Abnormality location determination device, abnormality location determination method, and program

Abstract

To determine a point where an abnormality has occurred in a transmission line of an optical fiber communication system using a signal quality measurement function provided in an optical transceiver.SOLUTION: An abnormality occurrence point determination device includes a collection unit that collects transmission signal information in a transmission section acquired by an optical transceiver from a plurality of optical nodes that make up an optical network, a diagnosis unit that diagnoses the normality of the transmission section on the basis of the transmission signal information, and a determination unit that determines an abnormal location in the optical network on the basis of a plurality of results of the diagnosis by the diagnosis unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an abnormality location determination device, an abnormality location determination method, and a program. [Background technology]

[0002] An OTDR (Optical Time Domain Reflectometer) is generally used to detect abnormalities in the transmission path of an optical fiber communication system. OTDR is a measuring instrument that can evaluate the loss of an optical fiber by observing the reflected light (backscattered light) of an optical pulse sent to the optical fiber. OTDRs are used for testing during optical fiber installation and maintenance work, as well as in active transmission paths where data is actually being transmitted. OTDRs can display the loss level as a waveform relative to the distance from the incident point of the optical pulse. Using an OTDR, it is possible to detect abnormalities such as optical fiber breaks or abnormalities causing loss, such as connector connection loss, based on the location of waveform disturbances and the shape of the waveform.

[0003] Meanwhile, attempts are also being made to detect abnormalities occurring in the transmission path of an optical fiber communication system using the optical signals themselves used in actual data communications. For example, the technology described in Non-Patent Document 1 uses a constellation, in which a digitally modulated signal obtained at a receiver of a digital coherent optical transceiver is represented as a two-dimensional image of real and imaginary axes, as a learning parameter in machine learning. The technology described in Non-Patent Document 1 then uses a trained neural network to identify the presence or absence of bending of the optical fiber from the distortion of the constellation.

[0004] For example, when identifying whether an optical fiber is bent or not, different labels are assigned to the constellations when the optical fiber is not bent and the constellations when the optical fiber is bent. These constellations are input to a neural network, which then learns the regularity of the constellation shape for each label. When an unknown, unlabeled constellation is input to the trained neural network, the neural network outputs the most appropriate label based on the past regularity. For example, changes in the constellation shape due to bending of an optical fiber, etc., are so small that they cannot be distinguished by human vision, but these changes have recently become detectable thanks to the use of machine learning techniques such as neural networks.

[0005] In addition, optical transceivers generally have a function for measuring, for example, the reception power and the bit error rate in order to detect quality degradation of the received signal. In the operation and maintenance of optical networks, it is desirable to not only use the above-mentioned machine learning-based detection means for detecting the location of an abnormality, but also to utilize technologies that are already installed in the optical transceiver, to quickly detect the occurrence of an abnormality that is a sign of a communication interruption and identify the location of the abnormality before the communication interruption actually occurs. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] T. Tanaka, S. Kuwabara, H. Nishizawa, T. Inui, S. Kobayashi and A. Hirano, “Field Demonstration of Real-time Optical Network Diagnosis Using Deep Neural Network and Telemetry”, Optical Fiber Communications Conference and Exhibition (OFC) 2019, Tu2E.5., February, 2019 Summary of the Invention [Problem to be solved by the invention]

[0007] As mentioned above, OTDRs can accurately estimate the location of anomalies in the transmission path of an optical fiber communication system. However, because OTDRs use a light source different from that of the optical transceiver they are measuring, it is difficult to detect anomalies occurring in the optical transceiver itself, such as laser malfunctions. Furthermore, OTDRs are measurement devices dedicated to anomaly detection and are installed additionally in optical fiber communication systems. Furthermore, OTDRs are more expensive than optical transceivers. Thus, in terms of functionality and cost, OTDRs are not suitable for comprehensively detecting anomalies occurring at every point in an optical network.

[0008] On the other hand, a detection means for detecting anomalies in the transmission path of an optical fiber communication system using the signal quality measurement function built into the optical transceiver can detect anomalies in the optical transceiver itself. This detection means is also more cost-effective because it does not require a dedicated measurement device for anomaly detection, such as an OTDR. However, when an anomaly such as degradation of signal quality occurs, it is difficult to determine which section of the transmission path the anomaly is occurring in.

[0009] The present invention has been made in consideration of the above points, and aims to provide an abnormality location determination device, an abnormality location determination method, and a program that can determine the location of an abnormality in the transmission path of an optical fiber communication system by using the signal quality measurement function provided in an optical transceiver. [Means for solving the problem]

[0010] One aspect of the present invention is an abnormality location determination device that includes a collection unit that collects transmission signal information of a transmission section obtained by an optical transceiver from multiple optical nodes that constitute an optical network, a diagnosis unit that diagnoses the normality of the transmission section based on the transmission signal information, and a determination unit that determines an abnormal location in the optical network based on multiple results of the diagnosis by the diagnosis unit.

[0011] Another aspect of the present invention is a method for determining the location of an abnormality, comprising: a collection step of collecting transmission signal information of a transmission section obtained by an optical transceiver from a plurality of optical nodes constituting an optical network; a diagnosis step of diagnosing the normality of the transmission section based on the transmission signal information; and an estimation step of estimating an abnormal location in the optical network based on a plurality of results of the diagnosis by the diagnosis step.

[0012] Another aspect of the present invention is a program for causing a computer to function as the abnormality occurrence location determination device. [Effects of the Invention]

[0013] According to the present invention, it is possible to determine the location of an abnormality in the transmission path of an optical fiber communication system by using the signal quality measurement function provided in the optical transceiver. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a diagram illustrating the overall configuration of an optical network system 1 according to a first embodiment of the present invention. [Figure 2]3 is a flowchart showing the operation of the optical network state estimating device 20 in the first embodiment of the present invention. [Figure 3] FIG. 2 is a diagram illustrating an example of the configuration of an optical network for explaining the operation of the optical network state estimation device 20. [Figure 4] 10 is a diagram showing an example of the correspondence between patterns of abnormality occurrence locations and optical transceivers in which abnormalities are detected by a signal state diagnostic unit 22. FIG. [Figure 5] FIG. 1 is an overall configuration diagram of an optical network system 1b according to a first modified example of the first embodiment of the present invention. [Figure 6] FIG. 10 is an overall configuration diagram of an optical network system 1c according to a second modified example of the first embodiment of the present invention. [Figure 7] FIG. 10 is a cross-sectional view of a multi-core optical fiber 30c of an optical network system 1c according to a second modification of the first embodiment of the present invention. [Figure 8] 10 is a flowchart showing the operation of the optical network state estimating device 20d in the second embodiment of the present invention. [Figure 9] FIG. 2 is a diagram illustrating an example of the configuration of an optical network for explaining the operation of an optical network state estimation device 20d. [Figure 10] 10 is a diagram showing an example of the correspondence between patterns of abnormality occurrence locations and optical transceivers in which abnormalities are detected by a signal state diagnostic unit 22. FIG. [Figure 11] 10 is a flowchart showing the operation of the optical network state estimating device in a modified example of the second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] First Embodiment A first embodiment of the present invention will be described below with reference to the drawings.

[0016] [Optical network system configuration] The configuration of the optical network system in this embodiment will be described below. Fig. 1 is an overall configuration diagram of an optical network system 1 in a first embodiment of the present invention. The optical network system 1 is an optical fiber communication system. As shown in Fig. 1, the optical network system 1 in this embodiment is configured to include four optical node devices 10 and an optical network state estimation device 20. Note that in this embodiment, as an example, the number of optical node devices 10 included in the optical network system 1 is four, but this is not limited to this and any number may be used.

[0017] The four optical node devices 10 are communicatively connected to one another via optical links using optical fibers to form an optical network. As shown in FIG. 1, the optical node device 10 includes an optical signal input / output unit 11 and an optical cross-connect unit 12.

[0018] The optical signal input / output unit 11 inputs and outputs signals transmitted through optical links connecting optical node devices 10. The optical signal input / output unit 11 is equipped with optical transceivers 110 (Tx / Rx (Transmitter / Receiver)) that transmit client signals depending on the actual communication situation. Transmission signal information of the transmission section acquired by the optical transceiver 110 is sent to the optical network state estimation device 20. The transmission signal information includes information related to optical communication that is necessary to estimate the state of signals transmitted through the optical links. For example, the transmission signal information includes the digitally modulated signal received by the optical transceiver 110, the received power value, the bit error rate value, etc.

[0019] The optical cross-connect unit 12 determines the input and output paths of the optical signals.

[0020] The optical network state estimation device 20 evaluates the communication state of an optical network configured by four optical node devices 10. As shown in Fig. 1, the optical network state estimation device 20 includes a transmission signal information collection unit 21, a signal state diagnosis unit 22, and an abnormality occurrence location estimation unit 23.

[0021] The transmission signal information collecting unit 21 receives transmission signal information from each optical node device 10 in the monitored section of the optical network. The transmission signal information collecting unit 21 outputs the received transmission signal information to the signal state diagnosing unit 22.

[0022] The signal state diagnostic unit 22 acquires the transmission signal information output from the transmission signal information collecting unit 21. The signal state diagnostic unit 22 diagnoses the normality of the transmission section based on the acquired transmission signal information. Note that the diagnosis of normality here refers to detecting the presence or absence of an abnormality. Specifically, the signal state diagnostic unit 22 determines whether the transmission section through which each optical transceiver 110 passes (is used) is normal (whether an abnormality has occurred). For example, the signal state diagnostic unit 22 determines that an abnormality has occurred in the transmission section when the value of the received power or the value of the bit error rate falls below a predetermined threshold. The signal state diagnostic unit 22 outputs information indicating the diagnosis result of the normality of the transmission section (the abnormality detection result) to the abnormality occurrence location estimating unit 23.

[0023] In addition, the signal condition diagnosis unit 22 may be configured to perform machine learning using a neural network or the like using a digitally modulated signal, etc., and determine whether or not an abnormality has occurred in the transmission section by using the trained neural network or the like.

[0024] The abnormality location estimation unit 23 acquires information indicating the diagnosis result of the normality of the transmission section output from the signal state diagnosis unit 22. Based on the acquired information indicating the diagnosis result, the abnormality location estimation unit 23 estimates the location where the abnormality has occurred in the optical network (hereinafter referred to as the "abnormality location"). Note that the abnormality location in this embodiment refers to the optical link where the abnormality has occurred and the optical transceiver 110 where the abnormality has occurred.

[0025] [Operation of the optical network state estimator] 2 to 4, an example of the operation of the optical network state estimation device 20 will be described. In this embodiment, it is assumed that the configuration of the optical network, the connection status of each optical transceiver 110, and the diagnosis result of the signal state diagnosis unit 22 regarding the normality of each optical transceiver 110 are known.

[0026] In this embodiment, for ease of explanation, it is assumed that an abnormality occurs in only one location in the optical network, and that an abnormality does not occur in multiple locations at the same time. Specifically, in this embodiment, it is assumed that an abnormality occurs in one of the optical links or one of the optical transceivers 110.

[0027] Fig. 2 is a flowchart showing the operation of the optical network state estimating device 20 in the first embodiment of the present invention. Fig. 3 is a diagram showing an example of the configuration of an optical network for explaining the operation of the optical network state estimating device 20. Fig. 4 is a diagram showing an abnormality occurrence pattern and a normality diagnosis result in the optical network shown in Fig. 3.

[0028] The operation of the optical network state estimating device 20 shown in the flowchart of FIG. 2 starts, for example, when the signal state diagnosing unit 22 diagnoses that at least one of the optical transceivers 110 is abnormal.

[0029] First, the abnormality occurrence location estimation unit 23 of the optical network state estimation device 20 determines whether all optical transceivers 110 using each optical link in the optical network being evaluated have been diagnosed as abnormal (step S001).

[0030] If all optical transceivers 110 using the optical link are diagnosed as abnormal (step S001: YES), the abnormality occurrence location estimation unit 23 performs a process of setting an abnormality occurrence flag for the optical link (step S002). After repeating the above process for all optical links in the optical network to be evaluated, the abnormality occurrence location estimation unit 23 proceeds to the next step.

[0031] Next, for each optical transceiver 110 diagnosed as abnormal by the signal condition diagnosis unit 22, the abnormality occurrence location estimation unit 23 determines whether an abnormality occurrence flag has been set (by the processing of step S002) in all optical links through which the optical transceiver 110 passes (step S003). In other words, the abnormality occurrence location estimation unit 23 determines whether an abnormality occurrence flag has been set (by the processing of step S002) in at least one optical link through which the optical transceiver 110 passes.

[0032] If an abnormality occurrence flag has not been set for all optical links through which the optical transceiver 110 passes (step S003: YES), the abnormality occurrence location estimation unit 23 performs a process of setting an abnormality occurrence flag for the optical transceiver 110 (step S005).

[0033] On the other hand, if an abnormality occurrence flag is set (by the processing of step S002 above) in at least one optical link through which the optical transceiver 110 passes (step S003: NO), the abnormality occurrence location estimation unit 23 determines whether or not there is an optical link among the optical links for which an abnormality occurrence flag is set that is being used only by the optical transceiver 110 (and is not being used by other optical transceivers 110) (step S004).

[0034] If there is an optical link among the optical links for which an abnormality occurrence flag is set that is being used only by the optical transceiver 110 (not being used by other optical transceivers 110) (step S004: YES), the abnormality occurrence location estimation unit 23 performs a process of setting an abnormality occurrence flag for the optical transceiver 110 (step S005).

[0035] When the abnormality occurrence location estimation unit 23 has repeated the processing from step S003 onwards for all optical transceivers 110 diagnosed as abnormal by the signal state diagnosis unit 22, the operation of the optical network state estimation device 20 shown in the flowchart of Figure 2 ends.

[0036] A specific example of the process of the flowchart shown in FIG. 2 will be described below with reference to FIGS.

[0037] The overall configuration of an optical network system 1a and the configuration of an optical network in a specific example described below are shown in Fig. 3. As shown in Fig. 3, the optical network system 1a in a specific example described below is configured to include an optical node device 10A, an optical node device 10B, an optical node device 10C, an optical node device 10D, and an optical network state estimation device 20.

[0038] The optical node device 10A, the optical node device 10B, the optical node device 10C, and the optical node device 10D are communicatively connected to one another by optical links using single-mode optical fibers 30, forming an optical network. The optical node device 10A, the optical node device 10B, the optical node device 10C, and the optical node device 10D each include an optical signal input / output unit 11 and an optical cross-connect unit 12. The optical cross-connect unit 12 also includes a wavelength multiplexing unit 15.

[0039] Hereinafter, the optical link connecting the optical node device 10A and the optical node device 10B will be referred to as "optical link AB", the optical link connecting the optical node device 10B and the optical node device 10C will be referred to as "optical link BC", and the optical link connecting the optical node device 10C and the optical node device 10D will be referred to as "optical link CD".

[0040] The optical signal input / output unit 11 is provided with optical transceivers (Tx / Rx) for transmitting client signals depending on the actual communication situation. In the specific example described below, it is assumed that an optical transceiver 110-1 is provided between the optical node device 10A and the optical node device 10C, an optical transceiver 110-2 is provided between the optical node device 10A and the optical node device 10B, and an optical transceiver 110-3 is provided between the optical node device 10B and the optical node device 10D, as shown in Fig. 3.

[0041] 3, the optical links that the optical transceiver 110-1 passes through are optical link AB and optical link BC, the optical link that the optical transceiver 110-2 passes through is only optical link AB, and the optical links that the optical transceiver 110-3 passes through are optical link BC and optical link CD. With the above configuration, wavelength multiplexed communications are performed by the optical transceivers 110-1, 110-2, and 110-3 between the optical node device 10A and the optical node device 10C, between the optical node device 10A and the optical node device 10B, and between the optical node device 10B and the optical node device 10D, respectively.

[0042] The optical network state estimation device 20 evaluates the communication state of an optical network configured by the optical node device 10A, the optical node device 10B, the optical node device 10C, and the optical node device 10D. As shown in Fig. 3, the optical network state estimation device 20 includes a transmission signal information collection unit 21, a signal state diagnosis unit 22, and an abnormality occurrence location estimation unit 23.

[0043] As described above, in this embodiment, when an abnormality occurs in the optical network, it is assumed that the abnormality occurs in one location and that abnormalities do not occur in multiple locations at the same time. Therefore, in this specific example, the location where the abnormality occurs in the optical network is any one of optical link AB, optical link BC, and optical link CD, or any one of optical transceiver 110-1, optical transceiver 110-2, and optical transceiver 110-3. In other words, there are six possible locations where an abnormality may occur in the optical network of this specific example.

[0044] An abnormality occurring in optical link AB, optical link BC, and optical link CD may be, for example, a communication failure caused by bending of the optical fiber, and an abnormality occurring in optical transceiver 110-1, optical transceiver 110-2, and optical transceiver 110-3 may be, for example, a malfunction of the optical transceiver itself.

[0045] Figure 4 shows six patterns of abnormality locations that can occur in the optical network of Figure 3, and the correspondence between them and the optical transceivers in which the signal status diagnosis unit 22 detects an abnormality when an abnormality occurs at each abnormality location.

[0046] 4, if the abnormality occurs in optical link AB, the abnormality is detected in optical transceivers 110-1 and 110-2, which are optical transceivers (Tx / Rx) passing through optical link AB. If the abnormality occurs in optical link BC, the abnormality is detected in optical transceivers 110-1 and 110-3, which are optical transceivers passing through optical link BC. If the abnormality occurs in optical link CD, the abnormality is detected in optical transceiver 110-3, which is an optical transceiver passing through optical link CD.

[0047] 4, if the abnormality occurs in the optical transceiver 110-1, the abnormality is detected in the optical transceiver 110-1, if the abnormality occurs in the optical transceiver 110-2, the abnormality is detected in the optical transceiver 110-2, and if the abnormality occurs in the optical transceiver 110-3, the abnormality is detected in the optical transceiver 110-3. Based on the correspondence between the abnormality occurrence locations and the optical transceivers in which the abnormality is detected, it is possible to narrow down or identify the abnormality occurrence location from the optical transceiver in which the abnormality is detected.

[0048] [Example of setting an error flag] Hereinafter, a flow up to the setting of an abnormality occurrence flag by the operation of the optical network state estimating device 20 shown in FIG. 2 will be described for each of six patterns of abnormality occurrence locations that can occur in the optical network of FIG.

[0049] First, consider the first case, where an abnormality occurs in optical link AB due to, for example, bending of the optical fiber. In this case, as described above, an abnormality is detected in optical transceiver 110-1 and optical transceiver 110-2. For each of optical link AB, optical link BC, and optical link CD, the abnormality location estimation unit 23 of the optical network state estimation device 20 determines whether all optical transceivers using the optical link have been diagnosed as abnormal (step S001 in FIG. 2).

[0050] 3, the optical transceivers using the optical link AB are the optical transceiver 110-1 and the optical transceiver 110-2. As described above, since both the optical transceiver 110-1 and the optical transceiver 110-2 have been diagnosed as abnormal (YES in step S001 of FIG. 2), the abnormality occurrence location estimation unit 23 sets an abnormality occurrence flag for the optical link AB (step S002 of FIG. 2).

[0051] 3, the optical transceivers using the optical link BC are the optical transceiver 110-1 and the optical transceiver 110-3. As described above, the optical transceiver 110-1 has been diagnosed as having an abnormality, but the optical transceiver 110-3 has not been diagnosed as having an abnormality (step S001: NO in FIG. 2), so the abnormality occurrence location estimation unit 23 does not set an abnormality occurrence flag for the optical link BC.

[0052] 3, the optical transceiver using the optical link CD is the optical transceiver 110-3. Since the optical transceiver 110-3 has not been diagnosed as being abnormal (step S001: NO in FIG. 2), the abnormality occurrence location estimation unit 23 does not set an abnormality occurrence flag for the optical link CD.

[0053] Next, for each of the optical transceivers 110-1 and 110-2 diagnosed as abnormal by the signal condition diagnosis unit 22, the abnormality occurrence location estimation unit 23 determines whether an abnormality occurrence flag is set in all optical links through which the optical transceiver passes (step S003 in Figure 2).

[0054] As shown in FIG. 3, the optical links through which the optical transceiver 110-1 passes are optical link AB and optical link BC. As described above, the abnormality flag is not set for optical link BC, but the abnormality flag is set for optical link AB. Therefore, among the optical links through which the optical transceiver 110-1 passes, there is an optical link (i.e., optical link AB) for which the abnormality flag is set. In this case (step S003 in FIG. 2: NO), the abnormality location estimation unit 23 determines whether the optical link AB for which the abnormality flag is set is an optical link used only by the optical transceiver 110-1 (not used by other optical transceivers) (step S004 in FIG. 2).

[0055] Since the optical link AB is used not only by the optical transceiver 110-1 but also by the optical transceiver 110-2 (step S004: NO in FIG. 2), the abnormality occurrence location estimation unit 23 does not set an abnormality occurrence flag for the optical transceiver 110-1.

[0056] 3, the optical link through which the optical transceiver 110-2 passes is only the optical link AB. As described above, the abnormality flag is set on the optical link AB. Therefore, among the optical links through which the optical transceiver 110-2 passes, there is an optical link (i.e., the optical link AB) for which the abnormality flag is set. In this case (step S003 in FIG. 2: NO), the abnormality location estimation unit 23 determines whether the optical link AB for which the abnormality flag is set is an optical link used only by the optical transceiver 110-2 (and not used by other optical transceivers) (step S004 in FIG. 2).

[0057] Since the optical link AB is used not only by the optical transceiver 110-2 but also by the optical transceiver 110-1 (step S004: NO in FIG. 2), the abnormality occurrence location estimation unit 23 does not set an abnormality occurrence flag for the optical transceiver 110-2.

[0058] 3, in a pattern in which an abnormality occurs in optical link AB, an abnormality occurrence flag is set only for optical link AB. In other words, when an abnormality occurs in optical link AB, the abnormality occurrence location estimation unit 23 can correctly estimate that an abnormality has occurred in optical link AB.

[0059] FIG. 4 shows six patterns of abnormality occurrence locations that can occur in the optical network of FIG. 3, and the correspondence between the abnormality occurrence flags that are set when an abnormality occurs at each abnormality occurrence location.

[0060] Next, consider the second case, where an abnormality occurs in optical link BC due to, for example, bending of the optical fiber. In this case, as described above, abnormalities are detected in optical transceivers 110-1 and 110-3. For each of optical links AB, BC, and CD, the abnormality location estimation unit 23 of the optical network state estimation device 20 determines whether all optical transceivers using the optical links have been diagnosed as abnormal (step S001 in FIG. 2).

[0061] 3, the optical transceivers using the optical link AB are the optical transceiver 110-1 and the optical transceiver 110-2. As described above, the optical transceiver 110-1 has been diagnosed as abnormal, but the optical transceiver 110-2 has not been diagnosed as abnormal (step S001: NO in FIG. 2), so the abnormality occurrence location estimation unit 23 does not set an abnormality occurrence flag for the optical link AB.

[0062] 3, the optical transceivers using the optical link BC are the optical transceiver 110-1 and the optical transceiver 110-3. As described above, since both the optical transceiver 110-1 and the optical transceiver 110-3 have been diagnosed as abnormal (YES in step S001 in FIG. 2), the abnormality occurrence location estimation unit 23 sets an abnormality occurrence flag for the optical link BC (step S002 in FIG. 2).

[0063] 3, the only optical transceiver using the optical link CD is the optical transceiver 110-3. Because the optical transceiver 110-3 has been diagnosed as abnormal (YES in step S001 of FIG. 2), the abnormality occurrence location estimation unit 23 would normally set an abnormality occurrence flag for the optical link CD. However, if an abnormality occurs in the optical link CD, this would contradict the fact that the optical transceiver 110-1, which does not use the optical link CD, has been diagnosed as abnormal (as described above) (because it is assumed that abnormalities do not occur at multiple locations simultaneously). Therefore, the abnormality occurrence location estimation unit 23 does not set an abnormality occurrence flag for the optical link CD.

[0064] Next, for each of the optical transceivers 110-1 and 110-3 diagnosed as abnormal by the signal condition diagnosis unit 22, the abnormality occurrence location estimation unit 23 determines whether an abnormality occurrence flag is set in all optical links through which the optical transceiver passes (step S003 in Figure 2).

[0065] As shown in FIG. 3, the optical links through which the optical transceiver 110-1 passes are optical link AB and optical link BC. As described above, the abnormality flag is not set for optical link AB, but the abnormality flag is set for optical link BC. Therefore, among the optical links through which the optical transceiver 110-1 passes, there is an optical link for which the abnormality flag is set (i.e., optical link BC). In this case (step S003 in FIG. 2: NO), the abnormality location estimation unit 23 determines whether the optical link BC for which the abnormality flag is set is an optical link used only by the optical transceiver 110-1 (not used by other optical transceivers) (step S004 in FIG. 2).

[0066] Since the optical link AB is used not only by the optical transceiver 110-1 but also by the optical transceiver 110-2 (step S004: NO in FIG. 2), the abnormality occurrence location estimation unit 23 does not set an abnormality occurrence flag for the optical transceiver 110-1.

[0067] 3, the optical links through which the optical transceiver 110-3 passes are optical link BC and optical link CD. As described above, the abnormality flag is not set for optical link CD, but the abnormality flag is set for optical link BC. Therefore, among the optical links through which the optical transceiver 110-3 passes, there is an optical link for which the abnormality flag is set (i.e., optical link BC). In this case (step S003 in FIG. 2: NO), the abnormality location estimation unit 23 determines whether the optical link BC for which the abnormality flag is set is an optical link used only by the optical transceiver 110-3 (and not used by other optical transceivers) (step S004 in FIG. 2).

[0068] Since the optical link BC is used not only by the optical transceiver 110-3 but also by the optical transceiver 110-1 (step S004: NO in FIG. 2), the abnormality occurrence location estimation unit 23 does not set an abnormality occurrence flag for the optical transceiver 110-3.

[0069] 3, in a pattern in which an abnormality occurs in the optical link BC, an abnormality occurrence flag is set only for the optical link BC. In other words, when an abnormality occurs in the optical link BC, the abnormality occurrence location estimation unit 23 can correctly estimate that the abnormality has occurred in the optical link BC.

[0070] Next, consider the third case, where an abnormality occurs in optical link CD due to, for example, bending of the optical fiber. In this case, as described above, an abnormality is detected in optical transceiver 110-3. The abnormality location estimation unit 23 of the optical network state estimation device 20 determines whether all optical transceivers using the optical links AB, BC, and CD have been diagnosed as abnormal (step S001 in FIG. 2).

[0071] 3, the optical transceivers using the optical link AB are the optical transceiver 110-1 and the optical transceiver 110-2. As described above, neither the optical transceiver 110-1 nor the optical transceiver 110-2 has been diagnosed as abnormal (step S001: NO in FIG. 2), so the abnormality occurrence location estimation unit 23 does not set an abnormality occurrence flag for the optical link AB.

[0072] 3, the optical transceivers using the optical link BC are the optical transceiver 110-1 and the optical transceiver 110-3. As described above, the optical transceiver 110-3 has been diagnosed as being abnormal, but the optical transceiver 110-1 has not been diagnosed as being abnormal (step S001: NO in FIG. 2), so the abnormality occurrence location estimation unit 23 does not set an abnormality occurrence flag for the optical link BC.

[0073] 3, the only optical transceiver using the optical link CD is the optical transceiver 110-3. Since the optical transceiver 110-3 is diagnosed as abnormal (YES in step S001 in FIG. 2), the abnormality occurrence location estimation unit 23 sets an abnormality occurrence flag for the optical link CD (step S002 in FIG. 2).

[0074] Next, the abnormality occurrence location estimation unit 23 determines whether an abnormality occurrence flag is set in all optical links through which the optical transceiver 110-3 diagnosed as abnormal by the signal condition diagnosis unit 22 passes (step S003 in Figure 2).

[0075] As shown in FIG. 3, the optical links through which the optical transceiver 110-3 passes are optical link BC and optical link CD. As described above, the abnormality flag is not set for optical link BC, but the abnormality flag is set for optical link CD. Therefore, among the optical links through which the optical transceiver 110-3 passes, there is an optical link (i.e., optical link CD) for which the abnormality flag is set. In this case (step S003 in FIG. 2: NO), the abnormality location estimation unit 23 determines whether the optical link CD for which the abnormality flag is set is an optical link used only by the optical transceiver 110-3 (not used by other optical transceivers) (step S004 in FIG. 2).

[0076] Since the optical link CD is used only by the optical transceiver 110-3 (step S004 in FIG. 2: YES), the abnormality occurrence location estimating unit 23 sets an abnormality occurrence flag for the optical transceiver 110-3 (step S005 in FIG. 2).

[0077] 3, in a pattern in which an abnormality occurs in the optical link CD, an abnormality occurrence flag is set for the optical link CD and the optical transceiver 110-3. In other words, when an abnormality occurs in the optical link CD, the abnormality occurrence location estimation unit 23 cannot uniquely estimate the abnormality occurrence location, but can narrow down the abnormality occurrence location by assuming that an abnormality has occurred in either the optical link CD or the optical transceiver 110-3.

[0078] Next, consider the fourth case, where an abnormality occurs in optical transceiver 110-1, for example. In this case, as described above, an abnormality is detected only in optical transceiver 110-1. For each of optical links AB, BC, and CD, the abnormality location estimation unit 23 of the optical network state estimation device 20 determines whether all optical transceivers using the optical links have been diagnosed as abnormal (step S001 in FIG. 2).

[0079] 3, the optical transceivers using the optical link AB are the optical transceiver 110-1 and the optical transceiver 110-2. As described above, the optical transceiver 110-1 has been diagnosed as abnormal, but the optical transceiver 110-2 has not been diagnosed as abnormal (step S001: NO in FIG. 2), so the abnormality occurrence location estimation unit 23 does not set an abnormality occurrence flag for the optical link AB.

[0080] 3, the optical transceivers using the optical link BC are the optical transceiver 110-1 and the optical transceiver 110-3. As described above, the optical transceiver 110-1 has been diagnosed as having an abnormality, but the optical transceiver 110-3 has not been diagnosed as having an abnormality (step S001: NO in FIG. 2), so the abnormality occurrence location estimation unit 23 does not set an abnormality occurrence flag for the optical link BC.

[0081] 3, the optical transceiver using the optical link CD is the optical transceiver 110-3. Since the optical transceiver 110-3 has not been diagnosed as being abnormal (step S001: NO in FIG. 2), the abnormality occurrence location estimation unit 23 does not set an abnormality occurrence flag for the optical link CD.

[0082] Next, the abnormality occurrence location estimation unit 23 determines whether an abnormality occurrence flag is set in all optical links through which the optical transceiver 110-1 diagnosed as abnormal by the signal condition diagnosis unit 22 passes (step S003 in Figure 2).

[0083] As shown in FIG. 3, the optical links through which the optical transceiver 110-1 passes are optical link AB and optical link BC. As described above, the abnormality occurrence flag is not set for optical link AB or optical link BC. In this case (YES in step S003 of FIG. 2), the abnormality occurrence location estimation unit 23 sets an abnormality occurrence flag for the optical transceiver 110-1 (step S005 of FIG. 2).

[0084] 3, in a pattern in which an abnormality occurs in the optical transceiver 110-1, an abnormality occurrence flag is set only for the optical transceiver 110-1. In other words, when an abnormality occurs in the optical transceiver 110-1, the abnormality occurrence location estimation unit 23 can correctly estimate that the abnormality has occurred in the optical transceiver 110-1.

[0085] Next, consider the fifth case, where an abnormality occurs in optical transceiver 110-2, for example. In this case, as described above, an abnormality is detected only in optical transceiver 110-2. The abnormality location estimation unit 23 of the optical network state estimation device 20 determines whether all optical transceivers using the optical links AB, BC, and CD have been diagnosed as abnormal (step S001 in FIG. 2).

[0086] 3, the optical transceivers using the optical link AB are the optical transceiver 110-1 and the optical transceiver 110-2. As described above, the optical transceiver 110-2 has been diagnosed as abnormal, but the optical transceiver 110-1 has not been diagnosed as abnormal (step S001: NO in FIG. 2), so the abnormality occurrence location estimation unit 23 does not set an abnormality occurrence flag for the optical link AB.

[0087] 3, the optical transceivers using the optical link BC are the optical transceiver 110-1 and the optical transceiver 110-3. As described above, the optical transceiver 110-1 and the optical transceiver 110-3 have not been diagnosed as being abnormal (step S001: NO in FIG. 2), so the abnormality occurrence location estimation unit 23 does not set an abnormality occurrence flag for the optical link BC.

[0088] 3, the optical transceiver using the optical link CD is the optical transceiver 110-3. Since the optical transceiver 110-3 has not been diagnosed as being abnormal (step S001: NO in FIG. 2), the abnormality occurrence location estimation unit 23 does not set an abnormality occurrence flag for the optical link CD.

[0089] Next, the abnormality occurrence location estimation unit 23 determines whether an abnormality occurrence flag is set in all optical links through which the optical transceiver 110-2 diagnosed as abnormal by the signal condition diagnosis unit 22 passes (step S003 in Figure 2).

[0090] As shown in FIG. 3, the optical link through which the optical transceiver 110-2 passes is optical link AB only. As described above, an abnormality occurrence flag has not been set for optical link AB. In this case (YES in step S003 of FIG. 2), the abnormality occurrence location estimation unit 23 sets an abnormality occurrence flag for the optical transceiver 110-2 (step S005 of FIG. 2).

[0091] 3, in a pattern in which an abnormality occurs in the optical transceiver 110-2, an abnormality occurrence flag is set only for the optical transceiver 110-2. In other words, when an abnormality occurs in the optical transceiver 110-2, the abnormality occurrence location estimation unit 23 can correctly estimate that the abnormality has occurred in the optical transceiver 110-2.

[0092] Finally, consider the sixth case, where an abnormality occurs in optical transceiver 110-3, for example. In this case, as described above, an abnormality is detected only in optical transceiver 110-3. The abnormality location estimation unit 23 of the optical network state estimation device 20 determines whether all optical transceivers using the optical links AB, BC, and CD have been diagnosed as abnormal (step S001 in FIG. 2).

[0093] 3, the optical transceivers using the optical link AB are the optical transceiver 110-1 and the optical transceiver 110-2. As described above, the optical transceiver 110-1 and the optical transceiver 110-2 have not been diagnosed as being abnormal (step S001: NO in FIG. 2), so the abnormality occurrence location estimation unit 23 does not set an abnormality occurrence flag for the optical link AB.

[0094] 3, the optical transceivers using the optical link BC are the optical transceiver 110-1 and the optical transceiver 110-3. As described above, the optical transceiver 110-3 has been diagnosed as being abnormal, but the optical transceiver 110-1 has not been diagnosed as being abnormal (step S001: NO in FIG. 2), so the abnormality occurrence location estimation unit 23 does not set an abnormality occurrence flag for the optical link BC.

[0095] 3, the only optical transceiver using the optical link CD is the optical transceiver 110-3. Since the optical transceiver 110-3 is diagnosed as abnormal (YES in step S001 in FIG. 2), the abnormality occurrence location estimation unit 23 sets an abnormality occurrence flag for the optical link CD (step S002 in FIG. 2).

[0096] Next, the abnormality occurrence location estimation unit 23 determines whether an abnormality occurrence flag is set in all optical links through which the optical transceiver 110-3 diagnosed as abnormal by the signal condition diagnosis unit 22 passes (step S003 in Figure 2).

[0097] As shown in Fig. 3, the optical links through which the optical transceiver 110-3 passes are optical link BC and optical link CD. As described above, the abnormality occurrence flag is not set in optical link BC, but the abnormality occurrence flag is set in optical link CD (step S003: NO in Fig. 2). In this case, the abnormality occurrence location estimation unit 23 determines whether the optical link CD, for which the abnormality occurrence flag is set, is used only by the optical transceiver 110-3 (and not used by other optical transceivers) (step S004 in Fig. 2).

[0098] Since the optical link CD is used only by the optical transceiver 110-3 (step S004 in FIG. 2: YES), the abnormality occurrence location estimating unit 23 sets an abnormality occurrence flag for the optical transceiver 110-3 (step S005 in FIG. 2).

[0099] 3, in a pattern in which an abnormality occurs in the optical transceiver 110-3, an abnormality occurrence flag is set for the optical link CD and the optical transceiver 110-3. In other words, when an abnormality occurs in the optical transceiver 110-3, the abnormality occurrence location estimation unit 23 cannot uniquely estimate the abnormality location, but can narrow down the abnormality location by assuming that the abnormality occurs in either the optical link CD or the optical transceiver 110-3.

[0100] The results of setting the abnormality occurrence flag in each of the six patterns of the abnormality occurrence location described above are as shown in Fig. 4. As shown in Fig. 4, except for the case where the abnormality occurrence location is optical link BC or optical transceiver 110-3, the abnormality occurrence location estimation unit 23 can uniquely and correctly estimate the abnormality occurrence location. Even when the abnormality occurrence location is optical link BC or optical transceiver 110-3, the abnormality occurrence location estimation unit 23 cannot determine whether the abnormality occurrence location is optical link BC or optical transceiver 110-3, but it can narrow down the candidates for the abnormality occurrence location to those two locations.

[0101] As described above, the optical network system 1 in the first embodiment can determine the location of an abnormality that has occurred in the optical network. In the maintenance and operation of an optical network, it is important to early detect an abnormality that is a sign of a failure and identify the location of the abnormality before a communication interruption occurs. The optical network system 1 in this embodiment is characterized by having a transmission signal information collection unit 21 that collects transmission signal information of the transmission section acquired by the optical transceiver 110 from multiple optical node devices 10 that constitute the optical network, a signal status diagnosis unit 22 that diagnoses the normality of the transmission section based on the transmission signal information, and an abnormality occurrence location estimation unit 23 that estimates the location of the abnormality from multiple diagnosis results by the signal status diagnosis unit 22.

[0102] With this configuration, the optical network system 1 of this embodiment can estimate the optical link section and transmitter / receiver in which degradation of transmission quality has occurred based on the transmission signal information obtained by the multiple optical transceivers 110. As a result, the optical network system 1 of this embodiment can realize efficient operation and maintenance of the optical network by quickly identifying the location of the abnormality.

[0103] (First Modification of the First Embodiment) A first modified example of the first embodiment of the present invention will be described below. In the optical network system 1 in the first embodiment described above, the optical network state estimation device 20 is configured to include the signal state diagnosis unit 22. However, the present invention is not limited to this configuration, and for example, each optical node device may be configured to include a signal state diagnosis unit.

[0104] [Optical network system configuration] The configuration of an optical network system according to a first modification of the first embodiment will be described below. Fig. 5 is an overall configuration diagram of an optical network system 1b according to a first modification of the first embodiment of the present invention. In the overall configuration diagram of Fig. 5, functional units having the same functions as those of the optical network system 1 according to the first embodiment described above are denoted by the same reference numerals, and a description of the functions may be omitted.

[0105] 5, an optical network system 1b in this modification includes four optical node devices 10b and an optical network state estimation device 20b. In this modification, as an example, the number of optical node devices 10b included in the optical network system 1b is four, but this is not limited to this and any number may be used.

[0106] As shown in FIG. 5, the optical node device 10b includes an optical signal input / output unit 11, an optical cross-connect unit 12, and a signal state diagnostic unit 13.

[0107] The optical signal input / output unit 11 inputs and outputs signals transmitted over optical links connecting the optical node devices 10. The optical signal input / output unit 11 is equipped with optical transceivers 110 (Tx / Rx) that transmit client signals depending on the actual communication situation. The optical signal input / output unit 11 outputs transmission signal information for the transmission section acquired by the optical transceiver 110 to the signal status diagnosis unit 13.

[0108] The signal state diagnostic unit 13 acquires the transmission signal information output from the optical signal input / output unit 11. The signal state diagnostic unit 13 diagnoses the normality of the transmission section based on the acquired transmission signal information (detects whether an abnormality has occurred). Specifically, the signal state diagnostic unit 13 determines whether the transmission section passing through each optical transceiver 110 is normal (whether an abnormality has occurred). For example, the signal state diagnostic unit 13 determines that an abnormality has occurred when the value of the received power or the value of the bit error rate falls below a predetermined threshold. The signal state diagnostic unit 13 transmits information indicating the diagnosis result of the normality of the transmission section (the abnormality detection result) to the optical network state estimation device 20b.

[0109] In addition, the signal condition diagnosis unit 13 may be configured to perform machine learning using a neural network or the like using, for example, a digitally modulated signal, and determine whether or not an abnormality has occurred in the transmission section by using the trained neural network or the like.

[0110] 5, the optical network state estimation device 20 includes a transmission signal information collection unit 21b and an abnormality occurrence location estimation unit 23. The transmission signal information collection unit 21b receives information indicating the diagnosis result of the normality of the transmission section (the abnormality detection result) from each optical node device 10b in the monitored section of the optical network. The transmission signal information collection unit 21b outputs the received information indicating the diagnosis result of the normality of the transmission section (the abnormality detection result) to the signal state diagnosis unit 22.

[0111] The abnormality location estimation unit 23 acquires information indicating the diagnosis result of the normality of the transmission section output from the transmission signal information collection unit 21b. The abnormality location estimation unit 23 estimates the abnormality location based on the acquired information. Note that the abnormality location in this embodiment refers to the optical link in which the abnormality has occurred and the optical transceiver 110 in which the abnormality has occurred.

[0112] (Second Modification of the First Embodiment) A second modified example of the first embodiment of the present invention will be described below. In the optical network system 1 in the first embodiment described above, a single-mode optical fiber 30 is used for the optical link connecting the optical node devices 10, and wavelength multiplexing communication is performed by the wavelength multiplexing unit 15. However, the present invention is not limited to this configuration, and for example, any medium may be used for the optical link connecting the optical node devices.

[0113] In a second modification of the first embodiment described below, a multi-core optical fiber 30c is used for the optical link connecting the optical node devices 10c, and spatial multiplexing communication is performed by fan-in / fan-out 15c.

[0114] [Optical network system configuration] The configuration of an optical network system according to a second modified example of the first embodiment will be described below. Fig. 6 is an overall configuration diagram of an optical network system 1c according to the second modified example of the first embodiment of the present invention. In the overall configuration diagram of Fig. 6, functional units having the same functions as those of the optical network system 1 according to the first embodiment described above are denoted by the same reference numerals, and a description of the functions may be omitted.

[0115] 6, an optical network system 1c in this modification includes four optical node devices 10c and an optical network state estimation device 20. In this modification, as an example, the number of optical node devices 10c included in the optical network system 1c is four, but this is not limited to this and any number may be used.

[0116] As shown in FIG. 6, the optical node device 10c includes an optical signal input / output unit 11 and an optical cross-connect unit 12c.

[0117] The optical signal input / output unit 11 inputs and outputs signals transmitted through optical links connecting the optical node devices 10c. The optical signal input / output unit 11 is provided with optical transceivers (Tx / Rx) that transmit client signals depending on the actual communication situation. As shown in Fig. 6, in this modification, it is assumed that optical transceivers 110-1 to 110-3 are provided.

[0118] The optical cross-connect unit 12c determines the input / output paths of optical signals. The optical cross-connect unit 12c includes a fan-in / fan-out 15c. A multi-core optical fiber 30c is used for the optical link connecting the optical node devices 10c. The fan-in / fan-out 15c accommodates the optical transceivers 110-1 to 110-3 in any of the cores. This allows spatial multiplexing communication to be performed.

[0119] 7 is a cross-sectional view of a multi-core optical fiber 30c of an optical network system 1c in a second modified example of the first embodiment of the present invention. For example, as shown in FIG. 7, an optical transceiver (Tx / Rx) 110-1 is accommodated in one core, and an optical transceiver 110-2 and an optical transceiver 110-3 are accommodated in the other core, thereby performing spatial multiplexing communication.

[0120] In this way, even in the optical network system 1c having a configuration in which multi-core optical fibers are used in the optical links connecting optical node devices and spatial multiplexing communication is performed, it is possible to estimate the location of the abnormality in the optical network (the optical link or optical transceiver where the abnormality occurred), just like the optical network system 1 in the first embodiment described above that performs wavelength multiplexing communication.

[0121] <Second embodiment> The second embodiment of the present invention will be described below with reference to the drawings. The optical network system 1 in the first embodiment described above is configured to determine the location of an abnormality in the optical network using a function that is pre-installed in the optical transceiver 110 to measure signal quality, such as the value of received power or the value of bit error rate.

[0122] In contrast, the optical network system of the second embodiment described below combines the above functions with an OTDR to determine the location of an abnormality in the optical network with higher accuracy. Although the OTDR cannot detect abnormalities in optical transceivers, it can evaluate the loss of optical fibers by observing the reflected light (backscattered light) of optical pulses sent to the optical fibers. This allows the OTDR to estimate the location of an abnormality in the optical link with higher accuracy.

[0123] [Optical network system configuration] 9, in an optical network system 1d in this embodiment, an optical node device 10A is provided with an OTDR 111. The OTDR 111 transmits an OTDR signal from the optical node device 10A to an optical node device 10D via the optical node device 10B and the optical node device C. In the optical node device 10D, the termination point of the OTDR signal is open.

[0124] [Operation of the optical network state estimator] An example of the operation of the optical network state estimation device 20d in this embodiment will be described below with reference to Figures 8 to 10. In this embodiment, it is assumed that the configuration of the optical network, the connection status of each optical transceiver, and the diagnosis result of the normality of each optical transceiver by the signal state diagnosis unit 22 are known.

[0125] In this embodiment, similarly to the first embodiment, it is assumed that an abnormality occurs in only one location in the optical network, and that an abnormality does not occur in multiple locations at the same time. Specifically, in this embodiment, it is assumed that an abnormality occurs in one of the optical links or one of the optical transceivers in the optical network.

[0126] Fig. 8 is a flowchart showing the operation of the optical network state estimating device 20d in the second embodiment of the present invention. Fig. 9 is a diagram showing an example of the configuration of an optical network for explaining the operation of the optical network state estimating device 20d. Fig. 10 is a diagram showing the pattern of abnormality occurrence and the normality diagnosis result in the optical network shown in Fig. 9.

[0127] 8 is started when, for example, transmission loss information is transmitted to the optical network state estimation device 20d from the OTDR 111. The transmission loss information is information that indicates the loss of an optical fiber in the optical network, measured by the OTDR 111.

[0128] First, the abnormality occurrence location estimation unit 23d of the optical network state estimation device 20d acquires transmission loss information output from the OTDR 111 of the optical node device 10A (step S101). As a result, it is determined whether an abnormality has occurred in all optical links from the optical node device 10A to the optical node device 10D.

[0129] If the transmission loss information includes information about an abnormality occurrence (YES in step S102), the abnormality occurrence location estimation unit 23d sets an abnormality occurrence flag for the optical link in which it is determined that an abnormality has occurred (step S103).

[0130] Next, for each optical transceiver diagnosed as abnormal by the signal state diagnosis unit 22, the abnormality occurrence location estimation unit 23d determines whether an abnormality occurrence flag has been set (by the processing of step S103) in all optical links through which the optical transceiver passes (step S104). In other words, the abnormality occurrence location estimation unit 23d determines whether an abnormality occurrence flag has been set (by the processing of step S103) in at least one optical link through which the optical transceiver passes.

[0131] If an abnormality occurrence flag has not been set for all optical links through which the optical transceiver passes (step S104: YES), the abnormality occurrence location estimation unit 23d performs a process of setting an abnormality occurrence flag for the optical transceiver 110 (step S105).

[0132] When the abnormality occurrence location estimation unit 23d has repeated the processing from step S104 onwards for all optical transceivers diagnosed as abnormal by the signal state diagnosis unit 22, the operation of the optical network state estimation device 20d shown in the flowchart of Figure 8 ends.

[0133] A specific example of the process of the flowchart shown in FIG. 8 will be described below with reference to FIGS.

[0134] Fig. 9 shows the overall configuration of an optical network system 1d and the configuration of an optical network in a specific example described below. As shown in Fig. 8, the optical network system 1d in a specific example described below is configured to include an optical node device 10A, an optical node device 10B, an optical node device 10C, an optical node device 10D, and an optical network state estimation device 20d.

[0135] The optical node device 10A, the optical node device 10B, the optical node device 10C, and the optical node device 10D are communicatively connected to one another by optical links using single-mode optical fibers 30, forming an optical network. The optical node device 10A, the optical node device 10B, the optical node device 10C, and the optical node device 10D each include an optical signal input / output unit 11 and an optical cross-connect unit 12. The optical cross-connect unit 12 also includes a wavelength multiplexing unit 15.

[0136] Furthermore, only the optical node device 10A is equipped with an OTDR 111. The OTDR 111 transmits an OTDR signal from the optical node device 10A to the optical node device 10D via the optical node device 10B and the optical node device C. The OTDR 111 also transmits transmission loss information, which indicates loss of optical fibers in the optical network, measured by transmitting the OTDR signal to the optical network state estimation device 20d.

[0137] Hereinafter, the optical link connecting the optical node device 10A and the optical node device 10B will be referred to as "optical link AB", the optical link connecting the optical node device 10B and the optical node device 10C will be referred to as "optical link BC", and the optical link connecting the optical node device 10C and the optical node device 10D will be referred to as "optical link CD".

[0138] The optical signal input / output unit 11 is provided with optical transceivers (Tx / Rx) for transmitting client signals depending on the actual communication situation. In the specific example described below, it is assumed that an optical transceiver 110-1 is provided between the optical node device 10A and the optical node device 10C, an optical transceiver 110-2 is provided between the optical node device 10A and the optical node device 10B, and an optical transceiver 110-3 is provided between the optical node device 10B and the optical node device 10D, as shown in Fig. 9.

[0139] 9, the optical links that the optical transceiver 110-1 passes through are optical link AB and optical link BC, the optical link that the optical transceiver 110-2 passes through is only optical link AB, and the optical links that the optical transceiver 110-3 passes through are optical link BC and optical link CD. With the above configuration, wavelength multiplexed communications are performed by the optical transceivers 110-1, 110-2, and 110-3 between the optical node device 10A and the optical node device 10C, between the optical node device 10A and the optical node device 10B, and between the optical node device 10B and the optical node device 10D, respectively.

[0140] The optical network state estimation device 20d evaluates the communication state of an optical network configured by the optical node device 10A, the optical node device 10B, the optical node device 10C, and the optical node device 10D. As shown in Fig. 9, the optical network state estimation device 20d includes a transmission signal information collection unit 21, a signal state diagnosis unit 22, and an abnormality occurrence location estimation unit 23d.

[0141] As described above, in this embodiment, when an abnormality occurs in the optical network, it is assumed that the abnormality occurs in one location and that abnormalities do not occur in multiple locations at the same time. Therefore, in this specific example, the location where the abnormality occurs in the optical network is any one of optical link AB, optical link BC, and optical link CD, or any one of optical transceiver 110-1, optical transceiver 110-2, and optical transceiver 110-3. In other words, there are six possible locations where an abnormality may occur in the optical network of this specific example.

[0142] An abnormality occurring in optical link AB, optical link BC, and optical link CD may be, for example, a communication failure caused by bending of the optical fiber, and an abnormality occurring in optical transceiver 110-1, optical transceiver 110-2, and optical transceiver 110-3 may be, for example, a malfunction of the optical transceiver itself.

[0143] Figure 10 shows six patterns of abnormality locations that can occur in the optical network of Figure 9, and the correspondence between them and the optical transceivers in which the signal status diagnosis unit 22 detects an abnormality when an abnormality occurs at each abnormality location.

[0144] 10, if the abnormality occurs in optical link AB, the abnormality is detected in optical transceivers 110-1 and 110-2, which are optical transceivers (Tx / Rx) passing through optical link AB. If the abnormality occurs in optical link BC, the abnormality is detected in optical transceivers 110-1 and 110-3, which are optical transceivers passing through optical link BC. If the abnormality occurs in optical link CD, the abnormality is detected in optical transceiver 110-3, which is an optical transceiver passing through optical link CD.

[0145] 10, if the abnormality occurs in the optical transceiver 110-1, the abnormality is detected in the optical transceiver 110-1, if the abnormality occurs in the optical transceiver 110-2, the abnormality is detected in the optical transceiver 110-2, and if the abnormality occurs in the optical transceiver 110-3, the abnormality is detected in the optical transceiver 110-3. Based on the correspondence between the abnormality occurrence locations and the optical transceivers in which the abnormality is detected, it is possible to narrow down or identify the abnormality occurrence location from the optical transceiver in which the abnormality is detected.

[0146] [Example of setting an error flag] Hereinafter, the flow up to setting an abnormality occurrence flag by the operation of the optical network state estimating device 20d shown in FIG. 8 will be described for each of six patterns of abnormality occurrence locations that can occur in the optical network of FIG.

[0147] First, consider the first pattern, where an abnormality occurs in optical link AB due to, for example, bending of the optical fiber. In this case, the OTDR 111 detects an abnormality in optical link AB (steps S101 and S102 in FIG. 8). The abnormality occurrence location estimation unit 23d sets an abnormality occurrence flag for optical link AB (step S103 in FIG. 8). Thus, in the network configuration shown in FIG. 9, in the pattern where an abnormality occurs in optical link AB, an abnormality occurrence flag is set only for optical link AB. In other words, when an abnormality occurs in optical link AB, the abnormality occurrence location estimation unit 23d can correctly estimate that an abnormality has occurred in optical link AB.

[0148] FIG. 10 shows six patterns of abnormality occurrence locations that can occur in the optical network of FIG. 9, and the correspondence between the abnormality occurrence flags that are set when an abnormality occurs at each abnormality occurrence location.

[0149] Next, consider the second pattern, where an abnormality occurs in the optical link BC due to, for example, bending of the optical fiber. In this case, the OTDR 111 detects an abnormality in the optical link BC (steps S101 and S102 in FIG. 8). The abnormality occurrence location estimation unit 23d sets an abnormality occurrence flag for the optical link BC (step S103 in FIG. 8). Thus, in the network configuration shown in FIG. 9, in the pattern where an abnormality occurs in the optical link BC, the abnormality occurrence flag is set only for the optical link BC. In other words, when an abnormality occurs in the optical link BC, the abnormality occurrence location estimation unit 23d can correctly estimate that an abnormality has occurred in the optical link BC.

[0150] Next, consider the third pattern, where an abnormality occurs in the optical link CD due to, for example, bending of the optical fiber. In this case, the OTDR 111 detects an abnormality in the optical link CD (steps S101 and S102 in FIG. 8). The abnormality occurrence location estimation unit 23d sets an abnormality occurrence flag for the optical link CD (step S103 in FIG. 8). Thus, in the network configuration shown in FIG. 9, in the pattern where an abnormality occurs in the optical link CD, the abnormality occurrence flag is set only for the optical link CD. In other words, when an abnormality occurs in the optical link BC, the abnormality occurrence location estimation unit 23d can correctly estimate that an abnormality has occurred in the optical link CD.

[0151] Next, consider the fourth case, where an abnormality occurs in the optical transceiver 110-1, for example. In this case, as described above, an abnormality is detected only in the optical transceiver 110-1. In addition, in this case, the OTDR 111 does not detect an abnormality in any of the optical links (step S102 in FIG. 8: NO).

[0152] Next, the abnormality occurrence location estimation unit 23d determines whether an abnormality occurrence flag is set in all optical links through which the optical transceiver 110-1 diagnosed as abnormal by the signal status diagnosis unit 22 passes (step S104 in Figure 8).

[0153] As shown in Fig. 9, the optical links through which the optical transceiver 110-1 passes are optical link AB and optical link BC. As described above, the abnormality occurrence flag is not set for optical link AB or optical link BC. In this case (step S104 in Fig. 8; YES), the abnormality occurrence location estimation unit 23 sets the abnormality occurrence flag for the optical transceiver 110-1 (step S105 in Fig. 8).

[0154] 9, in a pattern in which an abnormality occurs in the optical transceiver 110-1, an abnormality occurrence flag is set only for the optical transceiver 110-1. In other words, when an abnormality occurs in the optical transceiver 110-1, the abnormality occurrence location estimation unit 23d can correctly estimate that the abnormality has occurred in the optical transceiver 110-1.

[0155] Next, consider the fifth case, where an abnormality occurs in the optical transceiver 110-2, for example. In this case, as described above, an abnormality is detected only in the optical transceiver 110-2. In this case, the OTDR 111 does not detect an abnormality in any of the optical links (step S102 in FIG. 8: NO).

[0156] Next, the abnormality occurrence location estimation unit 23d determines whether an abnormality occurrence flag is set in all optical links through which the optical transceiver 110-2 diagnosed as abnormal by the signal status diagnosis unit 22 passes (step S104 in Figure 8).

[0157] As shown in Fig. 9, the optical link through which the optical transceiver 110-2 passes is optical link AB only. As described above, an abnormality occurrence flag has not been set for optical link AB. In this case (step S104 in Fig. 8; YES), the abnormality occurrence location estimation unit 23 sets an abnormality occurrence flag for the optical transceiver 110-2 (step S105 in Fig. 8).

[0158] 9, in a pattern in which an abnormality occurs in the optical transceiver 110-2, an abnormality occurrence flag is set only for the optical transceiver 110-2. In other words, when an abnormality occurs in the optical transceiver 110-2, the abnormality occurrence location estimation unit 23d can correctly estimate that the abnormality has occurred in the optical transceiver 110-2.

[0159] Finally, consider the sixth case, where an abnormality occurs in the optical transceiver 110-3, for example. In this case, as described above, an abnormality is detected only in the optical transceiver 110-3. In addition, in this case, the OTDR 111 does not detect an abnormality in any of the optical links (step S102 in FIG. 8: NO).

[0160] Next, the abnormality occurrence location estimation unit 23d determines whether an abnormality occurrence flag is set in all optical links through which the optical transceiver 110-3 diagnosed as abnormal by the signal status diagnosis unit 22 passes (step S104 in Figure 8).

[0161] As shown in FIG. 9, the optical links through which the optical transceiver 110-3 passes are optical link BC and optical link CD. As described above, the abnormality occurrence flags have not been set for optical link BC and optical link CD. In this case (YES in step S104 of FIG. 8), the abnormality occurrence location estimation unit 23 sets an abnormality occurrence flag for the optical transceiver 110-3 (step S105 of FIG. 8).

[0162] 9, in a pattern in which an abnormality occurs in the optical transceiver 110-3, an abnormality occurrence flag is set only for the optical transceiver 110-3. In other words, when an abnormality occurs in the optical transceiver 110-3, the abnormality occurrence location estimation unit 23d can correctly estimate that the abnormality has occurred in the optical transceiver 110-3.

[0163] The results of setting the abnormality occurrence flag in each of the six patterns of the abnormality occurrence location described above are as shown in Fig. 10. As shown in Fig. 10, in this embodiment, unlike the first embodiment described above, the abnormality occurrence location estimation unit 23d can uniquely and correctly estimate the abnormality occurrence location in any of the six patterns of the abnormality occurrence location described above. This is because, unlike the first embodiment described above, in this embodiment, an abnormality in the optical link can be identified by the OTDR 111, and therefore it is possible to determine whether the abnormality is in the optical link or in the optical transceiver.

[0164] (Modification of the second embodiment) The optical network system 1d in the second embodiment described above is configured to first determine whether or not an abnormality has occurred in an optical link based on transmission loss information acquired from the OTDR 111. If an abnormality is detected in the optical link, the optical network system 1d identifies the optical link where the abnormality has occurred, and if no abnormality is detected in the optical link, the optical network system 1d is configured to identify the optical transceiver where the abnormality has occurred based on transmission signal information.

[0165] In contrast, the optical network system according to the modification of the second embodiment first performs the same operation as the optical network system 1 according to the first embodiment, as shown in the flowchart of FIG. 2. Then, when the optical network system according to this modification is unable to determine whether the abnormality is in the optical link or in the optical transceiver, it uses an OTDR to identify whether an abnormality has occurred in the optical link. This allows the optical network system according to this modification to determine whether the abnormality is in the optical link or in the optical transceiver.

[0166] In addition, a case where it is not possible to determine whether the abnormality is in the optical link or the optical transceiver is, for example, a case in the first embodiment described above where it is not possible to determine whether the abnormality is in the optical link CD or the optical transceiver 110-3, as shown in Figure 4.

[0167] The configuration of the optical network system in this modification is similar to the configuration of the optical network system 1d in the second embodiment shown in FIG. 9, and therefore a description thereof will be omitted.

[0168] [Operation of the optical network state estimator] An example of the operation of the optical network state estimation device in this modification will be described below with reference to Fig. 11. In this modification, it is assumed that the configuration of the optical network, the connection status of each optical transceiver 110, and the diagnosis result of the signal state diagnosis unit 22 regarding the normality of each optical transceiver 110 are known.

[0169] 11 is a flowchart showing the operation of the optical network state estimator according to a modification of the second embodiment of the present invention. The operation of the optical network state estimator shown in the flowchart of FIG. 11 is initiated, for example, when the signal state diagnostic unit 22 diagnoses that at least one of the optical transceivers 110 is abnormal.

[0170] Note that the operation of the optical network state estimator from step S201 to step S205 in the flowchart shown in FIG. 11 is similar to the operation of the optical network state estimator 20 in the first embodiment from step S001 to step S005 in the flowchart shown in FIG. 2 described above, and therefore a description thereof will be omitted.

[0171] When multiple abnormality occurrence flags are set, the abnormality occurrence location estimating unit 23d acquires the transmission loss information output from the OTDR 111. Based on the acquired transmission loss information, the abnormality occurrence location estimating unit 23d identifies whether or not an abnormality has occurred in the optical link for which the abnormality occurrence flag is set (step S206).

[0172] When it is determined that an abnormality has occurred in the optical link for which the abnormality flag has been set, the abnormality location estimation unit 23d deletes the abnormality flag set in the optical transceiver. Furthermore, when it is determined that no abnormality has occurred in the optical link for which the abnormality flag has been set, the abnormality location estimation unit 23d deletes the abnormality flag set in the optical link. This completes the operation of the optical network state estimation device shown in the flowchart of FIG. 11.

[0173] According to the optical network system of this modification described above, unlike the first embodiment, the abnormality occurrence location estimation unit 23d can uniquely and correctly estimate the abnormality location. This is because, unlike the first embodiment, in this embodiment, an abnormality in the optical link can be identified by the OTDR 111, and therefore it is possible to determine whether the abnormality is in the optical link or in the optical transceiver.

[0174] According to the above-described embodiment, the abnormality location determination device includes a collection unit, a diagnosis unit, and a determination unit. For example, the abnormality location determination device is the optical network status estimation device 20, 20b, or 20d in the embodiment, the collection unit is the transmission signal information collection unit 21 or 21b in the embodiment, the diagnosis unit is the signal status diagnosis unit 13 or 22 in the embodiment, and the determination unit is the abnormality location estimation unit 23 or 23d in the embodiment.

[0175] The collection unit collects transmission signal information of the transmission section acquired by the optical transceiver from multiple optical nodes constituting the optical network. The diagnosis unit diagnoses the normality of the transmission section based on the transmission signal information. The determination unit determines an abnormality location in the optical network based on the results of multiple diagnoses by the diagnosis unit. For example, the optical node is the optical node device 10, 10b in the embodiment, the optical transceiver is the optical transceiver 110 in the embodiment, the transmission section is the optical link in the embodiment, and the abnormality location is the location where the abnormality occurs in the embodiment.

[0176] The abnormality location determination device may further include an optical pulse tester. In this case, the optical pulse tester determines whether an abnormality has occurred in the optical link between the optical nodes and generates optical link status information indicating the determination result. If the determination unit cannot identify whether the abnormality is in the optical link or the optical transceiver based on the diagnosis result, it identifies the abnormality based on the optical link status information. For example, the optical pulse tester is the OTDR 111 in the embodiment, and the optical link status information is transmission loss information in the embodiment.

[0177] In addition, the judgment unit may determine whether or not an abnormality has occurred in the optical link based on the optical link status information, and then determine the location of the abnormality based on the results of the above judgment for each optical link and the results of the above diagnosis.

[0178] In addition, the judgment unit may extract optical links and optical transceivers that are candidates for the abnormal location based on the results of the above diagnosis, and identify whether the abnormal location is the optical link or the optical transceiver based on the optical link status information.

[0179] The diagnostic unit may be provided in each of a plurality of optical nodes.

[0180] The transmission signal information may be information including a digitally modulated signal received by the optical transceiver, a received power value, or a bit error rate value.

[0181] The optical network state estimation device and the optical node device in the above-described embodiments may be partially or entirely implemented by a computer. In this case, a program for implementing the functions may be recorded on a computer-readable recording medium, and the program may be loaded into a computer system and executed. The term "computer system" as used herein includes an operating system (OS) and peripheral hardware. The term "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, as well as storage devices such as hard disks built into computer systems. The term "computer-readable recording medium" may also include devices that dynamically store programs for a short period of time, such as communication lines used when transmitting programs via networks such as the Internet or telephone lines, or devices that store programs for a fixed period of time, such as volatile memory within a computer system serving as a server or client. The program may be for implementing some of the above-described functions, or may be capable of implementing the above-described functions in combination with a program already stored in the computer system, or may be implemented using a programmable logic device such as an FPGA (Field Programmable Gate Array).

[0182] Although an embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs within the scope of the gist of the present invention. [Explanation of symbols]

[0183] 1, 1a, 1b, 1c, 1d... Optical network system, 10, 10b... Optical node device, 11... Optical signal input / output unit, 12, 12c... Optical cross-connect unit, 13... Signal status diagnosis unit, 15... Wavelength multiplexing unit, 15c... Fan-in / fan-out, 20, 20b, 20d... Optical network status estimation device, 21, 21b... Transmission signal information collection unit, 22... Signal status diagnosis unit, 23, 23d... Abnormality location estimation unit, 30... Single-mode optical fiber, 30c... Multi-core optical fiber, 110... Optical transceiver

Claims

1. a collection unit that collects transmission signal information of a transmission section acquired by an optical transceiver from a plurality of optical nodes that constitute an optical network; a diagnosis unit that diagnoses the normality of the transmission section based on the transmission signal information; a determination unit that determines an abnormality location in the optical network based on a plurality of results of the diagnosis by the diagnosis unit; Equipped with The determination unit determines that, for each optical link in the transmission section, the optical link is the abnormal location when all the optical transceivers using the optical link are diagnosed as abnormal, and determines that the optical transceiver is the abnormal location when all the optical links through which the optical transceiver diagnosed as abnormal passes are determined to be normal. An abnormality location determination device.

2. A collection unit that collects transmission signal information of a transmission section acquired by an optical transceiver from a plurality of optical nodes that constitute an optical network; a diagnosis unit that diagnoses the normality of the transmission section based on the transmission signal information; a determination unit that determines an abnormality location in the optical network based on a plurality of results of the diagnosis by the diagnosis unit; an optical time domain tester that determines whether an abnormality has occurred in the optical link between the optical nodes and generates optical link status information indicating the determination result; Equipped with When the determination unit cannot determine whether the abnormal part is in the optical link or the optical transceiver based on the result of the diagnosis, the determination unit determines whether the abnormal part is in the optical link or the optical transceiver based on the optical link status information. An abnormality location determination device.

3. The determining unit determines whether or not an abnormality has occurred in the optical link based on the optical link status information, and then determines the location of the abnormality based on the result of the determination and the result of the diagnosis for each optical link. The abnormality location determining device according to claim 2 .

4. The determination unit extracts optical links and optical transceivers that are candidates for the abnormal location based on the results of the diagnosis, and identifies whether the abnormal location is the optical link or the optical transceiver based on the optical link status information. The abnormality location determining device according to claim 2 .

5. The diagnostic unit is provided in each of the plurality of optical nodes. The abnormality occurrence location determination device according to any one of claims 1 to 4.

6. The transmission signal information includes a digitally modulated signal received by the optical transceiver, a received power value, or a bit error rate value. The abnormality location determining device according to claim 1 .

7. a collecting step of collecting transmission signal information of a transmission section acquired by an optical transceiver from a plurality of optical nodes constituting the optical network; a diagnosis step of diagnosing the normality of the transmission section based on the transmission signal information; an estimation step of estimating an abnormality location in the optical network based on a plurality of results of the diagnosis in the diagnosis step; and In the estimation step, for each optical link in the transmission section, if all the optical transceivers using the optical link are diagnosed as abnormal, the optical link is determined to be the abnormal location, and if all the optical links through which the optical transceivers diagnosed as abnormal pass are determined to be normal, the optical transceiver is determined to be the abnormal location. Method for determining the location of an abnormality.

8. A program for causing a computer to function as the abnormality occurrence location determination device according to any one of claims 1 to 6.

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