Optical transmission line monitoring device, optical transmission line monitoring method, and optical transmission line monitoring program

Abstract

To reliably monitor an optical transmission line using opposing bidirectional monitor signals.SOLUTION: An optical transmission line monitoring device 50 is one of two opposing optical transmission line monitoring devices connected to each other by an optical transmission line 71 relayed by a relay 70, and includes a transmitter 51 for transmitting an own device monitoring signal 500 to the optical transmission line 71, a receiver 52 for receiving a monitoring signal 520 containing a mixture of a return monitoring signal 700 obtained by returning the own device monitoring signal 500 via the relay 70 and an other device monitoring signal 600 that is transmitted from an opposing optical transmission line monitoring device 60 and differs in pulse width and amplitude from those of the own device monitoring signal 500, a discrimination unit 53 for discriminating the return monitoring signal 700 and the other device monitoring signal 600 included in the monitoring signal 520 by using a discrimination criterion 530 for discriminating the return monitoring signal 700 and the other device monitoring signal 600 from the monitoring signal 520, and an output unit 54 for outputting a discrimination result 540 of the return monitoring signal 700 and the other device monitoring signal 600.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an optical transmission line monitoring device, an optical transmission line monitoring method, and an optical transmission line monitoring program. [Background technology]

[0002] In optical transmission systems that are part of the social infrastructure, there is a need for a technology that can detect faults in a short time with a simple configuration.

[0003] In relation to the above-mentioned technology, Patent Document 1 discloses a line monitoring method in which the main line signals of the upstream and downstream optical transmission lines are set to different wavelengths so that the wavelength of the return signal returned from each repeater does not overlap with the wavelength of the main line signal transmitted from the transmitting terminal. In this method, the main line signal and the return signal are separated using a branching circuit in the receiving terminal. In addition, this method detects the monitoring signal in the return signal in a short time by increasing the level of the separated return signal. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 08-265261 Summary of the Invention [Problem to be solved by the invention]

[0005] In optical transmission systems, a method for monitoring the status of repeaters and optical transmission paths may involve using a supervisory signal of a specific wavelength and adding information to the fluctuation state of the optical level or to the supervisory signal. In this case, in monitoring by opposing stations, in order to determine which of the two stations a supervisory signal originates from, for example, in the aforementioned Patent Document 1, the supervisory signals from both stations are set to different wavelengths (pulse widths). However, it is desirable to make it easier to distinguish the supervisory signals from both stations, thereby enabling more reliable monitoring of the optical transmission path using the supervisory signals. In other words, the challenge is to more reliably monitor the optical transmission path using supervisory signals from opposing two directions.

[0006] A primary object of the present invention is to more reliably monitor an optical transmission line using opposing bidirectional monitoring signals. [Means for solving the problem]

[0007] An optical transmission line monitoring device according to one embodiment of the present invention is one of two opposing optical transmission line monitoring devices connected by an optical transmission line relayed by a repeater, and comprises: a transmitting means for transmitting a local device monitoring signal to the optical transmission line; a receiving means for receiving a monitoring signal that is a mixture of a return monitoring signal obtained by returning the local device monitoring signal through control by the repeater and an other device monitoring signal that is transmitted from the opposing optical transmission line monitoring device and has a pulse width and amplitude different from that of the local device monitoring signal; a distinguishing means for distinguishing between the return monitoring signal and the other device monitoring signal included in the monitoring signal using a distinguishing criterion for distinguishing between the return monitoring signal and the other device monitoring signal; and an output means for outputting a distinguishing result between the return monitoring signal and the other device monitoring signal.

[0008] In another aspect of achieving the above object, an optical transmission line monitoring method according to one embodiment of the present invention includes: transmitting a local device monitoring signal to the optical transmission line by one of two opposing optical transmission line monitoring devices connected by an optical transmission line relayed by a repeater; receiving a monitoring signal that is a mixture of a return monitoring signal obtained by returning the local device monitoring signal through control by the repeater and an other device monitoring signal that is transmitted from the opposing optical transmission line monitoring device and has a pulse width and amplitude different from that of the local device monitoring signal; using an identification criterion for identifying the return monitoring signal and the other device monitoring signal from the monitoring signal, identifying the return monitoring signal and the other device monitoring signal included in the monitoring signal; and outputting an identification result between the return monitoring signal and the other device monitoring signal.

[0009] In addition, in a further aspect of achieving the above object, an optical transmission line monitoring program according to one embodiment of the present invention executes a transmission process of transmitting a local apparatus monitoring signal to one of two opposing optical transmission line monitoring devices connected by an optical transmission line relayed by a repeater; a reception process of receiving a monitoring signal that is a mixture of a return monitoring signal obtained by returning the local apparatus monitoring signal through control by the repeater and an other apparatus monitoring signal that is transmitted from the opposing optical transmission line monitoring device and has a pulse width and amplitude different from that of the local apparatus monitoring signal; an identification process of identifying the return monitoring signal and the other apparatus monitoring signal included in the monitoring signal using an identification criterion for identifying the return monitoring signal and the other apparatus monitoring signal from the monitoring signal; and an output process of outputting an identification result between the return monitoring signal and the other apparatus monitoring signal.

[0010] Furthermore, the present invention can also be realized by a computer-readable non-volatile recording medium in which such an optical transmission line monitoring program (computer program) is stored. [Effects of the Invention]

[0011] The present invention makes it possible to more reliably monitor an optical transmission line using opposing bidirectional monitoring signals. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a block diagram showing a configuration of an optical transmission line monitoring system 1 according to the present disclosure. [Figure 2] 10 is a diagram showing an example of a definition of a waveform of a supervisory signal indicated by a supervisory signal reception result 181 in the optical transmission line monitoring device 10 according to the present disclosure. FIG. [Figure 3A] 10 is a diagram (1 / 2) showing an example of a waveform pattern of a supervisory signal indicated by a supervisory signal reception result 181 in the optical transmission path monitoring device 10 according to the present disclosure. FIG. [Figure 3B] 10 is a diagram (2 / 2) showing an example of a waveform pattern of a supervisory signal indicated by a supervisory signal reception result 181 in the optical transmission line monitoring device 10 according to the present disclosure. FIG. [Figure 4] 10 is a diagram illustrating an example of the contents of an identification criterion 182 in the optical transmission line monitoring device 10 according to the present disclosure. FIG. [Figure 5] 10 is a diagram illustrating an example of a manner in which the optical transmission line monitoring device 10 according to the present disclosure displays an identification result 183 on the display screen 400 of the management terminal 40. FIG. [Figure 6] 4 is a flowchart showing the operation of the optical transmission line monitoring device 10 according to the present disclosure. [Figure 7] 1 is a block diagram showing a configuration of an optical transmission line monitoring device 50 according to the present disclosure. [Figure 8] 5 is a flowchart showing the operation of the optical transmission line monitoring device 50 according to the present disclosure. [Figure 9] FIG. 9 is a block diagram showing a configuration of an information processing device 900 that can realize an optical transmission line monitoring device according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0014] First Embodiment 1 is a block diagram showing the configuration of an optical transmission line monitoring system 1 according to the present disclosure. The optical transmission line monitoring system 1 includes two opposing optical transmission line monitoring devices 10 and 20, an optical transmission line 31 that communicatively connects the optical transmission line monitoring device 10 and the optical transmission line monitoring device 20 via one or more repeaters 30, and a management terminal 40. In this embodiment, the optical transmission line monitoring device 10 may be referred to as a local station, and the optical transmission line monitoring device 20 may be referred to as an opposing station. The optical transmission line monitoring devices 10 and 20 are devices that monitor the status of the repeater 30 and the optical transmission line 31 and diagnose the occurrence of a fault in the repeater 30 or the optical transmission line 31.

[0015] The management terminal 40 is an information processing device such as a personal computer, tablet terminal, or smartphone used by a user of the optical transmission line monitoring device 10 or the optical transmission line monitoring device 20. The management terminal 40 accepts input operations by the user and inputs the information input by the user to the optical transmission line monitoring device 10 or the optical transmission line monitoring device 20. The management terminal 40 has a display screen 400, and displays information output from the optical transmission line monitoring device 10 or the optical transmission line monitoring device 20 on the display screen 400.

[0016] The optical transmission line monitoring devices 10 and 20 are, for example, information processing devices such as servers. The optical transmission line monitoring devices 10 and 20 may be devices whose configuration is at least partially configured as a server that provides services in a cloud computing environment. The optical transmission line monitoring devices 10 and 20 have equivalent functions, and in this embodiment, the operation of the optical transmission line monitoring device 10 will be mainly described.

[0017] The optical transmission line monitoring device 10 includes a transmitting unit 11, a receiving unit 12, a discrimination unit 13, an output unit 14, a discrimination criterion learning unit 15, a diagnosis unit 16, a diagnostic criterion learning unit 17, and a storage unit 18. The transmitting unit 11, the receiving unit 12, the discrimination unit 13, the output unit 14, the discrimination criterion learning unit 15, the diagnosis unit 16, and the diagnostic criterion learning unit 17 are examples of a transmitting means, a receiving means, a discrimination means, an output means, a discrimination criterion learning means, a diagnosis means, and a diagnostic criterion learning means, respectively.

[0018] The storage unit 18 is, for example, a storage device such as a RAM (Random Access Memory) or a hard disk 904, which will be described later with reference to Fig. 9. The storage unit 18 may be provided in one or more external devices that can communicate with the optical transmission line monitoring device 10. The storage unit 18 stores a monitoring signal reception result 181, an identification criterion 182, an identification result 183, a diagnostic criterion 184, and a diagnostic result 185. The information stored in the storage unit 18 will be described later.

[0019] The transmitter 11 transmits the local equipment monitoring signal 100 to the optical transmission line 31, destined for the optical transmission line monitoring device 20, which is the opposite station. The local equipment monitoring signal 100 is emitted, for example, singly at predetermined time intervals, in order to monitor the status of the repeater 30 and the optical transmission line 31. The local equipment monitoring signal 100 is, for example, a square wave, but it may be a signal with a waveform other than a square wave, as long as it has a waveform that allows the signal peak level to be captured.

[0020] Like the optical transmission line monitoring device 10, the optical transmission line monitoring device 20 also transmits an other-device monitoring signal 200 to the optical transmission line 31 toward the opposing optical transmission line monitoring device 10. Like the self-device monitoring signal 100, the other-device monitoring signal 200 is also transmitted singly at predetermined time intervals, for example, to monitor the states of the repeater 30 and the optical transmission line 31.

[0021] The own device monitoring signal 100 and the other device monitoring signal 200 have different specifications, more specifically, different signal pulse widths and amplitudes (signal peak levels).

[0022] A part of the local device monitoring signal 100 transmitted from the transmitter 11 to the optical transmission line monitoring device 20 is returned under the control of the repeater 30 to become a returned monitoring signal 300 and head to the optical transmission line monitoring device 10. A part of the other device monitoring signal 200 transmitted from the optical transmission line monitoring device 20 to the optical transmission line monitoring device 10 reaches the optical transmission line monitoring device 10 without being returned under the control of the repeater 30.

[0023] The receiver 12 receives the monitor signal, which is a mixture of the other-device monitor signal 200 and the return monitor signal 300, via the optical transmission line 31, and stores the monitor signal reception result 181 representing the result in the memory 18. The local monitor signal 100 transmitted from the transmitter 11 is attenuated as it travels through the optical transmission line 31 and as it is returned by the repeater 30. Therefore, the amplitude of the return monitor signal 300 is usually smaller than that of the local monitor signal 100. The local monitor signal 100 and the return monitor signal 300 have the same pulse width. The other-device monitor signal 200 transmitted from the optical transmission line monitoring device 20 is attenuated as it travels through the optical transmission line 31 and as it passes through the repeater 30. Therefore, the amplitude of the other-device monitor signal 200 received by the receiver 12 is usually smaller than that when it was transmitted from the optical transmission line monitoring device 20. The pulse width of the other device monitor signal 200 does not change while traveling through the optical transmission line 31 and while passing through the repeater 30 .

[0024] 2 is a diagram showing an example of a definition of the waveform of a monitor signal indicated by a monitor signal reception result 181 in the optical transmission path monitoring device 10 according to the present disclosure. Since the monitor signal received by the receiving unit 12 is a mixture (overlap) of an other device monitor signal 200 and a return monitor signal 300, the waveform is defined as shown in FIG.

[0025] 2, the pulse widths of the local device monitoring signal 100 and the return monitoring signal 300 are set to Ta, and the pulse width of the other device monitoring signal 200 is set to Tb. In this embodiment, Ta is set to a larger value than Tb, and the amplitude of the other device monitoring signal 200 is set to a larger value than the amplitude of the local device monitoring signal 100.

[0026] In the waveform of the monitoring signal shown in Figure 2, the period when the amplitude is at its maximum is defined as Tp, and its amplitude (i.e., the maximum amplitude) is defined as Xp. In the waveform of the monitoring signal shown in Figure 2, the period when the amplitude is smaller than its maximum before it reaches its maximum is defined as Tl, and its amplitude is defined as Xl. In the waveform of the monitoring signal shown in Figure 2, the period after the amplitude drops from its maximum to a smaller value is defined as Tr, and its amplitude is defined as Xr.

[0027] The discrimination unit 13 discriminates between the loopback supervisory signal 300 and the other device supervisory signal 200 contained in the supervisory signal from the waveform of the supervisory signal indicated by the supervisory signal reception result 181, using a discrimination criterion 182. The method by which the discrimination unit 13 discriminates between the loopback supervisory signal 300 and the other device supervisory signal 200 will be described with reference to FIGS. 3A, 3B, and 4.

[0028] 3A and 3B are diagrams showing examples of waveform patterns of a monitor signal indicated by a monitor signal reception result 181 in the optical transmission path monitoring device 10 according to the present disclosure. As shown in Fig. 3A and 3B, there are nine types of waveform patterns of the monitor signal received by the receiving unit 12, shown as waveform patterns 1 to 9, depending on the degree of overlap between the return monitor signal 300 and the other device monitor signal 200.

[0029] 4 is a diagram illustrating the contents of the discrimination criterion 182 in the optical transmission path monitoring device 10 according to the present disclosure. As illustrated in FIG. 4, the discrimination criterion 182 represents a discrimination method for discriminating between the return monitoring signal 300 and the other device monitoring signal 200 included in the monitor signal, for each of the waveform patterns 1 to 9 illustrated in FIG. 3A and FIG. 3B. As will be described later, the discrimination criterion 182 represents the relationship between the return monitoring signal 300 and the other device monitoring signal 200 and represents a relationship between the discrimination result 183 and any of the following states on the time axis: a state in which there is no overlap and they are not adjacent, a state in which there is no overlap, a state in which they are overlapping so that one is included in the other, and a state in which they are partially overlapping.

[0030] 3A has a waveform characterized by a pulse width Tb, as shown in FIG. 4, and therefore the loopback supervisory signal 300, whose pulse width is Ta, which is greater than Tb, is not included in the supervisory signal received by the receiver 12. Therefore, the identifier 13 identifies (determines) that the supervisory signal contains only the other device supervisory signal 200, as shown in FIG.

[0031] 3A has a pulse width of Ta and no amplitude step, as shown in FIG. 4, and therefore does not include the other-device monitoring signal 200, which has a larger amplitude than the local-device monitoring signal 100 (i.e., the return monitoring signal 300). Therefore, the identification unit 13 identifies that the monitor signal contains only the return monitoring signal 300, as shown in FIG.

[0032] 4, waveform pattern 3 shown in FIG. 3A has waveform characteristics in which the pulse width is Ta and Xl=Xr. Waveform pattern 4 shown in FIG. 3A has waveform characteristics in which the pulse width is Ta and Xl=0. Waveform pattern 5 shown in FIG. 3A has waveform characteristics in which the pulse width is Ta and Xr=0. Waveform patterns 3 to 5 are in a state in which the other device monitor signal 200 is completely included in and overlaps with the return supervisory signal 300. In the case of waveform patterns 3 to 5, as shown in FIG. 4, the amplitude of the other device monitor signal 200 portion is expressed as "Xp-max(Xl,Xr)," and the amplitude of the return supervisory signal 300 portion is expressed as "max(Xl,Xr)." Therefore, the identification unit 13 uses the above-mentioned formula to identify the other device monitor signal 200 and the return supervisory signal 300, which are included in the supervisory signal received by the receiving unit 12. In the above formula, "max(Xl, Xr)" represents the larger of Xl and Xr, and "-" is an operator that allows division.

[0033] 4, waveform pattern 6 shown in FIG. 3B has waveform characteristics in which the pulse width is longer than Ta, neither Xl nor Xr is 0, and Xl is larger than Xr. Waveform pattern 7 shown in FIG. 3B has waveform characteristics in which the pulse width is longer than Ta, neither Xl nor Xr is 0, and Xl is smaller than Xr, as shown in FIG. 4. Waveform patterns 6 and 7 are in a state in which a portion of the other device monitor signal 200 overlaps with the return supervisory signal 300. In the case of waveform patterns 6 and 7, as shown in FIG. 4, the amplitude of the portion of the other device monitor signal 200 is expressed as "Xp-max(Xl, Xr)," and the amplitude of the portion of the return supervisory signal 300 is expressed as "min(Xl, Xr)." Therefore, the identification unit 13 uses the above-mentioned formula to identify the other device monitor signal 200 and the return supervisory signal 300, which are included in the supervisory signal received by the receiving unit 12. In the above formula, "min(Xl, Xr)" represents the smaller of Xl and Xr.

[0034] As shown in Fig. 4, waveform pattern 8 shown in Fig. 3B is characterized by a pulse width longer than Ta and Tl being 0. As shown in Fig. 4, waveform pattern 9 shown in Fig. 3B is characterized by a pulse width longer than Ta and Xr being 0. Waveform patterns 8 and 9 are states in which the other device monitor signal 200 and the return monitor signal 300 are adjacent to each other without overlapping. In the case of waveform patterns 8 and 9, as shown in FIG. 4 , the amplitude of the other device monitor signal 200 portion is expressed as “max((Xl or Xr),Xp” and the amplitude of the loopback monitor signal 300 portion is expressed as “min((Xl or Xr),Xp” so that the identification unit 13 uses the above-mentioned formula to identify the other device monitor signal 200 and the loopback monitor signal 300 contained in the monitor signal received by the receiving unit 12. However, in the above-mentioned formula, “(Xl or Xr)” represents Xl or Xr. More specifically, “(Xl or Xr)” represents Xr whose value is not 0 in waveform pattern 8, and represents Xl whose value is not 0 in waveform pattern 9.

[0035] The identifying unit 13 identifies the other device monitor signal 200 and the return monitor signal 300 contained in the monitor signal received by the receiving unit 12 as described above, and stores the identification result 183 in the storage unit 18 .

[0036] The output unit 14 outputs the identification result 183 to the management terminal 40 , and displays the identification result 183 on the display screen 400 .

[0037] 5 is a diagram illustrating an example of an aspect in which the optical transmission path monitoring device 10 according to the present disclosure displays an identification result 183 on the display screen 400 of the management terminal 40. In the example illustrated in Fig. 5, a monitoring signal reception result 181 by the receiving unit 12 indicates that a monitoring signal of waveform pattern 6 illustrated in Fig. 3B has been received. In this case, the output unit 14 may display the waveform of the return monitoring signal 300 and the waveform of the other device monitoring signal 200 represented by the identification result 183 by the identifying unit 13 individually on the same time axis on the display screen 400, as illustrated in the lower part of Fig. 5.

[0038] The discrimination reference learning unit 15 generates or updates the discrimination reference 182 as a learning model that learns the relationship between the waveform of the monitoring signal received by the receiving unit 12, the specifications of the local device monitoring signal 100 and the other device monitoring signal 200, and the discrimination result 183 by the discrimination unit 13, as shown in Figures 3A and 3B, for example. The specifications of the local device monitoring signal 100 and the other device monitoring signal 200 that the discrimination reference learning unit 15 uses in the above-mentioned learning may include, for example, the pulse width, amplitude, and time interval at which the local device monitoring signal 100 and the other device monitoring signal 200 are transmitted to the optical transmission path 31. The waveform of the monitoring signal that the discrimination reference learning unit 15 uses in the above-mentioned learning may include, for example, the values ​​of Tp, Tl, Tr, Xp, Xl, and Xr shown in Figure 2.

[0039] In the above-mentioned learning, the discrimination standard learning unit 15 may also use information representing the communication environment via the optical transmission line 31, including, for example, the distance between the optical transmission line monitoring device 10 and the optical transmission line monitoring device 20, and the distance between the optical transmission line monitoring device 10 and the optical transmission line monitoring device 20 and each repeater 30.

[0040] The diagnosing unit 16 diagnoses the states of the repeater 30 and the optical transmission line 31 using a diagnostic criterion 184 for diagnosing the states of the repeater 30 and the optical transmission line 31 from the return supervisory signal 300 and the other device monitor signal 200 represented by the identification result 183 by the identification unit 13. The diagnostic criterion 184 indicates that a fault may have occurred in at least one of the repeater 30 and the optical transmission line 31, for example, when the return supervisory signal 300 or the other device monitor signal 200 that should have been received by the receiving unit 12 is missing, or when the amplitude of the received return supervisory signal 300 or the other device monitor signal 200 is smaller than a predetermined threshold (i.e., is significantly attenuated). The diagnostic criterion 184 indicates that a fault may have occurred in at least one of the repeater 30 and the optical transmission line 31, for example, when a difference between the state of the return supervisory signal 300 or the other device monitor signal 200 received by the receiving unit 12 and the state received under normal conditions when no fault has occurred exceeds a predetermined threshold.

[0041] The diagnosing unit 16 stores the diagnosis result 185 obtained by diagnosing the states of the repeater 30 and the optical transmission line 31 in the storage unit 18 .

[0042] The diagnostic criterion learning unit 17 generates or updates the diagnostic criterion 184 as a learning model that learns the relationship between the identification result 183 by the identification unit 13, the specifications of the local device monitoring signal 100 and the other device monitoring signal 200, and the states of the repeater 30 and the optical transmission line 31. The specifications of the local device monitoring signal 100 and the other device monitoring signal 200 that the diagnostic criterion learning unit 17 uses in the above-mentioned learning may include, for example, the pulse width, amplitude, and time interval at which the local device monitoring signal 100 and the other device monitoring signal 200 are transmitted to the optical transmission line 31 of the local device monitoring signal 100 and the other device monitoring signal 200. Similarly to the identification criterion learning unit 15, the diagnostic criterion learning unit 17 may also use information representing the communication environment of the optical transmission line 31 in the above-mentioned learning.

[0043] Next, the operation (processing) of the optical transmission line monitoring device 10 according to the present disclosure will be described in detail with reference to the flowchart of FIG.

[0044] The transmitter 11 transmits a local device monitor signal 100, which has a different pulse width and amplitude from an other device monitor signal 200 transmitted from an optical transmission line monitoring device 20 opposite the optical transmission line monitoring device 10, to the optical transmission line 31 (step S101). The receiver 12 receives a monitor signal that is a mixture of the other device monitor signal 200 and a return monitor signal 300 obtained by returning the local device monitor signal 100 via the repeater 30, and stores the monitor signal reception result 181 in the memory unit 18 (step S102).

[0045] The identification unit 13 identifies the other device monitor signal 200 and the return monitor signal 300 contained in the received monitor signal based on the monitor signal reception result 181 and the identification criterion 182, and stores the identification result 183 in the storage unit 18 (step S103). The output unit 14 displays the waveforms of the return monitor signal 300 and the other device monitor signal 200 indicated by the identification result 183 on the display screen 400 of the management terminal 40, respectively (step S104).

[0046] The diagnosing unit 16 diagnoses the repeater 30 and the optical transmission line 31 based on the identification result 183 by the identifying unit 13 and the diagnostic criteria 184, and stores the diagnosis result 185 in the storage unit 18 (step S105). The output unit 14 displays the diagnosis result 185 by the diagnosing unit 16 on the display screen 400 of the management terminal 40 (step S106), and the entire process ends.

[0047] The optical transmission line monitoring device 10 according to the present disclosure can more reliably monitor an optical transmission line using opposing bidirectional monitoring signals. This is because the optical transmission line monitoring device 10 transmits to the optical transmission line 31 a local device monitoring signal 100 having a different pulse width and amplitude from the other device monitoring signal 200 from the opposing optical transmission line monitoring device 20, and distinguishes between the other device monitoring signal 200 contained in the received monitoring signal and a return monitoring signal 300 formed by returning the local device monitoring signal 100 via the repeater 30 using the discrimination criterion 182.

[0048] The effects achieved by the optical transmission line monitoring device 10 according to the present disclosure will be described in detail below.

[0049] In optical transmission systems, a method for monitoring the status of repeaters and optical transmission paths is sometimes used, which involves using a supervisory signal of a specific wavelength and adding information to the fluctuations in the optical level of the supervisory signal or to the supervisory signal. In this case, in monitoring by opposing stations, a method exists in which the supervisory signals from the two stations are set to have different pulse widths, for example, to distinguish which of the two stations is sending the supervisory signal. However, it is desirable to make it easier to distinguish the supervisory signals from the two stations, thereby enabling more reliable monitoring of the optical transmission path using the supervisory signals. In other words, the challenge is to more reliably monitor the optical transmission path using supervisory signals from opposing bidirectional stations.

[0050] To address this issue, an optical transmission line monitoring device 10 according to the present disclosure transmits a local device monitor signal 100 to an optical transmission line 31. The optical transmission line monitoring device 10 receives a monitor signal that contains a mixture of a return monitor signal 300, which is the local device monitor signal 100 returned via control by a repeater 30, and an other device monitor signal 200, which is transmitted from the opposing optical transmission line monitoring device 20 and has a different pulse width and amplitude from the local device monitor signal 100. The optical transmission line monitoring device 10 uses an identification criterion 182 for identifying the return monitor signal 300 and the other device monitor signal 200 from the monitor signal to identify the return monitor signal 300 and the other device monitor signal 200 contained in the monitor signal. The optical transmission line monitoring device 10 then outputs an identification result 183 between the return monitor signal 300 and the other device monitor signal 200. That is, the optical transmission line monitoring device 10 transmits a monitor signal with a different pulse width and amplitude from the monitor signal from the opposite station, thereby making it easier to distinguish between the monitor signal from its own station and the monitor signal from the opposite station, and then identifies the individual monitor signals from both stations using the discrimination criterion 182 for discriminating between the monitor signals from its own station and the opposite station in a state in which monitor signals from both stations are mixed. This allows the optical transmission line monitoring device 10 to more reliably monitor the optical transmission line using the opposing bidirectional monitor signals.

[0051] 5, the optical transmission line monitoring device 10 according to the present disclosure individually displays the waveform of the return monitoring signal 300 and the waveform of the other device monitor signal 200, which are represented by the identification result 183 by the identification unit 13, on the display screen 400. This allows the optical transmission line monitoring device 10 to present the reception status of the return monitoring signal 300 and the other device monitor signal 200 to the user in an easily understandable manner.

[0052] Furthermore, the optical transmission line monitoring device 10 according to the present disclosure generates or updates an identification criterion 182 that represents the result of learning the relationship between the waveform of the monitor signal represented by the monitor signal reception result 181, the specifications of the local device monitor signal 100 and the other device monitor signal 200, and the identification result 183 by the identification unit 13. This allows the optical transmission line monitoring device 10 to efficiently improve the accuracy of identifying the return monitor signal 300 and the other device monitor signal 200 included in the monitor signal represented by the monitor signal reception result 181.

[0053] Furthermore, the optical transmission line monitoring device 10 according to the present disclosure generates or updates an identification criterion 182 representing the result of learning the relationship between the distance between the optical transmission line monitoring devices 20 and the distance between the two optical transmission line monitoring devices 10 and 20 and the repeater 30, and the identification result 183 by the identification unit 13. That is, the optical transmission line monitoring device 10 generates or updates the identification criterion 182 based on the communication environment of the optical transmission line 31, and therefore, can further improve the accuracy of identifying the return monitoring signal 300 and the other device monitoring signal 200 included in the monitoring signal represented by the monitoring signal reception result 181.

[0054] Furthermore, the optical transmission line monitoring device 10 according to the present disclosure diagnoses the states of the repeater 30 and the optical transmission line 31 by using the identification result 183 and the diagnostic criteria 184 for diagnosing the states of the repeater 30 and the optical transmission line 31 from the return monitoring signal 300 and the other device monitoring signal 200 represented by the identification result 183. In this way, the optical transmission line monitoring device 10 can reduce the burden on the user in relation to the work of diagnosing the repeater 30 and the optical transmission line 31.

[0055] Furthermore, the optical transmission line monitoring device 10 according to the present disclosure generates or updates a diagnostic criterion 184 that represents the result of learning the relationship between the identification result 183, the specifications of the local device monitor signal 100 and the other device monitor signal 200, and the states of the repeater 30 and the optical transmission line 31. This allows the optical transmission line monitoring device 10 to efficiently improve the accuracy of diagnosing the repeater 30 and the optical transmission line 31.

[0056] <Second embodiment> FIG. 7 is a block diagram showing the configuration of an optical transmission line monitoring device 50 according to the present disclosure.

[0057] The optical transmission line monitoring device 50 according to this embodiment includes a transmitter 31, a receiver 52, an identifier 53, and an output unit 54. The transmitter 31, receiver 52, identifier 53, and output unit 54 are examples of a transmitter, a receiver, an identifier, and an output unit, respectively. The optical transmission line monitoring device 50 is an opposite device to an optical transmission line monitoring device 60 connected by an optical transmission line 71 relayed by a repeater 70. The repeater 70 is, for example, a device similar to the repeater 30 in the optical transmission line monitoring system 1. The optical transmission line 71 is, for example, a transmission line similar to the optical transmission line 31 in the optical transmission line monitoring system 1.

[0058] The transmitter 51 transmits a local apparatus monitoring signal 500 to the optical transmission line 71. The local apparatus monitoring signal 500 is, for example, a signal similar to the local apparatus monitoring signal 100 related to the optical transmission line monitoring system 1. The transmitter 51 operates in the same manner as the transmitter 11 related to the optical transmission line monitoring system 1, for example.

[0059] The receiver 52 receives a monitor signal 520 that is a mixture of a return monitor signal 700, which is obtained by returning the local device monitor signal 500 via control by the repeater 70, and an other device monitor signal 600, which is transmitted from the opposing optical transmission line monitoring device 60 and has a different pulse width and amplitude from the local device monitor signal 500. The return monitor signal 700 is, for example, a signal similar to the return monitor signal 300 related to the optical transmission line monitoring system 1. The other device monitor signal 600 is, for example, a signal similar to the other device monitor signal 200 related to the optical transmission line monitoring system 1. The monitor signal 520 is, for example, a signal similar to the signal represented by the monitor signal reception result 181 related to the optical transmission line monitoring system 1. The receiver 52 operates in the same manner as the receiver 12 related to the optical transmission line monitoring system 1, for example.

[0060] The identification unit 53 identifies the return supervisory signal 700 and the other device supervisory signal 600 included in the supervisory signal 520 using an identification criterion 530 for identifying the return supervisory signal 700 and the other device supervisory signal 600 from the supervisory signal 520. The identification criterion 530 is, for example, the same as the identification criterion 182 related to the optical transmission line monitoring system 1. The identification unit 53 operates in the same manner as the identification unit 13 related to the optical transmission line monitoring system 1, for example.

[0061] The output unit 54 outputs a discrimination result 540 between the return supervisory signal 700 and the other device supervisory signal 600. The output unit 54 operates in the same manner as the output unit 14 in the optical transmission line monitoring system 1, for example.

[0062] Next, the operation (processing) of the optical transmission line monitoring device 50 according to the present disclosure will be described in detail with reference to the flowchart of FIG.

[0063] The transmitter 51 transmits the local device monitor signal 500 to the optical transmission line 71 (step S201). The receiver 52 receives the monitor signal 520, which is a mixture of the other device monitor signal 600 transmitted from the optical transmission line monitoring device 60 and the return monitor signal 700 obtained by returning the local device monitor signal 500 under the control of the repeater 70 (step S202).

[0064] The identification unit 53 uses the identification criterion 530 to identify the other device monitor signal 600 and the return monitor signal 700 included in the monitor signal 520 (step S203). The output unit 54 outputs the identification result 540 of the other device monitor signal 600 and the return monitor signal 700 (step S204), and the entire process ends.

[0065] The optical transmission line monitoring device 50 according to the present disclosure can more reliably monitor an optical transmission line using opposing bidirectional monitoring signals. This is because the optical transmission line monitoring device 50 transmits to the optical transmission line 31 a local device monitoring signal 500 having a different pulse width and amplitude from an other device monitoring signal 600 from the opposing optical transmission line monitoring device 60, and distinguishes, using a discrimination criterion 530, the other device monitoring signal 600 contained in the received monitoring signal 520 from a return monitoring signal 700 that is the local device monitoring signal 500 returned via a repeater 70.

[0066] <Hardware configuration example> In each of the above-described embodiments, each unit in the optical transmission line monitoring device shown in Fig. 1 and Fig. 7 can be realized by dedicated HW (Hardware) (electronic circuitry). In Fig. 1 and Fig. 7, at least the following components can be considered as functional (processing) units (software modules) of a software program including instructions executed by a processor. Transmission control function in the transmitters 11 and 51; Reception control function in the receivers 12 and 52; Identification units 13 and 53, Output units 14 and 54, · Identification standard learning unit 15, · Diagnostic section 16, ·Diagnostic criteria learning part 17, ·Memory control function in the memory unit 18.

[0067] However, the division of the various components shown in these drawings is for the sake of convenience of explanation, and various configurations may be assumed for implementation. An example of the hardware environment in this case will be described with reference to FIG.

[0068] Fig. 9 is a diagram illustrating an example of the configuration of an information processing device 900 (computer) capable of realizing the optical transmission line monitoring device according to the present disclosure. That is, Fig. 9 shows the configuration of a computer (information processing device) capable of realizing the optical transmission line monitoring device shown in Figs. 1 and 7, and represents a hardware environment capable of realizing each function in the above-described embodiment. However, each unit in the optical transmission line monitoring device described above may be distributed among multiple information processing devices 900, or at least some of the functions may be provided in a server or the like that constitutes a cloud computing environment.

[0069] The information processing device 900 shown in FIG. 9 includes the following components. ·CPU(Central_Processing_Unit)901, ·ROM(Read_Only_Memory)902, ·RAM(Random_Access_Memory)903, Hard disk (storage device) 904, a communication interface 905; Bus 906 (communication line), A reader / writer 908 capable of reading and writing data stored in a recording medium 907 such as a CD-ROM (Compact Disc Read Only Memory), · Input / output interface 909 such as a monitor, speaker, keyboard, etc.

[0070] That is, the information processing device 900 having the above-mentioned components is a general computer in which these components are connected via a bus 906. The information processing device 900 may have multiple CPUs 901, or may have a CPU 901 configured with multiple cores. The information processing device 900 may also not have some of the above-mentioned components.

[0071] The present invention, explained using the above-mentioned embodiment as an example, supplies a computer program capable of realizing the following functions to the information processing device 900 shown in FIG. 9. The functions are the functions described above in the block diagrams (FIGS. 1 and 7) or flowcharts (FIGS. 6 and 8) referred to in the description of the embodiment. The present invention is then achieved by reading the computer program into the CPU 901 of the hardware, interpreting it, and executing it. The computer program supplied to the device may be stored in a readable / writable volatile memory (RAM 903) or a non-volatile storage device such as a ROM 902 or a hard disk 904.

[0072] In the above case, the method of supplying the computer program to the hardware can be a currently common procedure, such as installing the program in the device via a recording medium 907 such as a CD-ROM, or downloading the program from an external source via a communication line such as the Internet. In such a case, the present invention can be considered to be constituted by the code constituting the computer program or the recording medium 907 on which the code is stored.

[0073] The present invention has been described above using the above-described embodiments as exemplary examples. However, the present invention is not limited to the above-described embodiments. In other words, the present invention can be applied in various aspects that can be understood by a person skilled in the art within the scope of the present invention.

[0074] Note that part or all of the above-described embodiments can also be described as follows: However, the present invention, which has been exemplarily described using the above-described embodiments, is not limited to the following.

[0075] (Appendix 1) Any of two opposing optical transmission line monitoring devices connected by an optical transmission line relayed by a repeater, a transmitting means for transmitting a device-specific monitoring signal to the optical transmission line; a receiving means for receiving a supervisory signal that includes a loopback supervisory signal obtained by looping back the local equipment supervisory signal through control by the repeater, and an other equipment supervisory signal that is transmitted from an opposing optical transmission line supervisory device and has a pulse width and amplitude different from those of the local equipment supervisory signal; a discrimination unit for discriminating between the loopback supervisory signal and the other device supervisory signal included in the supervisory signal using a discrimination criterion for discriminating between the loopback supervisory signal and the other device supervisory signal from the supervisory signal; an output means for outputting a result of distinguishing between the loopback supervisory signal and the other device supervisory signal; An optical transmission line monitoring device comprising:

[0076] (Appendix 2) the output means displays the waveform of the loopback supervisory signal and the waveform of the other device supervisory signal, which are represented by the identification result, on a display screen, respectively. 2. The optical transmission line monitoring device according to claim 1.

[0077] (Appendix 3) further comprising an identification criterion learning means for generating or updating the identification criterion, which represents a result of learning the relationship between the waveform of the monitoring signal, the specifications of the local device monitoring signal and the other device monitoring signal, and the identification result; 3. The optical transmission line monitoring device according to claim 1 or 2.

[0078] (Appendix 4) the discrimination criterion learning means generates or updates the discrimination criterion, which represents a result of learning a relationship between the distance between the two optical transmission line monitoring devices and the distance between the two optical transmission line monitoring devices and the repeater, and the discrimination result; 4. The optical transmission line monitoring device according to claim 3.

[0079] (Appendix 5) The identification criterion represents a relationship between the loopback supervisory signal and the other device supervisory signal and the identification result, in a state where they are not adjacent to each other on the time axis, a state where they are adjacent to each other without overlapping, a state where they are overlapping so that one is included in the other, or a state where they are partially overlapping. 3. The optical transmission line monitoring device according to claim 1 or 2.

[0080] (Appendix 6) a diagnostic unit for diagnosing the states of the repeater and the optical transmission line by using a diagnostic criterion for diagnosing the states of the repeater and the optical transmission line from the identification result and the return supervisory signal and the other device supervisory signal represented by the identification result; the output means outputs the diagnosis results of the states of the repeater and the optical transmission line. 3. The optical transmission line monitoring device according to claim 1 or 2.

[0081] (Appendix 7) a diagnostic criterion learning means for generating or updating the diagnostic criterion representing a result of learning a relationship between the identification result, specifications of the local device monitor signal and the other device monitor signal, and states of the repeater and the optical transmission line; 7. The optical transmission line monitoring device according to claim 6.

[0082] (Appendix 8) By either of two opposing optical transmission line monitoring devices connected by an optical transmission line relayed by a repeater, transmitting a device monitoring signal to the optical transmission line; receiving a supervisory signal that includes a loopback supervisory signal obtained by looping back the local equipment supervisory signal through control by the repeater, and an other equipment supervisory signal that is transmitted from an opposing optical transmission line supervisory device and has a pulse width and amplitude different from those of the local equipment supervisory signal; identifying the loopback supervisory signal and the other device supervisory signal included in the supervisory signal using an identification criterion for identifying the loopback supervisory signal and the other device supervisory signal from the supervisory signal; outputting a result of distinguishing between the loopback supervisory signal and the other device supervisory signal; Optical transmission line monitoring method.

[0083] (Appendix 9) a display screen that displays the waveform of the loopback monitoring signal and the waveform of the other device monitoring signal, which are represented by the identification result; 9. An optical transmission line monitoring method according to claim 8.

[0084] (Appendix 10) generating or updating the identification criterion representing a result of learning the relationship between the waveform of the monitoring signal, the specifications of the local device monitoring signal and the other device monitoring signal, and the identification result; 10. The optical transmission line monitoring method according to claim 8 or 9.

[0085] (Appendix 11) generating or updating the identification criterion representing a result of learning a relationship between the distance between the two optical transmission line monitoring devices and the distance between the two optical transmission line monitoring devices and the repeater, and the identification result; 11. An optical transmission line monitoring method according to claim 10.

[0086] (Appendix 12) The identification criterion represents a relationship between the loopback supervisory signal and the other device supervisory signal and the identification result, in a state where they are not adjacent to each other on the time axis, a state where they are adjacent to each other without overlapping, a state where they are overlapping so that one is included in the other, or a state where they are partially overlapping. 10. The optical transmission line monitoring method according to claim 8 or 9.

[0087] (Appendix 13) diagnosing the states of the repeater and the optical transmission line using diagnostic criteria for diagnosing the states of the repeater and the optical transmission line from the identification result and the return supervisory signal and the other device supervisory signal represented by the identification result; outputting a diagnosis result of the state of the repeater and the optical transmission line; 10. The optical transmission line monitoring method according to claim 8 or 9.

[0088] (Appendix 14) generating or updating the diagnostic criteria representing the results of learning the relationship between the identification result, the specifications of the local device monitor signal and the other device monitor signal, and the states of the repeater and the optical transmission line; 14. The optical transmission line monitoring method according to claim 13.

[0089] (Appendix 15) In one of two opposing optical transmission line monitoring devices connected by an optical transmission line relayed by a repeater, a transmission process of transmitting a local device monitor signal to the optical transmission line; a receiving process for receiving a supervisory signal that includes a loopback supervisory signal obtained by looping back the local equipment supervisory signal through control by the repeater, and an other equipment supervisory signal that is transmitted from an opposing optical transmission line supervisory device and has a pulse width and amplitude different from those of the local equipment supervisory signal; an identification process for identifying the loopback supervisory signal and the other device supervisory signal included in the supervisory signal using an identification criterion for identifying the loopback supervisory signal and the other device supervisory signal from the supervisory signal; an output process for outputting a result of distinguishing between the loopback supervisory signal and the other device supervisory signal; An optical transmission line monitoring program for executing the above.

[0090] (Appendix 16) the output process includes individually displaying the waveform of the loopback supervisory signal and the waveform of the other device supervisory signal, which are represented by the identification result, on a display screen; 17. The optical transmission line monitoring program according to claim 15 or 16.

[0091] (Appendix 17) causing the optical transmission line monitoring device to further execute an identification criterion learning process for generating or updating the identification criterion, which represents a result of learning the relationship between the waveform of the monitoring signal, the specifications of the local device monitoring signal and the other device monitoring signal, and the identification result; 17. The optical transmission line monitoring program according to claim 15 or 16.

[0092] (Appendix 18) the discrimination criterion learning process generates or updates the discrimination criterion, which represents a result of learning a relationship between the distance between the two optical transmission line monitoring devices and the distance between the two optical transmission line monitoring devices and the repeater, and the discrimination result; 18. The optical transmission line monitoring program according to claim 17.

[0093] (Appendix 19) The identification criterion represents a relationship between the loopback supervisory signal and the other device supervisory signal and the identification result, in a state where they are not adjacent to each other on the time axis, a state where they are adjacent to each other without overlapping, a state where they are overlapping so that one is included in the other, or a state where they are partially overlapping. 17. The optical transmission line monitoring program according to claim 15 or 16.

[0094] (Appendix 20) further causing the optical transmission line monitoring device to execute a diagnostic process for diagnosing the states of the repeater and the optical transmission line using a diagnostic criterion for diagnosing the states of the repeater and the optical transmission line from the identification result and the return supervisory signal and the other device supervisory signal represented by the identification result; the output process outputs a diagnosis result of the state of the repeater and the optical transmission line. 17. The optical transmission line monitoring program according to claim 15 or 16.

[0095] (Appendix 21) and causing the optical transmission line monitoring device to further execute a diagnostic criterion learning process for generating or updating the diagnostic criterion, which represents a result of learning a relationship between the identification result, the specifications of the local device monitor signal and the other device monitor signal, and the states of the repeater and the optical transmission line. 21. The optical transmission line monitoring program according to claim 20. [Explanation of symbols]

[0096] 1. Optical transmission line monitoring system 10 Optical transmission line monitoring equipment 11 Transmitter 12 Receiving unit 13 Identification unit 14 Output section 15. Classification criteria learning unit 16 Diagnostic Department 17 Diagnostic Criteria Learning Section 18 Memory section 181 Monitoring signal reception results 182 Identification Criteria 183 Identification Results 184 Diagnostic Criteria 185 Diagnosis Results 100 Own device monitoring signal 20 Optical transmission line monitoring equipment 200 Other device monitoring signal 30 Repeater 31 Optical transmission line 300 Return monitoring signal 40 Management terminal 400 display screen 50 Optical transmission line monitoring device 51 Transmitter 52 Receiving unit 520 Supervisory Signal 53 Identification unit 530 Identification Criteria 54 Output section 540 Identification Results 500 Own device monitoring signal 60 Optical transmission line monitoring equipment 600 Other device monitoring signal 70 Repeater 71 Optical transmission line 700 Return monitoring signal 900 Information Processing Equipment 901 CPU 902 ROM 903 RAM 904 Hard disk (storage device) 905 Communication Interface 906 Bus 907 Recording Media 908 Reader / Writer 909 Input / Output Interface

Claims

1. Any of two opposing optical transmission line monitoring devices connected by an optical transmission line relayed by a repeater, a transmitting means for transmitting a local device monitor signal to the optical transmission line; a receiving means for receiving a monitor signal including a return monitor signal obtained by returning the local equipment monitor signal through control by the repeater and an other equipment monitor signal transmitted from an opposing optical transmission line monitor device and having a pulse width and amplitude different from those of the local equipment monitor signal; a discrimination means for discriminating between the loopback supervisory signal and the other device supervisory signal included in the supervisory signal by using a discrimination criterion for discriminating between the loopback supervisory signal and the other device supervisory signal from the supervisory signal; an output means for outputting a result of discrimination between the loopback supervisory signal and the other device supervisory signal; An optical transmission line monitoring device comprising:

2. the output means displays on a display screen a waveform of the loopback monitoring signal and a waveform of the other device monitoring signal, which are represented by the identification result; 2. An optical transmission line monitoring device according to claim 1.

3. a discrimination criterion learning means for generating or updating the discrimination criterion representing a result of learning a relationship between a waveform of the monitoring signal, specifications of the local device monitoring signal and the other device monitoring signal, and the discrimination result; 3. An optical transmission line monitoring device according to claim 1 or 2.

4. the discrimination criterion learning means generates or updates the discrimination criterion representing a result of learning a relationship between the distance between the two optical transmission line monitoring devices and the distance between the two optical transmission line monitoring devices and the repeater, and the discrimination result; 4. An optical transmission line monitoring device according to claim 3.

5. The identification criterion represents a relationship between the loopback supervisory signal and the other device supervisory signal and the identification result, in a state in which the loopback supervisory signal and the other device supervisory signal are not adjacent to each other on a time axis, in a state in which the loopback supervisory signal and the other device supervisory signal are adjacent to each other without overlapping, in a state in which the loopback supervisory signal and the other device supervisory signal are overlapping each other such that one loopback signal and the other device supervisory signal are included in each other, and 3. An optical transmission line monitoring device according to claim 1 or 2.

6. a diagnostic unit for diagnosing the states of the repeater and the optical transmission line by using a diagnostic criterion for diagnosing the states of the repeater and the optical transmission line from the identification result and the return supervisory signal and the other device supervisory signal represented by the identification result, the output means outputs a diagnosis result of the state of the repeater and the optical transmission line.

3. An optical transmission line monitoring device according to claim 1 or 2.

7. a diagnostic criterion learning means for generating or updating the diagnostic criterion representing a result of learning a relationship between the identification result, specifications of the local device monitor signal and the other device monitor signal, and states of the repeater and the optical transmission line; 7. An optical transmission line monitoring device according to claim 6.

8. By one of two opposing optical transmission line monitoring devices connected by an optical transmission line relayed by a repeater, Transmitting a local device monitor signal to the optical transmission line; receiving a monitor signal including a return monitor signal obtained by returning the local equipment monitor signal through control by the repeater and an other equipment monitor signal transmitted from an opposing optical transmission line monitor device and having a pulse width and amplitude different from those of the local equipment monitor signal; identifying the loopback supervisory signal and the other device supervisory signal included in the supervisory signal using an identification criterion for identifying the loopback supervisory signal and the other device supervisory signal from the supervisory signal; outputting a result of identifying the loopback supervisory signal and the other device supervisory signal; Optical transmission line monitoring method.

9. a waveform of the loopback monitoring signal and a waveform of the other device monitoring signal, which are represented by the identification result, are individually displayed on a display screen; 9. The optical transmission line monitoring method according to claim 8.

10. In one of two opposing optical transmission line monitoring devices connected by an optical transmission line relayed by a repeater, a transmission process of transmitting a local device monitor signal to the optical transmission line; a receiving process for receiving a monitor signal including a return monitor signal obtained by returning the local equipment monitor signal through control by the repeater and a remote equipment monitor signal having a pulse width and amplitude different from those of the local equipment monitor signal and transmitted from an opposing optical transmission line monitor device; an identification process for identifying the loopback supervisory signal and the other device supervisory signal included in the supervisory signal by using an identification criterion for identifying the loopback supervisory signal and the other device supervisory signal from the supervisory signal; an output process for outputting a result of discrimination between the loopback supervisory signal and the other device supervisory signal; An optical transmission line monitoring program for executing the above.

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