Compensated light output device, compensated light output method, and compensated light output system

Abstract

The present invention provides a compensating optical output device that suppresses fluctuations in the optical level of an optical signal propagating through an optical transmission path when a break occurs in the optical transmission path. [Solution] In the compensated light output system 20, the compensated light output device 30 includes a monitoring signal receiving unit 301 that receives monitoring signals from adjacent repeaters 40 connected via an optical transmission path OL, a measuring unit 302 that measures the intensity of the main signal and the monitoring signal propagating through the optical transmission path, and a compensated light output unit 303 that outputs compensation light in a wavelength band corresponding to the wavelength band of the main signal to the optical transmission path when both a decrease in the intensity of the main signal and a decrease in the intensity of the monitoring signal occur.

Description

Technical Field

[0001] The present disclosure relates to a compensation light output device, a compensation light output method, and a compensation light output system.

Background Art

[0002] FIG. 1 is a diagram for explaining an example of the optical level versus wavelength characteristic of an optical signal propagated through an optical transmission line OL when the optical transmission line OL is normal. In FIG. 1, the upper diagram shows an example in which an optical signal is propagated in single-band transmission using the C band (C-band), and the lower diagram shows an example in which an optical signal is propagated in multi-band transmission using the C band and the L band (L-band) (the same applies to FIG. 2 hereinafter).

[0003] Also, in FIG. 1, the optical level versus wavelength characteristic in the figure shows that the horizontal axis represents the wavelength and the vertical axis represents the optical level (the same applies to FIGS. 2, 3, 8, and 9 hereinafter). Also, in FIG. 1, it is assumed that the optical signal is propagated in the direction from left to right in the figure (the same applies to FIGS. 2, 3, 5, 7 to 10, 12, and 13 hereinafter).

[0004] As shown in FIG. 1, when an optical signal is propagated through the optical transmission line OL, stimulated Raman scattering (SRS) occurs, and the optical signal is affected by SRS, and the optical level versus wavelength characteristic changes in a tilt shape (for example, Patent Document 1).

[0005] The tilt-shaped optical level versus wavelength characteristic occurs due to the transition of energy from the short wavelength side to the long wavelength side in the optical signal propagated through the optical transmission line OL. Furthermore, the wider the wavelength bandwidth of the optical signal propagating through the optical transmission path OL, and the higher the total optical level of the optical signal propagating through the optical transmission path OL, the greater the amount of energy the optical signal contributes to the optical transmission path OL and the greater the amount of energy the optical signal receives from the optical transmission path OL. As a result, the tilt of the optical level-to-wavelength characteristic increases (i.e., the angle of the tilt increases). Therefore, in the case of multiband transmission, the tilt of the optical level-to-wavelength characteristic is greater compared to single-band transmission. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2015-119235 [Overview of the project] [Problems that the invention aims to solve]

[0007] As mentioned above, optical signals propagating through the optical transmission path OL are affected by SRS, causing the optical level-to-wavelength characteristics to change in a tilt-like manner. Furthermore, if a break occurs in the optical transmission path OL, the optical level of the optical signal propagating through the optical transmission path OL will fluctuate significantly (decrease), and the optical level may deviate from the design value.

[0008] Figure 2 illustrates an example of the optical level versus wavelength characteristics of an optical signal propagating through the optical transmission path OL when a break occurs in the optical transmission path OL. As shown in Figure 2, if a break occurs in the optical transmission path OL, the optical signal propagating through the optical transmission path OL will have a narrower wavelength bandwidth and a lower total optical level. As a result, the tilt-like optical level-to-wavelength characteristic will change transiently, and ultimately, optical signals other than the longest wavelength optical signal will be blocked, and the optical level of the longest wavelength optical signal will also fluctuate (decrease) significantly. Furthermore, in the case of multiband transmission, the fluctuation in the optical level of the longest wavelength optical signal will be larger compared to single-band transmission.

[0009] Therefore, when a break occurs in the optical transmission path (OL), suppressing fluctuations in the optical level of the optical signal propagating through the OL becomes a crucial challenge. This challenge is particularly pronounced in multiband transmission, where fluctuations in the optical level of the optical signal are larger compared to single-band transmission.

[0010] Therefore, in view of the above-mentioned problems, the purpose of this disclosure is to provide a compensating light output device, a compensating light output method, and a compensating light output system that can suppress fluctuations in the optical level of an optical signal propagating through an optical transmission path when a break occurs in the optical transmission path. [Means for solving the problem]

[0011] A compensated light output device according to one embodiment is: A monitoring signal receiving means that receives monitoring signals from an adjacent repeater connected via an optical transmission path, A measuring means for measuring the intensity of the main signal and the monitoring signal propagating through the optical transmission path, The system includes a compensation light output means that outputs compensation light in a wavelength band corresponding to the wavelength band of the main signal to the optical transmission path when both a decrease in the intensity of the main signal and a decrease in the intensity of the monitoring signal occur.

[0012] One embodiment of the compensated light output method is: A compensating light output method performed by a compensating light output device, Receiving monitoring signals from adjacent repeaters connected via optical transmission lines, To measure the intensity of the main signal and the monitoring signal propagating through the optical transmission path, The system includes, when both a decrease in the intensity of the main signal and a decrease in the intensity of the monitoring signal occur, outputting compensation light in a wavelength band corresponding to the wavelength band of the main signal to the optical transmission path.

[0013] A compensated light output system according to one embodiment is: A monitoring signal receiving means that receives monitoring signals from an adjacent repeater connected via an optical transmission path, Measuring means for measuring the intensities of the main signal and the monitoring signal propagating through the optical transmission line; Compensation light output means for outputting compensation light in a wavelength band corresponding to the wavelength band of the main signal to the optical transmission line when both a decrease in the intensity of the main signal and a decrease in the intensity of the monitoring signal occur.

Effect of the Invention

[0014] According to the above-described aspect, when a disconnection occurs in the optical transmission line, an effect can be obtained in that a compensation light output device, a compensation light output method, and a compensation light output system capable of suppressing fluctuations in the optical level of an optical signal propagating through the optical transmission line can be provided.

Brief Description of the Drawings

[0015] [Figure 1] It is a diagram for explaining an example of the optical level vs. wavelength characteristic of an optical signal propagating through an optical transmission line when the optical transmission line is normal. [Figure 2] It is a diagram for explaining an example of the optical level vs. wavelength characteristic of an optical signal propagating through an optical transmission line when a disconnection occurs in the optical transmission line. [Figure 3] In the present disclosure, it is a diagram for explaining an example of inserting compensation light when a disconnection occurs in an optical transmission line. [Figure 4] It is a diagram for explaining an example of the time transition of the total optical level of an optical signal propagating through each of PIN and POUT in FIG. 3. [Figure 5] It is a diagram for explaining an example of a problem when compensation light is inserted at a node that is not directly below among the nodes on the downstream side of the disconnection occurrence position when a disconnection occurs in an optical transmission line. [Figure 6] In the present disclosure, it is a diagram for explaining an example of a table used for determining whether a disconnection has occurred in an optical transmission line. [Figure 7] It is a diagram showing a configuration example of a node according to the present disclosure. [Figure 8] It is a diagram for explaining an example of an operation performed in advance by a node according to the present disclosure. [Figure 9]This is a diagram for explaining an operation example performed during operation by a node according to the present disclosure. [Figure 10] This is a block diagram showing a configuration example of a compensation optical output system according to the present disclosure. [Figure 11] This is a flowchart for explaining an example of the operation flow of a compensation optical output device according to the present disclosure. [Figure 12] This is a block diagram showing a configuration example of a compensation optical output system according to the present disclosure. [Figure 13] This is a block diagram showing a configuration example of a compensation optical output system according to the present disclosure. [Figure 14] This is a block diagram showing a hardware configuration example of a computer that realizes a compensation optical output device and a node according to the present disclosure.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that, for the sake of clarity of explanation, the following description and drawings are appropriately omitted and simplified. Also, in the following drawings, the same reference numerals are assigned to the same elements, and redundant explanations are omitted as necessary.

[0017] <Concept of the Present Disclosure> Before explaining each embodiment of the present disclosure, the concept of the present disclosure will be explained. In the present disclosure, when a disconnection occurs in the optical transmission line OL, compensation light (ASE (Amplified Spontaneous Emission) light) is inserted.

[0018] FIG. 3 is a diagram for explaining an example of inserting compensation light when a disconnection occurs in the optical transmission line OL in the present disclosure.

[0019] As shown in FIG. 3, when a disconnection occurs in the optical transmission line OL, the optical signal propagated through the optical transmission line OL is lost due to the disconnection of the optical transmission line OL. Therefore, in this disclosure, when a break occurs in the optical transmission path OL, compensation light is inserted to compensate for the optical signal lost due to the break in the optical transmission path OL.

[0020] Figure 4 illustrates an example of the time evolution of the total optical level of the optical signal propagating through each point of PIN and POUT in Figure 3. In Figure 4, the horizontal axis represents time, and the vertical axis represents the total optical level. As shown in Figure 4, when a break occurs in the optical transmission path OL, the total optical level decreases at both PIN and POUT downstream of the break location.

[0021] Therefore, in this disclosure, compensatory light is inserted. As a result, at POUT downstream of the compensatory light insertion point, the total light level increases due to the insertion of the compensatory light and returns to the state before the break occurred in the optical transmission path OL. Therefore, even if a break occurs in the optical transmission path OL, fluctuations in the light level of the optical signal propagating through the optical transmission path OL can be suppressed.

[0022] However, if a break occurs in the optical transmission path OL, and compensation light is inserted at a node downstream of the break location, but not directly below it, the following problem will occur. Therefore, in this disclosure, when a break occurs in the optical transmission path OL, compensation light is inserted at the node directly downstream of the location where the break occurred.

[0023] Figure 5 illustrates an example of a problem that occurs when a break occurs in the optical transmission path OL, and compensation light is inserted at a node downstream of the break location, but not directly below it. In the example shown in Figure 5, the optical transmission path OL propagates the main signal and SV (Supervisory) light. The main signal is an optical signal obtained by wavelength multiplexing multiplexing multiple wavelength bands. SV light is an optical signal used to communicate device information, signal information, etc., between adjacent nodes. Furthermore, two nodes 10A and 10B are provided along the optical transmission path OL. Before explaining the problem described above, let's first describe the configuration of nodes 10A and 10B.

[0024] Node 10A comprises a demultiplexer 101, an SV optical receiver 102, a receiving amplifier 103, a demultiplexer 104, a main signal receiver 105, a multiplexer 106, a main signal light source 107, a transmitting amplifier 108, a multiplexer 109, an SV optical light source 110, a multiplexer 111, and a compensation light source 112. Hereinafter, the combination of the main signal receiver 105 and the main signal light source 107 will be appropriately referred to as a transponder. Also, the combination of the SV optical receiver 102 and the SV optical light source 110 will be appropriately referred to as an SV transceiver.

[0025] Here, among the components that make up node 10A, the demultiplexer 101, the SV optical receiver 102, the receiving amplifier 103, the demultiplexer 104, the main signal receiver 105, the multiplexer 106, the main signal light source 107, the transmitting amplifier 108, the multiplexer 109, and the SV optical light source 110 are components that make up a typical node.

[0026] On the other hand, among the components constituting node 10A, the multiplexer 111 and the compensation light source 112 are components newly added to a typical node in this disclosure in order to insert compensation light.

[0027] The following describes each component that makes up node 10A. The demultiplexer 101 is connected to an upstream node (not shown) via the optical transmission path OL, and demultiplexes the SV light from the main signal and SV light propagated from the upstream node. The SV light receiver 102 receives the SV light demultiplexed by the demultiplexer 101.

[0028] The receiving amplifier 103 amplifies the main signal that has passed through the demultiplexer 101 and the multiplexer 111. The demultiplexer 104 separates the optical signal in the wavelength band assigned to node 10A from the main signal that has passed through the receiving amplifier 103. The main signal receiver 105 receives the optical signal separated by the demultiplexer 104.

[0029] The main signal light source 107 generates an optical signal in the wavelength band assigned to node 10A. The multiplexer 106 outputs the optical signal generated by the main signal light source 107 to the optical transmission path OL. As a result, the optical signal generated by the main signal light source 107 is combined with the main signal that has passed through the demultiplexer 104.

[0030] For example, suppose the main signal propagated through the optical transmission path OL is an optical signal obtained by wavelength multiplexing of optical signals in the wavelength band λ1 to λ5, and the wavelength band assigned to node 10A is wavelength band λ5. In this case, the demultiplexer 104 separates the optical signal in the wavelength band λ5 from the main signal in the wavelength band λ1 to λ5. The main signal light source 107 generates an optical signal in the wavelength band λ5, and the multiplexer 106 outputs the optical signal in the wavelength band λ5 to the optical transmission path OL.

[0031] The transmitting amplifier 108 amplifies the main signal that has passed through the demultiplexer 104 and the multiplexer 106. The SV light source 110 generates SV light. The multiplexer 109 is connected to the downstream node 10B via the optical transmission path OL and outputs the SV light generated by the SV light source 110 to the optical transmission path OL. As a result, the SV light generated by the SV light source 110 is combined with the main signal that has passed through the transmitting amplifier 108, and the combined main signal and SV light are propagated to the downstream node 10B.

[0032] The compensation light source 112 generates compensation light when a break occurs in the optical transmission line OL. The multiplexer 111 outputs the compensation light generated by the compensation light source 112 to the optical transmission line OL. For example, suppose the main signal propagated through the optical transmission path OL is an optical signal obtained by wavelength multiplexing of optical signals in the wavelength band λ1 to λ5. In this case, if a break occurs in the optical transmission path OL, the compensation light source 112 generates compensation light in the wavelength band λ1 to λ5, and the multiplexer 111 outputs the compensation light in the wavelength band λ1 to λ5 to the optical transmission path OL.

[0033] The configuration of node 10B is the same as that of node 10A. However, node 10B is assigned a different wavelength band than node 10A. For example, suppose the main signal propagated through the optical transmission path OL is an optical signal obtained by wavelength multiplexing of optical signals in wavelength bands λ1 to λ5, the wavelength band assigned to node 10A is wavelength band λ5, and the wavelength band assigned to node 10B is wavelength band λ4. In this case, at node 10B, the demultiplexer 104 separates the optical signal in wavelength band λ4 from the main signal in wavelength bands λ1 to λ5. The main signal light source 107 generates an optical signal in wavelength band λ4, and the multiplexer 106 outputs the optical signal in wavelength band λ4 to the optical transmission path OL. Furthermore, if a break occurs in the optical transmission path OL, the compensation light source 112 generates compensation light in wavelength bands λ1 to λ5, and the multiplexer 111 outputs the compensation light in wavelength bands λ1 to λ5 to the optical transmission path OL.

[0034] Here, we will explain the problem that arises when a break occurs in the optical transmission path OL, and compensation light is inserted at a node downstream of the location of the break, but not directly below it. In the following, we will assume that a break occurred in the optical transmission path OL immediately before node 10A.

[0035] If a break occurs in the optical transmission path OL immediately preceding node 10A, the optical level of the input optical signal at node 10A will decrease. Consequently, the optical level of the output optical signal from node 10A will also decrease. As a result, the optical level of the input optical signal at node 10B, downstream of node 10A, will also decrease.

[0036] However, if compensation light is inserted at node 10B, the optical signal generated by the main signal light source 107 at node 10A and combined with the main signal by the multiplexer 106 may be overwhelmed by the compensation light inserted at node 10B.

[0037] Therefore, if a break occurs in the optical transmission path OL immediately preceding node 10A, compensation light must be inserted at node 10A, which is one of the nodes 10A and 10B downstream of the location of the break.

[0038] Therefore, in this disclosure, each of nodes 10A and 10B monitors the optical level of the optical signal input via the optical transmission path OL in order to determine whether or not a break has occurred in the optical transmission path OL immediately before its own node. In detail, each of nodes 10A and 10B monitors the optical levels of the main signal and the SV light as optical signals propagating through the optical transmission path OL.

[0039] Figure 6 illustrates an example of a table used in this disclosure to determine whether or not a break has occurred in the optical transmission path OL. As shown in Figure 6, if a malfunction occurs in the transponder, the main signal is eventually blocked, but the SV light remains normal. Similarly, if a malfunction occurs in the SV transceiver, the SV light is eventually blocked, but the main signal remains normal. On the other hand, if a break occurs in the optical transmission line (OL), both the main signal and the SV light will be affected, and ultimately both the main signal and the SV light will be cut off.

[0040] Therefore, in this disclosure, each node 10A and 10B determines that a break has occurred in the optical transmission path OL immediately before its node when the decrease in the optical levels of both the main signal and the SV light exceeds a threshold, and inserts compensatory light.

[0041] For example, if a break occurs in the optical transmission path OL immediately before node 10A, the node directly downstream of the break location (nodes 10A and 10B) will be node 10A. Therefore, node 10A will exceed the threshold for the decrease in both the main signal and SV light levels earlier than node 10B.

[0042] Therefore, compensatory light can be inserted at node 10A, directly below the location of the disconnection. As a result, downstream of node 10A, fluctuations in the optical signal level can be suppressed by the insertion of compensatory light at node 10A. Consequently, no compensatory light is inserted at node 10B, and deviations from the design value in the optical level are avoided. The embodiments of this disclosure will be described below.

[0043] <Embodiment 1> First, the configuration of Node 10 related to this disclosure will be described. Figure 7 shows an example configuration of node 10 according to this disclosure. It is assumed that node 10 is connected to at least one of its upstream and downstream sides, and that node 10 is an example of a compensated light output device.

[0044] As shown in Figure 7, node 10 differs from nodes 10A and 10B shown in Figure 5 in that it has an additional demultiplexer 113, a main signal monitor 114, and an SV optical monitor 115.

[0045] The main signal monitor 114 monitors the optical level (intensity) of the main signal input to node 10 via the optical transmission path OL. More specifically, the main signal monitor 114 monitors the total optical level of the main signal. In the example in Figure 7, a demultiplexer 113 is provided between the demultiplexer 101 and the multiplexer 111, and the main signal monitor 114 monitors the optical level of the main signal demultiplexed by the demultiplexer 113.

[0046] The SV optical monitor 115 monitors the optical level (intensity) of the SV optical signal input to node 10 via the optical transmission path OL. In the example shown in Figure 7, the SV optical monitor 115 is inserted between the demultiplexer 101 and the SV optical receiver 102, and monitors the optical level of the SV optical signal demultiplexed by the demultiplexer 101. However, it is not limited to this configuration; another demultiplexer may be provided in the optical transmission path OL, and the SV optical monitor 115 may monitor the optical level of the SV optical signal demultiplexed by the other demultiplexer.

[0047] The compensation light source 112 uses the monitoring results from the main signal monitor 114 to determine whether the decrease in the light level of the main signal exceeds a threshold, and also uses the monitoring results from the SV light monitor 115 to determine whether the decrease in the light level of the SV light exceeds a threshold. The decrease in the light level of the main signal may be the decrease from the normal light level of the main signal. Similarly, the decrease in the light level of the SV light may be the decrease from the normal light level of the SV light. The thresholds for the main signal and the SV light may be the same.

[0048] The compensation light source 112 determines that a break has occurred in the optical transmission path OL immediately before node 10 if the decrease in the optical levels of both the main signal and the SV light exceeds a threshold, and generates compensation light. This compensation light is output (inserted) into the optical transmission path OL by the multiplexer 111.

[0049] On the other hand, the compensation light source 112 determines that an abnormality has occurred in the transponder if the decrease in the light level of the main signal exceeds the threshold, but the decrease in the light level of the SV light does not exceed the threshold, and therefore does not generate compensation light. As a result, compensation light is not inserted by the multiplexer 111.

[0050] Furthermore, the compensation light source 112 determines that an abnormality has occurred in the SV transceiver if the decrease in the SV light level exceeds the threshold, but the decrease in the main signal light level does not exceed the threshold, and therefore does not generate compensation light. For this reason, compensation light is not inserted by the multiplexer 111.

[0051] Next, we will explain the operation of Node 10 related to this disclosure. First, we will explain the actions performed in advance by Node 10 related to this disclosure. Figure 8 illustrates an example of the operations performed in advance by Node 10 according to this disclosure. Note that in Figure 8, only some of the components shown in Figure 7 are shown, and the other components are omitted from the illustration (the same applies to Figure 9 thereafter).

[0052] As shown in Figure 8, the main signal monitor 114 monitors the optical level of the main signal input to node 10 via the optical transmission path OL in advance and under normal conditions. The compensation light source 112 is pre-adjusted, under normal conditions, to have a light level equivalent to that of the main signal monitored by the main signal monitor 114.

[0053] For example, suppose the main signal propagated through the optical transmission path OL is an optical signal obtained by wavelength multiplexing of optical signals in the wavelength band λ1 to λ5. In this case, the compensation light source 112 is pre-adjusted to have the optical levels of each wavelength band λ1 to λ5 of the compensation light equal to the optical levels of each wavelength band λ1 to λ5 of the main signal.

[0054] In the example shown in Figure 8, under normal conditions, the optical level-to-wavelength characteristic of the main signal input to node 10 is flat. Therefore, the optical level-to-wavelength characteristic of the compensation light is adjusted to be flat. However, under normal conditions, the optical level-to-wavelength characteristic of the main signal input to node 10 may be tilted. In this case, the optical level-to-wavelength characteristic of the compensation light will be adjusted to be tilted.

[0055] Next, we will explain the operations performed by Node 10 during operation as described in this disclosure. Figure 9 illustrates an example of operations performed by Node 10 during operation according to this disclosure. As shown in Figure 9, during operation, the main signal monitor 114 monitors the optical level of the main signal input to node 10 via the optical transmission path OL, and the SV light monitor 115 monitors the optical level of the SV light input to node 10 via the optical transmission path OL.

[0056] The compensation light source 112 uses the monitoring results from the main signal monitor 114 and the SV light monitor 115 to determine whether the decrease in the light levels of the main signal and SV light exceeds a threshold.

[0057] When the decrease in the optical levels of both the main signal and the SV light exceeds a threshold, the compensation light source 112 determines that a break has occurred in the optical transmission path OL immediately before node 10, generates compensation light, and the multiplexer 111 outputs the compensation light generated by the compensation light source 112 to the optical transmission path OL.

[0058] As described above, according to this embodiment 1, node 10 monitors the optical levels of the main signal and SV light input to node 10 via the optical transmission path OL. If the decrease in the optical levels of both the main signal and SV light exceeds a threshold, node 10 determines that a break has occurred in the optical transmission path OL immediately before it and outputs compensation light to the optical transmission path OL.

[0059] This allows compensation light to be inserted at node 10 directly downstream of the point where the break occurred. As a result, fluctuations in the optical signal level can be suppressed downstream of node 10 by the insertion of compensation light by node 10.

[0060] <Embodiment 2> This second embodiment corresponds to an embodiment that expands upon the concept of the first embodiment described above. First, the configuration of the compensated light output system 20 related to this disclosure will be described. Figure 10 is a block diagram showing an example configuration of the compensated light output system 20 according to this disclosure.

[0061] As shown in Figure 10, the compensated light output system 20 comprises a compensated light output device 30 and an adjacent relay station 40. The compensated light output device 30 corresponds to node 10, and the adjacent relay station 40 corresponds to another node (not shown) upstream of node 10.

[0062] The compensated optical output device 30 and the adjacent relay station 40 are connected to each other via the optical transmission path OL. The optical transmission path OL propagates the main signal and the monitoring signal. The monitoring signal corresponds to SV light.

[0063] The compensation light output device 30 comprises a monitoring signal receiving unit 301, a measurement unit 302, and a compensation light output unit 303.

[0064] The monitoring signal receiving unit 301 receives monitoring signals propagated from the adjacent relay station 40 via the optical transmission path OL. The monitoring signal receiving unit 301 corresponds to the demultiplexer 101 and the SV optical monitor 115. The monitoring signal receiving unit 301 may also have a function to receive optical signals in the wavelength band allocated to the compensating optical output device 30 from the main signals propagated via the optical transmission path OL. This function corresponds to the demultiplexer 113 and the main signal monitor 114.

[0065] The measurement unit 302 measures the intensity of the main signal and monitoring signal propagated through the optical transmission path OL. The measurement unit 302 corresponds to the main signal monitor 114 and the SV optical monitor 115.

[0066] When both a decrease in the intensity of the main signal and a decrease in the intensity of the monitoring signal occur, the compensation light output unit 303 outputs compensation light in a wavelength band corresponding to the wavelength band of the main signal to the optical transmission path OL. The compensation light output unit 303 corresponds to the demultiplexer 104, the multiplexer 111, and the compensation light source 112.

[0067] Next, the operation flow of the compensation light output device 30 related to this disclosure will be explained. Figure 11 is a flowchart illustrating an example of the operation flow of the compensated light output device 30 according to this disclosure.

[0068] As shown in Figure 11, first, the monitoring signal receiving unit 301 receives the monitoring signal propagated from the adjacent relay station 40 via the optical transmission path OL (step S11). Next, the measurement unit 302 measures the intensity of the main signal and the monitoring signal propagated through the optical transmission path OL (step S12). Next, the compensation light output unit 303 determines whether both a decrease in the intensity of the main signal and a decrease in the intensity of the monitoring signal have occurred (step S13).

[0069] If, in step S13, neither a decrease in the intensity of the main signal nor a decrease in the intensity of the monitoring signal occurs (No. in step S13), the compensation light output unit 303 returns to the processing of step S13.

[0070] On the other hand, if both a decrease in the intensity of the main signal and a decrease in the intensity of the monitoring signal occur in step S13 (Yes in step S13), the compensation light output unit 303 outputs compensation light in a wavelength band corresponding to the wavelength band of the main signal to the optical transmission path OL (step S14).

[0071] As described above, according to this embodiment 2, the compensating light output device 30 measures the intensity of the main signal and the monitoring signal propagated through the optical transmission path OL, and when both a decrease in the intensity of the main signal and a decrease in the intensity of the monitoring signal occur, it outputs compensating light in a wavelength band corresponding to the wavelength band of the main signal to the optical transmission path OL.

[0072] This allows compensation light to be inserted into the compensation light output device 30 directly downstream of the point where the break occurred. As a result, fluctuations in the optical level of the optical signal can be suppressed downstream of the compensation light output device 30 by the insertion of compensation light by the compensation light output device 30.

[0073] <Embodiment 3> Figure 12 is a block diagram showing an example configuration of the compensated light output system 20A according to this disclosure. As shown in Figure 12, the compensated light output system 20A differs from the compensated light output system 20 shown in Figure 10 in that the compensated light output device 30 is replaced with the compensated light output device 30A. Furthermore, the compensated light output device 30A differs from the compensated light output device 30 shown in Figure 10 in that it has an added optical transmission unit 304.

[0074] The optical transmission unit 304 outputs an additional optical signal to the optical transmission path OL. The optical transmission unit 304 corresponds to the multiplexer 106 and the main signal light source 107. The additional optical signal corresponds to the optical signal generated by the main signal light source 107 and output to the optical transmission path OL by the multiplexer 106. At this time, the compensation light output unit 303 outputs compensation light in wavelength bands other than the wavelength band of the additional optical signal within the wavelength band of the main signal.

[0075] For example, suppose the main signal propagated through the optical transmission path OL is an optical signal obtained by wavelength multiplexing of optical signals in wavelength bands λ1 to λ5, the wavelength band allocated to the compensation optical output device 30A is wavelength band λ5, and the wavelength band of the monitoring signal is wavelength band λx. In this case, the optical transmission unit 304 outputs an additional optical signal in wavelength band λ5, and the compensation optical output unit 303 outputs compensation light in wavelength bands λ1 to λ4.

[0076] As a result, according to this embodiment 3, the compensating light output device 30A can insert compensating light in an appropriate wavelength band. Other effects are the same as those of Embodiment 2 described above.

[0077] <Embodiment 4> Figure 13 is a block diagram showing an example configuration of the compensated light output system 20B according to this disclosure. As shown in Figure 13, the compensated light output system 20B differs from the compensated light output system 20A shown in Figure 12 in that the compensated light output device 30A is replaced with the compensated light output device 30B. Furthermore, the compensating light output device 30B differs from the compensating light output device 30A shown in Figure 12 in that it has an additional determination unit 305.

[0078] The determination unit 305 determines that the optical transmission path OL is broken when both a decrease in the intensity of the main signal and a decrease in the intensity of the monitoring signal occur. Furthermore, the determination unit 305 determines that an abnormality has occurred in the transponder when only a decrease in the intensity of the main signal occurs. Also, the determination unit 305 determines that an abnormality has occurred in the monitoring transceiver when only a decrease in the intensity of the monitoring signal occurs. The monitoring transceiver corresponds to the SV transceiver.

[0079] As a result, according to this embodiment 4, the compensating light output device 30B can determine the occurrence of a break in the optical transmission path OL, a malfunction in the transponder, and a malfunction in the monitoring transceiver. Other effects are the same as those of Embodiment 3 described above.

[0080] <Hardware configuration of this disclosure> Next, the hardware configuration of the computer 90 that implements the compensated light output devices 30, 30A, 30B and node 10 according to this disclosure will be described. Figure 14 is a block diagram showing an example of the hardware configuration of a computer 90 that implements the compensated light output devices 30, 30A, 30B and node 10 according to this disclosure.

[0081] As shown in Figure 14, the computer 90 includes a processor 91, memory 92, storage 93, input / output interface (I / F) 94, and communication interface (Communication I / F) 95. The processor 91, memory 92, storage 93, input / output interface 94, and communication interface 95 are connected to each other by a data transmission path for sending and receiving data.

[0082] The processor 91 is a processing unit such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). The memory 92 is a type of memory such as RAM (Random Access Memory) or ROM (Read Only Memory). The storage 93 is a storage device such as an HDD (Hard Disk Drive), SSD (Solid State Drive), or memory card. The storage 93 may also be a type of memory such as RAM or ROM.

[0083] A program is stored in the storage 93. This program includes a set of instructions (or software code) that, when loaded into a computer, causes the computer 90 to perform one or more functions in the compensated light output devices 30, 30A, 30B and node 10. The components of the compensated light output devices 30, 30A, 30B and node 10 may also be realized by the processor 91 loading and executing the program stored in the storage 93. The storage function of the compensated light output devices 30, 30A, 30B and node 10 may also be realized by memory 92 or storage 93.

[0084] Furthermore, the programs described above may be stored on non-temporary computer-readable media or tangible storage media. Examples, but not limited to, include RAM, ROM, flash memory, SSD or other memory technologies, CD (Compact Disc)-ROM, DVD (Digital Versatile Disc), Blu-ray® disc or other optical disc storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices. The programs may also be transmitted over temporary computer-readable media or communication media. Examples, but not limited to, include electrical, optical, acoustic or other forms of propagating signals.

[0085] The input / output interface 94 is connected to a display device 941, an input device 942, a sound output device 943, and the like. The display device 941 is a device that displays a screen corresponding to the drawing data processed by the processor 91, such as an LCD (Liquid Crystal Display), a CRT (Cathode Ray Tube) display, or a monitor. The input device 942 is a device that receives operator input, such as a keyboard, mouse, and touch sensor. The display device 941 and the input device 942 may be integrated and implemented as a touch panel. The sound output device 943 is a device that outputs sound corresponding to the acoustic data processed by the processor 91, such as a speaker.

[0086] The communication interface 95 transmits and receives data to and from external devices. For example, the communication interface 95 communicates with external devices via a wired communication path or a wireless communication path.

[0087] Although the present disclosure has been described above with reference to embodiments, the present disclosure is not limited to the embodiments described above. Various modifications to the structure and details of the present disclosure can be made as can be understood by those skilled in the art within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0088] Furthermore, each drawing is merely illustrative to illustrate one or more embodiments. Each drawing may be associated not only with one specific embodiment but also with one or more other embodiments. As those skilled in the art will understand, various features or steps described with reference to any one drawing may be combined with features or steps shown in one or more other drawings to create embodiments that are not explicitly illustrated or described. Not all features or steps shown in any one drawing to illustrate an exemplary embodiment are necessarily required, and some features or steps may be omitted. The order of steps shown in any of the drawings may be changed as appropriate.

[0089] Furthermore, some or all of the embodiments described above may also be described as follows, but are not limited to these. (Note 1) A monitoring signal receiving means that receives monitoring signals from an adjacent repeater connected via an optical transmission path, A measuring means for measuring the intensity of the main signal and the monitoring signal propagating through the optical transmission path, The system includes a compensation light output means that, when both a decrease in the intensity of the main signal and a decrease in the intensity of the monitoring signal occur, outputs compensation light in a wavelength band corresponding to the wavelength band of the main signal to the optical transmission path. Compensated light output device. (Note 2) The system further includes optical transmission means for outputting additional optical signals to the optical transmission path, The compensation light output means outputs compensation light in a wavelength band other than the wavelength band of the additional light signal within the wavelength band of the main signal. The compensating light output device described in Appendix 1. (Note 3) The system further includes a determination means for determining that the optical transmission path is broken when both a decrease in the intensity of the main signal and a decrease in the intensity of the monitoring signal occur. The compensating light output device described in Appendix 1. (Note 4) The aforementioned determination means determines that an abnormality has occurred in the transponder when only a decrease in the intensity of the main signal occurs. The compensatory light output device described in Appendix 3. (Note 5) The aforementioned determination means determines that an abnormality has occurred in the monitoring transceiver when only a decrease in the intensity of the monitoring signal occurs. The compensatory light output device described in Appendix 3. (Note 6) A compensating light output method performed by a compensating light output device, Receiving monitoring signals from adjacent repeaters connected via optical transmission lines, To measure the intensity of the main signal and the monitoring signal propagating through the optical transmission path, When both a decrease in the intensity of the main signal and a decrease in the intensity of the monitoring signal occur, the system includes outputting compensation light in a wavelength band corresponding to the wavelength band of the main signal to the optical transmission path. Compensated light output method. (Note 7) A monitoring signal receiving means that receives monitoring signals from an adjacent repeater connected via an optical transmission path, A measuring means for measuring the intensity of the main signal and the monitoring signal propagating through the optical transmission path, The system includes a compensation light output means that, when both a decrease in the intensity of the main signal and a decrease in the intensity of the monitoring signal occur, outputs compensation light in a wavelength band corresponding to the wavelength band of the main signal to the optical transmission path. Compensated light output system.

[0090] Furthermore, some or all of the elements (e.g., configuration and function) described in Appendices 2 to 5 that are subordinate to Appendice 1 may also be subordinate to Appendices 6 and 7 in the same manner as those described in Appendices 2 to 5. Some or all of the elements described in any appendice may be applied to various hardware, software, recording means, systems, and methods for recording software. [Explanation of Symbols]

[0091] Nodes 10, 10A, 10B 101,104,113 Duplexer 102 SV Optical Receiver 103 Receiving Amplifier 105 Main signal receiver 106,109,111 Multiplexer 107 Main signal light source 108 Transmitter Amplifier 110 SV light source 112 Light source for compensation light 114 Main signal monitor 115 SV Optical Monitor 20, 20A, 20B Compensated Light Output System 30,30A,30B Compensated light output device 301 Monitoring signal receiving unit 302 Measuring part 303 Compensation light output section 304 Optical Transmission Section 305 Judgment Department 40 Adjacent relay stations 90 Computer 91 processors 92 memory 93 Storage 94 Input / Output Interfaces 941 Display device 942 Input device 943 Sound output device 95 Communication Interface OL Optical transmission path

Claims

1. A monitoring signal receiving means that receives monitoring signals from an adjacent repeater connected via an optical transmission path, A measuring means for measuring the intensity of the main signal and the monitoring signal propagating through the optical transmission path, The system includes a compensation light output means that, when both a decrease in the intensity of the main signal and a decrease in the intensity of the monitoring signal occur, outputs compensation light in a wavelength band corresponding to the wavelength band of the main signal to the optical transmission path. Compensated light output device.

2. The system further includes optical transmission means for outputting additional optical signals to the optical transmission path, The compensation light output means outputs compensation light in a wavelength band other than the wavelength band of the additional light signal within the wavelength band of the main signal. The compensated light output device according to claim 1.

3. The system further includes a determination means for determining that the optical transmission path is broken when both a decrease in the intensity of the main signal and a decrease in the intensity of the monitoring signal occur. The compensated light output device according to claim 1.

4. The aforementioned determination means determines that an abnormality has occurred in the transponder when only a decrease in the intensity of the main signal occurs. The compensated light output device according to claim 3.

5. The aforementioned determination means determines that an abnormality has occurred in the monitoring transceiver when only a decrease in the intensity of the monitoring signal occurs. The compensated light output device according to claim 3.

6. A compensating light output method performed by a compensating light output device, Receiving monitoring signals from adjacent repeaters connected via optical transmission lines, To measure the intensity of the main signal and the monitoring signal propagating through the optical transmission path, When both a decrease in the intensity of the main signal and a decrease in the intensity of the monitoring signal occur, the system includes outputting compensation light in a wavelength band corresponding to the wavelength band of the main signal to the optical transmission path. Compensated light output method.

7. A monitoring signal receiving means that receives monitoring signals from an adjacent repeater connected via an optical transmission path, A measuring means for measuring the intensity of the main signal and the monitoring signal propagating through the optical transmission path, The system includes a compensation light output means that, when both a decrease in the intensity of the main signal and a decrease in the intensity of the monitoring signal occur, outputs compensation light in a wavelength band corresponding to the wavelength band of the main signal to the optical transmission path. Compensated light output system.

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