Test system, test method, and test device

Abstract

A test system 5 includes: a first optical splitter P1 for branching an optical signal of a first path L21 to a subscriber device 4 in a second loop network L2 connected to a first loop network L1; a second optical splitter P2 for branching an optical signal of a second path to the subscriber device 4 in the second loop network L2; a first optical sensor 13a provided at a branch destination of the first optical splitter P1, for detecting an optical signal in the first path L21; a second optical sensor 13b provided at a branch destination of the second optical splitter P2, for detecting an optical signal in the second path L22; and a test device 1. When a failure in the second loop network L2 is detected, the test device 1 determines the occurrence of a failure in a path corresponding to the sensor that has detected the light among the first optical sensor 13a and the second optical sensor 13b.

Description

Test system, test method and test device

[0001] The present disclosure relates to a test system, a test method, and a test apparatus.

[0002] A pulse tester is used to detect faults in optical fibers (see Non-Patent Document 1). The pulse tester can measure the condition of the optical fiber by injecting an optical pulse into the optical fiber and extracting the returned light due to Fresnel reflection.

[0003] A multi-ring network that connects multiple loop networks is known (see Non-Patent Document 2). At the connection point between two loop networks, a reconfigurable optical add / drop multiplexer (ROADM) that enables adding and dropping of optical signals is installed.

[0004] Nippon Telegraph and Telephone Corporation, "Search Method for Optical Fiber Faults," NTT Technical Journal, October 2006, pp. 53-54. Yohei Sakamaki and two others, "Optical Switch Technology for Realizing More Flexible Optical Nodes," NTT Technical Journal, November 2013, pp. 16-20.

[0005] However, in a multi-ring network, there may be multiple routes to a destination depending on the settings of the ROADM. Even if the pulse test equipment detects a fault on a route to the destination, it may not be able to identify the route on which the fault occurred.

[0006] If the ROADM settings are known, the route to the destination can be identified, and the location of the fault can be identified from the results of the pulse test equipment. However, if the ROADM settings are unknown, the currently used route among multiple routes to the destination cannot be identified, and the route where the fault occurred cannot be identified.

[0007] The present disclosure has been made in consideration of the above circumstances, and an object of the present disclosure is to provide a technology that can easily identify a fault path in a multi-ring network that transmits and receives optical signals.

[0008] A test system according to one aspect of the present disclosure includes a first optical splitter in a second loop network connected to a first loop network, which splits an optical signal on a first path to an indoor device; a second optical splitter in the second loop network, which splits an optical signal on a second path to the indoor device; a first optical sensor provided at the branch point of the first optical splitter, which detects an optical signal on the first path; a second optical sensor provided at the branch point of the second optical splitter, which detects an optical signal on the second path; and a test device that, when it detects a fault in the second loop network, determines whether a fault has occurred on the path corresponding to the sensor that detected light, either the first optical sensor or the second optical sensor.

[0009] A testing method of one aspect of the present disclosure is used in a communication network system comprising: a first optical splitter in a second loop network connected to a first loop network, which splits an optical signal of a first route to an indoor device; a second optical splitter in the second loop network, which splits an optical signal of a second route to the indoor device; a first optical sensor provided at the branch point of the first optical splitter, which detects an optical signal of the first route; and a second optical sensor provided at the branch point of the second optical splitter, which detects an optical signal of the second route; wherein a computer acquires the detection of an optical signal by at least one of the first optical sensor and the second optical sensor, and when the computer detects a fault in the second loop network, determines that a fault has occurred in the route corresponding to the sensor of the first optical sensor or the second optical sensor that detected light.

[0010] A test apparatus according to one aspect of the present disclosure is used in a communication network system including: a first optical splitter in a second loop network connected to a first loop network, which splits an optical signal on a first path to an indoor device; a second optical splitter in the second loop network, which splits an optical signal on a second path to the indoor device; a first optical sensor provided at the branch point of the first optical splitter, which detects the optical signal on the first path; and a second optical sensor provided at the branch point of the second optical splitter, which detects the optical signal on the second path. The test apparatus includes a memory unit that stores sensor data recording the detection of the optical signal by at least one of the first optical sensor and the second optical sensor; and a determination unit that, upon detecting a fault in the second loop network, refers to the sensor data and determines whether a fault has occurred on the path corresponding to the first optical sensor or the second optical sensor that detected light.

[0011] According to the present disclosure, it is possible to provide a technology that can easily identify a fault path in a multi-ring network that transmits and receives optical signals.

[0012] Fig. 1 is a diagram illustrating the system configuration of a test system according to an embodiment of the present disclosure. Fig. 2 is a block diagram illustrating the configuration of a test device. Fig. 3 is a diagram illustrating an example of a result obtained by a pulse test device. Fig. 4 is a flowchart illustrating processing in the test device. Fig. 5 is a diagram illustrating the hardware configuration of a computer used in the test device.

[0013] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the description of the drawings, the same parts are designated by the same reference numerals and the description thereof will be omitted.

[0014] (Test System) The test system 5 identifies a path in which a failure has occurred in a multi-ring network that transmits and receives optical signals.

[0015] In the present disclosure, the multi-ring network includes a first loop network L1 and a second loop network L2. The first loop network L1 connects an on-site device 2 and an off-site device 3. The second loop network L2 connects to the first loop network L1 via the off-site device 3. An on-site device 4 connected to the second loop network L2 connects to the first loop network L1 via the second loop network L2 and the off-site device 3.

[0016] The on-premise device 2 is installed in, for example, a communication building and is connected to a higher-level communication network. The on-premise device 2 relays communications between the higher-level communication network and the on-premise devices connected to the first loop network L1 and the second loop network L2.

[0017] The off-site device 3 is installed, for example, at a location away from the communication building, and relays communications via a plurality of loop networks.

[0018] The home device 4 is installed in the home of a user who uses the multi-ring network. The home device 4 is connected to a user terminal (not shown) and provides the user terminal with communication services with a higher-level communication network, etc. The home device 4 converts optical signals received from the multi-ring network into electrical signals and provides the converted electrical signals to the user terminal.

[0019] The first loop network L1 has paths L11 and L12 as paths connecting the on-site device 2 and the off-site device 3. The second loop network L2 has paths L21 and L22 as paths connecting the off-site device 3 and the on-site device.

[0020] The on-site device 2 and the off-site device 3 are, for example, ROADMs that output input optical signals to predetermined paths. The on-site device 2 and the off-site device 3 can change the output destination of the input optical signals as needed. For example, the off-site device 3 can output an optical signal input from path L11 to either path L21 or path L22, depending on the settings of the off-site device 3.

[0021] 1, there are four routes for communication from the on-premises device 2 to the home device 4: route L11-L21, route L11-L22, route L12-L21, and route L12-L22. Depending on the settings of the on-premises device 2 and the off-premises device 3, one of the four routes is used as the active route, and the other routes are used as standby routes.

[0022] The pulse tester inputs an optical pulse to the path L11 or L12 of the first loop network. If a fault is detected at a distance corresponding to the first loop network L1, it can be determined that the fault occurred on the path to which the pulse tester input the optical pulse.

[0023] On the other hand, consider a case where a pulse tester inputs an optical pulse to path L11 of the first loop network L1 and detects a fault at a distance corresponding to the second loop network L2. If it is known from the settings of the off-site device 3 which of path L21 and path L22 the optical signal from path L11 will travel on, the location of the fault can be easily identified. However, if the settings of the off-site device 3 are unknown, it is not possible to identify which of path L21 and path L22 is at fault by pulse testing alone.

[0024] Therefore, the test system 5 according to the present disclosure includes a first optical splitter P1 and a second optical splitter P2 in the second loop network L2. The first optical splitter P1 splits an optical signal on a first path L21 to the home device 4 in the second loop network L2. The second optical splitter P2 splits an optical signal on a second path L22 to the home device 4 in the second loop network L2.

[0025] Each splitter transmits the branched optical signal to the test device 1. The test device 1 identifies the path on which the splitter that detected the optical signal is installed as the active path, and can determine that a fault will occur on that path.

[0026] The first optical splitter P1 and the second optical splitter P2 are provided to detect the presence or absence of an optical signal and identify the current route. The first optical splitter P1 and the second optical splitter P2 are each installed at a position closer to the connection point between the first loop network L1 and the second loop network L2 than to the home device 4. More specifically, the first optical splitter P1 is installed in the first route L21, immediately adjacent to the off-site device 3. The second optical splitter P2 is installed in the second route L22, immediately adjacent to the off-site device 3. This reduces the possibility of failure between the off-site device 3 and each splitter, and identifies the current route.

[0027] (Test Apparatus) The test apparatus 1 according to the present disclosure will be described with reference to Fig. 2. In the example shown in Fig. 2, the test apparatus 1 includes a pulse test apparatus 11, a first optical sensor 13a, and a second optical sensor 13b, but is not limited to this. The pulse test apparatus 11, the first optical sensor 13a, and the second optical sensor 13b may be provided outside the test apparatus 1.

[0028] The test device 1 includes a pulse test device 11, result data 12, a first optical sensor 13a, a second optical sensor 13b, sensor data 14, and a determination unit 15. The result data 12 and the sensor data 14 are stored in a storage device (storage unit) such as a memory 902 or a storage 903. The determination unit 15 is implemented in a CPU 901.

[0029] The pulse test device 11 inputs an optical pulse signal to the first loop network L1 and outputs the result. In the present disclosure, the pulse test device 11 inputs the pulse signal to a connection point C1 on a path L11 of the first loop network L1 and a connection point C2 on a path L12 of the first loop network L1. The pulse test device 11 outputs result data 12.

[0030] The result data 12 stores data specifying the test results of the pulse test device 11. The result data 12 indicates the distance on the horizontal axis and the intensity of the light returned by Fresnel reflection on the vertical axis, as shown in Fig. 3, for example.

[0031] The first optical sensor 13 a and the second optical sensor 13 b each detect light and output the detection results to the sensor data 14 .

[0032] The first optical sensor 13a is provided at the branching destination of the first optical splitter P1. The first optical splitter P1 branches an optical signal from the outside device 3 into a path L21 toward the home device 4 and a path toward the first optical sensor 13a. The first optical sensor 13a detects the presence or absence of an optical signal on the first path L21 in the second loop network L2.

[0033] The second optical sensor 13b is provided at the branching destination of the second optical splitter P2. The second optical splitter P2 branches the optical signal from the outside device 3 into a path L22 toward the indoor device 4 and a path toward the second optical sensor 13b. The second optical sensor 13b detects the presence or absence of an optical signal on the second path L22 in the second loop network L2.

[0034] The sensor data 14 specifies the detection status of the optical signal by each of the first optical sensor 13 a and the second optical sensor 13 b. The sensor data 14 may indicate, for example, the detection status of each sensor in chronological order.

[0035] The sensor data 14 may record the detection of an optical signal by at least one of the first optical sensor 13a and the second optical sensor 13b.

[0036] In the present disclosure, one of the first path L21 and the second path L22 is in use and the other is in standby use in the test system 5. If the detection status of the optical signal of at least one of the first optical sensor 13 a and the second optical sensor 13 b is identified, the active path is identified.

[0037] When the judgment unit 15 detects a fault in the second loop network L2, it refers to the sensor data 14 and judges whether a fault has occurred in the path corresponding to the sensor that detected the light, either the first optical sensor 13a or the second optical sensor 13b.

[0038] The determining unit 15 detects a fault in the second loop network L2 from the result of the pulse test equipment 11 inputting an optical pulse signal to the first loop network L1. As shown in Fig. 3, the result data 12 from the pulse test equipment 11 indicates that, under normal conditions, returned light due to Fresnel reflection occurs at a certain distance from the indoor device 4. Under fault conditions, noise occurs at a distance shorter than the certain distance from the indoor device 4. If the distance at which noise occurs in the result data 12 is between the outdoor device 3 and the indoor device 4, the determining unit 15 determines that a fault has occurred in the second loop network L2.

[0039] When detecting a fault in the second loop network L2, the determination unit 15 determines that a fault has occurred in the first path L21 if the first optical sensor 13a receives an optical signal, and determines that a fault has occurred in the second path L22 if the second optical sensor 13b receives an optical signal.

[0040] (Test Method) A test method according to the present disclosure will be described with reference to FIG.

[0041] In step S101, the test device 1 detects a fault in the second loop network L2 from the result of the pulse test. In step S102, the test device 1 refers to the sensor data 14 to check the detection status of the optical sensor.

[0042] If the first optical sensor 13a detects an optical signal, the test apparatus 1 determines in step S103 that a fault has occurred in the first path L21. The first path L21 is the path from which the light detected by the first optical sensor 13a branches.

[0043] If the second optical sensor 13b detects an optical signal, the test apparatus 1 determines in step S104 that a fault has occurred in the second path L22. The second path L22 is the path from which the light detected by the second optical sensor 13b branches.

[0044] In step S105, the test apparatus 1 outputs the path identified in step S103 or step S104.

[0045] The test system 5 according to the present disclosure can easily identify a fault path in a multi-ring network that transmits and receives optical signals.

[0046] The test apparatus 1 of the present embodiment described above uses, for example, a general-purpose computer system including a CPU (Central Processing Unit, processor) 901, a memory 902, a storage 903 (HDD: Hard Disk Drive, SSD: Solid State Drive), a communication device 904, an input device 905, and an output device 906. In this computer system, the CPU 901 executes a program loaded on the memory 902, thereby realizing each function of the test apparatus 1.

[0047] The test apparatus 1 may be implemented as one computer or as multiple computers, or may be a virtual machine implemented on a computer.

[0048] The program for the test device 1 can be stored in a computer-readable recording medium such as a HDD, SSD, USB (Universal Serial Bus) memory, CD (Compact Disc), or DVD (Digital Versatile Disc), or can be distributed via a network. The computer-readable recording medium is, for example, a non-transitory recording medium.

[0049] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the present disclosure.

[0050] REFERENCE SIGNS LIST 1 Test equipment 2 On-site equipment 3 Off-site equipment 4 On-site equipment 11 Pulse test equipment 12 Result data 13a, 13b Optical sensors 14 Sensor data 15 Determination unit 901 CPU 902 Memory 903 Storage 904 Communication device 905 Input device 906 Output device L1, L2 Loop network P1, P2 Optical splitter

Claims

1. In a second loop network connected to a first loop network, a first optical splitter that branches an optical signal of a first path to a home device, a second optical splitter that branches an optical signal of a second path to the home device in the second loop network, a first optical sensor provided at a branching destination of the first optical splitter and detecting an optical signal in the first path, a second optical sensor provided at a branching destination of the second optical splitter and detecting an optical signal in the second path, and a test device that, when detecting a failure in the second loop network, determines the occurrence of a failure in a path corresponding to the sensor that detected light among the first optical sensor and the second optical sensor. A test system comprising the same.

2. The test system according to claim 1, wherein the test device detects a failure in the second loop network from a result of inputting an optical pulse signal to the first loop network by a pulse test device.

3. The test system according to claim 1, wherein the first optical splitter and the second optical splitter are each installed at a position closer to a connection point between the first loop network and the second loop network than a distance to the home device.

4. In a communication network system comprising a first optical splitter that branches an optical signal of a first path to a home device in a second loop network connected to a first loop network, a second optical splitter that branches an optical signal of a second path to the home device in the second loop network, a first optical sensor provided at a branching destination of the first optical splitter and detecting an optical signal in the first path, and a second optical sensor provided at a branching destination of the second optical splitter and detecting an optical signal in the second path, a computer acquires detection of an optical signal in at least one of the first optical sensor and the second optical sensor, and when the computer detects a failure in the second loop network, determines the occurrence of a failure in a path corresponding to the sensor that detected light among the first optical sensor and the second optical sensor. A test method.

5. In a second loop network connected to the first loop network, a first optical splitter that branches an optical signal of a first path to an in-house device, a second optical splitter that branches an optical signal of a second path to the in-house device in the second loop network, a first optical sensor provided at a branching destination of the first optical splitter and detecting an optical signal in the first path, and a second optical sensor provided at a branching destination of the second optical splitter and detecting an optical signal in the second path, which are used in a communication network system, a storage unit that stores sensor data for recording detection of an optical signal in at least any one of the first optical sensor and the second optical sensor, and a determination unit that, when detecting a failure in the second loop network, determines the occurrence of a failure in a path corresponding to the sensor that detected light among the first optical sensor and the second optical sensor with reference to the sensor data. A test device comprising.

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