Determination device, determination method, and determination program

Abstract

To provide a technique for narrowing down a link in which abnormality occurs in an optical transmission network.SOLUTION: A determination device 10 includes a calculation unit 12 that generates an observation matrix A that defines links through which a plurality of paths pass with respect to a plurality of links that connect nodes of an optical transmission network, calculates end-to-end transmission-quality value variations y of the plurality of paths, and calculates a transmission-quality value variation x of each link that satisfies a determinant y = Ax by solving a minimization problem of a l1 norm of x, and a determination unit 13 that determines an abnormal link based on the transmission-quality value variation x of each link.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] In a system where an unknown vector is observed as a linear sum, a compressed sensing technique has been proposed that estimates the unknown vector with fewer observations than the unknowns, assuming that the unknown vector is sparse (see Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Matsuda, "Application of Compressed Sensing to Communication Networks," Institute of Electronics, Information and Communication Engineers, IEICE Technical Report IN2014-22, June 2014, pp. 37-42 Summary of the Invention [Problem to be solved by the invention]

[0004] However, Non-Patent Document 1 merely describes a technique for estimating the packet loss rate, buffering delay, etc. of a node using compressed sensing technology.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technique for narrowing down a link in an optical transmission network where an abnormality has occurred. [Means for solving the problem]

[0006] A determination device according to one embodiment of the present invention includes a calculation unit that generates an observation matrix A that defines the links through which multiple paths pass for multiple links connecting nodes in an optical transmission network, calculates a change y in the end-to-end transmission quality value of each of the multiple paths, and calculates a change x in the transmission quality value of each link that satisfies the determinant y = Ax by solving a minimization problem of the l1 norm of x, and a determination unit that determines whether a link is abnormal based on the change x in the transmission quality value of each link.

[0007] In one aspect of the present invention, a determination method is performed by a determination device, which generates an observation matrix A that defines the links through which multiple paths pass for multiple links connecting nodes in an optical transmission network, calculates the amount of change y in the end-to-end transmission quality value of each of the multiple paths, calculates the amount of change x in the transmission quality value of each link that satisfies the determinant y = Ax by solving the problem of minimizing the l1 norm of x, and determines whether a link is abnormal based on the amount of change x in the transmission quality value of each link.

[0008] A determination program according to one aspect of the present invention causes a computer to function as the determination device. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a technique for narrowing down a link in an optical transmission network where an abnormality has occurred. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a determination system. [Figure 2] FIG. 2 is a diagram illustrating an example of 1 / GSNRLink and 1 / GSNREtoE. [Figure 3] FIG. 3 is a diagram illustrating an example of the operation of the determination device. [Figure 4] FIG. 4 is a diagram illustrating an example of a network configuration and route information of an observation path. [Figure 5] FIG. 5 is a diagram illustrating an example of an observation matrix. [Figure 6]FIG. 6 is a diagram illustrating an example of an abnormal link. [Figure 7] FIG. 7 is a diagram illustrating an example of an increment of 1 / GSNR from a steady value from end to end of an observation path. [Figure 8] FIG. 8 is a diagram showing an image of the optimization calculation. [Figure 9] FIG. 9 is a diagram showing an example of an increment of 1 / GSNR from the steady-state value of each link. [Figure 10] FIG. 10 is a diagram illustrating an example of a hardware configuration of the determination device. [Figure 11] FIG. 11 is a diagram illustrating an example of a network configuration and route information of an observation path. [Figure 12] FIG. 12 is a diagram illustrating an example of an observation matrix. [Figure 13] FIG. 13 is a diagram illustrating an example of a link in an access network. [Figure 14] FIG. 14 is a diagram illustrating an example of an increment of 1 / GSNR from a steady value from end to end of an observation path. [Figure 15] FIG. 15 is a diagram showing an example of an increment of 1 / GSNR from the steady-state value of each link. [Figure 16] FIG. 16 is a diagram illustrating an example of an increment of 1 / GSNR from a steady value from end to end of an observation path. [Figure 17] FIG. 17 is a diagram showing an example of an increment of 1 / GSNR from the steady-state value of each link. [Figure 18] FIG. 18 is a diagram illustrating an example of the operation of the determination device. [Figure 19] FIG. 19 illustrates an example of a link in an access network. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention 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.

[0012] [Summary of this disclosure] The present disclosure relates to a technique for narrowing down links in which an abnormality has occurred in an optical transmission network using the compressed sensing technique of Non-Patent Document 1.

[0013] In order to use this compressed sensing technology, 1. the system must be one in which the unknown vector is observed as a linear sum, and 2. the unknown vector must be sparse (many elements must be zero or have values ​​that can be approximated to zero).

[0014] 2. Let us discuss this.

[0015] In Non-Patent Document 1, it is assumed that the packet loss rate of a node is zero and the buffering delay of the node is also sufficiently small in a steady state. On the other hand, in this disclosure, the packet loss rate of a node in Non-Patent Document 1 and the like are applied to the transmission quality value of each link. In other words, in this disclosure, the transmission quality value of each link is treated as an unknown vector.

[0016] The transmission quality value is, for example, a generalized signal-to-noise ratio (GSNR) or an optical signal-to-noise ratio (OSNR). Hereinafter, the transmission quality value will be described as GSNR.

[0017] However, the GSNR of each link in an optical transport network is not sparse. That is, even in a steady state, it is not 0 but takes a constant value that is not small. Therefore, in this disclosure, we ensure the sparsity of the unknown vector under the assumption that the GSNR of each link does not change significantly in a steady state.

[0018] That is, in this disclosure, the decrease in GSNR of each link from its steady state value is treated as an unknown vector x, and the decrease in GSNR of the end-to-end observation path from its steady state value is treated as a vector y.

[0019] The end-to-end GSNR of some or all of the observation paths is observed, and the decrease from the steady-state value of the GSNR of each link (unknown vector x) is estimated by using the observed value (vector y) and solving the problem using the method described in the compressed sensing technology in Non-Patent Document 1. Then, from the estimation result, the link in which an abnormality has occurred in the optical transmission network is determined.

[0020] In summary, this disclosure focuses on the fact that, with regard to 1, the end-to-end GSNR of an observation path passing through an optical transmission network can be calculated as a linear sum of the GSNRs of each link it passes through, and with regard to 2, it also focuses on the fact that the GSNR of each link in an optical transmission network does not change significantly in a steady state.

[0021] Then, the compressed sensing technology of Non-Patent Document 1 is used to estimate the GSNR of each link, and based on the estimation results, the links that are commonly passed by a group of paths whose quality has simultaneously deteriorated due to an abnormality in the optical transmission network are narrowed down.

[0022] [System Configuration] FIG. 1 is a diagram showing an example of the configuration of a determination system 1 according to this embodiment.

[0023] The determination system 1 includes a determination device 10, a monitoring device 20, and an optical transmission network 30.

[0024] (Configuration of Determination Device 10) The determination device 10 is disposed within the monitoring device 20. The determination device 10 may be disposed outside the monitoring device 20 so as to be able to communicate with the monitoring device 20. The determination device 10 includes a collection unit 11, a calculation unit 12, a determination unit 13, a display unit 14, and a storage unit 15.

[0025] The collection unit 11 has the function of collecting from the monitoring device 20 network configuration information of the optical transmission network 30, route information of each observation path passing through the optical transmission network 30, and the GSNR observation value observed end to end of each observation path.

[0026] The calculation unit 12 has a function of generating an observation matrix A that defines the links through which the observation paths pass for the links that make up the optical transmission network 30, using network configuration information of the optical transmission network 30 and route information of each observation path that passes through the optical transmission network 30.

[0027] The calculation unit 12 has a function of calculating the decrease in the end-to-end GSNR of each observation path from its steady-state value when the observed value of the end-to-end GSNR of any of the observation paths becomes equal to or less than a threshold, and setting the decrease as vector y.

[0028] The calculation unit 12 has a function of calculating the unknown vector x by solving the problem of minimizing the l1 norm of x, where x is the decrease in GSNR of each link from its steady-state value and x satisfies the determinant y = Ax. This allows the decrease in GSNR of each link from its steady-state value to be estimated.

[0029] The determining unit 13 has a function of determining whether a link is normal or abnormal based on the calculated estimated value of the GSNR of each link.

[0030] The display unit 14 has a function of displaying the determination results of normal links and abnormal links on the screen.

[0031] The storage unit 15 has a function of storing various data handled by the determination device 10.

[0032] (Configuration of monitoring device 20) The monitoring device 20 has a function of monitoring the optical transport network 30. For example, the monitoring device 20 manages network configuration information of the optical transport network 30 and monitors route information (e.g., node IDs, link IDs) of each observation path passing through the optical transport network 30.

[0033] The monitoring device 20 has a function of receiving, from the optical transmission network 30, the observed value of the GSNR observed from end to end of each observation path.

[0034] (Configuration of optical transmission network 30) The optical transmission network 30 is made up of a plurality of nodes N and a plurality of links L connecting the nodes N. The nodes N are optical transmission devices, routers, switches, etc. The links L are optical fibers, etc.

[0035] For example, the optical transmission network 30 is configured with a ROADM (Reconfigurable Optical Add / Drop Multiplexer) and optical amplifiers, and transponders are placed on the input and output sides. The output transponder (node ​​N' shown in FIG. 1) monitors the GSNR of the path from which it serves as the receiving end point and transmits the observed value to the monitoring device 20.

[0036] [Actual Calculation Method of the Calculation Unit 12 of the Determination Device 10] Up to this point, the decrease in GSNR from the steady-state value of each link has been treated as unknown vector x, and the decrease in GSNR from the steady-state value of the end-to-end observation path has been treated as vector y. In other words, the decrease in GSNR from the steady-state value has been treated as vector y and unknown vector x.

[0037] Hereafter, the increment of 1 / GSNR from the steady-state value of each link is treated as unknown vector x, and the increment of 1 / GSNR from the end-to-end steady-state value of the observed path is treated as vector y. In other words, the increment of 1 / GSNR from the steady-state value is treated as vector y and unknown vector x.

[0038] In this case, as shown in equation (1), the end-to-end 1 / GSNR of the observation path passing through the optical transmission network 30 EtoE is the 1 / GSNR of each link it passes through Link It can be calculated as a linear sum of

[0039]

number

[0040] Figure 2(a) shows the 1 / GSNR for each link in the path. Link When an abnormality occurs in the third link, the 1 / GSNR of the third link isLink It can be seen that the difference between normal and abnormal conditions is

[0041] Figure 2(b) shows that the GSNR is 1 / GSNR for each link traversal. EtoE This figure shows how the linear sum of 1 / GSNR is accumulated. Link As increases, 1 / GSNR EtoE The linear sum of increases.

[0042] In the following operation example, the end-to-end GSNR of some or all of the observed paths is observed, and the increase from the steady-state value of 1 / GSNR for each link is estimated. Then, links with large changes are extracted to narrow down the suspected locations.

[0043] [Example of operation of determination device 10] FIG. 3 is a diagram illustrating an example of the operation of the determination device 10. As shown in FIG.

[0044] Step S1; The collection unit 11 collects from the monitoring device 20 network configuration information of the optical transmission network 30, route information of each observation path passing through the optical transmission network 30, and the GSNR observation values ​​observed end to end of each observation path, and stores them in the memory unit 15.

[0045] The collection unit 11 periodically performs the above collection, and updates the network configuration information and route information of each observation path in the memory unit 15 every time the network configuration of the optical transmission network 30 changes (for example, every time a node or link is added and / or deleted) or every time the route of the observation path changes.

[0046] Step S2; The calculation unit 12 uses the network configuration information and route information of each observation path to generate an observation matrix A that defines the links through which the observation paths pass for the links that make up the optical transport network 30. Furthermore, the calculation unit 12 updates the observation matrix A every time the network configuration of the optical transport network 30 or the routes of the observation paths change.

[0047] An example of the network configuration and route information of the observation path is shown in FIG.

[0048] In this example, 12 nodes N1 to N12 are arranged in a 3x4 matrix, and the nodes N on the top, bottom, left, and right are connected by links. Nodes N1, N5, and N9 are input-side End nodes, and nodes N4, N8, and N12 are output-side End nodes.

[0049] Three paths pass through this network. Observation path P 1,12 The observed path P passes through nodes N1 → N2 → N6 → N7 → N11 → N12. 5,8 The observed path P passes through nodes N5 → N6 → N7 → N8. 9,4 The route passes through nodes N9 → N10 → N11 → N7 → N3 → N4.

[0050] The calculation unit 12 generates an observation matrix A in which, among the links constituting the optical transmission network 30, links through which the observation path passes are assigned a value of 1, and links through which the observation path does not pass are assigned a value of 0. In the case of Fig. 4, the observation matrix A shown in Fig. 5 is generated. Note that in Fig. 5, the element e shown in the first and fifth rows corresponds to the link x shown in Fig. 4.

[0051] Step S3; The calculation unit 12 determines whether the observed value of the end-to-end GSNR of each collected observation path has deteriorated beyond a preset threshold, or whether the operator has instructed to narrow down the abnormal links. If there is a change or an instruction, the calculation unit 12 narrows down the abnormal links as described below.

[0052] Here, as shown in Figure 6, the link x between node N6 and node N7 6,7 An abnormality occurs in the observation path P 1,12 and observation path P 5,8 Assume that the observed values ​​of the GSNRs of each end-to-end are equal to or less than the threshold.

[0053] Step S4; The calculation unit 12 calculates the difference between the observed end-to-end GSNR value in a normal state and the observed end-to-end GSNR value in an abnormal state for all observation paths, thereby calculating the increment of 1 / GSNR from end to end for each observation path.The calculation unit 12 then sets the increment as a vector y.The observed end-to-end GSNR value in a normal state is the average value of the observed values, etc.

[0054] An example of the calculation result of the vector y in the above example is shown in Figure 7. Here, it is shown as an integer for ease of understanding, but in reality it is often a decimal such as "0.000148580".

[0055] Step S5; The calculation unit 12 calculates x that satisfies the determinant y=Ax (y is vector y, A is observation matrix A) by using the increment of 1 / GSNR of each link from the steady-state value as an unknown vector x. This x corresponds to the solution of the problem of minimizing the l1 norm of x.

[0056] That is, the calculation unit 12 calculates the unknown vector x by solving the l1 optimization problem of equation (2) (optimizing the l1 norm (p=1) as a mathematical programming problem) (see FIG. 8).

[0057]

number

[0058] This allows the increase in 1 / GSNR from the steady-state value of each link to be estimated.

[0059] If the unknown vector x is approximately sparse, the unknown vector x may be approximately calculated using equation (3).

[0060]

number

[0061] γ (γ>0) is a predetermined parameter.

[0062] Step S6; The determination unit 13 determines that the link of the element (value of 1 / GSNR of each link) of the unknown vector x that is greater than a preset threshold is an abnormal link. For example, if the estimation result of the unknown vector x is the result shown in FIG. 9 and the threshold is 1, the determination unit 13 determines that the link of the element (value of 1 / GSNR of each link) that is greater than a preset threshold is an abnormal link. 6、7 is determined to be an abnormal link. After that, the display unit 14 displays the ID and position of the abnormal link on the screen.

[0063] [effect] According to this embodiment, an observation matrix A is generated that defines the links through which the observation path passes for the links that make up the optical transmission network 30. The increment of 1 / GSNR from the steady-state value from end to end of the observation path is calculated to be a vector y. By setting x to satisfy the determinant y=Ax, the increment x from the steady-state value of 1 / GSNR for each link is calculated by solving the problem of minimizing the l1 norm of x. Based on the calculated increment x for each link, an abnormal link is identified, thereby narrowing down the link where an abnormality has occurred in the optical transmission network 30.

[0064] Furthermore, according to this embodiment, abnormal links are determined using only the network configuration information of the optical transport network 30, the route information of each observation path passing through the optical transport network 30, and the GSNR observed end-to-end for each observation path, so there is no need to use an external measuring device such as an optical spectrum analyzer, and therefore abnormal links can be narrowed down simply and with a small amount of calculation.

[0065] Furthermore, according to this embodiment, since the increment x of 1 / GSNR of each link from the steady-state value is solved as a mathematical programming problem to determine an abnormal link, the calculation time can be reduced and scalability can be improved compared to a method of determining multiple faults by exhaustively. Furthermore, even when an abnormality occurs due to a node failure or when an abnormality cannot be clearly detected, such as when the node is only slightly deteriorated and does not require an alarm to be issued, the abnormality can be detected and the abnormal link can be narrowed down.

[0066] Furthermore, according to this embodiment, the increment of 1 / GSNR from the steady-state value is calculated for each link, so even if abnormalities occur in multiple links at the same time, the abnormal link can be isolated.

[0067] [Note] (Appendix 1) a calculation unit that generates an observation matrix A that defines the links through which each of a plurality of paths passes for a plurality of links connecting nodes in an optical transmission network, calculates a variation y of an end-to-end transmission quality value of each of the plurality of paths, and calculates a variation x of the transmission quality value of each link that satisfies the determinant y=Ax by solving a minimization problem of the l1 norm of x; a determination unit for determining whether a link is abnormal based on the amount of change x in the transmission quality value of each link; A determination device comprising:

[0068] (Appendix 2) The change in the end-to-end transmission quality value of the path, y, and the change in the transmission quality value of each link, x, are expressed as follows: 2. The determination device according to claim 1, wherein the amount of decrease in GSNR is an amount of increase in 1 / GSNR.

[0069] (Appendix 3) In the determination method performed by the determination device, generating an observation matrix A that defines the links through which each of the multiple paths passes for multiple links connecting nodes in the optical transmission network; Calculating a change y in the end-to-end transmission quality value of each of the plurality of paths; The change x in the transmission quality value of each link that satisfies the determinant y = Ax is calculated by solving the problem of minimizing the l1 norm of x. determining whether a link is abnormal based on the amount of change x in the transmission quality value of each link; Judgment method.

[0070] (Appendix 4) A determination program that causes a computer to function as the determination device described in Appendix 1 or 2.

[0071] [others] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the present disclosure.

[0072] The determination device 10 of the present embodiment described above can be realized, for example, by using a general-purpose computer system including a CPU 901, a memory 902, a storage 903, a communication device 904, an input device 905, and an output device 906, as shown in Fig. 10. The memory 902 and the storage 903 are storage devices. In the computer system, the CPU 901 executes a predetermined program loaded onto the memory 902, thereby realizing each function of the determination device 10.

[0073] The determination device 10 may be implemented by one computer, or by multiple computers, or may be a virtual machine implemented in a computer.

[0074] The program for the determination device 10 can be stored in a computer-readable recording medium such as a HDD, SSD, USB memory, CD, or DVD. The computer-readable recording medium is, for example, a non-transitory recording medium. The program for the determination device 10 can also be distributed via a communication network.

[0075] [Extended method] Up to this point, the end-to-end 1 / GSNR of the observation path via the optical transmission network 30 has been calculated. EtoE We focused on the fact that the GSNR can be calculated as a linear sum of 1 / GSNR of the links between all nodes on the path.

[0076] Then, by applying compressed sensing technology, the 1 / GSNR observed end-to-end for multiple paths is calculated. EtoE The 1 / GSNR of each link was estimated from the change in 1 / GSNR, and links with large changes were extracted to narrow down the suspected areas.

[0077] However, since this method only focuses on the links between nodes, there is no solution if degradation occurs in the transceiver (transmitter, receiver) connected to the node. In other words, it cannot determine whether the transceiver is faulty.

[0078] So, 1 / GSNR EtoE It is noted that is calculated by linearly adding the 1 / GSNR of the links between all nodes on the path route and the 1 / GSNR at the transmitter and receiver.

[0079] That is, link L2 between the end node of the observation path and the transmitter / receiver is added to observation matrix A, which has link L1 between nodes as an element. If the estimated value of 1 / GSNR for link L2 changes significantly, it is detected as an abnormality in the transmitter / receiver.

[0080] A specific example of the extension method will be described below.

[0081] According to the reference document below, the end-to-end transmission quality of the observation path can be calculated by linearly adding the quality values ​​of the transmitter and receiver to the linear sum of the transmission quality values ​​of each link through which the observation path passes. The calculation formula for this is shown in Equation (4).

[0082]

number

[0083] References: Elizabeth Rivera Hartling and others, “Design, Acceptance and Capacity of Subsea Open Cables”, JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL.39, NO.3, February 1, 2021, p.742-p.756.

[0084] Fig. 14 in the above reference is shown as equation (5).

[0085]

number

[0086] 1 / SNR TOT is the signal-to-noise ratio (SNR) measured at the receiver.

[0087] 1 / SNR ASE is the ASE (Amplified Spontaneous Emission) noise added by the optical amplifier.

[0088] 1 / SNR NLI is the noise mainly caused by the nonlinear optical effect of the optical fiber.

[0089] 1 / SNR GAWBS is the Guided Acoustic-Wave Brillouin Scattering noise.

[0090] 1 / SNR i is the other noise generated in the ith optical fiber.

[0091] 1 / SNR m is the noise-free SNR limit for a transmitter-receiver pair.

[0092] 1 / SNR TOT is 1 / GSNR in Equation (4). EtoE This is equivalent to 1 / SNR ASE +1 / SNR NLI +1 / SNR GAWBS " is 1 / GSNR in equation (4). Link This is equivalent to 1 / SNR i +1 / SNR m " is 1 / GSNR in equation (4). transceiver is equivalent to

[0093] From equation (5), 1 / GSNR Link The fiber-dependent noise term (1 / SNR i ) and the transmitter / receiver noise term (1 / SNR m ) can be linearly added.

[0094] Therefore, the transceiver is treated as an external device of the optical transport network 30, and the link between the transceiver and the end node of the observation path is added as a management target. That is, the link L2 between the transceiver and the end node is added as an element of the observation matrix A, which has the link L1 between the nodes as an element.

[0095] For example, consider 3x3 nodes N1 to N9 as shown in Figure 11. Transceiver A (40) and transceiver B (40) are connected to node N1. Transceiver C (40) and transceiver D (40) are connected to node N4. Transceiver E (40) and transceiver F (40) are connected to node N6. Transceiver G (40) and transceiver H (40) are connected to node N9. Nodes N1, N3, N4, N6, N7, and N9 are End nodes.

[0096] Transceiver A and transceiver G are connected via path P 1,9 Transceiver B and transceiver E communicate via path P 1,6 Transceiver C and transceiver F communicate via path P 4,6 Transceiver D and transceiver H communicate via path P 4,9 We are communicating via.

[0097] In this case, the calculation unit 12 generates an observation matrix A shown in FIG. 12. This observation matrix A includes the links (e 1,2 , …, e 6,9 ) and the link between the transmitter and receiver and the end node (e A,1 , …, e H,9 ) and.

[0098] Specifically, as shown in FIG. 13, in an access network 100 including a transceiver 40 and a node N4, two transceivers C and D are connected to the node N4 via a wavelength division multiplexer 41, and the node N4 is configured with a wavelength selection device 42 and an optical amplifier 43. In this case, the link between the transceiver C and the wavelength selection device 42 is a link x C、4 , the link x between the transceiver D and the wavelength selection device 42 D、4 is.

[0099] Assume that an abnormality occurs in transceiver C. Calculation unit 12 calculates vector y in the same manner as in step S4 (see FIG. 14). Calculation unit 12 also calculates unknown vector x that satisfies the determinant y=Ax in the same manner as in step S5. Then, calculation unit 12 outputs the calculation result of unknown vector x.

[0100] 15(a), (b), or (c) as a solution for the unknown vector x. The determination unit 13 narrows down the abnormal links from the calculation result of the unknown vector x, and determines that the transceiver connected to the abnormal link is the abnormal transceiver.

[0101] However, if an abnormality also occurs in the link between nodes, it may not be possible to properly determine the abnormal transmitter. For example, if transmitter / receiver C fails and link x 5,6 If the link x also fails, the vector y will be as shown in Figure 16 and the unknown vector x will be as shown in Figure 17. 5,6 Due to a failure, multiple transceivers appear to be out of order.

[0102] Therefore, the suspected locations are narrowed down in two steps: Fig. 18 is a diagram showing an example of the operation of the determination device 10 in the extended method.

[0103] First stage; The calculation unit 12 calculates a solution for the unknown vector x using an observation matrix A that includes only links between nodes (step S101).

[0104] If the solution of the unknown vector x can be calculated in step S101, the determination unit 13 determines that the link between the nodes is abnormal, and outputs the abnormal link based on the solution of the unknown vector x as a suspected location (steps S102, S103).

[0105] If the solution for the unknown vector x cannot be calculated in step S101, or after step S103, the process proceeds to step S104.

[0106] Second stage; The calculation unit 12 adds links between the transmitter and receiver and the nodes to the observation matrix A, and calculates a solution for the unknown vector x using the observation matrix A after the addition (step S104).

[0107] If the solution of the unknown vector x can be calculated in step S104, the judgment unit 13 judges that the transmitter / receiver is abnormal, identifies the abnormal link based on the solution of the unknown vector x, and outputs the transmitter / receiver connected to the abnormal link as a suspected location (steps S105, S106).

[0108] When steps S101 to S106 are performed after step S103, solutions for abnormal links between nodes are excluded.

[0109] If the solution for the unknown vector x cannot be calculated in step S104, the decision unit 13 determines that the decision is impossible and ends the process (step S107).

[0110] (Variation 1) Although both the sending and receiving links are added to the observation matrix A, it is also possible to add only one of the links to the observation matrix A. For example, only the link between the transmitter and the end node is added to the observation matrix A. By adding only the sending link, the solution can be narrowed down to, for example, only the solution shown in Figure 15(a), thereby reducing the calculation time.

[0111] (Variation 2) The internal wiring within the access network 100 may be managed. For example, as shown in FIG. 19, the link x between the transceiver C and the wavelength division multiplexer 41 α , the link x between the transceiver D and the wavelength division multiplexer 41 β , the link x between the wavelength division multiplexer 41 and the wavelength selection device 42 γ , the link x between the two wavelength selection devices 42 δ are set as elements of the observation matrix A. This allows the suspected locations to be narrowed down at an even finer granularity.

[0112] As described above, it is possible to narrow down the location of an anomaly in the link L1 between nodes and the link L2 between the transmitter / receiver and the end node while reducing the amount of calculations using the transmission quality values ​​of the path endpoints, the network configuration, and the path route, without adding any devices to the optical transmission network 30. When an anomaly (soft failure) occurs at a node due to deterioration or breakdown that does not warrant an alarm, it is possible to detect the anomaly and locate the location of the anomaly.

[0113] [Note] (Appendix 5) the calculation unit calculates a change x in the transmission quality value of each link by including links between a transceiver, which is a transmitter and / or a receiver, and a node connected to the transceiver in the observation matrix A; The determination unit 2. The determination device according to claim 1, wherein the determination device determines whether a transmitter / receiver is abnormal based on the amount of change x in the transmission quality value of each link.

[0114] (Appendix 6) The link between the transceiver and the node connected to the transceiver comprises: The determination device described in Supplementary Note 5, which is a plurality of links connected via devices in an access network including the transceiver and a node connected to the transceiver. [Explanation of symbols]

[0115] 1 Judgment System 10 Judgment device 11 Collection Department 12 Calculation section 13 Judgment section 14 Display section 15 Storage section 20 Monitoring equipment 30 Optical Transmission Network 901 CPU 902 memory 903 Storage 904 Communication equipment 905 Input Device 906 Output Device 40 Transceiver 41 Wavelength division multiplexer 42 Wavelength selection device 43 Optical Amplifier 100 Access Network

Claims

1. An observation matrix A is generated that defines the links through which each of a plurality of paths passes for a plurality of links connecting nodes in an optical transmission network, and the amount of change y in the end-to-end transmission quality value of each of the plurality of paths is calculated. The amount of change x in the transmission quality value of each link that satisfies the determinant y = Ax is calculated by multiplying the amount of change x by the number of x. １ a calculation unit that calculates by solving a norm minimization problem; a determination unit for determining whether a link is abnormal based on the amount of change x in the transmission quality value of each link; A determination device comprising:

2. the calculation unit calculates a change x in the transmission quality value of each link by including links between a transceiver, which is a transmitter and / or a receiver, and a node connected to the transceiver in the observation matrix A; The determination unit 2. The determination device according to claim 1, wherein an abnormal transmitter / receiver is determined based on the amount of change x in the transmission quality value of each link.

3. The link between the transceiver and the node connected to the transceiver comprises: The determination device according to claim 2 , which is a plurality of links connected via devices in an access network including the transceiver and a node connected to the transceiver.

4. The change amount y of the end-to-end transmission quality value of the path and the change amount x of the transmission quality value of each link are expressed as follows: The determination device according to claim 1 , wherein the amount of decrease in a generalized signal-to-noise ratio (GSNR) or the amount of increase in 1 / GSNR is determined.

5. In the determination method performed by the determination device, generating an observation matrix A that defines links through which each of a plurality of paths passes for a plurality of links connecting nodes of an optical transmission network; Calculating a change y in the end-to-end transmission quality value of each of the plurality of paths; The amount of change x in the transmission quality value of each link that satisfies the determinant y = Ax is expressed as the l １ It is calculated by solving a norm minimization problem, determining whether a link is abnormal based on the amount of change x in the transmission quality value of each link; Judgment method.

6. A determination program that causes a computer to function as the determination device according to any one of claims 1 to 4.

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