JP4979362B2 - Re-transmission device, re-transmission method, and re-transmission program - Google Patents

Description

  The present invention relates to a retransmission apparatus, a retransmission method, and a retransmission program, and more particularly to a retransmission apparatus, a retransmission method, and a retransmission program for easily reducing the data acquisition time on the receiving side.

  2. Description of the Related Art Conventionally, in digital broadcasting and the like, there are information services such as character data and image data called data broadcasting in addition to video and audio service video. Digital broadcast video, audio, data, and other control information are transmitted in units of TS (Transport Stream) packets.

  Further, TS packets that transmit information such as video, audio, and data can be distinguished by PID (Packet Identification) described in the packet header. Furthermore, control information such as a table indicating which information is transmitted by a TS packet having which PID is also transmitted, so that the type of service desired and detailed information can be grasped on the receiving side. ing.

  On the other hand, in cable television or the like, a service is provided in which a digital broadcast transmitted from a receiving side is once received by a retransmission facility called a head end and retransmitted from the head end to a target home. In addition, the transmission line from the head end to the home may be a wired transmission line such as a coaxial cable or an optical fiber, and the transmission line from the broadcast station to the head end may be used. In some cases, the bandwidth is wider than the transmission line up to.

  When performing a retransmission service using such a transmission path, a null packet may be inserted into the TS to convert the TS rate to match the bandwidth of the transmission path. For example, in the cable television trans-modulation system, a null packet is inserted into a TS to be retransmitted in accordance with a transmission band (31.644 Mbps) of one carrier and a frame configuration for cable television (TSMF: Transport Stream Multiplexing Frame). Is transmitting.

  Further, as a data broadcasting transmission method, there is a method of repeatedly transmitting contents called a carousel method in addition to an independent PES (Packetized Elementary Stream) method and an event message method (see Non-Patent Document 1, for example).

  In the carousel method, data constituting the content of data broadcasting is transmitted in units called modules divided by blocks called DDB (Download Data Block). In the carousel method, management information (directory information) and carousel identification information about each module are also transmitted. This management information is called DII (Download Info Indication). The DII and DDB described above are both stored in TS packets as DSM-CC (Digital Storage Media Command and Control) sections and repeatedly transmitted.

  Here, in the data broadcasting service transmitted by the carousel method, a service for automatically displaying and updating the screen as the program progresses, a service for acquiring and displaying the content according to the user's request, etc. There is. For example, in a data broadcasting service in which screen display and update are performed according to a user request, the content is displayed on the screen after the request signal arrives at the receiver body by an operation such as the user pressing a request button on the remote controller. It may take several seconds before the update is performed. This is partly because the transmission band of data broadcasting is limited, and therefore the period of carousel data (the time until transmission of each module constituting the content) is long.

As described above, when there is a large time lag between the content request by the user and the screen display / update, there is a difference between the user's operation and the display screen, which is stressful for the user. Here, in order to cope with the above-described problems, there are a method for shortening a time from a data broadcast content request to an actual screen display and update, and a method for a retransmission facility (for example, Patent Document 1). ~ 4).
ARIB STD-B24 Chapter 3 Chapter 4 JP 2005-94051 A Japanese Patent Laid-Open No. 2005-39964 JP 2004-23379 A JP 2004-260758 A

  Here, the techniques disclosed in Patent Documents 1 to 3 described above mainly show methods for shortening the time from data broadcast content request to actual screen display and update. This method is applied when TS is multiplexed in a station, and is not a technique that can be easily performed in a retransmission facility.

  In addition, the technique shown in Patent Document 4 shows a technique for retransmission equipment, but is applied only when content is transmitted using a plurality of carrier waves. For example, it cannot be used when it is limited to one carrier per TS, or when the retransmission service is performed by a baseband signal that does not use a carrier.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a retransmission apparatus, a retransmission method, and a retransmission program for easily reducing the data acquisition time on the reception side. To do.

  In order to solve the above problems, the present invention employs means for solving the problems having the following characteristics.

The invention described in claim 1 is a retransmission apparatus that receives a TS transmitted from a transmission side and retransmits the data by a carousel method , and includes data including a response to a request from a user from a packet sequence included in the TS. Target packet identification / separation means for identifying and separating the target packet in which the packet is stored, redundant packet position grasping means for grasping the packet position of redundant data with respect to the packet sequence, and target packet identification / separation means For the separated target packet, the carousel transmission unit and transmission cycle are grasped, and further, the carousel cycle / update detection means for detecting whether the received data is updated, and the carousel transmission obtained by the carousel cycle / update detection means. The packet sequence is stored in correspondence with the unit and transmission cycle, and the data When there new comprises a carousel data storage means for replacing in the updated the packets accumulated packets, among the stored the packet sequence by the carousel data storage means, the redundancy obtained by the redundant packet locating means The target packet is repeatedly stored in a packet position in a carousel transmission unit, and re-multiplexing means for re-multiplexing as a TS, and at the time of re-multiplexing of packets by the re-multiplexing means, a preset limit is set. And carousel data monitoring means for monitoring to store carousel data correspondingly .

According to the first aspect of the present invention, carousel data can be transmitted efficiently. Therefore, the data acquisition time on the receiving side can be easily reduced. In addition, it is possible to easily store the target packet for shortening the data acquisition time on the receiving side. In addition, carousel transmission corresponding to various restrictions already standardized can be realized.

  In the invention described in claim 2, the redundant packet position grasping means performs rate conversion by inserting a redundant packet into the TS based on a bandwidth of a transmission path at the time of retransmission or a preset transmission speed. When performing, the position of the redundant packet inserted by the rate conversion and the transmission rate of the redundant data are grasped.

  According to the second aspect of the invention, the target packet can be efficiently stored in the redundant packet by grasping the position of the redundant packet inserted by rate conversion and the transmission rate of the redundant data.

  According to a third aspect of the present invention, the redundant packet position grasping means grasps the position of the redundant data packet and the transmission rate of the redundant data from the packet sequence included in the TS.

  According to the third aspect of the present invention, the target packet can be efficiently stored in the redundant packet by grasping the position of the redundant data packet included in the packet string and the transmission rate of the redundant data.

  According to a fourth aspect of the present invention, the carousel period / update detection means uses the type of data divided and transmitted in the DSM-CC section from the information described in the TS packet header and the DSM-CC section. And further, the presence or absence of update of the received data is grasped based on the description content of a predetermined item described in the DSM-CC section.

  According to the invention described in claim 4, it is possible to easily grasp the carousel cycle and the data update from the contents described in the existing standardized data.

According to a fifth aspect of the present invention, there is provided a retransmission method for receiving a TS transmitted from a transmission side and retransmitting the data by a carousel method , and including data including a response to a request from a user from a packet sequence included in the TS. A target packet identification / separation step for identifying and separating a target packet in which data is stored, a redundant packet position grasping step for grasping a packet position of redundant data with respect to the packet sequence, and a target packet identification / separation step For the separated target packet, the carousel transmission unit and transmission cycle are grasped, and further, the carousel cycle / update detection step for detecting whether the received data is updated, and the carousel transmission obtained by the carousel cycle / update detection step. The packet sequence is stored corresponding to the unit and transmission cycle. Further when there is update of the data, and the carousel data storage step of replacing at updated the packets accumulated packets, among the stored the packet sequence by the carousel data storage step, grasping the redundant packet position The target packet is repeatedly stored in the carousel transmission unit at the redundant packet position obtained by the step , re-multiplexing step for re-multiplexing as a TS, and at the time of packet re-multiplexing by the re-multiplexing step , And a carousel data monitoring step for monitoring to store carousel data in accordance with the set restriction .

According to invention of Claim 5 , carousel data can be transmitted efficiently. Therefore, the data acquisition time on the receiving side can be easily reduced. In addition, it is possible to easily store the target packet for shortening the data acquisition time on the receiving side. In addition, carousel transmission corresponding to various restrictions already standardized can be realized.

The invention described in claim 6 is a retransmission program for causing a computer to function as each unit included in the retransmission apparatus according to any one of claims 1 to 4 .

According to invention of Claim 6 , carousel data can be transmitted efficiently. Therefore, the data acquisition time on the receiving side can be easily reduced. In addition, retransmission can be easily realized by installing an execution program in a computer.

  According to the present invention, it is possible to easily shorten the data acquisition time on the receiving side.

<Outline of the present invention>
The present invention shortens the acquisition time of content transmitted by the carousel method or the like, for example, in a service for retransmitting a digital broadcast TS including data broadcast content transmitted by the carousel method. Further, the acquisition time can be shortened easily by processing at the TS packet level for storing the content without analyzing / changing the data structure of the content transmitted by the carousel method or the content of the data.

  Specifically, in a re-transmission facility (head end), a TS packet or the like that stores data broadcast content premised on, for example, obtaining a response to a user request transmitted in a carousel from a received TS. The set target packet is separated and stored in a storage means such as a memory. Further, the TS packet of the accumulated data content is duplicated in units of carousel transmission cycles, and repeatedly stored in the redundant packet band existing in the TS at the time of retransmission.

  With this method, the transmission band of data broadcast included in the TS is widened, and the data broadcast carousel transmission cycle is shortened. Therefore, on the receiving side, the time from data broadcast content request to acquisition is shortened.

<Embodiment>
Next, a preferred embodiment of the retransmission apparatus, the retransmission method, and the retransmission program according to the present invention having the above-described features will be described with reference to the drawings.

<Broadcasting system>
FIG. 1 is a diagram illustrating a configuration example of an embodiment of a broadcasting system to which a retransmission apparatus according to the present invention is applied. The broadcast system 10 illustrated in FIG. 1 is configured to include a transmission device 11, a retransmission device 12, and a reception device 13.

  The transmission device 11 transmits a TS such as cable television or terrestrial digital broadcast to the retransmission device 12 by wire or wireless. The transmission device 11 includes, for example, a broadcast satellite (transmission device 11-1), a broadcast tower (transmission device 11-2), and the like.

  The retransmitting device 12 receives TS such as cable television and terrestrial digital broadcasting transmitted by wire or wireless. In addition, the retransmitting device 12 converts the receiving device 13-1 to 13-n into a transmission method that can be retransmitted to each receiving device 13-1 to 13-n, and transmits it to each receiving device 13-1 to 13-n.

  The receiving device 13 receives the TS transmitted from the retransmitting device 12, decodes the video and audio, and decodes the data broadcast content, and provides the desired video to the receiver (viewer).

<Retransmission device 12: First embodiment>
Next, a specific apparatus configuration example of the retransmission apparatus 12 according to the present invention will be described with reference to the drawings. FIG. 2 is a diagram illustrating a configuration example of the retransmission apparatus according to the first embodiment. FIG. 3 is a diagram illustrating an example of a carousel TS packet structure.

  The retransmission apparatus 12-1 in the first embodiment shown in FIG. 2 includes a bit rate acquisition unit 21, a target packet identification / separation unit 22, a carousel cycle / update detection unit 23, and a redundant packet position determination unit. The rate comparison unit 24, the redundant packet insertion / position grasping unit 25, the carousel data storage unit 26, the carousel data monitoring unit 27, and the target packet remultiplexing unit 28 are configured. In FIG. 2, solid line arrows indicate data of TS packet sequences, and dotted line arrows indicate control information for controlling the corresponding components.

  The bit rate acquisition means 21 acquires the number of bits per unit time of the input TS as the bit rate. Further, the bit rate acquisition unit 21 outputs the acquired bit rate to the rate comparison unit 24. In addition to the method of obtaining the bit rate from the number of received bits per unit time as described above, for example, the method of obtaining the bit rate from, for example, a time stamp described in a PCR (Program Clock Reference) packet in the TS packet sequence Etc.

  Further, the target packet identifying / separating means 22 duplicates and repeatedly stores TS packets in which the contents of the data broadcast transmitted by carousel are stored, that is, the TS packets of the digital broadcast to be retransmitted. The target TS packet is identified and separated from the TS packet sequence. Further, the target packet identification / separation means 22 stores a TS packet made of redundant data instead at a corresponding position in the separated TS packet sequence. A detailed description of the packet identification and separation method in the target packet identification / separation means 22 will be described later.

  Further, the target packet identification / separation means 22 outputs the packet data separated and stored with the redundant data to the carousel cycle / update detection means 23, the redundant packet insertion / position grasping means 25, and the carousel data storage means 26.

  The carousel cycle / update detection means 23 cancels the CAS (Conditional Access System) encryption for the TS packet train of the separated data broadcast.

  Note that the CAS encryption cancellation in the carousel cycle / update detection unit 23 is performed using related information, key information, or the like for canceling (decrypting) the previously acquired encryption. Since the decryption is performed in units of TS packets, it is possible to easily compare a TS packet that has been canceled for confirmation of the DSM-CC section and a TS packet that is retransmitted without being canceled.

  Further, the carousel cycle / update detection means 23 reads the description content of a predetermined item from each item included in the TSP (packet) header, the section header, and the DII message shown in FIG. 3 from the decrypted TS packet sequence. By referring, the carousel transmission period of the content transmitted in the section and the presence / absence of update of the carousel data are detected. The carousel cycle / update detection means 23 will be described in detail later with respect to a carousel transmission cycle and a method for detecting whether or not there is an update. The carousel cycle / update detection unit 23 outputs the detected result to the carousel data storage unit 26.

  The redundant packet position grasping means grasps the packet position of the redundant data from the input TS packet sequence and controls the storage of the separated data broadcast content packet based on the result.

  Here, in the first embodiment, when rate conversion is performed by inserting redundant packets into the TS in accordance with an external input clock or a preset transmission speed in accordance with the bandwidth of the transmission path at the time of retransmission, rate conversion is performed. Means for grasping the position of the redundant packet to be inserted and the transmission rate of the redundant data. That is, rate conversion is performed on the TS according to the bandwidth of the transmission path at the time of retransmission, and the bandwidth of the redundant packet inserted at the time of rate conversion is used.

  More specifically, the rate comparison means 24 included in the redundant packet position grasping means includes the bit rate of the TS packet to be retransmitted obtained from the bit rate acquisition means 21 and a preset transmission at the time of retransmission. A bit rate set based on the bandwidth of the path or a preset bit rate (external input clock) inputted externally is compared. Further, the rate comparison means 24 grasps information on an increase in the bit rate (transmission band) of the TS packet sequence by comparison, generates control information in rate conversion from the information, and inserts redundant packet insertion / position grasping means 25 and The data is output to the carousel data storage means 26.

  Here, the bit rate of the TS packet sequence to be retransmitted can be grasped by receiving TMCC (Transmission and Multiplexing Configuration Control) information, for example, when receiving a modulated wave encoded with a transmission path and demodulating it. It is. Further, when TMCC information cannot be obtained as in the case where a TS packet sequence to be retransmitted is transmitted over an IP network, it is necessary to measure the bit rate by another method. In such a case, there are a method of obtaining from the number of received bits per unit time, or obtaining from a time stamp described in a PCR packet in a TS packet sequence.

  The redundant packet insertion / position grasping means 25 included in the redundant packet position grasping means 25 is a bit rate set based on the bandwidth of the transmission path at the time of retransmission, or a preset bit rate (externally inputted) The rate of the TS packet sequence is converted based on the input clock). The rate conversion is performed by inserting a TS packet made up of redundant data. The redundant packet insertion / position grasping means 25 outputs the packet to the target packet remultiplexing means 28 after the converted rate.

  Further, the redundant packet insertion / position grasping means 25 corrects the PCR value accompanying rate conversion for the packet transmitting the PCR, and outputs the corrected packet to the target packet remultiplexing means 28.

  The carousel data storage means 26 stores data broadcast packets to be duplicated and repeatedly inserted in units of one cycle of carousel transmission. In addition, the carousel data storage means 26 repeatedly outputs packets in units of one cycle of carousel transmission in order to re-multiplex data broadcast packets into TS packet sequences.

  The carousel data storage means 26 replaces the stored data broadcast packet with the updated data broadcast packet, for example, when the data broadcast content is updated from the information obtained by the carousel cycle / update detection means 23.

  The carousel data monitoring means 27 performs packet insertion scheduling when the target packet remultiplexing means 28 remultiplexes the data broadcast packet sequence. The carousel data monitoring means 27, when there is a restriction set in advance as the arrangement method in the TS packet string in the data broadcast packet, converts the data broadcast packet to the TS packet string so as to satisfy the restriction. Control storage.

  Note that, as the above-described limitation, for example, six or more TS packets with the same PID are not transmitted continuously, or the total bit rate of components (including DII, DDB, and event message) received simultaneously is 4 Mbps or less. Alternatively, a restriction such as a maximum bit rate per sub-table of 2 Mbps can be used. Thereby, carousel transmission corresponding to various restrictions already standardized can be realized.

  Note that one PID corresponds to one component described above, and the above sub-table is a unit of a data stream distinguished by “table_id_extension” shown in the section header shown in FIG. 3 transmitted in the DSM-CC section. Is shown.

  The target packet remultiplexing means 28 uses the data broadcast packet as the target packet output from the carousel data storage means 26 as the redundant packet for the TS packet sequence including the null packet obtained from the redundant packet insertion / position grasping means 25. The replacement data is stored, and the remultiplexed data is transmitted to the receiving device 13.

  Further, the target packet remultiplexing means 28 prevents the value of “continuity_counter” described in the TSP header shown in FIG. 3 from becoming discontinuous for TS packets having the same PID in the TS packet sequence at the time of storage. rewrite. Further, the target packet remultiplexing means 28 replaces the redundant packet that has not been replaced with the data broadcast packet, if the redundant packet is not a null packet, and transmits it to the receiving device 13 by replacing it with a null packet.

  Here, FIG. 4 is a diagram illustrating an example of rate conversion in the first embodiment. As shown in FIG. 4, the retransmission apparatus 12 performs rate conversion on the transmission band at the time of reception according to the clock and bit rate of each transmission path at the time of retransmission, thereby reducing the data amount per unit time. Can be increased. Therefore, for example, data broadcast packets can be efficiently transmitted through DDB and DII.

  FIG. 5 is a diagram illustrating a storage example of the target packet in the first embodiment. In FIG. 5, P1 to P4 indicate packets (non-target packets) that do not have a quick response to user requests such as video and audio, and Pt1 to Pt4 are transmitted by, for example, a carousel method. As in data broadcasting, a packet (target packet) having a quick response to a user request is shown.

  In the first embodiment, the input TS as shown in FIG. 5A is separated into target packets and non-target packets as shown in FIG. 5B. Further, based on the transmission path at the time of re-transmission, the target packet is repeatedly stored as shown in FIG. In this way, the data acquisition time on the receiving side can be easily shortened by storing the target packet using the redundant packet area corresponding to the rate increase.

<Packet Identification and Separation Method in Target Packet Identification / Separation Unit 22>
Next, the packet identification and separation method in the target packet identification / separation means 22 will be described in detail.

  First, for identification of TS packets, for example, PAT (Program Association Table) which is management information of TS shown in ISO / IEC 13818-1 2.4.4, ARIB STD-B10 Part 2 5.2 etc. ) Or PMT (Program Map Table) or the like.

  Also, for example, by referring to the stream type “stream_type” for each stream in the PMT indicated in ISO / IEC 13818-1 2.4.4, etc., the PID TS packet for transmitting the data broadcast is grasped. .

  As shown in ARIB STD-B24 Chapter 4 and the like, the stream types of data broadcasts transmitted by the carousel method are “stream_type = 0x0B” and “stream_type = 0x0D”. Therefore, with reference to the PMT, TS packets having PIDs “stream_type = 0x0B” and “stream_type = 0x0D” are set as candidates for duplication.

  For a TS packet having a PID that is a candidate for duplication, the table identification “table_id” described in the DSM-CC section in the payload of the TS packet is referred to. For example, as shown in ARIB STD-B24 Chapter 6.5, etc., the table identification of the DII message transmitted by the carousel method is “table_id = 0x3B”, and the table identification of the DDB message is “table_id = 0x3C”. It is. Therefore, among the duplication target candidates, TS packets having “table_id = 0x3B” and “table_id = 0x3C” are identified as duplication targets and separated from the TS packet sequence.

<Carousel cycle / update detection means 23 for detecting carousel transmission cycle and update>
Next, the carousel cycle / update detection means 23 for detecting the carousel transmission cycle and the presence / absence of update will be described in detail.

  First, with reference to “number of modules (number_of modules)” and “module_size” described in the DII message shown in FIG. 3, the number of modules to be carousel transmitted and the size of each module are grasped. In addition, by receiving each module transmitted by the transmitted DII message and DDB message, the transmission cycle of each module transmitted by carousel is detected. Further, the update of the data broadcast content is grasped by referring to “download_id” shown in FIG. 3 described in the DII message.

  For example, as shown in ARIB STD-B24 Volume 3, 6.1, etc., the first 4 bits (= data_event_id) and DII in all 32 bits of “download_id” described in the DII message shown in FIG. With reference to “module_version” described for each module in the message, the presence / absence of update of the data broadcast content is detected. That is, when the value described in each item described above has been changed, the data broadcast content has been updated.

<Carousel data storage means 26>
Here, the carousel accumulating unit 26 stores one unit of the carousel composed of the DII message and the DDB message. When the data broadcast content is updated, specifically, the carousel cycle / update detecting unit 23 specifies “data_event_id”. ”Is updated, all the units of the carousel including the corresponding DII message and DDB message are cleared, and new DII message and DDB message are stored again.

  The carousel storage means 26 clears the DDB message corresponding to the corresponding “module_id” when the update of the data broadcast content occurs, specifically, when the “module_version” is updated, and the same “ The DDB message having “module_id” is accumulated again.

  As described above, according to the first embodiment, it is possible to shorten the acquisition time of content (data) that is easily transmitted by the carousel method. Thereby, the response with respect to a user's content request can be improved, for example.

<Retransmission device 12: Second embodiment>
Next, a second embodiment of the retransmission apparatus 12 will be described. In general, a TS packet includes a redundant packet called a null packet. A null packet is a packet that does not have information, and since the amount contained in the TS is not specified, if the consistency as a TS is satisfied, it is possible to replace the null packet and transmit another packet. Therefore, in the second embodiment, the data acquisition time on the receiving side can be easily shortened by retransmitting the bandwidth of the null packet included in the TS.

  FIG. 6 is a diagram illustrating a configuration example of a retransmission apparatus according to the second embodiment. In the retransmitting apparatus 12-2 in the second embodiment shown in FIG. 6, the same reference numerals are given to the configurations that perform the same operations as those of the retransmitting apparatus 12-1 described above. Omitted.

  The retransmission apparatus 12-2 in the second embodiment shown in FIG. 6 includes a target packet identification / separation unit 22, a carousel cycle / update detection unit 23, a null packet position determination unit 35, a carousel data storage unit 36, The carousel data monitoring means 27 and the target packet remultiplexing means 38 are provided. A solid line arrow indicates data of the TS packet sequence, and a dotted line arrow indicates control information for controlling each corresponding component.

  Similar to the first embodiment described above, the target packet identification / separation unit 22 stores the data broadcast content transmitted in the carousel with respect to the input TS packet sequence to be retransmitted. A packet, that is, a TS packet to be duplicated and repeatedly stored is identified and separated from the TS packet sequence. Further, the target packet identification / separation means 22 stores a TS packet made of redundant data instead at a corresponding position in the separated TS packet sequence.

  The target packet identification / separation means 22 outputs the packet data separated and stored with redundant data to the carousel cycle / update detection means 23, the carousel data accumulation means 36, and the null packet position grasping means 35.

  The carousel cycle / update detection means 23 cancels the CAS encryption for the TS packet train of the separated data broadcast. Further, the carousel cycle / update detection means 23 refers to the TSP header, section header, and DII message for the TS packet sequence that has been decrypted, so that the carousel transmission cycle of the content transmitted in the section, and the carousel Detects whether data has been updated. The carousel cycle / update detection unit 23 outputs the detected result to the carousel data storage unit 36.

  Further, the null packet position grasping means 35 as the redundant packet position grasping means in the second embodiment grasps the position of the null packet included in the TS packet sequence and the bandwidth of the null packet. Further, the null packet position grasping means 35 grasps information such as the position of the null packet and the increased bandwidth with respect to the carousel data accumulating means 36 for repeatedly storing the data broadcast packet separated as the replication target, and the information From the information, control information for replacing the null packet with the target packet is generated and output to the carousel data storage means 36.

  The carousel data storage means 36 acquires the target packet separated from the target packet identification / separation means 22, information obtained from the carousel cycle / update detection means 23, null packet position information obtained by the null packet position grasping means 35, and Based on the above, data broadcast packets to be duplicated and repeatedly inserted are stored in units of one cycle of carousel transmission. In addition, the carousel data storage means 36 repeatedly outputs packets in units of one cycle of carousel transmission in order to re-multiplex data broadcast packets into TS packet sequences.

  In addition, when the data broadcast content is updated, the carousel data storage unit 36 replaces the stored data broadcast packet with the updated data broadcast packet.

  The carousel data monitoring means 27 performs packet insertion scheduling when the target packet remultiplexing means 38 remultiplexes the data broadcast packet sequence. In addition, when there is a restriction set in advance as the arrangement method in the TS packet string in the data broadcast packet, the carousel data monitoring unit 27 stores the data broadcast packet in the TS packet string so as to satisfy the restriction. To control. As the above-described restriction, for example, the same restriction as in the first embodiment can be used.

  The target packet remultiplexing means 38 replaces the data broadcast packet output from the carousel data storage means 36 with the null packet and stores the TS packet string including the null packet, and stores the remultiplexed data in the receiving device 13. To transmit.

  Further, the target packet remultiplexing means 38 rewrites the value of “continuity_counter” described in the TS packet header so as not to be discontinuous for the TS packets having the same PID in the TS packet sequence at the time of storage. Furthermore, the target packet remultiplexing means 38 transmits the null packet that has not been replaced with the data broadcast packet as it is.

  Here, FIG. 7 is a diagram illustrating a storage example of the target packet in the second embodiment. In FIG. 7, P1 to P4 indicate non-prompt packets (non-target packets) such as data broadcasting, and Pt1 to Pt4 indicate promptness such as a response to a user request, for example. N1 and N2 indicate null packets.

  In the second embodiment, the input TS as shown in FIG. 7A is separated into target packets and non-target packets as shown in FIG. 7B. Further, at the time of retransmission, the target packet is repeatedly stored as shown in FIG. 7C by using the areas of the null packets N1 and N2 transmitted earlier. As described above, by repeatedly storing the target packet using the redundant packet area included in the TS, the data acquisition time on the receiving side can be easily reduced.

  Thus, according to the second embodiment, it is possible to shorten the acquisition time of content (data) that is easily transmitted by the carousel method. Thereby, the response with respect to a user's content request can be improved, for example.

  In the present invention, data carousel transmission can be realized by combining the first embodiment and the second embodiment described above.

<Execution program>
Here, the above-described retransmission apparatus 12 can perform the retransmission process according to the present invention using the dedicated apparatus configuration described above, but generates an execution program for causing the computer to execute the process in each configuration. For example, the retransmission processing according to the present invention can be realized by installing the program in a general-purpose personal computer, a server, or the like.

<Hardware configuration>
Here, a hardware configuration example of a computer capable of executing the retransmission processing according to the present invention will be described with reference to the drawings. FIG. 8 is a diagram illustrating an example of a hardware configuration capable of realizing the retransmission process according to the present invention.

  8 includes an input device 41, an output device 42, a drive device 43, an auxiliary storage device 44, a memory device 45, a CPU (Central Processing Unit) 46 that performs various controls, and a network connection device. 47, which are connected to each other by a system bus B.

  The input device 41 includes a keyboard and a pointing device such as a mouse operated by a user, a voice input device, and the like, and inputs various operation signals and voice signals such as a program execution instruction from the user. The output device 42 has a display, a speaker, and the like that display various windows and data necessary for operating the computer main body for performing processing in the present invention. Display or audio output is possible.

  In the present invention, the execution program installed in the computer main body is provided by the recording medium 48 such as a CD-ROM. The recording medium 48 on which the program is recorded can be set in the drive device 43, and the execution program included in the recording medium 48 is installed in the auxiliary storage device 44 from the recording medium 48 via the drive device 43.

  Further, the drive device 43 can record the execution program according to the present invention on the recording medium 48. As a result, the recording medium 48 can be used to easily install on a plurality of other computers, and the retransmission process can be easily realized.

  The auxiliary storage device 44 is a storage means such as a hard disk, and can store an execution program according to the present invention, a control program provided in a computer, and the like, and can perform input / output as necessary. The auxiliary storage device 44 can also be used as a storage unit that stores the above-described packets, various control information, and the like.

  The memory device 45 stores an execution program read from the auxiliary storage device 44 by the CPU 46. The memory device 45 includes a ROM (Read Only Memory), a RAM (Random Access Memory), and the like.

  The CPU 46 performs processing of the entire computer such as various operations and input / output of data with each hardware component based on a control program such as OS (Operating System) and an execution program stored in the memory device 45. The retransmission process can be realized by controlling. Various information necessary during the execution of the program can be acquired from the auxiliary storage device 44 and can also be stored.

  The network connection device 47 is connected to an antenna device that can transmit or receive radio waves, a communication network (various transmission paths) such as a telephone line, a LAN (Local Area Network) cable, and the like, thereby executing an execution program and various data. Can be obtained from another terminal or the like, or the execution result obtained by executing the program or the execution program of the present invention can be provided to another terminal or the like.

  With the hardware configuration described above, it is possible to realize the retransmission process at a low cost without requiring a special device configuration. In addition, the retransmission process can be easily realized by installing the program.

<Retransmission procedure>
Next, the retransmission processing procedure using the execution program in the present invention will be described with reference to a flowchart. FIG. 9 is a flowchart showing an example of a retransmission processing procedure in the present invention.

  In FIG. 9, first, a content signal transmitted from a broadcasting satellite, a broadcasting tower, or the like is received (S01), and a target packet corresponding to the content is identified and separated from TS data included in the transmission signal (S02).

  Next, the position of the redundant packet is grasped (S03). Specifically, by comparing the bit rate of the TS packet sequence to be retransmitted with the bit rate set based on the bandwidth of the transmission path at the time of retransmission or an externally input clock, It grasps the increase in bit rate of the packet sequence and controls rate conversion. Also, the TS packet string rate is converted in accordance with the bit rate set according to the bandwidth of the transmission path at the time of retransmission or the clock input from the outside (first embodiment). In the process of S03, in addition to the above-described method, for example, the bandwidth of the null packet included in the TS may be grasped (second embodiment).

  Next, the carousel cycle and the presence / absence of update of the carousel data are detected based on the TS packet sequence of the data broadcast separated by the process of S02 described above (S04). In addition, a plurality of data broadcast packets as carousel data to be repeatedly inserted are accumulated in units of one cycle of carousel transmission (S05), and the data broadcast accumulated by the process of S05 is performed on a TS packet sequence including null packets. The packet is replaced with a null packet and remultiplexed (S06), and the remultiplexed data is transmitted to the receiving device 13 (S07).

  As described above, according to the retransmission process, carousel data can be transmitted efficiently, so that the data acquisition time on the receiving side can be easily reduced. In addition, retransmission can be easily realized by installing an execution program in a computer.

  As described above, according to the present invention, since carousel data can be transmitted efficiently, the data acquisition time on the receiving side can be easily reduced. Specifically, for example, in a service for retransmitting a digital broadcast TS including data broadcast content transmitted by the carousel method, the acquisition time of the content transmitted by the carousel method or the like can be shortened. Further, the acquisition time can be shortened easily by TS packet level processing for storing content without analyzing or changing the data structure of the content transmitted by the carousel method or the content of the data.

  In the above-described embodiment, a data broadcast packet is used as an example of a packet. However, the present invention is not particularly limited to this, and for example, the present invention is applicable to a packet included in content in other fields. be able to.

  Although the preferred embodiment of the present invention has been described in detail above, the present invention is not limited to the specific embodiment, and various modifications are possible within the scope of the gist of the present invention described in the claims. Can be changed.

It is a figure which shows the structural example of one Embodiment of the broadcast system to which the retransmission apparatus in this invention is applied. It is a figure which shows one structural example of the retransmission apparatus in 1st Embodiment. It is a figure which shows an example of the TS packet structure of a carousel system. It is a figure which shows an example of the rate conversion in 1st Embodiment. It is a figure which shows the example of storage of the object packet in 1st Embodiment. It is a figure which shows the example of 1 structure of the retransmission apparatus in 2nd Embodiment. It is a figure which shows the example of storage of the object packet in 2nd Embodiment. It is a figure which shows an example of the hardware constitutions which can implement | achieve the retransmission process in this invention. It is a flowchart which shows an example of the resending process procedure in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Broadcasting system 11 Transmission apparatus 12 Retransmission apparatus 13 Reception apparatus 21 Bit rate acquisition means 22 Target packet identification / separation means 23 Carousel cycle / update detection means 24 Rate comparison means 25 Redundant packet insertion / position grasping means 26, 36 Carousel data accumulation Means 27 Carousel data monitoring means 28, 38 Target packet re-multiplexing means 35 Null packet position grasping means 41 Input device 42 Output device 43 Drive device 44 Auxiliary storage device 45 Memory device 46 CPU
47 Network connection device 48 Recording medium

Claims (6)

In the re-transmission apparatus that receives the TS transmitted from the transmission side and re-transmits by the carousel method,
A target packet identifying / separating means for identifying and separating a target packet in which data including a response to a request from a user is stored from the packet sequence included in the TS;
Redundant packet position grasping means for grasping a packet position of redundant data with respect to the packet sequence;
For the target packet separated by the target packet identification / separation means, grasp the transmission unit and transmission period of the carousel, and further detect the presence or absence of update of the received data,
The packet sequence is stored in correspondence with the transmission unit and transmission cycle of the carousel obtained by the carousel cycle / update detection means, and when the data is updated, the stored packet is updated. Carousel data storage means to replace with,
Of the packet sequence stored by the carousel data storage means, the target packet is repeatedly stored in the redundant packet position obtained by the redundant packet position grasping means in units of carousel transmission, and remultiplexed as a TS. Re-multiplexing means ;
A re-transmission apparatus comprising: carousel data monitoring means for monitoring so as to store carousel data corresponding to a preset restriction when re-multiplexing packets by the re-multiplexing means . The redundant packet position grasping means includes:
When performing rate conversion by inserting redundant packets into the TS based on the bandwidth of the transmission path at the time of retransmission or a preset transmission rate, the position of the redundant packet inserted by the rate conversion and the redundant data The retransmission apparatus according to claim 1, wherein a transmission rate is grasped. The redundant packet position grasping means includes:
2. The retransmission apparatus according to claim 1, wherein a position of a redundant data packet and a transmission rate of the redundant data are grasped from a packet sequence included in the TS. The carousel cycle / update detection means includes:
From the information described in the TS packet header and the DSM-CC section, the type of data divided and transmitted in the DSM-CC section is ascertained, and further, description of predetermined items described in the DSM-CC section The retransmission apparatus according to any one of claims 1 to 3, wherein whether or not the received data is updated is determined based on the content. In the retransmission method of receiving the TS transmitted from the transmission side and retransmitting by the carousel method,
A target packet identification / separation step for identifying and separating a target packet in which data including a response to a request from a user is stored from the packet sequence included in the TS;
A redundant packet position grasping step for grasping a packet position of redundant data with respect to the packet sequence;
For the target packet separated by the target packet identification / separation step, a carousel transmission unit and a transmission cycle are grasped, and further, a carousel cycle / update detection step for detecting presence / absence of update of received data,
The packet sequence is stored in correspondence with the transmission unit and transmission cycle of the carousel obtained by the carousel cycle / update detection step, and when the data is updated, the stored packet is updated. Carousel data accumulation step to replace with,
Of the packet sequence accumulated in the carousel data accumulation step, the target packet is repeatedly stored in a redundant packet position obtained in the redundant packet position grasping step in a carousel transmission unit and remultiplexed as a TS. A remultiplexing step ;
And a carousel data monitoring step of monitoring so as to store carousel data in accordance with a preset limit when remultiplexing packets in the remultiplexing step . Computer
A retransmission program for causing each of the retransmission apparatuses according to claim 1 to function as each unit .

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