Retransmission device and retransmission method

Abstract

To more appropriately process time information.SOLUTION: There is provided a retransmission device including a conversion unit configured to convert first time information transmitted in a physical layer defined in a first broadcasting scheme into second time information in an NTP format stored in a packet transmitted in an upper layer that is an upper layer of the physical layer defined in a second broadcasting scheme different from the first broadcasting scheme, in which the first time information includes specific information regarding time, and the conversion unit converts the first time information into the second time information including the specific information and a predetermined fixed value. The present disclosure is applicable to, for example, a retransmission device for retransmitting terrestrial digital television broadcasting.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a retransmission device and a retransmission method, and more particularly to a retransmission device and a retransmission method that are capable of more appropriately processing time information. [Background technology]

[0002] BACKGROUND ART Terrestrial digital television broadcasts are being retransmitted using digital cable television broadcasts and the like (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-220241 Summary of the Invention [Problem to be solved by the invention]

[0004] In terrestrial digital television broadcasting, it is possible to transmit time information via the physical layer, but when retransmitting using the transmodulation method, it has not been possible to properly process the time information transmitted via the physical layer. In addition, there is a demand for processing the time information transmitted via the physical layer on the receiving device side, and a proposal for properly processing the time information has been sought.

[0005] The present disclosure has been made in consideration of such circumstances, and aims to enable more appropriate processing of time information. [Means for solving the problem]

[0006] A retransmission device according to one aspect of the present disclosure includes a receiving unit that receives a broadcast signal of a first broadcasting method, a conversion unit that converts first time information transmitted in a physical layer specified in the first broadcasting method into second time information in NTP format that is stored in a packet transmitted in an upper layer that is a layer higher than the physical layer specified in a second broadcasting method that is different from the first broadcasting method, and a transmitting unit that transmits the broadcast signal of the second broadcasting method.

[0007] A retransmission method according to one aspect of the present disclosure is a retransmission method in which a retransmission device receives a broadcast signal of a first broadcasting method, converts first time information transmitted in a physical layer specified in the first broadcasting method into second time information in NTP format stored in a packet transmitted in an upper layer that is a layer higher than the physical layer specified in a second broadcasting method different from the first broadcasting method, and transmits the broadcast signal of the second broadcasting method.

[0008] In a retransmission device and retransmission method according to one aspect of the present disclosure, a broadcast signal of a first broadcasting method is received, and first time information transmitted in a physical layer specified in the first broadcasting method is converted into second time information in NTP format stored in a packet transmitted in an upper layer that is a layer higher than the physical layer specified in a second broadcasting method different from the first broadcasting method, and the broadcast signal of the second broadcasting method is transmitted.

[0009] A receiving device according to one aspect of the present disclosure includes a receiving unit that receives and demodulates a broadcast signal of a first broadcasting method, and a processing unit that processes packets obtained by demodulating the broadcast signal, wherein the receiving unit has a conversion unit that converts first time information transmitted in a physical layer specified in the first broadcasting method into second time information in NTP format stored in a packet transmitted in an upper layer that is a layer higher than the physical layer specified in a second broadcasting method that is different from the first broadcasting method, and the processing unit processes packets that store the second time information output from the receiving unit.

[0010] A receiving method according to one aspect of the present disclosure is a receiving method for a receiving device including a receiving unit that receives and demodulates a broadcast signal of a first broadcasting system, and a processing unit that processes packets obtained by demodulating the broadcast signal, wherein the receiving unit converts first time information transmitted in a physical layer specified in the first broadcasting system into second time information in NTP format stored in a packet transmitted in an upper layer that is a layer higher than the physical layer specified in a second broadcasting system different from the first broadcasting system, and the processing unit processes the packet containing the second time information output from the receiving unit.

[0011] In a receiving device and a receiving method according to one aspect of the present disclosure, a broadcast signal in a first broadcasting format is received and demodulated, packets obtained by demodulating the broadcast signal are processed, and first time information transmitted in a physical layer specified in the first broadcasting format is converted into second time information in NTP format stored in packets transmitted in an upper layer that is a layer higher than the physical layer specified in a second broadcasting format different from the first broadcasting format, and the packets storing the second time information are processed.

[0012] The retransmission device and the reception device according to one embodiment of the present disclosure may be independent devices or may be internal blocks constituting a single device. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a block diagram illustrating a configuration example of an embodiment of a transmission system to which the present disclosure is applied. [Figure 2] 2 is a block diagram showing an example of the configuration of the transmitting device of FIG. 1. FIG. [Figure 3] 2 is a block diagram showing an example of the configuration of the retransmission device of FIG. 1; [Figure 4] 2 is a block diagram showing an example of the configuration of the receiving device of FIG. 1. FIG. [Figure 5] FIG. 1 is a diagram illustrating an example of a protocol stack for terrestrial digital television broadcasting. [Figure 6]FIG. 10 is a diagram illustrating an example of a protocol stack at the time of retransmission by digital cable television broadcasting. [Figure 7] FIG. 10 is a diagram illustrating an example of the arrangement of NTP time information. [Figure 8] FIG. 10 is a diagram illustrating an example of the syntax of NTP time information. [Figure 9] FIG. 10 is a diagram illustrating an example of conversion from physical layer time information to NTP time information. [Figure 10] FIG. 1 is a diagram illustrating an example of a protocol stack of ATSC 3.0. [Figure 11] 2 is a flowchart illustrating the flow of processing performed by each device in the transmission system of FIG. 1. [Figure 12] FIG. 10 is a block diagram illustrating another exemplary configuration of an embodiment of a transmission system to which the present disclosure is applied. [Figure 13] 13 is a block diagram showing an example of the configuration of the retransmission device of FIG. 12. FIG. [Figure 14] FIG. 10 is a block diagram illustrating yet another exemplary configuration of an embodiment of a transmission system to which the present disclosure is applied. [Figure 15] FIG. 15 is a block diagram showing an example of the configuration of the receiving device of FIG. 14. [Figure 16] 15 is a flowchart illustrating the flow of processing performed by each device in the transmission system of FIG. 14. [Figure 17] FIG. 1 is a block diagram illustrating an example of the configuration of a computer. DETAILED DESCRIPTION OF THE INVENTION

[0014] <1. First embodiment>

[0015] (Transmission system configuration) FIG. 1 is a block diagram showing an example of the configuration of an embodiment of a transmission system to which the present disclosure is applied.

[0016] In FIG. 1, the transmission system is made up of a transmitting device 10, a retransmitting device 20, and a receiving device 30.

[0017] The transmitting device 10 is a device that transmits content such as broadcast programs produced by terrestrial broadcasting stations. The transmitting device 10 generates a broadcast stream, performs necessary processing, and transmits the resulting terrestrial digital television broadcast signal from a transmitting antenna installed at a transmitting station.

[0018] The retransmission device 20 is a head-end device installed in a cable television station, etc. The retransmission device 20 performs necessary processing on the broadcast signal of the terrestrial digital television broadcast received via an antenna, and transmits the resulting broadcast signal of the digital cable television broadcast to the cable television transmission network.

[0019] The receiving device 30 is a fixed receiver such as a television receiver, a set-top box (STB), a recording device, a game console, a network storage, etc. The receiving device 30 is connected to a cable television transmission network by a cable such as an optical fiber cable or a coaxial cable.

[0020] The receiving device 30 receives a digital cable television broadcast signal transmitted from the retransmission device 20 via a cable television transmission network. The receiving device 30 processes a broadcast stream obtained from the broadcast signal to output video and audio of content such as a broadcast program, thereby allowing a user to view content such as a broadcast program.

[0021] In the following description, a broadcast signal for terrestrial digital television broadcasting will also be referred to as a terrestrial broadcast signal, and a broadcast signal for digital cable television broadcasting will also be referred to as a cable broadcast signal.

[0022] (Configuration of transmitting device) FIG. 2 is a block diagram showing an example of the configuration of the transmitting device 10 of FIG.

[0023] In FIG. 2, the transmission device 10 includes a generation unit 101 and a transmission unit 102.

[0024] The generating unit 101 generates a broadcast stream based on the data input thereto, and supplies it to the transmitting unit 102 .

[0025] A broadcast stream includes broadcast components that make up content such as broadcast programs and commercials produced by terrestrial broadcasting stations, control information related to the broadcast components, time information, etc. Broadcast components include components such as video streams, audio streams, and subtitle streams.

[0026] The transmitting unit 102 generates a physical layer frame that conforms to the terrestrial digital television broadcasting standard based on the broadcast stream supplied from the generating unit 101. The transmitting unit 102 performs necessary processing, such as modulation, on the physical layer frame and transmits it as a terrestrial broadcast signal. The terrestrial broadcast signal is transmitted from a transmitting antenna installed at a transmitting station.

[0027] The physical layer frame includes control information such as transmission multiplexing control information. In the following description, control information transmitted in the physical layer is also referred to as physical layer control information. Also, control information transmitted in a higher layer (e.g., transport layer) that is a layer higher than the physical layer is also referred to as upper layer control information. For example, control information related to broadcast components is upper layer control information.

[0028] (Configuration of retransmission device) FIG. 3 is a block diagram showing an example of the configuration of the retransmission device 20 of FIG.

[0029] In FIG. 3, the retransmission device 20 comprises a receiving unit 201, a processing unit 202, and a transmitting unit 203.

[0030] The receiving unit 201 receives a terrestrial broadcast signal transmitted from the transmitting device 10 via an antenna, performs necessary processing on the signal, and supplies the processed signal to the processing unit 202 .

[0031] The processing unit 202 processes the signal supplied from the receiving unit 201 in accordance with the transmodulation method, and supplies the resulting signal to the transmitting unit 203. The transmodulation method is a method in which the retransmission device 20 of the cable television station changes the modulation method of the received broadcast signal and retransmits it.

[0032] The processing unit 202 has a conversion unit 211. The conversion unit 211 converts time information transmitted in a physical layer defined by the broadcasting method of terrestrial digital television broadcasting into time information in NTP (Network Time Protocol) format stored in a packet transmitted in an upper layer defined by the broadcasting method of digital cable television broadcasting.

[0033] The physical layer frame includes time information. The time information may be included in the physical layer control information or may be transmitted separately from the physical layer control information. In the following description, time information transmitted on the physical layer is also referred to as physical layer time information. Furthermore, time information in NTP format stored in a packet (e.g., IP / UDP packet) transmitted on a higher layer (e.g., transport layer) higher than the physical layer is also referred to as NTP time information.

[0034] The transmitting unit 203 transmits the cable broadcasting signal based on the signal supplied from the processing unit 202. The cable broadcasting signal is transmitted via a cable television transmission network.

[0035] (Configuration of receiving device) FIG. 4 is a block diagram showing an example of the configuration of the receiving device 30 of FIG.

[0036] In FIG. 4, the receiving device 30 includes a receiving unit 301 and a processing unit 302 .

[0037] The receiving unit 301 is composed of a tuner, a demodulation LSI (Large Scale Integration), etc. The receiving unit 301 performs necessary processing such as demodulation on a cable broadcast signal received via a cable television transmission network, and supplies packets storing the resulting broadcast stream data to the processing unit 302.

[0038] The processing unit 302 is configured by a main SoC (System On Chip), etc. The processing unit 302 performs necessary processing such as decoding processing and playback processing on the packets supplied from the receiving unit 301.

[0039] A broadcast stream includes broadcast components and upper layer control information. For example, in decoding and playback processes, the data of the broadcast components is decoded and played back based on the upper layer control information.

[0040] The video and audio data obtained through the decoding process, playback process, etc. is output to the subsequent circuit, whereby the receiving device 30 displays the video of the content such as a broadcast program on the display, and outputs the audio synchronized with the video from the speaker.

[0041] In the transmission system of Figure 1 configured as described above, the broadcast stream generated by the transmitting device 10 is retransmitted by the retransmission device 20, and is received and processed by the receiving device 30 via the cable television transmission network, making it possible to view content such as broadcast programs.

[0042] In the above-described configuration, the transmission device 10 includes the generation unit 101 and the transmission unit 102, but the generation unit 101 and the transmission unit 102 may be provided in separate devices. In other words, the transmission system may be configured as a transmission system including a device including the generation unit 101 and a device including the transmission unit 102.

[0043] In the above-described configuration, the retransmission device 20 has the receiving unit 201, the processing unit 202, and the transmitting unit 203, but the receiving unit 201, the processing unit 202, and the transmitting unit 203 may be provided in separate devices. Furthermore, in the above-described configuration, the case where there is one receiving device 30 is exemplified, but in reality, a plurality of receiving devices 30 are provided, and each is connected to a cable television transmission network.

[0044] (Broadcasting method details) In Japan, ISDB-T (Integrated Services Digital Broadcasting - Terrestrial) is currently used as the broadcasting standard for terrestrial digital television broadcasting, but studies are underway on a next-generation standard for terrestrial digital television broadcasting. In this next-generation standard for terrestrial digital television broadcasting, control information will be transmitted along with the broadcast stream via multiple paths using TMCC (Transmission Multiplexing Configuration Control) and LLch (Low Latency Channel).

[0045] Figure 5 is a diagram showing an example of a protocol stack for next-generation terrestrial digital television broadcasting. In the protocol stack of Figure 5, terrestrial broadcasting, which is the lowest layer, corresponds to the physical layer, and TMCC and LLch are transmitted as physical layer control information. TMCC is transmission multiplex control information. LLch transmits additional information related to broadcasting. In addition, physical layer time information is transmitted in the physical layer.

[0046] Next-generation terrestrial digital television broadcasting will use the IP (Internet Protocol) method, which uses TLV (Type Length Value) packets to transmit IP / UDP packets over broadcast transmission paths. IP / UDP packets are IP packets that contain UDP (User Datagram Protocol) packets. TLV packets are variable-length packets. When the IP method is used, the MMT (MPEG Media Transport) method can be used as the media transport method (transport protocol).

[0047] The MMT method is a method for transmitting multimedia content using a variety of networks, including broadcasting and communications. Using the MMT method, data such as video, audio, subtitles, control information, and applications are loaded into the MMTP (MMT Protocol) payload in a specified format, converted into MMTP packets, and stored in IP / UDP packets. The IP / UDP packets are then stored in TLV packets and encapsulated, and the resulting broadcast stream is transmitted as a terrestrial broadcast signal.

[0048] MMT-SI (Signaling Information) is control information that includes the configuration of a broadcast program. MMT-SI is upper layer control information that is transmitted in the upper layer, the transport layer. IP / UDP packets can store and transmit data such as time information and content. The time information is information about time specified in NTP format. The MMT method is specified, for example, in Document A below.

[0049] Document A: ARIB STD-B60 1.6 Edition Association of Radio Industries and Businesses

[0050] It is anticipated that content such as broadcast programs broadcast on next-generation terrestrial digital television broadcasting will be retransmitted via digital cable television broadcasting. When retransmission via digital cable television broadcasting is performed using a transmodulation method, it is necessary to change the modulation method used for terrestrial digital television broadcasting to the modulation method used for digital cable television broadcasting.

[0051] When such retransmission is performed, there is no path to transmit the time information transmitted on the physical layer specified in the terrestrial digital television broadcasting broadcasting system, and the time information cannot be transmitted properly.The terrestrial digital television broadcasting broadcasting system and the digital cable television broadcasting broadcasting system are standardized independently, so there is no agreement on a system that harmonizes them.

[0052] 1, in the retransmission device 20, the conversion unit 211 of the processing unit 202 converts the physical layer time information transmitted in the physical layer specified in the broadcasting format of terrestrial digital television broadcasting into NTP time information stored in packets transmitted in the upper layer specified in the broadcasting format of digital cable television broadcasting, thereby enabling the time information to be appropriately processed and transmitted. As a result, the receiving device 30 that receives digital cable television broadcasting can easily receive NTP time information converted from the physical layer time information transmitted in the physical layer specified in the broadcasting format of terrestrial digital television broadcasting, and can perform processing based on the NTP time information.

[0053] The following describes in detail the conversion process performed by the conversion unit 211 of the processing unit 202 in the retransmission device 20. Here, two methods, a first method and a second method, are exemplified as the conversion process.

[0054] (First method) In the first method, the retransmission device 20 converts the physical layer time information from the transmission device 10 into NTP time information, and a TLV packet including an IP / UDP packet storing the NTP time information is transmitted to the reception device 30.

[0055] FIG. 6 is a diagram showing an example of a protocol stack at the time of retransmission by digital cable television broadcasting.

[0056] The protocol stack in Fig. 6 differs from the protocol stack in Fig. 5 in the following respects: In other words, in the protocol stack in Fig. 6, the broadcast corresponding to the physical layer represents digital cable television broadcast (cable broadcast) rather than terrestrial digital television broadcast (terrestrial broadcast). When the transmodulation method is used for retransmission by digital cable television broadcast, there is no appropriate path for transmitting physical layer time information, and therefore physical layer control information including physical layer time information is not shown.

[0057] In the protocol stack of Figure 6, time information is transmitted in the upper layer, the transport layer, as shown in the area enclosed by the thick line frame. Packets transmitted in the transport layer include IP / UDP packets and TLV packets. In the first method, physical layer time information is converted into NTP time information, and then the NTP time information can be stored in an IP / UDP packet. In addition, the IP / UDP packet containing the NTP time information can be stored in a TLV packet.

[0058] In this way, in the first method, the physical layer time information can be converted into an IP / UDP packet that stores NTP time information. Also, in the first method, the physical layer time information can be converted into a TLV packet that includes an IP / UDP packet that stores NTP time information. Figure 7 shows an example of the arrangement of NTP time information. In Figure 7, an NTP packet that includes NTP time information is stored in the payload of an IP / UDP packet.

[0059] FIG. 8 is a diagram illustrating an example of the syntax of the NTP time information.

[0060] The 2-bit leap_indicator indicates whether to insert or delete a leap second in the last minute of the current month. The 3-bit version indicates the version of NTP. The 3-bit mode indicates the operating mode of NTP.

[0061] The 8-bit stratum indicates the stratum and is coded accordingly. The 8-bit poll indicates the poll interval according to the maximum interval between successive NTP messages. The 8-bit precision indicates the accuracy of the system clock.

[0062] The 32-bit root_delay indicates the round-trip delay to the reference time in NTP short format. The 32-bit root_dispersion indicates the dispersion of the total delay to the reference time in NTP short format. The 32-bit reference_identification indicates an identifier representing the reference time.

[0063] The 64-bit reference_timestamp indicates the time the system time was last corrected in NTP long format. The 64-bit origin_timestamp indicates the time the client sent the request to the server in NTP long format.

[0064] The 64-bit receive_timestamp indicates the time of the server when it received the request from the client in NTP long format. The 64-bit transmit_timestamp indicates the time of the server when it sent the response to the client in NTP long format.

[0065] In the retransmission device 20, the conversion unit 211 of the processing unit 202 converts the physical layer time information from the transmission device 10 into NTP time information having the NTP format structure shown in FIG.

[0066] Fig. 9 is a diagram showing an example of conversion from physical layer time information to NTP time information. Fig. 9 shows how physical layer time information is converted in accordance with the NTP format shown in Fig. 8.

[0067] In leap_indicator, leap second control information relating to the control of leap seconds included in the physical layer time information transmitted in the physical layer defined by the broadcasting system of terrestrial digital television broadcasting is placed.

[0068] In broadcasting systems such as digital cable television broadcasting, the version field stores a fixed value of '4'. In broadcasting systems, the mode field stores a fixed value of '5'. The operating mode of '5' means broadcast.

[0069] In the broadcasting system, a fixed value of '0' is stored in stratum. In the broadcasting system, a fixed value of '0' is stored in poll. In the broadcasting system, a fixed value of '0' is stored in precision.

[0070] In the broadcasting system, a fixed value of '0' is stored in root_delay. In the broadcasting system, a fixed value of '0' is stored in root_dispersion. In the broadcasting system, a fixed value of '0' is stored in reference_identification. NULL (0000) is stored.

[0071] In the broadcasting system, a fixed value of '0' is stored in the reference_timestamp, a fixed value of '0' is stored in the origin_timestamp, and a fixed value of '0' is stored in the receive_timestamp.

[0072] The transmit_timestamp contains NTP format time information that corresponds to the physical layer time information transmitted in the physical layer specified in the terrestrial digital television broadcasting standard. The format of the physical layer time information is not particularly limited, but since there is a limit to the amount of information that can be transmitted in the physical layer, a predetermined format that corresponds to the amount of information that can be transmitted can be used.

[0073] In this way, by inserting a predetermined fixed value in addition to the specific information including leap_indicator and transmit_timestamp, the physical layer time information can be converted into NTP time information. Even if the information other than the specific information is set to a fixed value, the receiving device 30 can operate normally because it contains the information necessary as time information used in processing in the receiving device 30.

[0074] Here, since the physical layer time information is transmitted over the physical layer, there is a limit to the amount of information that can be transmitted, so it is assumed that not much information can be transmitted. However, if the minimum amount of information necessary as physical layer time information is transmitted, the conversion unit 211 can convert the physical layer time information into NTP time information.

[0075] For example, even if time information in NTP format cannot be transmitted on the physical layer, it is possible to transmit time information in NTP format on a higher layer by converting the minimum necessary information transmitted as physical layer time information into NTP time information by the converter 211. In this example, the physical layer time information transmits a total of 66 bits of information as the minimum necessary information (specific information), consisting of leap second control information corresponding to the 2-bit leap_indicator and time information in a predetermined format corresponding to the 64-bit transmit_timestamp.

[0076] In the syntax example in Figure 8, transmit_timestamp is defined as 64 bits, but if the clock precision is more than sufficient, it is possible to use only a portion of the 64 bits. In other words, the number of significant digits of the time information does not need to use 64 bits, and the number of bits in transmit_timestamp can be reduced to less than 64 bits, such as 48 bits.

[0077] As described above, the retransmission device 20 can convert the physical layer time information transmitted from the transmission device 10 at the physical layer into a TLV packet including an IP / UDP packet storing NTP time information and transmit it at a higher layer. This allows the reception device 30 to receive the NTP time information transmitted at a higher layer from the retransmission device 20 and process it appropriately.

[0078] (Second method) In the first method described above, a configuration is explained in which TLV packets are used as transmission packets when a broadcast program broadcast on a next-generation terrestrial digital television broadcasting system is retransmitted by digital cable television broadcasting.In contrast, in the second method, a configuration is explained in which ALP (ATSC Link-layer Protocol) packets are used as transmission packets when performing retransmission operations in accordance with the ATSC3.0 (Advanced Television Systems Committee 3.0) broadcasting system.

[0079] Figure 10 is a diagram showing an example of a protocol stack for ATSC 3.0. In the protocol stack of Figure 10, broadcasting and communication correspond to the physical layer, and the protocol stack supports both broadcasting and communication transmission paths. In addition, in the protocol stack of Figure 10, when the physical layer is broadcasting, the protocol stack supports both the ROUTE (Real-Time Object Delivery over Unidirectional Transport) method and the MMT method as media transport methods.

[0080] In the ROUTE method, video, audio, subtitle, and other data is processed as DASH segments defined by MPEG-DASH (Dynamic Adaptive Streaming over HTTP) and stored in IP / UDP packets, which are IP packets containing UDP packets. The IP / UDP packets are then stored and encapsulated in ALP packets, which serve as transmission packets, and the resulting broadcast stream is transmitted as a broadcast signal.

[0081] In the protocol stack of Figure 10, packets transmitted in the upper transport layer include IP / UDP packets and ALP packets. In the second method, after converting physical layer time information into NTP time information, the NTP time information can be stored in an IP / UDP packet. In addition, the IP / UDP packet containing the NTP time information can be stored in an ALP packet.

[0082] In this way, in the second method, the physical layer time information can be converted into an IP / UDP packet that stores NTP time information. Also, in the second method, the physical layer time information can be converted into an ALP packet that includes an IP / UDP packet that stores NTP time information. The ALP packet is specified, for example, in the following document B.

[0083] Document B: ATSC Standard: "Signaling, Delivery, Synchronization, and Error Protection (A / 331)", Doc. A / 331:2019 20 June 2019

[0084] When retransmission is performed in accordance with broadcasting standards such as DVB-T2 (Digital Video Broadcasting - Terrestrial 2), GSE (Generic Stream Encapsulation) packets can be used as transmission packets. In this operation, after converting physical layer time information to NTP time information, the IP / UDP packets containing the NTP time information can be stored in GSE packets. GSE packets are specified, for example, in the following document C.

[0085] Document C: ETSI TS 102 606-1 "Digital Video Broadcasting (DVB);Generic Stream Encapsulation (GSE) Protocol"

[0086] (Process flow) Next, the processing flow of each device in the transmission system of Fig. 1 will be described with reference to the flowchart of Fig. 11. Here, the explanation will be given taking as an example an operation in which a broadcast program broadcasted by terrestrial digital television broadcasting is retransmitted by digital cable television broadcasting.

[0087] First, a description will be given of the processes of steps S11 to S13 executed by the transmitting device 10. In step S11, the generating unit 101 generates physical layer time information.

[0088] In step S12, the transmitter 102 generates a physical layer frame conforming to the terrestrial digital television broadcasting standard. This physical layer frame includes physical layer time information. In step S13, the transmitter 102 transmits the physical layer frame as a terrestrial broadcast signal from a transmitting antenna installed at the transmitting station.

[0089] Next, a description will be given of the processes of steps S21 to S24 executed by the retransmission device 20. In step S21, the receiving unit 201 receives the terrestrial broadcast signal transmitted from the transmission device 10 via an antenna.

[0090] In step S22, the converter 211 converts the physical layer time information transmitted in the physical layer defined by the terrestrial digital television broadcasting standard into NTP time information transmitted in the upper layer defined by the digital cable television broadcasting standard, for example, using the first standard described above. The NTP time information is stored in an IP / UDP packet. The IP / UDP packet containing the NTP time information is stored in a TLV packet.

[0091] In step S23, the processing unit 202 performs processing corresponding to the transmodulation method. In step S24, the transmitting unit 203 transmits the cable broadcasting signal to the cable television transmission network. This cable broadcasting signal includes NTP time information transmitted in the upper layer.

[0092] Next, a description will be given of the processes of steps S31 to S33 executed by the receiving device 30. In step S31, the receiving unit 301 receives a cable broadcast signal via a cable television transmission network.

[0093] In step S32, the receiving unit 301 performs necessary processing such as demodulation on the received cable broadcast signal, and outputs a TLV packet storing the resulting NTP time information.

[0094] In step S33, the processing unit 302 performs a predetermined process based on the NTP time information output from the receiving unit 301. This NTP time information is time information in NTP format obtained by converting physical layer time information transmitted in the physical layer specified in the broadcasting format of terrestrial digital television broadcasting. The processing unit 302 also processes the broadcast stream, and decodes and plays back the data of the broadcast component based on the upper layer control information.

[0095] As described above, the retransmission device 20 converts the physical layer time information transmitted at the physical layer specified in the broadcasting method for terrestrial digital television broadcasting into NTP time information transmitted at the upper layer specified in the broadcasting method for digital cable television broadcasting, thereby enabling the receiving device 30 to process the time information appropriately.

[0096] <2. Second embodiment>

[0097] (Transmission system configuration) FIG. 12 is a block diagram showing another example configuration of an embodiment of a transmission system to which the present disclosure is applied.

[0098] In FIG. 12, the transmission system includes a transmitting device 10, a retransmitting device 20A, a receiving device 30, and a server 40.

[0099] The transmitting device 10 generates a broadcast stream, performs necessary processing, and transmits the resulting terrestrial broadcast signal from a transmitting antenna installed at a transmitting station.

[0100] The server 40 is a distribution server that distributes content and the like in response to requests from devices connected to a network such as the Internet. The server 40 generates a communication stream, performs necessary processing, and transmits the resulting communication signal to the retransmission device 20A via a network such as the Internet.

[0101] The communication stream includes communication components that constitute content such as a program, control information related to the communication components, time information, etc. The communication components include components such as a video stream, an audio stream, and a subtitle stream.

[0102] The retransmission device 20A performs necessary processing on a terrestrial broadcast signal received via an antenna and transmits the resulting cable broadcast signal (RF signal) to a cable television transmission network. The retransmission device 20A also receives a communication signal transmitted from a server 40 via a network such as the Internet. The retransmission device 20A performs necessary processing on the communication signal received from the server 40 and transmits the resulting cable broadcast signal (IP signal) to the cable television transmission network.

[0103] The receiving device 30 is a fixed receiver such as a television set. The receiving device 30 receives a cable broadcast signal (RF signal, IP signal) transmitted from the retransmission device 20A via a cable television transmission network. The receiving device 30 processes at least one of a broadcast stream and a communication stream obtained from the cable broadcast signal (RF signal, IP signal), thereby outputting video and audio of content such as a broadcast program. This allows a user to view content such as a broadcast program.

[0104] (Configuration of retransmission device) FIG. 13 is a block diagram showing an example of the configuration of the retransmission device 20A of FIG.

[0105] 13, the retransmission device 20A is made up of a receiving unit 201, a transmitting unit 203, a converting unit 211, a buffer 221, a communication unit 231, a comparing unit 232, a buffer 233, and a transmitting unit 234. The converting unit 211, the buffer 221, the comparing unit 232, and the buffer 233 are included in the processing unit 202.

[0106] In the retransmission device 20A in FIG. 13, parts corresponding to those in the retransmission device 20 in FIG. 3 are given the same reference numerals, and the description thereof will be omitted as appropriate.

[0107] The receiving unit 201 receives a terrestrial broadcast signal transmitted from the transmitting device 10 via an antenna. The processing unit 202 performs necessary processing on the signal output from the receiving unit 201, and stores the resulting broadcast component data in a buffer 221. The converting unit 211 converts physical layer time information transmitted in the physical layer defined by the terrestrial digital television broadcasting standard into NTP time information and supplies it to the comparing unit 232.

[0108] The communication unit 231 receives a communication signal transmitted from the server 40 via a network such as the Internet and performs necessary processing. The processing unit 202 performs necessary processing on the signal output from the communication unit 231 and stores the resulting communication component data in a buffer 233. The processing unit 202 also acquires time information in NTP format included in the communication stream and supplies it to the comparison unit 232.

[0109] The comparison unit 232 is supplied with the NTP time information from the conversion unit 211 and the time information in NTP format acquired via communication. The comparison unit 232 compares the NTP time information with the time information in NTP format acquired via communication. Based on the comparison result by the comparison unit 232, the processing unit 202 adjusts the delay occurring between the broadcast component data stored in the buffer 221 and the communication component data stored in the buffer 233.

[0110] Through delay adjustment control by processing unit 202, the broadcast component data stored in buffer 221 and the communication component data stored in buffer 233 are output at appropriate timing to transmitting unit 203 and transmitting unit 234, respectively. Transmitting unit 203 performs necessary processing on the broadcast component data output from buffer 221, and transmits the resulting cable broadcast signal (RF signal) to the cable television transmission network. Transmitting unit 234 performs necessary processing on the communication component data output from buffer 233, and transmits the resulting cable broadcast signal (IP signal) to the cable television transmission network.

[0111] The receiving device 30 receives a cable broadcast signal (RF signal, IP signal) transmitted from the retransmission device 20A via a cable television transmission network and performs the necessary processing to output video and audio of content such as a broadcast program. For example, it is assumed that a service will be provided by combining a broadcast component transmitted via broadcasting and a communication component transmitted via communication, and even when such a service is provided, it is possible to synchronize the components transmitted via different routes by adjusting the delay between them.

[0112] As described above, the retransmission device 20A compares the NTP time information obtained by converting the physical layer time information transmitted in the physical layer specified in the broadcasting system of terrestrial digital television broadcasting with the NTP format time information acquired via communication, and based on the comparison result, can adjust the delay between the broadcast signal (RF signal) acquired via broadcasting and the communication signal (IP signal) acquired via communication. In this way, by adjusting the signal delay on the retransmission device 20A side, the receiving device 30 can output a synchronized signal without adjusting the signal delay.

[0113] <3. Third Embodiment>

[0114] (Transmission system configuration) FIG. 14 is a block diagram showing yet another exemplary configuration of an embodiment of a transmission system to which the present disclosure is applied.

[0115] In FIG. 14, the transmission system is made up of a transmitting device 10 and a receiving device 30A.

[0116] The transmitting device 10 generates a broadcast stream, performs necessary processing, and transmits the resulting terrestrial broadcast signal from a transmitting antenna installed at a transmitting station.

[0117] The receiving device 30A is a fixed receiver such as a television set. The receiving device 30A receives the terrestrial broadcast signal transmitted from the transmitting device 10 via an antenna. The receiving device 30A processes the broadcast stream obtained from the terrestrial broadcast signal to output video and audio of content such as a broadcast program. This allows the user to view content such as a broadcast program.

[0118] (Configuration of receiving device) FIG. 15 is a block diagram showing an example of the configuration of the receiving device 30A of FIG.

[0119] 15, the receiving device 30A includes a receiving unit 301A and a processing unit 302. The receiving unit 301A includes a conversion unit 311.

[0120] The receiving unit 301A is composed of a tuner, a demodulation LSI, etc. The receiving unit 301A performs necessary processing such as demodulation processing on the terrestrial broadcast signal received from the transmitting device 10 via the antenna, and supplies packets storing the resulting broadcast stream data to the processing unit 302.

[0121] The converter 311 is included in a demodulator device such as a demodulator LSI. The converter 311 converts physical layer time information transmitted in the physical layer defined by the terrestrial digital television broadcasting standard into NTP time information transmitted in a higher layer such as the transport layer. This NTP time information is stored in an IP / UDP packet. The IP / UDP packet storing the NTP time information is stored in a TLV packet. The TLV packet storing the NTP time information is output to the processor 302.

[0122] The processing unit 302 is composed of a main SoC and the like. The processing unit 302 performs necessary processing such as decoding and playback on packets supplied from the receiving unit 301A. Data such as video and audio obtained through processing such as decoding and playback is output to a subsequent circuit. As a result, in the receiving device 30A, video of content such as a broadcast program is displayed on the display, and audio synchronized with the video is output from the speaker.

[0123] Furthermore, the processing unit 302 performs predetermined processing based on the NTP time information stored in the TLV packet supplied from the receiving unit 301 A. This NTP time information is time information in NTP format obtained by converting physical layer time information transmitted in the physical layer specified in the broadcasting format of terrestrial digital television broadcasting.

[0124] In the transmission system of Figure 14 configured as described above, in receiving device 30A, conversion unit 311 of receiving unit 301A converts the physical layer time information transmitted at the physical layer specified in the broadcasting method of terrestrial digital television broadcasting transmitted from transmitting device 10 into NTP time information transmitted at a higher layer such as the transport layer, and outputs a packet including the NTP time information to processing unit 302 at the subsequent stage.

[0125] With this configuration, receiving device 30A can multiplex and output NTP time information obtained by converting physical layer time information transmitted in the physical layer defined by the broadcasting standard of terrestrial digital television broadcasting with data, without increasing the number of output signals of the demodulation device having conversion unit 311. This allows processing unit 302, which is made up of a main SoC, to process the NTP time information output from receiving unit 301A, which includes a demodulation device, at an appropriate timing.

[0126] (Process flow) Next, the flow of processing by each device in the transmission system of FIG. 14 will be described with reference to the flowchart of FIG.

[0127] First, we will explain the processing of steps S111 to S113 executed by the transmitting device 10. In steps S111 to S113, similar to steps S11 to S13 in Fig. 11, a physical layer frame including physical layer time information is transmitted as a terrestrial broadcast signal from a transmitting antenna installed at a transmitting station.

[0128] Next, the processes of steps S131 to S134 executed by the receiving device 30A will be described. In step S131, the receiving unit 301A receives the terrestrial broadcast signal transmitted from the transmitting device 10 via the antenna.

[0129] In step S132, the conversion unit 311 converts the physical layer time information transmitted in the physical layer defined by the terrestrial digital television broadcasting standard into NTP time information transmitted in a higher layer such as the transport layer, using, for example, the first or second standard described above. In step S133, the receiving unit 301A outputs a TLV packet storing the NTP time information.

[0130] In step S134, the processing unit 302 performs a predetermined process based on the NTP time information output from the receiving unit 301. This NTP time information is NTP format time information obtained by converting physical layer time information transmitted in the physical layer specified in the broadcasting format of terrestrial digital television broadcasting. The processing unit 302 also processes the broadcast stream, and decodes and plays back the data of the broadcast component based on the upper layer control information.

[0131] As described above, in the receiving device 30A, the conversion unit 311 converts the physical layer time information transmitted at the physical layer specified in the broadcasting format of terrestrial digital television broadcasting into NTP time information transmitted at a higher layer such as the transport layer, thereby enabling the processing unit 302 to process the time information appropriately.

[0132] <4. Modifications>

[0133] (Other broadcasting systems) In the above explanation, we have mainly described the operation of retransmitting content such as broadcast programs broadcast by next-generation terrestrial digital television broadcasting via digital cable television broadcasting, but it may also be applied to combinations of other broadcasting methods. For example, broadcasting methods such as satellite digital broadcasting using broadcasting satellites (BS) and communications satellites (CS) can be applied. Furthermore, the digital broadcasting method is not limited to ISDB, and broadcasting methods specified by DVB, ATSC, etc. may also be used in combination.

[0134] (Another example of a receiving device) In the above description, the receiving device 30 or the receiving device 30A is exemplified by devices capable of receiving broadcast signals, such as a television receiver or a set-top box, but the receiving device 30 or the receiving device 30A may have a communication function for performing communication via a communication line (communication network) such as the Internet or a telephone network. In this case, the receiving device 30 performs two-way communication with a server via a communication line such as the Internet.

[0135] In the above description, the receiving device 30 or the receiving device 30A is described as a fixed receiver such as a television receiver or a set-top box, but the receiving device 30 or the receiving device 30A may be a mobile receiver such as a smartphone, a mobile phone, or a tablet computer, or an in-vehicle receiver mounted in a vehicle such as an in-vehicle television. In this specification, a system refers to a logical collection of multiple devices.

[0136] (Name of descriptor, etc.) Other names may be used for the above-mentioned descriptors, fields, packets, streams, etc. For example, a TLV packet may be called an ALP packet or a GSE packet. The difference between these names is a formal difference and does not affect the actual content of the target descriptors, etc.

[0137] (Computer Configuration) The above-described series of processes can be executed by hardware or software. When the series of processes is executed by software, a program constituting the software is installed in a computer. Fig. 17 is a block diagram showing an example of the hardware configuration of a computer that executes the above-described series of processes by a program.

[0138] In the computer, a CPU (Central Processing Unit) 1001, a ROM (Read Only Memory) 1002, and a RAM (Random Access Memory) 1003 are interconnected by a bus 1004. An input / output interface 1005 is further connected to the bus 1004. An input unit 1006, an output unit 1007, a storage unit 1008, a communication unit 1009, and a drive 1010 are connected to the input / output interface 1005.

[0139] The input unit 1006 includes a keyboard, a mouse, a microphone, etc. The output unit 1007 includes a display, a speaker, etc. The storage unit 1008 includes a hard disk, a non-volatile memory, etc. The communication unit 1009 includes a network interface, etc. The drive 1010 drives a removable recording medium 1011 such as a semiconductor memory, a magnetic disk, an optical disk, or a magneto-optical disk.

[0140] In a computer configured as described above, the CPU 1001 loads a program recorded in the ROM 1002 or memory unit 1008 into the RAM 1003 via the input / output interface 1005 and the bus 1004 and executes it, thereby performing the above-mentioned series of processes.

[0141] The program executed by the computer (CPU 1001) can be provided by being recorded on a removable recording medium 1011 such as a package medium, for example. The program can also be provided via a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting.

[0142] In a computer, the program can be installed in the storage unit 1008 via the input / output interface 1005 by inserting the removable recording medium 1011 into the drive 1010. The program can also be received by the communication unit 1009 via a wired or wireless transmission medium and installed in the storage unit 1008. Alternatively, the program can be installed in the ROM 1002 or the storage unit 1008 in advance.

[0143] Here, in this specification, the processing performed by a computer according to a program does not necessarily have to be performed chronologically in the order described in the flowchart. In other words, the processing performed by a computer according to a program also includes processing executed in parallel or individually (for example, parallel processing or object-based processing). Furthermore, the program may be processed by one computer (processor), or may be processed in a distributed manner by multiple computers.

[0144] It should be noted that the embodiments of the present disclosure are not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present disclosure. Furthermore, the effects described in this specification are merely examples and are not intended to be limiting, and other effects may also be obtained.

[0145] The present disclosure can also be configured as follows.

[0146] (1) a receiving unit that receives a broadcast signal in a first broadcasting system; a conversion unit that converts first time information transmitted in a physical layer defined in the first broadcasting system into second time information in an NTP format stored in a packet transmitted in an upper layer that is a layer higher than the physical layer defined in a second broadcasting system different from the first broadcasting system; a transmitting unit that transmits a broadcast signal of the second broadcasting system; A retransmission device comprising: (2) the upper layer is a transport layer, The packet is an IP / UDP packet. The retransmission device according to (1) above. (3) the first time information includes specific information related to time, The conversion unit converts the first time information into the second time information including the specific information and a predetermined fixed value. The retransmission device according to (2) above. (4) The specific information includes at least control information related to leap second control and time information in a predetermined format. The retransmission device according to (3) above. (5) the first broadcasting system is a terrestrial digital television broadcasting system, The second broadcasting system is a digital cable television broadcasting system. The retransmission device according to any one of (2) to (4). (6) The conversion unit converts the first time information into a TLV packet including an IP / UDP packet storing the second time information. The retransmission device according to (5) above. (7) The second broadcasting system is a broadcasting system conforming to ATSC3.0, The conversion unit converts the first time information into an ALP packet including an IP / UDP packet storing the second time information. The retransmission device according to any one of (2) to (4). (8) a communication unit that communicates with a server via a network; a comparison unit that compares the second time information with NTP format time information acquired via communication; Furthermore, Based on the comparison result by the comparison unit, a delay between the broadcast signal of the second broadcasting system and the communication signal acquired via communication is adjusted. The retransmission device according to any one of (1) to (7). (9) The retransmission device receiving a broadcast signal in a first broadcasting system; converting first time information transmitted in a physical layer defined in the first broadcasting system into second time information in an NTP format stored in a packet transmitted in an upper layer that is a layer higher than the physical layer defined in a second broadcasting system different from the first broadcasting system; Transmitting a broadcast signal of the second broadcasting system How to resend. (10) a receiving unit that receives and demodulates a broadcast signal of a first broadcasting system; a processing unit that processes packets obtained by demodulating the broadcast signal; Equipped with the receiving unit has a conversion unit that converts first time information transmitted in a physical layer defined in the first broadcasting system into second time information in an NTP format stored in a packet transmitted in an upper layer that is a layer higher than the physical layer defined in a second broadcasting system different from the first broadcasting system; The processing unit processes a packet storing the second time information output from the receiving unit. Receiving device. (11) the upper layer is a transport layer, The packet is an IP / UDP packet. The receiving device according to (10) above. (12) the first time information includes specific information related to time, The conversion unit converts the first time information into the second time information including the specific information and a predetermined fixed value. The receiving device according to (11) above. (13) The specific information includes at least control information related to leap second control and time information in a predetermined format. The receiving device according to (12) above. (14) the first broadcasting system is a terrestrial digital television broadcasting system, The second broadcasting system is a digital cable television broadcasting system. The receiving device according to any one of (11) to (13). (15) The conversion unit converts the first time information into a TLV packet including an IP / UDP packet storing the second time information. The receiving device according to (14) above. (16) The second broadcasting system is a broadcasting system conforming to ATSC3.0, The conversion unit converts the first time information into an ALP packet including an IP / UDP packet storing the second time information. The receiving device according to any one of (11) to (13). (17) The conversion unit is included in a demodulation device. The receiving device according to any one of (10) to (16). (18) a receiving unit that receives and demodulates a broadcast signal of a first broadcasting system; a processing unit that processes packets obtained by demodulating the broadcast signal; A receiving method for a receiving device comprising: The receiving unit converts first time information transmitted in a physical layer defined in the first broadcasting system into second time information in an NTP format stored in a packet transmitted in an upper layer that is a layer higher than the physical layer defined in a second broadcasting system different from the first broadcasting system; The processing unit processes a packet storing the second time information output from the receiving unit. Receiving method. [Explanation of symbols]

[0147] 10 transmitting device, 20 retransmission device, 20A retransmission device, 30 receiving device, 30A receiving device, 40 server, 101 generation unit, 102 transmitting unit, 201 receiving unit, 202 processing unit, 203 transmitting unit, 211 conversion unit, 221 buffer, 231 communication unit, 232 comparison unit, 233 buffer, 234 transmitting unit, 301 receiving unit, 301A receiving unit, 302 processing unit, 311 conversion unit, 1001 CPU

Claims

1. a conversion unit that converts first time information transmitted in a physical layer defined in a first broadcasting system into second time information in an NTP format stored in a packet transmitted in an upper layer that is a layer higher than the physical layer defined in a second broadcasting system different from the first broadcasting system; the first time information includes specific information related to time, The conversion unit converts the first time information into the second time information including the specific information and a predetermined fixed value. Re-sending device.

2. the upper layer is a transport layer, The packet is an IP / UDP packet. The retransmission device according to claim 1 .

3. The specific information includes at least control information related to leap second control and time information in a predetermined format. The retransmission device according to claim 1 .

4. the first broadcasting system is a terrestrial digital television broadcasting system, The second broadcasting system is a digital cable television broadcasting system. The retransmission device according to claim 2.

5. The conversion unit converts the first time information into a TLV packet including an IP / UDP packet storing the second time information. The retransmission device according to claim 4.

6. The second broadcasting system is a broadcasting system conforming to ATSC3.0, The conversion unit converts the first time information into an ALP packet including an IP / UDP packet storing the second time information. The retransmission device according to claim 2.

7. a comparison unit that compares the second time information with NTP format time information acquired from a server via communication, Based on the comparison result by the comparison unit, a delay between the broadcast signal of the second broadcasting system and the communication signal acquired via communication is adjusted. The retransmission device according to claim 1 .

8. The retransmission device converting first time information transmitted in a physical layer defined in a first broadcasting system into second time information in an NTP format stored in a packet transmitted in an upper layer that is a layer higher than the physical layer defined in a second broadcasting system different from the first broadcasting system; the first time information includes specific information related to time, converting the first time information into the second time information including the specific information and a predetermined fixed value. How to resend.

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