Communication system and fault detection method

• US 10,615,868 B2
• Filed: 11/22/2016
• Issued: 04/07/2020
• Est. Priority Date: 11/26/2015
• Status: Active Grant

• Current Assignee: Nippon Telegraph and Telephone Corporation
• Original Assignee: Nippon Telegraph and Telephone Corporation
• Inventors: Oda, Takuya, Inui, Tetsuro, Hirano, Akira, Imajuku, Wataru, Kobayashi, Shoukei, Tanaka, Takafumi, Miyamoto, Yutaka, Takara, Hidehiko
• Primary Examiner(s): Sanchez, Dibson J
• Application Number:
  US15/778,910
• Publication Number:
  US 20180359024A1
• Time in Patent Office: 1,232 Days
• Field of Search: 398 9- 38, 398 43-103, 398140-172
• CPC Class Codes: G02B 6/02042 Multicore optical fibres
• CPC Class Codes: H04B 10/077 using a supervisory or additional signal
• CPC Class Codes: H04B 10/0771 Fault location on the transmission path
• CPC Class Codes: H04B 10/25753 Distribution optical network, e.g. between a base station and a plurality of remote units
• CPC Class Codes: H04B 10/2581 Multimode transmission
• CPC Class Codes: H04J 14/00 Optical multiplex systems
• CPC Class Codes: H04J 14/02 Wavelength-division multiplex systems
• CPC Class Codes: H04J 14/0201 Add-and-drop multiplexing
• CPC Class Codes: H04L 12/437 Ring fault isolation or reconfiguration for SDH/SONET ring networks H04J3/085

Abstract

A communication system which includes: three or more nodes; a multi-core fiber having a plurality of cores, the multi-core fiber being used in at least a partial segment of a connection between the nodes; a detection signal output unit configured to output a fault detection signal transmitted by the core provided in the multi-core fiber configured to connect together the nodes; and a fault detection unit configured to determine whether a fault has occurred between the nodes on the basis of a detection result of the fault detection signal.

Claims

1. A communication system comprising:

three or more nodes;

a plurality of multi-core fibers, each of the plurality of multi-core fibers having a plurality of cores, each of the plurality of multi-core fibers being used in at least a partial segment of a connection between the nodes; and

a fault location specifying monitoring device comprising a transceiver and configured to specify a multi-core fiber in which a fault has occurred among the plurality of multi-core fibers;

wherein a starting node serving as starting point and an ending node serving as ending point in a network including the three or more nodes, include, respectively, a first detection signal output monitoring device comprising a first transmitter and configured to output a first fault detection signal to be transmitted to the ending node by at least one of the plurality of cores provided in each of the plurality of multi-core fibers configured to connect together the nodes and a second detection signal output monitoring device comprising a second transmitter and configured to output a second fault detection signal to be transmitted to the starting node by at least one of the plurality of cores provided in each of the plurality of multi-core fibers, and

wherein a node other than the starting node and the ending node among the three or more nodes, includes,

a connector configured to divide an optical signal of the at least one of the plurality of cores that transmits the first fault detection signal and the second fault detection signal that are output from the starting node or the ending node respectively, output a part of the optical signal and relay the other part of the optical signal to a next node, and

a first fault detection monitoring device comprising a first receiver and configured to determine whether the fault has occurred in a segment between the starting node and own node and a segment between the ending node and own node on the basis of a detection result of the first fault detection signal and the second fault detection signal in the part of the optical signal output from the connector,

wherein the fault location specifying monitoring device is configured to specify the multi-core fiber in which the fault has occurred among the plurality of multi-core fibers on the basis of a determination result at each node for the first fault detection signal and the second fault detection signal that are transmitted in both directions between the starting node and the ending node.

2. The communication system according to claim 1, wherein

the first detection signal output monitoring device and the second detection signal output monitoring device are configured to output the first fault detection signal and the second fault detection signal to the at least one of the plurality of cores which is not used for communication between the nodes, respectively.

3. The communication system according to claim 2, wherein

the first detection signal output monitoring device and the second detection signal output monitoring device are configured to output the first fault detection signal and the second fault detection signal including information on monitoring or operation in the communication system, respectively.

4. The communication system according to claim 1, wherein

the first detection signal output monitoring device and the second detection signal output monitoring device are configured to output the first fault detection signal and the second fault detection signal to the at least one of the plurality of cores which is used for communication between the nodes, respectively.

5. The communication system according to claim 4, wherein the first detection signal output monitoring device and the second detection signal output monitoring device are configured to output the first fault detection signal and the second fault detection signal including information on monitoring or operation in the communication system, respectively.

6. The communication system according to claim 1, wherein the one of the starting node and the ending node further includes,

a second fault detection monitoring device comprising a second receiver and configured to determine whether the fault has occurred in a segment between own node and the other one of the starting node and the ending node, on the basis of a detection result of each of the first fault detection signal and the second fault detection signal that is transmitted via the node other than the starting node and the ending node among the three or more nodes.

7. The communication system according to claim 1, wherein

the first fault detection monitoring device is configured to determine that the fault has occurred when reception light including the first fault detection signal or the second fault detection signal is not detected.

8. The communication system according to claim 1, wherein when it is determined that the fault has occurred between the nodes, the first fault detection monitoring device is configured to notify a higher-layer controller of fault information indicating the occurrence of the fault and the segment in which the fault is detected.

9. A fault detection method in a communication system comprising three or more nodes, and a plurality of multi-core fibers, each of the plurality of multi-core fibers having a plurality of cores, each of the plurality of multi-core fibers being used in at least a partial segment of a connection between the nodes, the fault detection method comprising:

a first detection signal output step of outputting, by a starting node serving as starting point in a network including the three or more nodes, a first fault detection signal to be transmitted to an ending node serving as ending point by at least one of the plurality of cores provided in each of the plurality of multi-core fibers configured to connect together the nodes;

a second detection signal output step of outputting, by the ending node in the network, a second fault detection signal to be transmitted to the starting node by at least one of the plurality of cores provided in each of the plurality of multi-core fibers; and

a fault detection step of determining, by a node other than the starting node and the ending node among the three or more nodes, whether a fault has occurred in a segment between the starting node and own node and a segment between the ending node and own node on the basis of a detection result of the first fault detection signal and the second fault detection signal in a part of an optical signal output from a connector, the connector being configured to divide an optical signal of the at least one of the plurality of cores that transmits the first fault detection signal and the second fault detection signal that are output from the starting node or the ending node respectively, output the part of the optical signal and relay the other part of the optical signal to a next node,

a fault location specifying step of specify a multi-core fiber in which the fault has occurred among the plurality of multi-core fibers on the basis of a determination result at each node for the first fault detection signal and the second fault detection signal that are transmitted in both directions between the starting node and the ending node.