JP2014039111A - Transmission system, transmission device and transmission method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission system for transmitting any data without switching a transmission path when a failure of the transmission path is detected and without the need of a circuit for synchronization.SOLUTION: A first transmission device 1 divides data to be transmitted into a plurality of packets to which numbers showing an order are attached, copies the divided packets, and incorporates the copied packets into a plurality of prescribed frames corresponding to a plurality of transmission paths 3 including the different type of transmission path 3 to transmit them. A second transmission device 2 receives the plurality of prescribed frames from the first transmission device 1, takes out the packets from the received frames, assembles the packet whose number showing the order attached to the taken out packet is a first browsed number in accordance with the number showing the order to restore the data.

Description

  The present invention relates to a transmission system, a transmission apparatus, and a transmission method, and more particularly to a transmission system, a transmission apparatus, and a transmission method that do not require switching to another transmission path even when a failure is detected in the transmission path.

  Generally, a transmission system that transmits data using multiplexed transmission lines transmits data using one of the multiplexed transmission lines as a main transmission line, and the main transmission line has a failure. If detected, the transmission is switched to another transmission path. For this reason, when a failure is detected in the transmission line, it is necessary to switch to another transmission line, which causes a problem that it takes a long time to switch.

  Patent Document 1 discloses a technique that solves this problem by eliminating the need to switch transmission lines due to the occurrence of a failure. An IP (Internet Protocol) packet transfer apparatus disclosed in Patent Document 1 includes a transmission side terminal, a reception side terminal, and two different IP networks. The transmitting terminal is connected to the receiving terminal via these two different IP networks. The transmitting terminal copies the IP packet to be transmitted and transmits it simultaneously to these two IP networks. The receiving side terminal receives each of the sent IP packets, identifies these IP packets with reference to the identification field of the IP packet, registers the newly received IP packet, and already receives the IP packet. The packet is discarded. In this way, the IP packet is transmitted from the transmission side terminal to the reception side terminal.

  As described above, the technique disclosed in Patent Document 1 connects a transmission-side terminal and a reception-side terminal using two IP networks. Then, the same IP packet is simultaneously transmitted from the transmission side terminal, and the reception side terminal receives each of these IP packets and registers the first IP packet. For this reason, it is not necessary to switch the transmission path when a failure occurs. Therefore, switching time is not required.

  Also, Patent Document 2 discloses a technique in which switching time is not required due to the occurrence of a failure so that switching time is not required. The packet transfer device disclosed in Patent Literature 2 includes a transmission-side packet transfer device, a reception-side packet transfer device, and a packet transmission network. The packet transfer device on the transmission side and the packet transfer device on the reception side are connected via a packet transmission network. The packet transfer device on the transmission side sequentially converts a predetermined number of packets or packets for a predetermined time in sequentially input packets into packet frames. Then, a synchronization packet including order identification information is inserted into each packet frame, and each packet frame is duplicated and transmitted to a plurality of transmission paths. The packet transfer apparatus on the receiving side identifies the same packet frame among a plurality of paths by using the order identification information of the synchronization packet included in each packet frame received from the transmission paths of the plurality of paths, and identifies the same packet A delay difference between a plurality of paths is determined based on a delay difference between frames. The delay difference is used to adjust the delay of packet frames of a plurality of routes (synchronization), and the packet frame of one route out of the packet frames of the plurality of routes adjusted (synchronized). Is selected and sent downstream.

  As described above, in the packet transfer device disclosed in Patent Literature 2, the packet transfer device on the transmission side transmits a plurality of identical packet frames using a plurality of routes. Then, the packet transfer apparatus on the receiving side determines the delay difference between the routes of the same packet frame, adjusts the delay of the packet frame of the plurality of routes using this delay difference, and adjusts the packet of the adjusted plurality of routes A packet frame of one route is selected from the frames.

  For this reason, the packet transfer device disclosed in Patent Document 2 can receive a packet frame from another route without switching the route when a failure occurs. For this reason, it is not necessary to switch the transmission path when a failure occurs. Therefore, switching time is not required.

JP 2011-35516 A JP 2008-227623 A

  The IP packet transfer apparatus disclosed in Patent Document 1 described above uses two IP networks to connect a transmission side terminal and a reception side terminal. Then, the same IP packet is simultaneously transmitted from the transmission side terminal, and the reception side terminal receives each of these IP packets and registers the first IP packet. In this way, there is no need to switch to another transmission line even when a failure is detected in the transmission line. However, since this IP packet transfer apparatus specializes in transferring IP packets, there is a problem that only IP packets can be transferred. In the packet transfer apparatus disclosed in Patent Document 2 described above, the packet transfer apparatus on the receiving side determines the delay difference between a plurality of paths based on the delay difference between the same packet frames. Then, the delay difference is used to adjust the delay of the packet frames of the plurality of routes, and the packet frame of one route is selected from the adjusted packet frames of the plurality of routes. For this reason, there is a problem that a circuit for determining a delay difference and adjusting the delay (a circuit for achieving synchronization) is required.

  The object of the present invention is to solve the above-mentioned problems, and even when a failure is detected in a transmission line, any data can be transmitted without switching to another transmission line and without requiring a circuit for synchronization. It is to provide a transmission system, a transmission apparatus, and a transmission method that can be performed.

  The transmission system of the present invention divides a plurality of transmission paths including different types of transmission paths and data to be transmitted into a plurality of packets to which numbers indicating the order are added, and duplicates the divided packets to generate a plurality of packets. A first transmission device that incorporates and transmits each of the plurality of predetermined frames according to the transmission path; and a plurality of the predetermined frames received from the first transmission device, and the packet from the received frame A second transmission device for reconstructing the data by assembling the packets whose numbers indicating the order added to the extracted packets are first-numbered based on the numbers indicating the order; I have.

  The transmission apparatus according to the present invention divides data to be transmitted into a plurality of packets to which numbers indicating the order are added, and duplicates each of the divided packets into a plurality of predetermined frames corresponding to a plurality of transmission paths. A transmission apparatus that receives the data transmitted as each of the built-in predetermined frames via a plurality of transmission paths including different types of transmission paths, and that includes the transmission path to which its receiver is connected. A plurality of receiving units that receive the predetermined frame according to the transmission path, output the packets extracted from the received frames, and receive the packets respectively extracted by the plurality of receiving units, This packet is stored when the number indicating the order added to the received packet is the first number, and when the number is not the first number, the packet is stored. A packet selector for discarding, the packet in which the packet selecting part is stored, and a, a data restoration unit for restoring the data assembled on the basis of the number indicating the order.

  The transmission method of the present invention is a transmission method for transmitting data from a first transmission device to a second transmission device via a plurality of transmission lines, wherein the data transmitted by the first transmission device is transmitted in order. Are divided into a plurality of packets to which numbers are added, the divided packets are duplicated, and the duplicated packets are incorporated into a plurality of predetermined frames corresponding to a plurality of transmission paths including different types of transmission paths, respectively. And the second transmission device receives the plurality of predetermined frames from the first transmission device, extracts the packets from the received frames, and adds them to the extracted packets. Further, the data indicating the order number is assembled based on the order number and the data is restored.

  According to the present invention, a transmission system capable of transmitting any data without requiring a circuit for synchronization without switching to another transmission path even when a failure is detected in the transmission path, A transmission apparatus and a transmission method can be provided.

It is a figure which shows an example of the transmission system which concerns on the 1st Embodiment of this invention. It is a figure which shows an example of the transmission system which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows an example of operation | movement of the transmission system of the 2nd Embodiment of this invention. It is a figure explaining the operation | movement which the 1st transmission apparatus which decomposes | disassembles the data to transmit into a some packet, incorporates this packet in a flame | frame, and transmits.

Next, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a diagram illustrating an example of a transmission system according to the first embodiment of the present invention.

  The transmission system according to the present embodiment includes a first transmission device 1 and a second transmission device 2.

  FIG. 1 also shows a plurality of transmission paths 3 including different types for connecting the first transmission apparatus 1 and the second transmission apparatus 2. The transmission path 3 is, for example, a PDH (Plesiochronous Digital Hierarchy) electric transmission network, an SDH (Synchronous Digital Hierarchy) optical transmission network, an IP (Internet Protocol) network, or the like. The PDH electric transmission network is an ITU-T (International Telecommunication Union Telecommunication Standardization Sector) G. Data is transmitted by a frame defined in 703. The SDH optical transmission network is an ITU-T G.264 standard. Data is transmitted by a frame defined in 707. The IP network transmits data using a frame defined by IEEE (Institut of Electrical and Electronic Engineers) 802.3. In FIG. 1, three transmission lines 3 are shown, but two or more or any number may be used without being particular about the three lines.

  The first transmission device 1 inputs data to be transmitted, divides the data into a plurality of packets to which numbers indicating the order are added, duplicates the divided packets, and generates a plurality of predetermined data corresponding to the plurality of transmission paths 3. Each frame is incorporated and transmitted. Here, the packet is, for example, 8-byte data. Alternatively, it is data having the number of bytes input in units of 1 ms (milliseconds). This number of bytes may be appropriately changed depending on the system. The number indicating the order is, for example, a sequence number for confirming the order of the packets. The predetermined frame is, for example, each frame used when data is transmitted through a PDH electric transmission network, an SDH optical transmission network, an IP network, or the like.

  The second transmission device 2 receives a plurality of predetermined frames from the first transmission device 1 and extracts packets from the received frames. Then, the first transmission device 1 divides and transmits the data, which is assembled in the order of the sequence number based on the sequence number, with the packet having the first sequence number added to the extracted packet.

  Next, the operation of the transmission system according to the present embodiment will be described. The first transmission device 1 divides data to be transmitted into a plurality of packets to which sequence numbers are added. A mark indicating the end is attached to the last divided packet. For example, an END bit indicating the last packet provided in the packet is set. Then, the same packet as the divided packet is duplicated for a plurality of transmission paths. Therefore, a plurality of packets are duplicated for each packet of the plurality of divided packets. Then, a plurality of predetermined frames are respectively incorporated into a plurality of predetermined frames corresponding to the plurality of transmission paths 3 by incorporating the same packets replicated for a plurality of transmission paths. Then, the predetermined frames are transmitted in the order of sequence numbers for the number of divided packets.

  The second transmission device 2 receives a plurality of predetermined frames from the first transmission device 1 and extracts packets from the received frames. Then, it is checked whether or not the sequence number added to the extracted packet is a first-looked number. If it is not the first-looked number, this packet is discarded. This packet is stored for the first-looked number. When all the packets divided by the first transmission apparatus 1 are received, that is, when the END bit indicating the last packet is set in the stored packet, the stored packets are assembled in sequence number order, The data transmitted by one transmission apparatus 1 is restored.

  As described above, according to the first embodiment of the present invention, the first transmission apparatus 1 divides the data to be transmitted into a plurality of packets to which sequence numbers are added, and duplicates the divided packets to generate a plurality of packets. Each is incorporated into a plurality of predetermined frames corresponding to the transmission path 3 and transmitted. Then, the second transmission apparatus 2 receives a plurality of predetermined frames from the first transmission apparatus 1 and extracts packets from the received frames. Then, the first transmission device 1 divides and transmits the data, which is assembled based on the sequence number and the packet whose sequence number added to the extracted packet is the first-looked number is restored. For this reason, according to the first embodiment of the present invention, since the data to be transmitted is not specialized for the data of the IP packet, it is not possible to transfer only the IP packet. Further, when restoring the transmitted data, a circuit for obtaining synchronization is not required.

  Therefore, according to the first embodiment of the present invention, even if a failure is detected in the transmission line, any data can be obtained without switching to another transmission line and without requiring a circuit for synchronization. But it can be transmitted.

Here, in the first embodiment of the present invention, the first transmission apparatus 1 divides the data to be transmitted into a plurality of packets to which the sequence number is added. You may divide | segment into the some packet which added the code | symbol. At this time, the second transmission device 2 extracts each packet from the frame received from the first transmission device 1, performs error detection of the packet based on the error detection code added to the extracted packet, and detects the error. The packet in which an error is detected is discarded. Here, the error detection code is, for example, a checksum, cyclic redundancy check (CRC) code, and error detection is a sum check check, cyclic redundancy check performed based on these codes. is there.
(Second Embodiment)
FIG. 2 is a diagram illustrating an example of a transmission system according to the second embodiment of the present invention.

  The second embodiment is a more specific operation of the first transmission device 1 and the second transmission device 2 of the first embodiment. Therefore, the difference from the first embodiment will be mainly described.

  The transmission system according to the present embodiment includes a first transmission device 1 and a second transmission device 2. In FIG. 2, three transmission lines 3 are illustrated, but as in FIG. 1, two or more or any number may be used without being particular about the three lines.

  The first transmission device 1 includes a packet generation unit 4 and a plurality of frame conversion transmission units 5. The packet generation unit 4 divides the data to be transmitted into a plurality of packets, and duplicates and outputs the number of transmission lines with packets added with a number indicating the order (sequence number) and an error detection code. The plurality of frame conversion transmission units 5 incorporate and transmit the duplicated packet output from the packet generation unit 4 in a predetermined frame corresponding to the transmission path 3 transmitted by the frame conversion transmission unit 5 itself.

  The second transmission device 2 includes a plurality of reception units 6, a plurality of packet check units 7, a packet selection unit 8, and a data restoration unit 9.

  Each receiving unit 6 of the plurality of receiving units 6 receives a predetermined frame corresponding to the transmission path 3 via the transmission path 3 to which the receiving section 6 is connected, and extracts a packet from the received frame.

  Each packet check unit 7 of the plurality of packet check units 7 performs error detection of the packet based on the error detection code added to the packet taken out by the reception unit 6, discards the packet in which the error is detected by error detection, and generates an error. Output packets for which no was detected.

  The packet selection unit 8 receives each of the packets output by the plurality of packet check units 7, stores the packet when the sequence number added to the received packet is the first number, and stores the packet when the sequence number is not the first number Discard. Then, the packet selection unit 8 checks whether all the packets divided by the first transmission device 1 have been received. That is, it is checked whether or not the END bit indicating the last packet is set in this packet when the packet is stored. If the END bit is set in the stored packet, it is determined that all packets divided by the first transmission apparatus 1 have been received, and a data reception signal is output.

  The data restoration unit 9 receives a data reception signal from the packet selection unit 8, assembles the packets stored in the packet selection unit 8 in the order of sequence numbers, and restores the data transmitted by the first transmission device 1 by dividing.

  Next, the operation of the transmission system according to the second embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 3 is a flowchart illustrating an example of the operation of the transmission system according to the second embodiment of this invention.

  FIG. 4 is a diagram for explaining an operation performed by the first transmission apparatus that disassembles data to be transmitted into a plurality of packets and incorporates the packets into a frame for transmission. (A) indicates data to be transmitted. (B) shows a plurality of packets obtained by disassembling the data transmitted in (a). The number described in each packet indicates a sequence number. Here, a case where data is decomposed into n packets is shown. (C) shows the duplicate packet which duplicated the some packet decomposed | disassembled by (b). (D) shows the frame according to the transmission line 3 incorporating the duplicate packet of (c). The number described in each frame indicates a sequence number, and indicates that the position of the packet having the sequence number in the frame differs depending on the frame. (E) shows a state in which the frames of (d) are transmitted in the order of sequence numbers.

  In step S1 of FIG. 3, the packet generation unit 4 of the first transmission device 1 inputs data to be transmitted, and divides this data into a plurality of packets (FIG. 4B). A number indicating the order (sequence number) and an error detection code (not shown) are added to the divided packets. A mark indicating the end is attached to the last divided packet. For example, an END bit (not shown) indicating the last packet provided in the packet is set. Then, the same packet as the divided packet is duplicated for a plurality of transmission paths ((c) in FIG. 4) and output. Therefore, the same plurality of packets are duplicated for each packet of the plurality of divided packets.

  In step S2 of FIG. 3, each frame conversion transmission unit 5 of the plurality of frame conversion transmission units 5 uses the duplicated packet ((c) of FIG. 4) output from the packet generation unit 4 as its own frame conversion transmission unit. 5 is incorporated in a predetermined frame corresponding to the transmission path 3 to be transmitted ((d) in FIG. 4). Then, as shown in FIG. 4E, a predetermined frame in which the packet is incorporated is transmitted to the transmission path 3 corresponding to its own frame conversion transmission unit 5 in the order of the sequence number for the divided number of packets.

  In step S3 of FIG. 3, each reception unit 6 of the plurality of reception units 6 of the second transmission device 2 transmits the first transmission device 1 via the transmission path 3 to which the reception unit 6 is connected. A predetermined frame corresponding to the transmission path 3 is received, and a packet is extracted from the received frame.

  In step S4 of FIG. 3, each packet check unit 7 of the plurality of packet check units 7 performs packet error detection based on the error detection code added to the packet taken out by the reception unit 6.

  In step S5 of FIG. 3, each packet check unit 7 checks whether or not an error is detected by the error detection performed in step S4. If no error is detected, the process proceeds to step S7. If an error is detected, the process proceeds to step S6.

  In step S6 of FIG. 3, the packet check unit 7 that has detected an error discards the packet in which the error has been detected, and proceeds to step S8.

  In step S7 of FIG. 3, the packet check unit 7 that has not detected an error outputs a packet in which no error has been detected, and proceeds to step S8.

  In step S8 of FIG. 3, the packet selection unit 8 receives the packet output by the plurality of packet check units 7 in step S7.

  Here, in FIG. 2, a plurality of packet check units 7 are provided between the plurality of reception units 6 and the packet selection unit 8, and a packet error is detected by the packet check unit 7. It output to the selection part 8. The packet selection unit 8 receives each of the packets output by the plurality of packet check units 7. However, a plurality of packet check units 7 are not provided between the plurality of reception units 6 and the packet selection unit 8, and packets are directly output from the plurality of reception units 6 to the packet selection unit 8. Each of the receiving units 6 may receive the output packets.

  The packet selection unit 8 checks whether or not the sequence number added to the received packet is a first-looked number. If the result of the check indicates that the number is not the first-looked number (NO), the process proceeds to step S9. If the result of the check indicates that the number is the first look (YES), the process proceeds to step S10.

  In step S9 of FIG. 3, the packet selector 8 discards the packet that is not the first sequence number, and returns to step S8.

  In step S10 of FIG. 3, the packet selection unit 8 stores a packet having a first-looked sequence number.

  In step S11 of FIG. 3, the packet selection unit 8 checks whether or not the END bit indicating the last packet is set in the packet stored in step S10. If the END bit is set in the stored packet, that is, if it is the last packet (in the case of YES), the process proceeds to step S12. If the END bit is not set in the packet stored in step S10, that is, if it is not the last packet (in the case of NOS), the process returns to step S8.

  In step S12 of FIG. 3, when the END bit is set, the packet selection unit 8 determines that all the packets divided in step S1 have been received, and outputs a data reception signal.

  In step S13 of FIG. 3, the data restoration unit 9 receives the data reception signal from the packet selection unit 8, assembles the packets stored in the packet selection unit 8 in the order of sequence numbers, and the first transmission apparatus 1 performs step S1. Restore the data sent in pieces.

  Thus, according to the second embodiment of the present invention, the first transmission apparatus 1 divides the data to be transmitted into a plurality of packets to which sequence numbers are added, and the divided packets are duplicated to obtain a plurality of packets. Each is incorporated into a plurality of predetermined frames corresponding to the transmission path 3 and transmitted. Then, the second transmission apparatus 2 receives a plurality of predetermined frames from the first transmission apparatus 1 and extracts packets from the received frames. Then, the first transmission device 1 divides and transmits the data, which is assembled based on the sequence number and the packet whose sequence number added to the extracted packet is the first-looked number is restored. For this reason, according to the second embodiment of the present invention, since the data to be transmitted is not specialized for the data of the IP packet, it is not possible to transfer only the IP packet. Further, when restoring the transmitted data, a circuit for obtaining synchronization is not required.

  Therefore, according to the second embodiment of the present invention, even if a failure is detected in the transmission line, any data can be obtained without switching to another transmission line and without requiring a circuit for synchronization. But it can be transmitted.

Part or all of the above-described embodiments can be described as in the following supplementary notes, but is not limited thereto.
(Appendix 1)
The data to be transmitted is divided into a plurality of packets to which numbers indicating the order are added, and the divided packets are duplicated to a plurality of predetermined frames respectively corresponding to a plurality of transmission paths including different types of transmission paths. A first transmission device that incorporates and transmits each;
The plurality of predetermined frames are respectively received from the first transmission devices connected via the plurality of transmission paths, the packets are respectively extracted from the received frames, and the packets added to the extracted packets are added. A second transmission device for reconstructing the data by assembling the packet whose number indicating the order is a first-looked number based on the number indicating the order;
A transmission system comprising:
(Appendix 2)
The first transmission device adds an error detection code to the packet;
The second transmission device takes out the packet from the frame received from the first transmission device, and performs error detection of the packet based on the error detection code added to the extracted packet; Discarding the packet in which an error is detected in the error detection;
The transmission system according to supplementary note 1, wherein:
(Appendix 3)
The first transmission device includes:
A packet generator that divides the data to be transmitted into a plurality of packets, adds a number indicating the order to the packets, and duplicates and outputs the packets with the numbers added to the number of transmission paths;
A plurality of frame conversion transmission units that transmit the duplicated packets output by the packet generation unit in a predetermined frame corresponding to the transmission path transmitted by the frame conversion transmission unit;
The transmission system according to appendix 1, characterized by comprising:
(Appendix 4)
The first transmission device includes:
A packet generation unit that divides data to be transmitted into a plurality of packets, and duplicates and outputs a packet with an order number and an error detection code added to the packets for the number of transmission paths;
A plurality of frame conversion transmission units that transmit the duplicated packets output by the packet generation unit in a predetermined frame corresponding to the transmission path transmitted by the frame conversion transmission unit;
The transmission system according to appendix 2, characterized by comprising:
(Appendix 5)
The transmission system according to appendix 1, 2, 3, or 4, wherein the number indicating the order is a sequence number for confirming the order of the packets.
(Supplementary note 6) Transmission system The transmission system according to Supplementary note 2 or 4, wherein the error detection code includes a checksum and a cyclic redundancy check (CRC) code.
(Appendix 7)
A transmission apparatus that receives a plurality of frames including any of a plurality of packets including a number indicating an order via the plurality of transmission paths including different types of transmission paths,
A plurality of receiving units for receiving a predetermined frame corresponding to the transmission path via the transmission path to which the receiving unit is connected, and extracting and outputting the packet from the received frame;
Each of the plurality of receiving units receives each of the packets taken out, stores the packet when the number added to the received packet is the first number, and stores the packet when it is not the first number A packet selector;
A data restoration unit for assembling the packets stored by the packet selection unit based on a number indicating the order and restoring the data;
A transmission apparatus comprising:
(Appendix 8)
A transmission apparatus that receives a plurality of frames including any of a plurality of packets including a number indicating an order and an error detection code via the plurality of transmission paths including different types of transmission paths,
A plurality of receiving units for receiving a predetermined frame corresponding to the transmission path through the transmission path to which the receiving unit is connected, and extracting the packet from the received frame;
Performs error detection of the packet based on the error detection code added to the packet taken out by the receiving unit connected to its own packet check unit, and outputs the packet in which no error was detected by the error detection A plurality of packet check units for discarding the packet in which an error is detected in the error detection;
Each of the plurality of packet check units receives the packet, and stores the packet when the number added to the received packet is the first number, and discards the packet when the number is not the first number. A packet selector to
A data restoration unit for assembling the packets stored by the packet selection unit based on a number indicating the order and restoring the data;
A transmission apparatus comprising:
(Appendix 9)
A transmission method for transmitting data from a first transmission device to a second transmission device via a plurality of transmission paths,
The first transmission device divides the data to be transmitted into a plurality of packets to which numbers indicating the order are added, duplicates the divided packets, and the duplicated packets include a plurality of different types of transmission paths. Each incorporated into a plurality of predetermined frames according to the transmission path, respectively,
The second transmission apparatus receives a plurality of the predetermined frames from the first transmission apparatus, extracts the packets from the received frames, and indicates the order added to the extracted packets. Reassembling the data by assembling the packet of the first-numbered number based on the number indicating the order;
A transmission method characterized by the above.
(Appendix 10)
The first transmission device divides the data to be transmitted into a plurality of packets to which a number indicating the order and an error detection code are added,
The second transmission device takes out the packet from the frame received from the first transmission device, and performs error detection of the packet based on the error detection code added to the extracted packet; Discarding the packet in which an error is detected in the error detection;
The transmission method according to supplementary note 9, wherein
(Appendix 11)
The transmission method according to appendix 9 or 10, wherein the number indicating the order is a sequence number for confirming the order of the packets.
(Appendix 12)
The transmission method according to claim 10, wherein the error detection code includes a checksum and a cyclic redundancy check (CRC) code.

DESCRIPTION OF SYMBOLS 1 1st transmission apparatus 2 2nd transmission apparatus 3 Transmission path 4 Packet generation part 5 Frame conversion transmission part 6 Reception part 7 Packet check part 8 Packet selection part 9 Data restoration part

Claims (10)

The data to be transmitted is divided into a plurality of packets to which numbers indicating the order are added, and the divided packets are duplicated to a plurality of predetermined frames respectively corresponding to a plurality of transmission paths including different types of transmission paths. A first transmission device that incorporates and transmits each;
The plurality of predetermined frames are respectively received from the first transmission devices connected via the plurality of transmission paths, the packets are respectively extracted from the received frames, and the packets added to the extracted packets are added. A second transmission device for reconstructing the data by assembling the packet whose number indicating the order is a first-looked number based on the number indicating the order;
A transmission system comprising: The first transmission device adds an error detection code to the packet;
The second transmission device takes out the packet from the frame received from the first transmission device, and performs error detection of the packet based on the error detection code added to the extracted packet; Discarding the packet in which an error is detected in the error detection;
The transmission system according to claim 1. The first transmission device includes:
A packet generator that divides the data to be transmitted into a plurality of packets, adds a number indicating the order to the packets, and duplicates and outputs the packets with the numbers added to the number of transmission paths;
A plurality of frame conversion transmission units that transmit the duplicated packets output by the packet generation unit in a predetermined frame corresponding to the transmission path transmitted by the frame conversion transmission unit;
The transmission system according to claim 1, further comprising: The first transmission device includes:
A packet generation unit that divides data to be transmitted into a plurality of packets, and duplicates and outputs a packet with an order number and an error detection code added to the packets for the number of transmission paths;
A plurality of frame conversion transmission units that transmit the duplicated packets output by the packet generation unit in a predetermined frame corresponding to the transmission path transmitted by the frame conversion transmission unit;
The transmission system according to claim 2, further comprising:   5. The transmission system according to claim 1, wherein the number indicating the order is a sequence number for confirming the order of the packets. The transmission system according to claim 2, wherein the error detection code includes a checksum and a cyclic redundancy check (CRC) code. A transmission apparatus that receives a plurality of frames including any of a plurality of packets including a number indicating an order via the plurality of transmission paths including different types of transmission paths,
A plurality of receiving units for receiving a predetermined frame corresponding to the transmission path via the transmission path to which the receiving unit is connected, and extracting and outputting the packet from the received frame;
Each of the plurality of receiving units receives each of the packets taken out, stores the packet when the number added to the received packet is the first number, and stores the packet when it is not the first number A packet selector;
A data restoration unit for assembling the packets stored by the packet selection unit based on a number indicating the order and restoring the data;
A transmission apparatus comprising: A transmission apparatus that receives a plurality of frames including any of a plurality of packets including a number indicating an order and an error detection code via the plurality of transmission paths including different types of transmission paths,
A plurality of receiving units for receiving a predetermined frame corresponding to the transmission path through the transmission path to which the receiving unit is connected, and extracting the packet from the received frame;
Performs error detection of the packet based on the error detection code added to the packet taken out by the receiving unit connected to its own packet check unit, and outputs the packet in which no error was detected by the error detection A plurality of packet check units for discarding the packet in which an error is detected in the error detection;
Each of the plurality of packet check units receives the packet, and stores the packet when the number added to the received packet is the first number, and discards the packet when the number is not the first number. A packet selector to
A data restoration unit for assembling the packets stored by the packet selection unit based on a number indicating the order and restoring the data;
A transmission apparatus comprising: A transmission method for transmitting data from a first transmission device to a second transmission device via a plurality of transmission paths,
The first transmission device divides the data to be transmitted into a plurality of packets to which numbers indicating the order are added, duplicates the divided packets, and the duplicated packets include a plurality of different types of transmission paths. Each incorporated into a plurality of predetermined frames according to the transmission path, respectively,
The second transmission apparatus receives a plurality of the predetermined frames from the first transmission apparatus, extracts the packets from the received frames, and indicates the order added to the extracted packets. Reassembling the data by assembling the packet of the first-numbered number based on the number indicating the order;
A transmission method characterized by the above. The first transmission device divides the data to be transmitted into a plurality of packets to which a number indicating the order and an error detection code are added,
The second transmission device takes out the packet from the frame received from the first transmission device, and performs error detection of the packet based on the error detection code added to the extracted packet; Discarding the packet in which an error is detected in the error detection;
The transmission method according to claim 9.

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