JP2018157467A - Multiplexing device, switching device, transmission system, and transmission method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To implement seamless switching without the need to analyze video data or audio data by identifying a switching point of a TLV packet between a main system and a redundant system.SOLUTION: A multiplexing device comprises: a detection part for detecting an MMTP packet corresponding to a switching point between a main system and a redundant system from the MMTP packet that is converted into a TLV packet; a TLV conversion part which converts the MMTP packet into the TLV packet; a multiplexing part which multiplexes the TLV packet; a main signal generation part which connects the multiplexed TLV packets to generate a main signal and connects null TLV packets in a predetermined constitution at the switching point to generate a main signal; a TMCC generation part which generates TMCC basic information from constitution information of the main signal; and a slot generation part which combines the main signal and the TMCC information to generate a TLV slot.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a multiplexing device, a switching device, a transmission system, and a transmission method for a hybrid content distribution service that links broadcasting and communication.

  Conventionally, an MMT (MPEG Media Transport) system has been adopted as a data multiplexing system for 4K and 8K broadcasting as a new multiplexing system for realizing a hybrid content distribution service that links broadcasting and communication. In a transmission system, a redundant configuration composed of two or more systems may be assembled so that functions can be maintained even when a failure occurs. If a failure occurs in the main system or maintenance is required, switching from the main system to the redundant system is performed by the switching device. Therefore, such a switching device is desired to seamlessly switch between the main system and the redundant system as much as possible. Non-Patent Document 1 describes “MMT Operation Guidelines at Redundant System Switching” as a specific operation rule.

  The “MMT operation guideline for redundant system switching” describes the transmission side guideline and the reception side guideline. Specifically, the transmission side guideline includes the following description.

(Guideline T1.1)
The redundant transmission system should match the GOP (Group of Pictures) phase with the main transmission system as much as possible. In addition, system switching should be performed in consideration of matching with pointer slot information transmitted two frames ahead of the main line signal. Switching in consideration of the consistency of the relationship between MPU (Media Processing Unit) time stamp and MPU.

(Guideline T1.2)
If the processing contents change, to prevent the version number from changing due to redundancy switching, further change the version number on the sending side.

(Guideline T1.3)
System switching should be performed with audio muted as much as possible.

  When the main system and the redundant system are seamlessly switched in accordance with such a transmission side guideline, a process for aligning the GOP phases of the main system and the redundant system is performed by the encoding device, and a switching point is created in the video data and the audio data. Is done.

  Accordingly, the switching point is identified by the switching device, and the system switching from the main system to the redundant system is performed at the switching point.

ARIB TR-B39 1.2 Edition Vol.7 Chapter 5 5.6 MMT Operation Guidelines for Redundant System Switching ARIB STD-B60 version 1.8

  However, such conventional methods have the following problems.

  That is, since the transmission format of the TLV slot cannot add information indicating a switching point, the switching device needs to analyze video data, audio data, and the like stored in the TLV slot in order to identify the switching point. There is a problem that an analysis processing load is applied.

  The problem to be solved by the present invention is to provide a multiplexing device that makes it possible to identify a switching point of a TLV slot between a main system and a redundant system. This also provides a switching device, a transmission system, and a transmission method that enable seamless switching of TLV slots between the main system and the redundant system without analyzing video data, audio data, and the like. is there.

  The transmission system of the embodiment includes a multiplexing device provided in each of the main system and the redundant system, and a switching device for performing switching between the main system and the redundant system. The multiplexing apparatus includes a first detection unit that detects an MMTP packet corresponding to a switching point between the primary system and the redundant system from an MMTP packet that is converted into a TLV packet, and a TLV conversion unit that converts the MMTP packet into a TLV packet. And a multiplexing unit that multiplexes TLV packets and a multiplexed TLV packet to generate a main signal (TLV), and at a switching point, a null TLV packet of a predetermined configuration is linked to generate a main signal (TLV). A main signal generation unit that generates TMCC basic information from the configuration information of the main signal (TLV), and a slotting unit that generates a TLV slot by combining the main signal (TLV) and the TMCC information. Prepare. The switching device has a second configuration that detects a null packet from the TLV slot, an identification unit that identifies that the null packet detected by the second detection unit has a predetermined configuration, and a predetermined configuration. And a switching unit that performs switching between the main system and the redundant system using the TLV slot in which the null packet identified as “a” is multiplexed as a switching point. A null TLV packet is a TLV packet whose packet type value is 0xFF.

It is a block diagram which shows the example of whole structure of the transmission system with which the transmission method of embodiment of this invention was applied. It is a block diagram which shows the structural example of an encoding apparatus. It is a figure which shows the structure of the MMTP packet defined by ARIB STD-B60. It is a figure which shows the structure of the MMTP payload defined by ARIB STD-B60. It is a block diagram which shows the structural example of a TLV multiplexing apparatus. It is a figure which shows the transmission format between the broadcaster and uplink station defined by ARIB TR-B39. It is a figure explaining the structure of the TMCC basic information defined by ARIB TR-B39. It is a figure for demonstrating the null packet multiplexing to an invalid slot. It is a block diagram which shows the structural example of a redundant switching apparatus. It is a flowchart (1/3) which shows the operation example of the transmission system to which the transmission method of embodiment of this invention was applied. It is a flowchart (2/3) which shows the operation example of the transmission system to which the transmission method of embodiment of this invention was applied. It is a flowchart (3/3) which shows the operation example of the transmission system to which the transmission method of embodiment of this invention was applied. It is a figure which shows the example of the slot allocation in a TLV frame.

  A transmission system to which a transmission method according to an embodiment of the present invention is applied will be described below with reference to the drawings.

  FIG. 1 is a block diagram illustrating an overall configuration example of a transmission system 10 that transmits a TLV slot as an example of a transmission system to which a transmission method according to an embodiment of the present invention is applied.

  The transmission system 10 according to the embodiment of the present invention includes two systems, a main system and a redundant system, for transmitting a TLV slot which is an example of a broadcast signal. The transmission system 10 writes a field-programmable gate array (FPGA), a central processing unit (CPU) or a combination thereof, and a program memory (for example, a solid state drive (SSD) or a hard disk drive (HDD)) as needed. As a function necessary for carrying out the present embodiment, the main system includes an encoding device 20 (# 1), an MMT multiplexing device 30 (# 1), a scrambler, and the like. Bra 50 (# 1), IP multiplexer 60 (# 1), and TLV multiplexer 70 (# 1). As a redundant system, encoder 20 (# 2), MMT multiplexer 30 (# 2) ), A scrambler 50 (# 2), an IP multiplexer 60 (# 2), and a TLV multiplexer 70 (# 2), which are common to the main system and the redundant system downstream of the main system and the redundant system. And a redundant switching device 90. All of these functions are realized by causing the FPGA or CPU to execute a program stored in the program memory.

  Further, the transmission system 10 is configured so that external inputs are made to the encoding devices 20 (# 1), (# 2), the TLV multiplexing devices 70 (# 1), (# 2), and the redundancy switching device 90. Is connected to the external input device 100.

  FIG. 2 is a block diagram illustrating a configuration example of the encoding device 20.

  The encoding devices 20 (# 1) and (# 2) convert, for example, a video signal, an audio signal, and a caption signal input from a broadcast master system (not shown) into a broadcast signal in an MMTP (MPEG Media Transport Protocol) packet format. A switching control receiving unit 21, a GOP phase adjusting unit 22, a signal encoding unit 23, a switching information setting unit 24, and an MMTP packetizing unit 25. Since the encoding devices 20 (# 1) and (# 2) both have the same configuration, the following description of each component will be made without distinguishing between the main system and the redundant system.

  The signal encoding unit 23 receives, for example, a video signal, an audio signal, and a caption signal input from a broadcast master system (not shown), encodes (compresses) the received signals, and encodes (compresses) them. The video signal, the audio signal, and the caption signal are output to the switching information setting unit 24 and the MMTP packetizing unit 25, respectively.

  The switching control receiving unit 21 receives a request for switching between the main system and the redundant system from the external input device 100. When the switching control accepting unit 21 receives a switching request, the GOP phase adjusting unit 22, the switching information setting unit 24, and the MMTP packetizing unit 25 perform the main system and the redundant system as described below. The process for switching is executed.

  After receiving the request by the switching control receiving unit 21, the GOP phase adjusting unit 22 outputs an adjustment signal for aligning the GOP (Group of Pictures) phase of the video signal to the signal encoding unit 23.

  The switching information setting unit 24 sets a predetermined value (for example, 0) to an MPU (Media Processing Unit) sequence number included in the MMTP packet corresponding to the switching point between the main system and the redundant system determined based on the adjustment signal. Generate an instruction input to set Then, this instruction input is output to the MMTP packetization unit 25.

  FIG. 3 is a diagram showing a configuration of an MMTP packet defined in ARIB STD-B60, which is a standard of ARIB (Radio Industry Association). A 32-bit time stamp field is defined. Further, FIG. 4 is a diagram showing a configuration defined by ARIB STD-B60 of the MMTP payload indicated by a box at the end of the data structure of FIG. MPU_sequence_number indicated by a box in FIG. 4 is an MPU sequence number.

  The MMTP packetizing unit 25 packetizes the video signal, the audio signal, and the caption signal encoded (compressed) by the signal encoding unit 23 to generate respective MMTP packets. At this time, as instructed by the instruction input from the switching information setting unit 24, the value of the MPU sequence number of each MMTP packet is set.

  In this way, the MMTP packetizing unit 25 outputs the MMTP packets of the video signal, the audio signal, and the caption signal to the MMT multiplexing apparatus 30 in a state where the switching point can be identified.

  Note that the video master signal, the audio signal, and the caption signal are not always input from the broadcast master system to the encoding device 20, and only one or two of these signals are input. There may be cases. For example, when only the video signal is input from the broadcast master system to the encoding device 20, the encoding device 20 outputs only the MMTP packet of the video signal to the MMT multiplexing device 30. When the video signal and the audio signal are input from the broadcast master system to the encoding device 20, the encoding device 20 outputs the MMTP packet of the video signal and the MMTP packet of the audio signal to the MMT multiplexing device 30. That's it.

  The MMT multiplexing devices 30 (# 1) and (# 2) have the same configuration, and the MMTP packets (for example, output from the corresponding encoding devices 20 (# 1) and (# 2)) (for example, MMTP packets for video signals, MMTP packets for audio signals, and MMTP packets for captions) and MMTP packet format data output from an unillustrated EPG (electronic program guide) sending device, etc. Are output to the scrambler 50 of the same system. In addition, the MMT multiplexing devices 30 (# 1) and (# 2) also internally generate (reconstruct) MMT-SI such as a PA message as necessary.

  The scramblers 50 (# 1) and (# 2) have the same configuration, and the MMTP packets output from the corresponding MMT multiplexers 30 (# 1) and (# 2) Encryption for copyright protection is performed, and the encrypted MMTP packet is output to the IP multiplexer 60 of the same system. Since encryption is not essential, the scrambler 50 may not be provided.

  The IP multiplexers 60 (# 1) and (# 2) have the same configuration, and the MMTP packets output from the corresponding scramblers 50 (# 1) and (# 2) are not shown. It is multiplexed with IP packet format data from other devices. Then, the MMTP packet and the IP packet obtained as a result of multiplexing are output to the TLV multiplexing device 70 of the same system.

  FIG. 5 is a block diagram illustrating a configuration example of the TLV multiplexing device 70. The TLV multiplexer 70 detects the MMTP packet corresponding to the switching point between the primary system and the redundant system from the MMTP packets output from the IP multiplexing apparatus 60 of the same system, and the transmission format of the TLV slot at the switching point In addition, it is an apparatus for multiplexing MMTP packets into TLV slots by multiplexing null packets having a predetermined configuration.

  That is, the TLV multiplexer 70 includes a receiving unit 71, a filter unit 72, a sequence number acquisition unit 73, a switching point detection unit 74, and a TLV conversion unit 77 provided for each type of MMTP packet / IP packet to be input. I have. Further, one each of the switching control reception unit 75, the multiplexing unit 76, the TLV-SI generation unit 78, the null packet generation unit 79, the main signal generation unit 80, the TMCC generation unit 81, the slotting unit 82, and the transmission unit 85. I have.

  The receiving units 71 (# 1),... (#N) are provided for each MMTP packet / IP packet input to the TLV multiplexer 70, and receive the MMTP packet / IP packet, respectively. To the filter unit 72.

  The filter units 72 (# 1),... (#N) are provided corresponding to the receiving units 71 (# 1),... 71 (#n), respectively. 1) performs a filtering process on the MMTP packet / IP packet output from the receiving unit 71 (# 1), and the filtering unit 72 (# 2) outputs an MMTP packet output from the receiving unit 71 (# 2). The filter unit 72 (#n) performs a filtering process on the MMTP packet / IP packet output from the receiving unit 71 (#n). Then, the filtered MMTP packet / IP packet is output to the corresponding sequence number acquisition unit 73.

  Sequence number acquisition units 73 (# 1),... (#N) are provided corresponding to the filter units 72 (# 1),... (#N), respectively. The MMTP packet / IP packet output from 72 is output to the corresponding switching point detector 74. At the same time, the MPU sequence number is acquired from the MTTP payload (see FIG. 4) included in the MMTP packet (see FIG. 3) of the MMTP packets / IP packets output from the corresponding filter unit 72, and the acquired MPU sequence The number is output to the corresponding switching point detector 74.

  The switching control receiving unit 75 receives a request for switching between the main system and the redundant system from the external input device 100. Then, when the switching control reception unit 75 receives a switching request, the TLV multiplexing device 70 executes a process described later.

  Switching point detection units 74 (# 1),... (#N) are provided corresponding to sequence number acquisition units 73 (# 1),... 73 (#n), respectively. The MMTP packet / IP packet output from the sequence number acquisition unit 73 to be output to the corresponding TLV conversion unit 77, and the sequence number value output from the corresponding sequence number acquisition unit 73 is a predetermined value (for example, 0) is detected.

  For example, the switching point detection unit 74 (# 1) detects that the sequence number output from the sequence number acquisition unit 73 (# 1) has reached a predetermined value (for example, 0). Thereby, each switching point detection unit 74 detects an MMTP packet / IP packet corresponding to a switching point between the main system and the redundant system. Then, the detection result is output to the null packet generator 79.

  TLV converters 77 (# 1),... (#N) are provided corresponding to the switching point detectors 74 (# 1),. The MMTP packet / IP packet output by the point detection unit 74 is converted into a TLV packet.

  TLV conversion unit 77 (# 1),... (#N) outputs the converted TLV packet to multiplexing unit 76.

  The TLV-SI generation unit 78 generates TLV-SI and outputs it to the multiplexing unit 76.

  The null packet generation unit 79 generates a null packet that can identify the switching point based on the detection result output from the switching point detection unit 74 (# 1),. The data is output to the generation unit 80.

  The multiplexing unit 76 multiplexes the TLV packet from the TLV conversion unit 77 (# 1),... (#N) and the TLV packet (TLV-SI) from the TLV-SI generation unit, and the main signal generation unit. Output to 80.

  The main signal generation unit 80 concatenates the TLV packet output from the multiplexing unit multiplexing unit 76 and the null packet output from the null packet generation unit 79 to generate a main signal (TLV), and the TMCC generation unit 81 and the slot To the conversion unit 82.

  The TMCC generation unit 81 generates TMCC basic information based on position information of a TLV packet arranged in the main signal (TLV) generated by the main signal generation unit 80. Also, TMCC transmission information is generated according to the control of the external input device and output to the slotting unit 82.

  The slotting unit 82 combines the main signal (TLV) output from the main signal generation unit 80 and the TMCC information output from the TMCC generation unit 81 to generate a TLV slot of a transmission format in the TLV format. As an example, the TLV format includes an inter-station TLV transmission format (TLV slot without TMCC transmission information) and a combined TLV format (TLV slot with TMCC transmission information) having a packet configuration different from the inter-station TLV transmission format.

  FIG. 6 is a diagram showing a transmission format between a broadcaster and an uplink station defined in ARIB TR-B39, and also shows a configuration diagram of a TLV frame. The TLV slot shown in FIG. 6A corresponds to the above-described combined TLV format (TLV slot with TMCC transmission information). As shown in FIG. 6B, the TLV slot includes a slot header, a main signal (TLV), a null, and TMCC basic information. Although detailed description is omitted, one frame is composed of 120 slots. It is transmitted at a period of about 33 msec per frame.

  In the TLV frame, a valid slot and an invalid slot are assigned every five slots according to the modulation method. For example, as shown in FIG. 13, when the modulation method is a sixteen-value amplitude phase modulation method (16APSK), four effective slots and one invalid slot are allocated every five slots.

  The TMCC basic information is information used as an inter-station signal between the broadcaster and the uplink station, and the configuration of the TMCC basic information is defined by ARIB TR-B39 as shown in FIG.

  The TMCC basic information is transmitted two frames ahead of the main line signal (slot header H, main signal (TLV)) (the main line signal (slot header H, main signal (TLV)) is transmitted to the TMCC basic information. Sent two frames later).

  The slotting unit 82 multiplexes the multiplexing unit TLV packet in the main signal (TLV) area of the TLV slot. At this time, the null packet output from the null packet generator 79 is inserted into the valid byte portion of the free main signal.

  When a switching point is detected in the switching point detection unit 74 (# 1),... (#N), the null packet generation unit 79 generates a null packet that can identify the switching point, and creates a slot. The data is output to the unit 82, and the slotting unit 82 replaces the null packet stored in the main signal (TLV) in the invalid slot. In replacement of the null packet stored in the main signal (TLV) in the invalid slot, inconsistency with the TMCC basic information transmitted in advance does not occur.

  The slotting unit 82 multiplexes the null packet output from the null packet generation unit 79 and capable of identifying the switching point in the TLV slot with a predetermined multiplexing configuration.

  As a transmission format of the TLV format in which null packets are multiplexed in this way, for example, there is an invalid slot as shown in FIG. The invalid slot is an allocation slot for a null TLV packet to be inserted in accordance with the frequency utilization efficiency determined by the modulation method.

  The slotting unit 82 outputs the TLV slot multiplexed with the null packet to the transmission unit 85 in this way.

  The transmission unit 85 transmits this TLV slot to the redundancy switching device 90.

  FIG. 9 is a block diagram illustrating a configuration example of the redundancy switching device 90.

  The redundancy switching device 90 is a device for switching between the primary system and the redundant system, and includes a switching control reception unit 91, packet detection units 92 (# 1) and (# 2), a switching point detection unit 94, And a system switching unit 95 is provided.

  The switching control receiving unit 91 receives a request for switching between the main system and the redundant system from the external input device 100. Then, when the switching control receiving unit 91 receives a switching request, the redundancy switching device 90 executes processing for switching as described below.

  The packet detector 92 (# 1) is connected to the main system. That is, it is connected to the TLV multiplexer 70 (# 1), receives the TLV slot transmitted from the transmitter 85 of the TLV multiplexer 70 (# 1), and uses the received TLV slot as the switching point detector. 94 and the system switching unit 95. Similarly, the packet detection unit 92 (# 2) connected to the redundant system receives the TLV slot output from the TLV multiplexing device 70 (# 2), and uses the received TLV slot as the switching point detection unit 94. And output to the system switching unit 95.

  The switching point detector 94 detects a main signal (TLV) from the TLV slots output from the packet detectors 92 (# 1) and (# 2), and has a predetermined multiplexing configuration (see, for example, FIG. 8). This is determined as a switching point, and the determined switching point is notified to the system switching unit 95.

  The system switching unit 95 switches between the main system and the redundant system at the switching point notified from the switching point detection unit 94 for the TLV slots output from the packet detection units 92 (# 1) and (# 2). To implement.

  In this way, the transmission system to which the transmission method of the present embodiment is applied identifies the switching point and performs switching between the main system and the redundant system without analyzing data such as video and audio. Therefore, it is possible to seamlessly switch TLV packets between the main system and the redundant system while reducing the processing load of the redundancy switching device 90.

  Next, the operation of the transmission system configured as shown in FIG. 1 will be described using the flowcharts of FIGS.

  For example, a video signal, an audio signal, and a caption signal are input to the main encoding device 20 (# 1) from a broadcast master system (not shown). Similarly, a video signal, an audio signal, and a caption signal are input to the redundant encoding device 20 (# 2), for example, from a broadcast master system (not shown) (S1).

  These signals are received by the signal encoding unit 23. The signal encoding unit 23 performs encoding on the received signals, and the encoded video signal, audio signal, and subtitle signal are switched to the switching information setting unit. 24 and the MMTP packetizing unit 25.

  In this state, when the switching control reception unit 21 receives a switching request from the external input device 100 (S2), the encoding device 20 performs processing for switching as described below. .

  First, the GOP phase adjustment unit 22 generates an adjustment signal for aligning the GOP phase of the video signal, and outputs it to the signal encoding unit 23 (S3).

  In the switching information setting unit 24, a predetermined value (for example, the MPU sequence number (FIG. 4) included in the MMTP packet (FIG. 4) corresponding to the switching point between the main system and the redundant system determined based on the adjustment signal is used. , 0) is generated (S4). This instruction input is output from the switching information setting unit 24 to the MMTP packetizing unit 25.

  In the MMTP packetizing unit 25, the MMTP packet of each of the video signal, the audio signal, and the caption signal is output to the MMT multiplexing apparatus 30 in a state where the MMTP packet is set to a predetermined value designated by the instruction input (S5) .

  In each of the MMT multiplexing devices 30 (# 1) and (# 2), the MMTP packets (for example, MMTP packets of video signals, audios) output by the corresponding encoding devices 20 (# 1) and (# 2), respectively. MMTP packet of signal and MMTP packet of caption) and data of MMTP packet format output from an EPG (electronic program guide) sending device (not shown) or the like is multiplexed, and the multiplexed MMTP packet is converted into the same system scrambler. 50 (S6).

  In the scramblers 50 (# 1) and (# 2), the MMTP packets output from the corresponding MMT multiplexers 30 (# 1) and (# 2) are encrypted for copyright protection. The applied and encrypted MMTP packet is output to the IP multiplexer 60 of the same system (S7).

  In the IP multiplexers 60 (# 1) and (# 2), the MMTP packets output from the corresponding scramblers 50 (# 1) and (# 2) are in the form of IP packets from other devices (not shown). Multiplexed with data (S8). Then, the MMTP packet / IP packet obtained as a result of multiplexing is output to the TLV multiplexing device 70 of the same system.

  In the TLV multiplexers 70 (# 1) and (# 2), the MMTP packets / IP packets output from the IP multiplexer 60 of the same system are received by the receivers 71 (# 1),... (#N) Are output to the corresponding filter units 72 (# 1),... (#N). Then, the MMTP packet / IP packet subjected to the filtering process in each filter unit 72 (# 1),... (#N) is output to the corresponding sequence number acquisition unit 73 (S9).

  Each sequence number acquisition unit 73 (# 1),... (#N) outputs the MMTP packet / IP packet output from the corresponding filter unit 72 to the corresponding switching point detection unit 74. Further, the value of the MPU sequence number in the MMTP packet among the MMTP packets / IP packets output from the corresponding filter unit 72 is acquired and output to the corresponding switching point detection unit 74 (S10).

  The switching control receiving unit 75 receives a request for switching between the main system and the redundant system from the external input device 100. When the switching control reception unit 75 receives a switching request (S11), it issues a switching point detection instruction to each switching point detection unit 74 (# 1),... (#N). Each MMTP packet / IP packet output from the corresponding sequence number acquisition unit 73 is subjected to switching point detection processing by each switching point detection unit 74.

  When it is detected that the value of the MPU sequence number output from the corresponding sequence number acquisition unit 73 is a predetermined value (for example, 0), the detection result is output to the null packet generation unit 79 (S12). ). The MMTP packet / IP packet that has undergone the switching point detection process is output to the corresponding TLV converter 77.

  The TLV conversion unit 77 generates a TLV packet from the MMTP packet, and outputs the generated TLV packet to the multiplexing unit 76 (S13).

  In the TLV-SI generation unit 78, TLV-SI is generated and output to the multiplexing unit 76.

  The multiplexing unit multiplexing unit 76 multiplexes the TLV packet from each TLV conversion unit 77 and the TLV-SI output from the TLV-SI generation unit 78.

  The null packet generation unit 79 generates a null packet that can identify the switching point based on the detection result output from the switching point detection unit 74 (# 1),. Is output to the unit 82 (S14).

  In the slotting unit 82, the TLV packet output from the multiplexing unit 76 and the null packet output from the null packet generation unit 79 are multiplexed in a predetermined multiplexing configuration (S15). Specifically, in the slotting unit 82, the null packet output from the null packet generation unit 79 is multiplexed with a predetermined multiplexing configuration in the main signal (TLV) area of the invalid slot.

  The TLV slot in which null packets are multiplexed in a predetermined multiplexing configuration as described above is output from the multiplexing unit 76 to the transmission unit 85 and further transmitted to the redundancy switching device 90 by the transmission unit 85.

  In the redundant switching device 90, when the switching control receiving unit 91 receives a request for switching between the primary system and the redundant system from the external input device 100 (S16), the redundant switching device 90 operates as follows.

  The TLV slot output from the main TLV multiplexer 70 (# 1) is detected by the packet detection unit 92 (# 1), and the detected TLV slot is the switching point detection unit 94 and the system switching unit 95. Is output. Further, the TLV slot output from the redundant TLV multiplexing device 70 (# 2) is detected by the packet detection unit 92 (# 2), and the detected TLV slot is changed to the switching point detection unit 94 and the system switching. The data is output to the unit 95 (S17).

  In the switching point detection unit 94, a null packet is detected from the TLV slots output from the packet detection units 92 (# 1) and (# 2), and is further determined as a switching point when a predetermined multiplexing configuration is achieved. The determined switching point is notified to the system switching unit 95 (S18).

  The system switching unit 95 switches between the main system and the redundant system at the switching point notified from the switching point detection unit 94 for the TLV slots output from the packet detection units 92 (# 1) and (# 2). Is implemented. When the switching point is detected, the TMCC basic information is switched from the main system to the redundant system. After two frames, the main line signal (slot header H, main signal (TLV)) is switched. (S19).

  As described above, according to the transmission system to which the transmission method of the present embodiment is applied, the switching point is identified and the main system and the redundant system are switched without analyzing data such as video and audio. Therefore, it is possible to realize seamless switching of the TLV slots between the main system and the redundant system while reducing the processing load of the redundancy switching device 90.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10 Transmission system, 20 Encoding apparatus, 21 Switching control reception part, 22 GOP phase adjustment part, 23 Signal encoding part, 24 Switching information setting part, 25 MMTP packetization part, 30 MMT multiplexing apparatus, 50 Scrambler, 60 IP multiplexer, 70 TLV multiplexer, 71 reception unit, 72 filter unit, 73 sequence number acquisition unit, 74 switching point detection unit, 75 switching control reception unit, 76 multiplexing unit, 77 TLV conversion unit, 78 TLV-SI Generating unit, 79 null packet generating unit, 80 main signal generating unit, 81 TMCC generating unit, 82 slotting unit, 85 transmitting unit, 90 redundant switching device, 91 switching control receiving unit, 92 packet detecting unit, 94 switching point detecting unit 95 System switching unit, 100 External input device.

Claims (8)

A multiplexing device applied to a transmission system including a main system and a redundant system for transmitting a TLV packet, and provided in each of the main system and the redundant system,
A detecting unit for detecting an MMTP packet corresponding to a switching point between the main system and the redundant system from the MMTP packet converted into the TLV packet;
A TLV converter that converts the MMTP packet into the TLV packet;
A multiplexing unit for multiplexing the TLV packets;
A main signal generator for connecting the multiplexed TLV packets to generate a main signal, and connecting the null TLV packets of a predetermined configuration to generate the main signal at the switching point;
A TMCC generator for generating TMCC basic information from the configuration information of the main signal;
And a slotting unit that generates a TLV slot by combining the main signal and the TMCC information.   The multiplexing apparatus according to claim 1, wherein the null TLV packet is a TLV packet having a packet type value of 0xFF.   The multiplexing apparatus according to claim 1 or 2, wherein the predetermined configuration is a combination of a plurality of null packets. A switching device applied to a transmission system having a main system and a redundant system for transmitting a TLV slot, and for switching between the main system and the redundant system,
A detector for detecting a null packet from the TLV slot;
An identification unit for identifying that the detected null packet has a predetermined configuration;
A switching device comprising: a switching unit that performs switching between the main system and the redundant system using a TLV slot in which a null packet identified as having the predetermined configuration is multiplexed as a switching point.   The switching device according to claim 4, wherein the null packet is a TLV packet having a packet type value of 0xFF.   The switching device according to claim 4 or 5, wherein the predetermined configuration is a combination of a plurality of null packets. A transmission system having a main system and a redundant system for transmitting TLV packets,
A multiplexing device provided in each of the main system and the redundant system;
A switching device for performing switching between the main system and the redundant system;
The multiplexing device comprises:
A first detection unit for detecting an MMTP packet corresponding to a switching point between the main system and the redundant system from the MMTP packet converted into the TLV packet;
A TLV converter that converts the MMTP packet into the TLV packet;
A multiplexing unit for multiplexing the TLV packets;
A main signal generator for connecting the multiplexed TLV packets to generate a main signal, and connecting the null TLV packets of a predetermined configuration to generate the main signal at the switching point;
A TMCC generator for generating TMCC basic information from the configuration information of the main signal;
A slotting unit that generates a TLV slot by combining the main signal and the TMCC information;
The switching device is
A second detector for detecting a null packet from the TLV slot;
An identification unit for identifying that the null packet detected by the second detection unit has a predetermined configuration;
A transmission system comprising: a switching unit that performs switching between the main system and the redundant system using a TLV slot in which a null packet identified as having the predetermined configuration is multiplexed as a switching point. A transmission method applied to a transmission system including a main system and a redundant system for transmitting a TLV packet,
In the multiplexing device provided in each of the main system and the redundant system,
Detecting an MMTP packet corresponding to a switching point between the main system and the redundant system from the MMTP packet converted into the TLV packet;
Converting the MMTP packet into the TLV packet;
Multiplex the TLV packet;
Concatenating the multiplexed TLV packets to generate a main signal, and at the switching point, concatenating null TLV packets of a predetermined configuration to generate the main signal,
TMCC basic information is generated from the configuration information of the main signal,
Combining the main signal and the TMCC information to generate a TLV slot;
In a switching device for performing switching between the main system and the redundant system,
Detecting a null packet from the TLV slot;
Identifying the detected null packet as having a predetermined configuration;
A transmission method for performing switching between the main system and the redundant system using a TLV slot in which a null packet identified as having the predetermined configuration is multiplexed as a switching point.