Monitoring system, monitoring method, and program

Abstract

To provide a monitoring system, monitoring method, and program for improving accuracy of normality confirmation of a multi core transmission path.SOLUTION: A monitoring system comprises: a first acquisition unit for acquiring light intensity of multiplexed light obtained by multiplexing scattered light transmitting in a first light transmission path of a multi core transmission path and crosstalk light transmitting in a second light transmission path caused by crosstalk between the first light transmission path and the second light transmission path; a second acquisition unit for acquiring light intensity of the crosstalk light; and a calculation unit for calculating light intensity of the scattered light on the basis of the light intensity of multiplexed light and the light intensity of the crosstalk light.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a monitoring system, a monitoring method, and a program. [Background technology]

[0002] Patent Document 1 discloses a technique for monitoring an optical communication system using an OTDR (Optical Time Domain Reflectometer). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-060665 Summary of the Invention [Problem to be solved by the invention]

[0004] When monitoring a multi-core transmission line, crosstalk may interfere with checking the normality of the transmission line.

[0005] The present disclosure has been made to solve such problems, and aims to provide a monitoring system, a monitoring method, and a program that improve the accuracy of checking the normality of a multi-core transmission line. [Means for solving the problem]

[0006] The monitoring system according to the present disclosure comprises: a first acquisition unit that acquires the optical intensity of combined light obtained by combining scattered light propagating through a first optical transmission line in a multi-core transmission line and crosstalk light propagating through the second optical transmission line due to crosstalk between the first optical transmission line and a second optical transmission line; a second acquisition unit that acquires the light intensity of the crosstalk light; a calculation unit that calculates the light intensity of the scattered light based on the light intensity of the combined light and the light intensity of the crosstalk light; Equipped with.

[0007] The monitoring method according to the present disclosure includes: acquiring the optical intensity of combined light obtained by combining scattered light propagating through a first optical transmission line in a multi-core transmission line and crosstalk light propagating through the second optical transmission line due to crosstalk between the first optical transmission line and a second optical transmission line; Obtaining the light intensity of the crosstalk light; The light intensity of the scattered light is calculated based on the light intensity of the combined light and the light intensity of the crosstalk light.

[0008] The program according to the present disclosure is a process of acquiring the optical intensity of combined light obtained by combining scattered light propagating through a first optical transmission line in a multi-core transmission line and crosstalk light propagating through the second optical transmission line due to crosstalk between the first optical transmission line and a second optical transmission line; A process of acquiring the light intensity of the crosstalk light; a process of calculating the light intensity of the scattered light based on the light intensity of the combined light and the light intensity of the crosstalk light; to be executed by the computer. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a monitoring system, a monitoring method, and a program that improve the accuracy of checking the normality of a multi-core transmission line. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 10 is a diagram for explaining a cable trace. [Figure 2] FIG. 10 is a diagram for explaining the configuration of a related repeater. [Figure 3] FIG. 10 is a diagram for providing a supplementary explanation of crosstalk light. [Figure 4] FIG. 10 is a diagram for providing a supplementary explanation of crosstalk light. [Figure 5] 1 is a block diagram illustrating an example of the configuration of a monitoring system according to the present disclosure. [Figure 6] 1 is a flowchart illustrating an example of the flow of a monitoring method according to the present disclosure. [Figure 7] FIG. 1 is a diagram illustrating an example of the configuration of a monitoring system according to the present disclosure. [Figure 8] 10A and 10B are diagrams illustrating a modified example of the configuration of a repeater according to the present disclosure. [Figure 9] FIG. 1 is a diagram for explaining the operation of a monitoring system according to the present disclosure. [Figure 10] 10 is a flowchart illustrating an example of the operation of the monitoring system according to the present disclosure. [Figure 11] FIG. 2 is a diagram illustrating an example of the configuration of a repeater according to the present disclosure. [Figure 12] 10A and 10B are diagrams illustrating a modified example of the configuration of a repeater according to the present disclosure. [Figure 13] 10A and 10B are diagrams illustrating a modified example of the configuration of a repeater according to the present disclosure. [Figure 14] 10A and 10B are diagrams illustrating a modified example of the configuration of a repeater according to the present disclosure. [Figure 15] 10A and 10B are diagrams illustrating a modified example of the configuration of a repeater according to the present disclosure. [Figure 16] 10A and 10B are diagrams illustrating a modified example of the configuration of a repeater according to the present disclosure. [Figure 17] 10 is a flowchart illustrating an example of the operation of the monitoring system according to the present disclosure. [Figure 18] 10 is a flowchart illustrating an example of the operation of the monitoring system according to the present disclosure. [Figure 19] FIG. 2 is a diagram illustrating an example of the configuration of a repeater according to the present disclosure. [Figure 20] 10A and 10B are diagrams illustrating a modified example of the configuration of a repeater according to the present disclosure. [Figure 21] 10 is a flowchart illustrating an example of the operation of the monitoring system according to the present disclosure. [Figure 22] FIG. 1 is a block diagram illustrating an example of a hardware configuration of a monitoring system according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] Considerations leading to embodiment 1 The issues with related monitoring systems are explained using Figures 1 to 4. Related monitoring systems use cable tracing with OTDR or COTDR (Coherent Optical Time Domain Reflectometry) to check the health of SCF (Single Core Fiber) cables. Figure 1 shows an example of a cable trace. The horizontal axis represents the distance from one end of the cable. The vertical axis represents the light intensity of scattered light (e.g., backscattered light).

[0012] In recent years, the application of MCF (Multi-Core Fiber) to submarine transmission lines has been promoted in order to increase the transmission capacity of these lines. When monitoring MCF fiber cables, crosstalk (XT) between cores may occur. If the monitoring system acquires a cable trace shown in Figure 1 that includes the XT component, it may hinder the confirmation of the cable health.

[0013] 2 is a diagram illustrating an example of the configuration of a repeater 3 included in a related monitoring system. The MCF fiber cable includes a first optical transmission path 1, which is an upstream optical transmission path, and a second optical transmission path 2, which is a downstream optical transmission path. The first optical transmission path 1, which is the upstream optical transmission path, includes cables 11 and 12. The second optical transmission path 2, which is the downstream optical transmission path, includes cables 21 and 22.

[0014] In a related monitoring system, an optical pulse is input from one end (e.g., the left end in FIG. 2) of a first optical transmission line 1, and scattered light L1 generated in the first optical transmission line 1 is guided to a second optical transmission line 2, which is a downstream transmission line. In addition, crosstalk light L2 is generated due to crosstalk between a cable 12 and a cable 22, and the crosstalk light L2 propagates through the second optical transmission line 2.

[0015] The repeater 3 is disposed between the cable 11 and the cable 12, and between the cable 21 and the cable 22. The repeater 3 includes amplifiers 31 and 32 and optical couplers 33 and 36. The amplifier 31 amplifies the optical pulse input from the cable 11. The optical coupler 33 outputs the amplified optical pulse to the cable 12 and outputs scattered light (e.g., Rayleigh scattered light) generated in the first optical transmission line 1 to the optical coupler 34. The path between the optical coupler 33 and the optical coupler 34 is called a loopback path 37. The loopback path 37 guides the scattered light L1 to the second optical transmission line 2. The optical coupler 34 multiplexes the scattered light L1 and the crosstalk light L2, and outputs the multiplexed light L3 to the amplifier 32. The amplifier 32 outputs the amplified multiplexed light L3 to the optical coupler 35. The optical coupler 35 outputs the amplified multiplexed light L3 to the cable 21. When monitoring the state of the second optical transmission line 2, the optical coupler 36 operates in the same manner as the optical coupler 34.

[0016] Next, with reference to Figures 3 and 4, a supplementary explanation will be given of the crosstalk light L2 input to the repeater 3. With reference to Figure 3, crosstalk light L01 of the pulsed light L0 propagates through the cable 22, and part of the crosstalk light L01 is scattered backward, generating the crosstalk light L2. With reference to Figure 4, scattered light L02 is generated when part of the pulsed light L0 is scattered backward, and part of the scattered light L02 crosstalks, generating the crosstalk light L2. The actual crosstalk light L2 includes both a component generated by scattering the crosstalk light L01 and a component generated by crosstalk of the scattered light L02.

[0017] A related monitoring system acquires trace data by measuring the optical intensity of the combined light L3 output from one end (e.g., the left end in FIG. 2) of the second optical transmission line 2. Because the combined light L3 includes crosstalk light L2, there is a risk that the accuracy of checking the normality of the cable may be reduced. Based on the above considerations, the inventors have conceived the invention leading to the embodiments.

[0018] Embodiment 1 Hereinafter, a first embodiment will be described with reference to the drawings. FIG. 5 is a block diagram showing the configuration of a monitoring system 10 according to the present disclosure. The monitoring system 10 may be a computer device that operates when a processor executes a program stored in a memory. The monitoring system 10 may be an information processing device, for example, a server device. The monitoring system 10 may also be composed of multiple computer devices. In this case, the components or functions that make up the monitoring system 10 may be distributed and arranged across multiple computer devices. The multiple computers may be connected via a network or directly via a cable or the like.

[0019] The monitoring system 10 includes a first acquisition unit 101, a second acquisition unit 102, and a calculation unit 103. The first acquisition unit 101, the second acquisition unit 102, and the calculation unit 103 may be software or modules that are executed by a processor executing a program stored in a memory. Alternatively, the first acquisition unit 101, the second acquisition unit 102, and the calculation unit 103 may be hardware such as a circuit or a chip.

[0020] The first acquisition unit 101 acquires the optical intensity of combined light obtained by combining scattered light and crosstalk light. The scattered light propagates through a first optical transmission line in the multi-core transmission line. The crosstalk light propagates through a second optical transmission line due to crosstalk between the first optical transmission line and the second optical transmission line.

[0021] The second obtaining unit 102 obtains the light intensity of the crosstalk light.

[0022] The calculation unit 103 calculates the light intensity of the scattered light based on the light intensity of the combined light and the light intensity of the crosstalk light.

[0023] 6 is a flowchart showing an example of the flow of a monitoring method according to the present disclosure. First, the first acquisition unit 101 acquires the light intensity of combined light obtained by combining scattered light and crosstalk light (step S11). Next, the second acquisition unit 102 acquires the light intensity of the crosstalk light (step S12). The order of steps S11 and S12 may be reversed. Finally, the calculation unit 103 calculates the light intensity of the scattered light based on the light intensity of the combined light and the light intensity of the crosstalk light (step S13).

[0024] As described above, the monitoring system 10 acquires the intensity of the crosstalk light and calculates the intensity of the scattered light based on the intensity of the combined light and the intensity of the crosstalk light. As a result, the monitoring system 10 can accurately monitor the intensity of the scattered light.

[0025] Embodiment 2 7 is a diagram illustrating an example of the configuration of a monitoring system 100 according to the present disclosure. The monitoring system 100 is a specific example of the above-described monitoring system 10. Comparing FIG. 2 with FIG. 7, a wavelength filter 41 is provided in the loopback path 37 of the monitoring system 100. The monitoring system 100 may include multiple repeaters 3.

[0026] The monitoring system 100 further includes a monitoring device 110. The monitoring device 110 can be considered as a specific example of the monitoring system 10. The monitoring device 110 includes a first acquisition unit 111, a second acquisition unit 112, and a calculation unit 113. The monitoring device 110 may transmit an optical pulse from one end of the first optical transmission line 1 and measure the optical intensity of the combined light L3 output from one end of the second optical transmission line 2. The monitoring device 110 may be installed on land. The repeater 3 and the multi-core transmission line including the first optical transmission line 1 and the second optical transmission line 2 may be placed on the seabed.

[0027] The first acquisition unit 111 is a specific example of the above-described first acquisition unit 101. The first acquisition unit 111 acquires trace data (hereinafter referred to as first trace data) that represents the intensity of the multiplexed light L3 for each distance of the first optical transmission line 1 from the light intensity of the wavelength component of the multiplexed light L3 that is not cut by the wavelength filter 41.

[0028] The second acquiring unit 112 is a specific example of the above-described second acquiring unit 102. The second acquiring unit 112 acquires trace data (hereinafter referred to as second trace data) that represents the light intensity of the crosstalk light L2 for each distance in the first optical transmission line 1 from the light intensity of the wavelength component of the multiplexed light L3 that is cut by the wavelength filter 41.

[0029] The calculation unit 113 is a specific example of the calculation unit 103. The calculation unit 113 generates trace data (referred to as third trace data) that represents the light intensity of the scattered light L1 for each distance of the first optical transmission path 1, based on the difference between the first trace data and the second trace data.

[0030] Fig. 8 is a diagram illustrating a modified configuration of repeater 3. Comparing repeater 3 in Fig. 7 with repeater 3 in Fig. 8, optical coupler 33 in Fig. 8 outputs scattered light L1 to optical coupler 35 instead of optical coupler 34.

[0031] 9, a supplementary explanation of the operation of the monitoring system 100 will be provided. The scattered light L1 before passing through the wavelength filter 41 contains a wavelength component having a wavelength W1 that is cut by the wavelength filter 41 and a wavelength component having a wavelength W2 that is not cut by the wavelength filter 41. The scattered light L1 after passing through the wavelength filter 41 contains a wavelength component having a wavelength W2 that is not cut by the wavelength filter 41. Therefore, when measuring light of wavelength W11 that is included in the range of wavelength W1, the light intensity of the crosstalk light L2 is measured by measuring the light intensity of the multiplexed light L3. When measuring light of wavelength W2, the light intensity of the multiplexed light L3 that includes the scattered light L1 and the crosstalk light L2 is measured.

[0032] 10 is a flowchart showing an example of the operation of the monitoring system 100. First, the first acquisition unit 111 of the monitoring device 110 measures the light intensity of the wavelength component of the multiplexed light L3 that is cut by the wavelength filter 41 to acquire trace data (second trace data) of the crosstalk light L2 (step S21). Next, the second acquisition unit 112 of the monitoring device 110 measures the light intensity of the wavelength component of the multiplexed light L3 that is not cut by the wavelength filter 41 to acquire trace data (first trace data) of the multiplexed light L3 that includes the scattered light L1 and the crosstalk light L2 (step S22). Finally, the calculation unit 113 of the monitoring device 110 subtracts the second trace data from the first trace data to generate trace data of the scattered light L1 (third trace data) as the difference (step S23).

[0033] The monitoring device 110 may newly measure the second trace data acquired in step S21 each time it monitors the first optical transmission line 1, or may reuse second trace data measured in the past, thereby enabling the monitoring device 110 to reduce the time required for monitoring.

[0034] When monitoring a multi-core transmission line having four or more cores, the monitoring device 110 may use the second trace data when monitoring another core pair. Note that, in a COTDR, trace data is acquired using two cores, so the two cores are treated as one pair.

[0035] The monitoring device 110 can use the wavelength filter 41 to improve the accuracy of checking the normality of the multi-core transmission line.

[0036] Embodiment 3 11 is a diagram illustrating an example of the configuration of a repeater 3 according to the present disclosure. Compared to the repeater 3 in FIG. 7, a variable optical attenuator 42 is provided in the loopback path 37 instead of the wavelength filter 41. The monitoring system according to the third embodiment may further include a monitoring device 110 shown in FIG. 7.

[0037] The repeater 3 may include a control unit (not shown). The control unit controls the variable optical attenuator 42 in response to a control signal received from the monitoring device 110. This changes the amount of attenuation in the loopback path 37. The second acquisition unit 112 of the monitoring device 110 acquires the optical intensity of the multiplexed light L3 when the amount of attenuation in the loopback path 37 is large as the optical intensity of the crosstalk light L2.

[0038] 12 is a diagram illustrating a modified configuration of the repeater 3. Comparing FIG. 11 with FIG. 12, the variable optical attenuator 42 is replaced with an optical switch 43. The control unit of the repeater 3 controls the optical switch 43 in response to a control signal received from the monitoring device 110 to change the open / close state of the loopback path 37. The second acquisition unit 112 of the monitoring device 110 may acquire the optical intensity of the multiplexed light L3 when the loopback path 37 is in an open state as the optical intensity of the crosstalk light L2.

[0039] Fig. 13 is a diagram illustrating a modified configuration of the repeater 3. Comparing Fig. 12 with Fig. 13, the loopback path 37 of the repeater 3 in Fig. 13 is further provided with a variable optical attenuator 42 connected in series to an optical switch 43. The second acquisition unit 112 of the monitoring device 110 may acquire, for example, the optical intensity of the multiplexed light L3 when the loopback path 37 is in an open state and the attenuation amount of the variable optical attenuator 42 is large, as the optical intensity of the crosstalk light L2.

[0040] FIG. 14 is a diagram illustrating a modified configuration of the repeater 3. Comparing FIG. 13 with FIG. 14, the optical switch 43 has been replaced with an optical switch 43a. The optical switch 43a switches the path through which the scattered light L1 passes between a path in which the variable optical attenuator 42 is disposed and a path in which the variable optical attenuator 42 is not disposed. For example, when acquiring trace data of the crosstalk light L2, the monitoring device may switch the path through which the scattered light L1 passes to a path in which the variable optical attenuator 42 is disposed and increase the attenuation amount of the variable optical attenuator 42.

[0041] Fig. 15 is a diagram illustrating a modified configuration of the repeater 3. Comparing Fig. 13 with Fig. 15, the variable optical attenuator 42 is replaced with a fixed optical attenuator 42a. The scattered light L1 attenuated by the fixed optical attenuator 42a is input to the optical coupler 34. The monitoring system may switch the state of the optical switch 43 to an open state when acquiring trace data of the crosstalk light L2.

[0042] Fig. 16 is a diagram illustrating a modified configuration of the repeater 3. Comparing Fig. 14 with Fig. 16, the variable optical attenuator 42 has been replaced with a fixed optical attenuator 42a. When acquiring trace data of the crosstalk light L2, the monitoring device switches the path through which the scattered light L1 passes to a path provided with the fixed optical attenuator 42a. This increases the amount of attenuation in the loopback path 37 through which the scattered light L1 is guided.

[0043] 17 is a flowchart showing an example of the operation of the monitoring system according to the present disclosure. First, the monitoring device 110 controls the variable optical attenuators 42, optical switches 43, or optical switches 43a of all repeaters 3 to increase the attenuation of the loopback path 37 or open the loopback path 37 (step S31). Next, the second acquisition unit 112 of the monitoring device 110 acquires trace data of the crosstalk light L2 (step S32). Next, the monitoring device 110 controls the variable optical attenuators 42, optical switches 43, or optical switches 43a to return the state of the loopback path 37 changed in step S31 to its original state (step S33). Next, the first acquisition unit 111 of the monitoring device 110 acquires trace data of the multiplexed light L3 including the scattered light L1 (step S34). Finally, the calculation unit 113 of the monitoring device 110 subtracts the trace data acquired in step S32 from the trace data acquired in step S34, and acquires the trace data of the scattered light L1 as the difference (step S35). As in the second embodiment, the trace data acquired in step S32 may be reused when performing new monitoring or when monitoring another core pair.

[0044] The third embodiment can improve the accuracy of checking the normality of a multi-core transmission line by using an optical switch or a variable optical attenuator.

[0045] Embodiment 4 The fourth embodiment is a modification of the third embodiment. When the monitoring system according to the fourth embodiment cannot generate trace data of the scattered light L1, it performs control to reduce the amount of attenuation in the loopback path 37 and remeasures the trace data of the multiplexed light L3.

[0046] 18 is a flowchart showing an example of the operation of the monitoring system according to the embodiment 4. Steps S41 to S45 correspond to steps S31 to S35 in FIG.

[0047] If the light intensity of the crosstalk light L2 is greater than the light intensity of the scattered light L1, it is not possible to generate trace data of the scattered light L1 in step S45. In step S46, the monitoring device 110 determines whether or not the generation of trace data of the scattered light L1 has failed. If the generation of trace data of the scattered light L1 has succeeded (NO in step S46), the monitoring device 110 ends the process.

[0048] If generation of trace data of scattered light L1 fails (YES in step S46), the monitoring device 110 controls the variable optical attenuator 42, the optical switch 43, or the optical switch 43a to reduce the attenuation of the loopback path 37 (step S47). For example, the repeater 3 shown in Fig. 11 or 13 may set the attenuation of the variable optical attenuator 42 to a minimum value.

[0049] Next, the first acquisition unit 111 of the monitoring device 110 measures the optical intensity of the multiplexed light L3 to acquire trace data of the multiplexed light L3 (step S48). Next, the calculation unit 113 of the monitoring system subtracts the trace data acquired in step S42 from the trace data acquired in step S48, and generates trace data of the scattered light L1 as the difference (step S49). Finally, the monitoring system controls the variable optical attenuator 42, etc., to restore the attenuation of the loopback path 37 that was changed in step S47 (step S410).

[0050] The monitoring system can generate trace data of the scattered light L1 even when the light intensity of the crosstalk light L2 is high.

[0051] Embodiment 5 In the fourth embodiment, the attenuation of the scattered light L1 is reduced when re-measurement is performed. On the other hand, in the fifth embodiment, the attenuation of the light intensity of the crosstalk light L2 is increased when re-measurement is performed. The fifth embodiment is a specific example of the first embodiment.

[0052] 19 is a diagram illustrating an example of the configuration of a repeater 3 according to the present disclosure. Compared to the repeater 3 in FIG. 7, a variable optical attenuator 42 is arranged in the second optical transmission line 2. The variable optical attenuator 42 attenuates the crosstalk light L2 and outputs the attenuated crosstalk light L2 to the optical coupler 34. A wavelength filter 41 may be arranged in the loopback path 37, and the variable optical attenuator 42 and an optical switch 43 may also be arranged in the loopback path 37.

[0053] Fig. 20 is a diagram for explaining a specific example of the configuration of the repeater 3 according to the present disclosure. Compared with Fig. 19, a variable optical attenuator 42 is arranged in the loopback path 37. The fifth embodiment can be combined with the third embodiment, and the loopback path 37 may be provided with an optical switch 43, an optical switch 43a, or a fixed optical attenuator 42a.

[0054] FIG. 21 is a flowchart illustrating an example of the operation of the monitoring system according to the present disclosure. It is assumed that generation of trace data for scattered light L1 has failed. First, the monitoring device 110 controls the variable optical attenuator 42 to increase the attenuation in the loopback path 37, or controls the optical switch 43 to open the loopback path 37 (step S51). Next, the monitoring device 110 increases the attenuation of the variable optical attenuator 42 connected to the optical coupler 34 (step S52). Next, the second acquisition unit 112 of the monitoring device 110 measures the optical intensity of the crosstalk light L2 to acquire trace data for the crosstalk light L2 (step S53). Next, the monitoring device 110 performs control to restore the state of the loopback path 37 changed in step S51 to its original state (step S54). Next, the first acquisition unit 111 of the monitoring device 110 measures the optical intensity of the multiplexed light L3 to acquire trace data for the multiplexed light L3 (step S55). Next, the monitoring device 110 performs control to return the amount of attenuation of the variable optical attenuator 42 changed in step S52 to its original value (step S56). Finally, the calculation unit 113 of the monitoring device 110 subtracts the trace data acquired in step S53 from the trace data acquired in step S55, and obtains the trace data of the scattered light L1 as the difference (step S57).

[0055] The fifth embodiment can also achieve the same effects as the fourth embodiment.

[0056] FIG. 22 is a block diagram showing an example of the hardware configuration of a monitoring system 10 and a monitoring device 110 (hereinafter referred to as the monitoring system 10, etc.). Referring to FIG. 22, the monitoring system 10, etc. includes a network interface 1001, a processor 1002, and a memory 1003. The network interface 1001 is used to communicate with other network node devices constituting a communication system. The network interface 1001 may be used for wireless communication. For example, the network interface 1001 may be used for wireless LAN communication defined in the IEEE 802.11 series or mobile communication defined in 3GPP (registered trademark) (3rd Generation Partnership Project). Alternatively, the network interface 1001 may include, for example, a network interface card (NIC) conforming to the IEEE 802.3 series.

[0057] The processor 1002 reads and executes software (computer programs) from the memory 1003 to perform the processes of steps S11 to S13 in Fig. 6, steps S21 to S23 in Fig. 10, steps S31 to S35 in Fig. 17, steps S41 to S410 in Fig. 18, and steps S51 to S57 in Fig. 21. The processor 1002 may be, for example, a microprocessor, an MPU, or a CPU. The processor 1002 may include multiple processors.

[0058] The memory 1003 is configured by a combination of volatile memory and non-volatile memory. The memory 1003 may include storage located remotely from the processor 1002. In this case, the processor 1002 may access the memory 1003 via an I / O (Input / Output) interface (not shown).

[0059] 22, memory 1003 is used to store software modules. Processor 1002 reads these software modules from memory 1003 and executes them to perform the processes of steps S11 to S13, S21 to S23, S31 to S35, S41 to S410, and S51 to S57.

[0060] As explained using FIG. 22, each of the processors of the monitoring system 10 etc. in the above-described embodiments executes one or more programs including a set of instructions for causing a computer to perform the algorithms explained using the drawings.

[0061] In the above examples, the program includes instructions (or software code) that, when loaded into a computer, cause the computer to perform one or more functions described in the embodiments. The program may be stored on a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, computer-readable medium or tangible storage medium includes random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technology, CD-ROM, digital versatile disc (DVD), Blu-ray disc or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The program may also be transmitted on a transitory computer-readable medium or communication medium. By way of example and not limitation, transitory computer-readable medium or communication medium includes electrical, optical, acoustic, or other forms of propagated signals.

[0062] The technical ideas of the present disclosure are not limited to the above-described embodiments, and can be modified as appropriate within the scope of the gist of the present disclosure.

[0063] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0064] Each drawing is merely an example for describing one or more embodiments. Each drawing may relate not only to one particular embodiment, but also to one or more other embodiments. As will be understood by those skilled in the art, various features or steps described with reference to any one drawing can be combined with features or steps shown in one or more other drawings to create, for example, an embodiment not explicitly shown or described. Not all features or steps shown in any one drawing are necessary to describe an exemplary embodiment, and some features or steps may be omitted. The order of steps described in any drawing may be changed as appropriate.

[0065] A part or all of the above-described embodiments can be described as, but not limited to, the following supplementary notes.

[0066] Some or all of the elements (e.g., configurations and functions) described in Supplementary Notes 2 to 8 that are dependent on Supplementary Note 1 may also be dependent on Supplementary Notes 9 and 10 in the same dependency relationship as Supplementary Notes 2 to 8. Some or all of the elements described in any Supplementary Note may be applied to various hardware, software, recording means for recording software, systems, and methods.

[0067] (Appendix 1) a first acquisition unit that acquires the optical intensity of combined light obtained by combining scattered light propagating through a first optical transmission line in a multi-core transmission line and crosstalk light propagating through the second optical transmission line due to crosstalk between the first optical transmission line and a second optical transmission line; a second acquisition unit that acquires the light intensity of the crosstalk light; a calculation unit that calculates the light intensity of the scattered light based on the light intensity of the combined light and the light intensity of the crosstalk light; A monitoring system comprising: (Appendix 2) the first acquisition unit acquires trace data representing the optical intensity of the multiplexed light for each distance of the first optical transmission line using an OTDR (Optical Time Domain Reflectometer) or a COTDR (Coherent Optical Time Domain Reflectometry); the second acquisition unit acquires trace data representing the optical intensity of the crosstalk light for each distance of the first optical transmission line using the OTDR or the COTDR; The calculation unit generates trace data representing the light intensity of the scattered light for each distance of the first optical transmission path. 1. A monitoring system as described in Appendix 1. (Appendix 3) a monitoring device including the first acquisition unit, the second acquisition unit, and the calculation unit; a repeater including a loopback path that guides the scattered light to the second optical transmission path, and an optical coupler that combines the crosstalk light with the scattered light that has passed through the loopback path; 3. The monitoring system of claim 1 or 2, comprising: (Appendix 4) a wavelength filter is provided in the loopback path; The second acquisition unit acquires, as the light intensity of the crosstalk light, the light intensity of the wavelength component of the combined light that is cut by the wavelength filter. 1. A monitoring system as described in Appendix 3. (Appendix 5) at least one of an optical switch and a variable optical attenuator is provided in the loopback path; the repeater includes a control unit that controls at least one of the optical switch and the variable optical attenuator to change the open / closed state or the attenuation of the loopback path, The second acquisition unit acquires, as the light intensity of the crosstalk light, the light intensity of the multiplexed light when the loopback path is in an open state or when the amount of attenuation in the loopback path is large. 1. A monitoring system as described in Appendix 3. (Appendix 6) at least one of an optical switch and a variable optical attenuator is provided in the loopback path; the repeater includes a control unit that controls at least one of the optical switch and the variable optical attenuator to change the attenuation amount in the loopback path; If the monitoring device cannot calculate the optical intensity of the scattered light, the monitoring device reduces the amount of attenuation in the loopback path, acquires the optical intensity of the multiplexed light again, and calculates the optical intensity of the scattered light again. 1. A monitoring system as described in Appendix 3. (Appendix 7) the repeater includes a variable optical attenuator that attenuates the crosstalk light input to the optical coupler, and a control unit that controls the variable optical attenuator; If the monitoring device cannot calculate the light intensity of the scattered light, it increases the attenuation amount of the variable optical attenuator, acquires the light intensity of the multiplexed light and the light intensity of the crosstalk light again, and calculates the light intensity of the scattered light again. 1. A monitoring system as described in Appendix 3. (Appendix 8) The repeater includes an amplifier for amplifying the multiplexed light. 1. A monitoring system as described in Appendix 3. (Appendix 9) acquiring the optical intensity of combined light obtained by combining scattered light propagating through a first optical transmission line in a multi-core transmission line and crosstalk light propagating through the second optical transmission line due to crosstalk between the first optical transmission line and a second optical transmission line; Obtaining the light intensity of the crosstalk light; The light intensity of the scattered light is calculated based on the light intensity of the combined light and the light intensity of the crosstalk light. Monitoring method. (Appendix 10) a process of acquiring the optical intensity of combined light obtained by combining scattered light propagating through a first optical transmission line in a multi-core transmission line and crosstalk light propagating through the second optical transmission line due to crosstalk between the first optical transmission line and a second optical transmission line; A process of acquiring the light intensity of the crosstalk light; a process of calculating the light intensity of the scattered light based on the light intensity of the combined light and the light intensity of the crosstalk light; A program that causes a computer to execute the following. [Explanation of symbols]

[0068] 1. First optical transmission path 11, 12, 21, 22 cables 2 Second optical transmission path 3 Repeater 31, 32 Amplifier 33, 34, 35, 36 Optical coupler 37 Loopback Route L1 scattered light L2 Crosstalk light L3 combined light L0 light pulse 10, 100 monitoring system 101, 111 First Acquisition Section 102, 112 Second acquisition section 103, 113 Calculation section Monitoring device 110 41 Wavelength filter 42 Variable Optical Attenuator 42a Fixed Optical Attenuator 43, 43a Optical switch

Claims

1. a first acquisition unit that acquires the optical intensity of combined light obtained by combining scattered light propagating through a first optical transmission line in a multi-core transmission line and crosstalk light propagating through the second optical transmission line due to crosstalk between the first optical transmission line and a second optical transmission line; a second acquisition unit that acquires the light intensity of the crosstalk light; a calculation unit that calculates the light intensity of the scattered light based on the light intensity of the combined light and the light intensity of the crosstalk light; A monitoring system comprising:

2. the first acquisition unit acquires trace data representing the optical intensity of the multiplexed light for each distance of the first optical transmission path using an OTDR (Optical Time Domain Reflectometer) or a COTDR (Coherent Optical Time Domain Reflectometry); the second acquisition unit acquires trace data representing the optical intensity of the crosstalk light for each distance of the first optical transmission line using the OTDR or the COTDR; The calculation unit generates trace data representing the light intensity of the scattered light for each distance of the first optical transmission path. The monitoring system of claim 1 .

3. a monitoring device including the first acquisition unit, the second acquisition unit, and the calculation unit; a repeater including a loopback path that guides the scattered light to the second optical transmission path, and an optical coupler that combines the crosstalk light with the scattered light that has passed through the loopback path; 3. The monitoring system according to claim 1, further comprising:

4. a wavelength filter is provided in the loopback path; The second acquisition unit acquires, as the light intensity of the crosstalk light, the light intensity of the wavelength component of the combined light that is cut by the wavelength filter. The monitoring system of claim 3 .

5. at least one of an optical switch and a variable optical attenuator is provided in the loopback path; the repeater includes a control unit that controls at least one of the optical switch and the variable optical attenuator to change the open / closed state or the attenuation of the loopback path, The second acquisition unit acquires, as the light intensity of the crosstalk light, the light intensity of the multiplexed light when the loopback path is in an open state or when the amount of attenuation in the loopback path is large. The monitoring system of claim 3 .

6. at least one of an optical switch and a variable optical attenuator is provided in the loopback path; the repeater includes a control unit that controls at least one of the optical switch and the variable optical attenuator to change the attenuation amount in the loopback path; If the monitoring device cannot calculate the optical intensity of the scattered light, the monitoring device reduces the amount of attenuation in the loopback path, acquires the optical intensity of the multiplexed light again, and calculates the optical intensity of the scattered light again. The monitoring system of claim 3 .

7. the repeater includes a variable optical attenuator that attenuates the crosstalk light input to the optical coupler, and a control unit that controls the variable optical attenuator; If the monitoring device cannot calculate the light intensity of the scattered light, it increases the attenuation amount of the variable optical attenuator, acquires the light intensity of the multiplexed light and the light intensity of the crosstalk light again, and calculates the light intensity of the scattered light again. The monitoring system of claim 3 .

8. The repeater includes an amplifier for amplifying the multiplexed light. The monitoring system of claim 3 .

9. acquiring the optical intensity of combined light obtained by combining scattered light propagating through a first optical transmission line in a multi-core transmission line and crosstalk light propagating through the second optical transmission line due to crosstalk between the first optical transmission line and a second optical transmission line; Obtaining the light intensity of the crosstalk light; The light intensity of the scattered light is calculated based on the light intensity of the combined light and the light intensity of the crosstalk light. Monitoring method.

10. a process of acquiring the optical intensity of combined light obtained by combining scattered light propagating through a first optical transmission line in a multi-core transmission line and crosstalk light propagating through the second optical transmission line due to crosstalk between the first optical transmission line and a second optical transmission line; A process of acquiring the light intensity of the crosstalk light; a process of calculating the light intensity of the scattered light based on the light intensity of the combined light and the light intensity of the crosstalk light; A program that causes a computer to execute the following.

Images