 and a decoder 820. The demodulator 810 demodulates and demultiplexes the modulated signal input from the transmission path, and the decoder 820 decodes the MPEG2-TS format signal into content data. And output to the display device 900.

  The display device 900 receives content data from the receiving network 800 and displays video and audio of the content data.

On the other hand, there is a broadcasting system that combines an existing transmission path such as a satellite and a communication network such as Gigabit Ethernet for realizing a storage type broadcasting service that stores content data in a receiver and restores and displays a stream after reception. The TLV transmission technology that has been considered and studied in the advanced ISDB-S is expected. The TLV transmission technique can store arbitrary variable length data in the Value field by indicating the type of data by the type field and the size of the data by the length field. In this TLV transmission technique, four types of data are assigned as packet types to enable transmission of IP (Internet Protocol) packets. (Non-Patent Document 1)
Council for Information and Communication Consultation No. 2023 “Technical Conditions for Advanced Satellite Digital Broadcasting” of “Technical Conditions for Broadcasting Systems” Report of Ministry of Internal Affairs and Communications July 29, 2008, page 29

  However, in the TLV transmission technology being studied in the operation of advanced ISDB-S, it is considered that the size of the TLV container is 4 bytes or more. In the conventional method, the TLV container including the content data is not used. When the packet size is shorter than 512 bytes limited by Gigabit Ethernet, if short packets are continuously input, the memory buffer of the block for MAC frame conversion will overflow, resulting in a GbE output failure and data There was a problem that omissions occurred.

  The present invention aims to solve the above problems, and in order to avoid overflow of the buffer memory when GbE is output on the receiving side, there is a problem in transmission using the Gigabit Ethernet on the receiving side. It is to provide a broadcasting system compatible with TLV transmission that transmits information to a user terminal device without omission.

  In order to solve the above-described conventional problems, a transmission-side network according to the present invention is a transmission-side network that containerizes content data from a content distribution device that distributes content, and that transmits content data distributed from the content distribution device. A containerization unit that containers the container so that it is equal to or less than a predetermined number of bytes, a multiplexing unit that multiplexes the container containerized by the containerization unit into a specific format for converting the containerized container into a signal format on the transmission path, and a multiplexing unit And a modulation unit that modulates the multiplexed signal to output to the transmission line, and limits the byte size of the container.

  In the TLV transmission system that is being studied in the operation of the advanced ISDB-S, by limiting the number of bytes of the container to be sent on the transmission side, there is no problem in transmission using the Gigabit Ethernet on the reception side. Information can be transmitted to the user terminal device without loss of information.

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
First, an outline of a TLV-compatible broadcasting system according to Embodiment 3 of the present invention will be described. FIG. 1 shows a configuration diagram of a TLV-compatible broadcasting system according to Embodiment 3 of the present invention. When transmitting content from a content distributor to an end user, the TLV-compatible broadcasting system transmits the content from the content distribution apparatus 100 to the transmission side network 200, the transmission path, the reception side network 300, and the user terminal apparatus 400 in this order. The broadcasting system of the present invention is mainly used for satellite broadcasting. For this reason, the transmission path is assumed to be a space where radio waves transmitted from a satellite pass. Although only one user terminal device 400 is shown in FIG. 1, a plurality of user terminal devices 400 are connected to the receiving-side network 300.

  The content distribution apparatus 100 outputs data such as video, audio, and character information to the transmission side network 200 as content. Note that the content distribution apparatus 100 can include MAC address information used in the receiving network 300, the user terminal apparatus 400, and the like.

  The transmission side network 200 includes a TLV containerization unit 210 that converts content data input from the content distribution apparatus 100 into a TLV container and a TLV container that is containerized by the TLV containerization unit 210 in order to output data to a transmission path. Is composed of a multiplexing unit 220 that multiplexes the signal into a specific format to convert the signal into a signal format on the transmission line, and a modulation unit 230 that modulates the signal multiplexed by the multiplexing unit 220 to be output on the transmission line. ing. In particular, the modulation unit 230, in addition to the function of modulating multiplexed data, information indicating a data range in a fixed-length slot period, which is the minimum unit of a transmission path, and the type of data multiplexed in the slot Has the function of modulating the information indicating the data as TMCC data.

  Here, the TLV container is composed of three types of data, Type data, Length data, and Value data. The Value data is data such as content transmitted from the content distribution apparatus 100, and the Length data is the size information of the TLV container. The type data is data including information on the type of the TLV container.

  The reception side network 300 receives data from the transmission side network 200 and outputs it to the user terminal device 400 in the Gigabit Ethernet format. Therefore, the receiving-side network 300 demodulates the modulated wave input from the transmission path, demultiplexes the data from the signal format on the transmission path, and the value data of the TLV container from the data demultiplexed by the demodulation section 310. TLV decontainer 320 for extracting data, MAC frame converter 330 for converting the data extracted by TLV decontainer 320 into Gigabit Ethernet format data, and the data converted by MAC frame converter 330 for external It is comprised by GbE_I / F340 output to GbE_I / F of the user terminal device 400. In particular, the demodulation unit 310 first demodulates TMCC data from the modulated modulation signal, and demodulates by recognizing the data range included in the slot from the TMCC data when demodulating the multiplexed data. ing. The demodulator 310 also recognizes the type of data multiplexed from the TMCC data and demultiplexes the multiplexed data when demultiplexing the multiplexed data.

  Here, the MAC frame conversion unit 330 is the Value data of the TLV container extracted by the TLV decontainer unit 320, that is, the MAC address information used in the content transmitted from the content distribution device 100, the user terminal device 400, and the like. Is converted to a MAC frame. At this time, it is possible to add only a specific MAC address or add a plurality of MAC addresses to the header of the MAC frame. Further, as the MAC address added to the header, the MAC address held by the MAC frame conversion unit 330 can be used, or the MAC address transmitted from the content distribution apparatus 100 can be used.

  The user terminal device 400 receives the Gigabit Ethernet format data input from the receiving-side network 300 and displays the content data in order to display the content data, and the content terminal 410 outputs the content data. The display unit 420 displays video data.

  The information terminal unit 410 can receive content data when a MAC address is added to the header as a destination in the MAC frame conversion unit 330. In addition, when a plurality of destination MAC addresses are added by the MAC frame conversion unit 330, data can be received by each of the plurality of information terminal units 410 corresponding to the destination. Further, the information terminal unit 410 does not need to output to the monitor in real time, and the content data can be stored by connecting or incorporating a recording unit such as a hard disk.

  Next, details of the receiving-side network of the TLV-compatible broadcasting system according to Embodiment 3 of the present invention will be described. The receiving-side network 300 has a function of converting TLV container data received from the transmitting-side network 200 via a transmission path into a MAC frame that is output by Gigabit Ethernet to the user terminal device 400 that is an external device. First, the MAC frame of the TLV container for outputting the TLV container with Gigabit Ethernet will be described. FIG. 2 is a configuration diagram of a MAC frame according to Embodiment 3 of the present invention.

  The MAC frame after the data format conversion of the TLV container is based on IEEE Standard 802.3, which is a Gigabit Ethernet standard. As shown in FIG. 2, since the minimum size from the destination MAC address to Carrier Extend is 512 bytes, the minimum size can be adjusted by adjusting the data size of Carrier Extend when the size of the TLV container is 466 bytes or less. 512 bytes. The MAC frame conversion of the TLV container has a minimum size of 532 bytes by further adding a preamble and an IFG.

  Further, description will be given of the MAC frame conversion unit 330 converting the TLV container into the MAC frame. FIG. 3 is a schematic diagram of the MAC frame conversion unit 330 according to Embodiment 3 of the present invention. The MAC frame conversion unit 330 temporarily stores the input TLV container in the buffer memory 331, adds the header header to the TLV container by the header addition unit 332, and then adds the IPv4 header to the IPv4 packet format. Furthermore, by adding the destination MAC address, the source MAC address, the type, and the FCS, a MAC frame is obtained. When the size of the MAC frame is less than 512 bytes, the carrier is set to be 512 bytes together with the size of the MAC frame. Extend data is added to the end. Then, a packet having a size including a preamble indicating the head and an IFG period indicating the interval between the packets is output to the GbE_I / F 340.

  The input speed to the MAC frame converter 330 is the data processing operating frequency of the receiving network 300, and the byte clock frequency is 18.5 MHz. On the other hand, the output speed of the MAC frame conversion unit 330 is determined by the GbE_I / F operation mode, and is 125 MHz in the GMII operation mode. Since the output speed is 6.7 times faster than the input speed, if the TLV container size, which is the packet size, is 79 bytes (1 / 6.7 of 532 bytes) or more, there is no theoretical buffer memory overflow. . However, when the TLV container size is less than 78 bytes, the header overhead increases, and as a result, the output throughput decreases.

  As an example of a state in which the output throughput of the MAC frame conversion unit 330 decreases, an internal process of the MAC frame conversion unit 330 of the TLV container shows an output process after adding a header to the input. FIG. 4 is a schematic diagram showing the internal operation of the MAC frame conversion unit 330 according to the present invention.

  The MAC frame conversion unit 330 uses a fixed-length slot period, which is the minimum unit of the transmission path, as a processing range, and N containers of the minimum byte size (4 bytes) with the largest header ratio in the MAC frame and 5049 bytes. One container having a remainder byte size size obtained by subtracting the total number of bytes of the N smallest containers is input. Then, the MAC frame conversion unit 330 outputs N MAC frames having the minimum MAC frame size (532 bytes) shown in FIG. 2, and the output throughput decreases when the output period becomes longer than the input period. To do. If the output period is longer than the input period, the container data continues to be stored in the buffer memory, and the container data will eventually overflow from the buffer memory.

  Next, details of the transmission-side network 200 will be described. In the sending network 200, in order to avoid overflow of container data that occurs in the receiving network 300, the TLV containerization unit 210 analyzes the size of the TLV container and adjusts the container size by combining two containers into one. It has a function to do. As means for adjusting the size of the container, FIG. 5 is a schematic diagram showing the internal operation of the TLV containerization unit 210 according to Embodiment 3 of the present invention.

  As illustrated in FIG. 5, the TLV containerization unit 210 includes a buffer memory 211, a data analysis unit 212, a header creation unit 213, a TLV container generation unit 214, a buffer memory 215, and a container analysis unit 216. The header creation unit 217, the TLV container regeneration unit 218, and the header information data conversion unit 219 are configured.

  The buffer memory 211 stores content data input from the content distribution device 100.

  The data analysis unit 212 analyzes the size and type of data input to the TLV containerization unit 210 and outputs the information to the header creation unit 213.

The header creation unit 213 creates Length data and Type data from the size and type of the data, and outputs them to the TLV container generation unit 214. The TLV container generation unit 214 reads the content data stored in the buffer memory 211 as Value data, By combining the Length data and Type data input from the header creation unit 213 with this Value data, a TLV container is generated.

  The buffer memory 215 stores the TLV container output from the TLV container generation unit 214.

  The container analysis unit 216 analyzes the length data, type data, and value data of the TLV container output from the TLV container generation unit 214, and outputs the analysis result to the duplicate header creation unit 217.

  The duplicate header 217 indicates that the analysis result obtained from the container analysis unit 216, that is, if the length data of the TLV container stored in the buffer memory 215 is less than a predetermined size, the next buffer memory input from the container analysis unit 216 Together with the analysis result of the TLV container input to 215, Length data when the value data of the two TLV containers are combined and Type data for recognizing it are newly created. If the size of the value data of the two TLV containers to be combined is different, the difference data of the size is also output to the TLV container regeneration unit 218. When the analysis result obtained from the container analysis unit 216, that is, when the length data of the TLV container stored in the buffer memory 215 is equal to or larger than the predetermined size, the container analysis unit 216 obtains the length data and the type data obtained from the container analysis unit 216. Is output to the TLV container regeneration unit 218 as it is.

  In addition, if the size of the TLV container is less than the predetermined size even when the two TLV containers are combined, the container analysis unit 216 combines the plurality of TLV containers up to the predetermined size, and adds the length data and the data. Type data for recognition is newly created.

  When the TLV container regeneration unit 218 calls the TLV container from the buffer memory 215 and is different from the type data input from the duplicate header creation unit 215, that is, the type data newly created by the duplicate header creation unit 215. If it is recognized that it is to be combined with the next TLV container, the next TLV container stored in the buffer memory 215 is also called, each of the Value data is extracted and combined, and the new Type data input from the duplicate header creation unit 215 The length data is combined and output to the multiplexing unit 220 as a new TLV container.

  By the way, when combining the Value data, irrelevant data (null data) for filling the difference is inserted from the difference data input from the duplicate header creation unit 217 at the end of the Value data having the smaller Value data size. To do. Therefore, the Length data is a value obtained by adding the size of the inserted null data.

  The header information data conversion unit 219 uses the size of the null data or the type generated by the duplicate header generation unit 217 so that the new TLV container combined by the TLV container regeneration unit 218 can be processed by the reception side network 300. Data indicating the meaning of the data is created and output to the TLV container regenerator 218 so as to be added to the new TLV container as data to be added to the TMCC data created by the modulator 230.

  For example, the case where the TLV container regeneration unit 218 inputs a TLV container having a size of 52 bytes and 96 bytes from the TLV container generation unit 214 via the buffer 215 will be described. The container analysis unit 216 analyzes the size and type of each TLV container stored in the buffer 215 from Length data and Type data, respectively. The duplicate header creation unit 217 determines whether the size of the TLV container analyzed by the container analysis unit 2106 is smaller than the predetermined size (76 bytes) provided. If the size is larger, the length data of the TLV container is output as it is, and is smaller. In this case, the length data obtained by adding the size of the value data of this TLV container and the next TLV container is output. When a 52-byte TLV container is input, it is smaller than the limit size. Therefore, the size of each TLV container is 52 bytes and 96 bytes, and 48 bytes and 92 are obtained by subtracting 4 bytes that is the total number of bytes of Type data and Length data. The bytes are added, and 140 (= 48 + 92) bytes of Length data are output to the TLV container regeneration unit 219.

  Then, the TLV container regeneration unit 218 calls the TLV container stored in the buffer 215, compares the size with the Length data obtained from the duplicate header creation unit 217, and 52 bytes and 140 bytes do not match. The 96-byte TLV container stored in the file is called from the buffer 215, each value data is extracted, and 44 bytes of null data, which is the difference between 96 bytes and 52 bytes, is combined with the end of the 48-byte value data, and 92 bytes. And 184 bytes of total value data are created. In order to convert the 184-byte value data into a TLV container, type data indicating that the null data and the two value data are combined is created, and the length data created by the duplicate header creation unit 217 is used. The Type data created by the duplicate header creation unit 217 is also sent to the header information data conversion unit 219 and converted into data as Type information stored in the TMCC data.

  Details of the specific limit size (76 bytes) will be described below. FIG. 6 is a diagram showing an expression for obtaining a specific limit size of the container according to the present invention. As the value of the specific limit size, a value that does not necessarily cause an overflow in the receiving network 300 can be considered. In the advanced ISDB-S standard, the modulation method is 32APSK, the number of data bytes in the slot is the largest when the coding rate is 9/10, and the number of data bytes in the slot is 5049 bytes. The output clock is a byte clock derived from a symbol rate of 32.5941 MHz. As the minimum container size that does not cause overflow, the number of containers of the minimum size that can be processed per slot unit is considered, and the calculated value is the minimum GbE (Gigabit Ethernet output size) × N ≧ slot period. When calculated as shown in FIG. 6, N ≦ 67. The minimum container size is 76 bytes with an integer value larger than the value obtained by dividing the number of data bytes in the slot 5049 and the minimum size container number 67 that can be processed.

  According to such a configuration, by setting the number of containers in the slot to be equal to or less than the limit number in the multiplexing unit of the transmission side network, the MAC frame conversion in the MAC frame conversion unit on the reception side does not cause an overflow and the Gigabit Ethernet Information can be transmitted to the user terminal device without omission without causing trouble in transmission using the network.

  In this embodiment, a Gigabit Ethernet is assumed as the GbE_I / F 340, but the operation is possible even with an Ethernet of less than 1000 Mbps. In this case, it is assumed that the MAC frame conversion of the MAC frame conversion unit 330 operates at a data transfer rate that conforms to the Ethernet standard of less than 1000 Mbps.

  In this embodiment, the TLV decontainer 320 extracts only the value data. However, after extracting the value data, the type data, and the TLV container including all of the length data, the data is subjected to MAC frame conversion. , GbE_I / F340 may be output. In this case, the information terminal unit 410 extracts the value data of the TLV container and outputs the content data to the display unit 420.

  In the present embodiment, the information data of the TLV container in which two Value data are combined from the TMCC data demodulated by the demodulation unit 310 is converted into a MAC frame by the MAC frame conversion unit 330 and output to the GbE_I / F 340. It is also possible. In this case, the combined value data is divided from the information data of the TLV containers combined by the information terminal unit 410, and the content data is restored and output to the display unit 420.

  There is an advantage of avoiding problems in the market in advance because there is no need to restrict content distribution on the sending side and complicated rate adjustment due to function restrictions on the receiving side. Therefore, there is a possibility that it will be established as an advanced ISDB-S transmission line standard.

Configuration diagram of a broadcasting system compatible with TLV transmission according to Embodiment 1 of the present invention MAC frame configuration diagram according to Embodiment 1 of the present invention Schematic diagram of MAC frame conversion unit 330 according to Embodiment 1 of the present invention Overview of internal operation of MAC frame conversion unit 330 of the present invention Outline diagram of internal operation of TLV containerization section 210 according to Embodiment 3 of the present invention The figure which shows the type | formula which calculates | requires the limit size of the container of this invention Configuration diagram of conventional broadcasting system

DESCRIPTION OF SYMBOLS 100 Content delivery apparatus 200 Transmission side network 210 TLV containerization part 211 Buffer memory 212 Data analysis part 213 Header creation part 214 TLV container generation part 215 Buffer memory 216 Container analysis part 217 Duplicate header creation part 218 TLV container regeneration part 219 Header information Data conversion unit 220 Multiplexing unit 300 Receiving side network 310 Demodulating unit 320 TLV decontainer unit 330 MAC frame converting unit 331 Buffer memory 332 Header adding unit 340 GbE_I / F
400 User terminal device 410 Information terminal unit 420 Display unit

Claims (3)

A transmission-side network for containerizing content data from a content distribution device that distributes content,
A containerization unit for containerizing content data distributed from the content distribution device so as to be a predetermined number of bytes or less, and a specific container for converting the containerized container by the containerization unit into a signal format on a transmission path A transmission-side network comprising: a multiplexing unit that multiplexes into a format; and a modulation unit that modulates a signal multiplexed by the multiplexing unit to output the signal to a transmission path. The containerization unit
A data analysis unit that analyzes the size and type of data output by the content distribution device;
A header creation unit that creates a header from the size and type of data calculated by the data analysis unit;
A TLV container generation unit that generates a TLV container by combining the header and data generated by the header generation unit;
A container analysis unit for analyzing the type and size of the TLV container from the TLV container generated by the TLV container generation unit;
If the size of the TLV container analyzed by the container analysis unit is smaller than a predetermined size, a duplicate header creation unit that outputs the size when combined with the data part of the TLV container of the next slot generated by the TLV container generation unit;
The size output by the duplicate header creation unit and the size of the TLV container output by the TLV container generation unit are compared. If they do not match, the data portion of the TLV container that did not match and the TLV container generation unit The TLV container regeneration part which couple | bonds the data part of the output TLV container, attaches the header which the said duplication header preparation part output, and produces a new TLV container, It is characterized by the above-mentioned. Sender network. A content distribution device that distributes content, a transmission-side network that containers content data distributed by the content distribution device, a reception-side network that converts containers containerized by the transmission-side network into MAC frames, and the reception side A broadcasting system comprising user terminal devices that receive MAC frames converted by a network,
The transmission side network converts the content data distributed from the content distribution apparatus into a signal format on a transmission path, and a containerization unit that containerizes the content data so as to be a predetermined number of bytes or less. A broadcasting system comprising: a multiplexing unit that multiplexes a signal in a specific format for conversion; and a modulation unit that modulates a signal multiplexed by the multiplexing unit to output the signal to a transmission path.

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