JP2013148561A - Optical line monitoring system, testing device, optical line monitoring method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical line monitoring system capable of promptly and accurately detecting a trouble of an optical line.SOLUTION: An optical line monitoring system 10 comprises: a plurality of monitoring optical lines 105 provided respectively for a plurality of optical lines; a filter 130 provided in each of the plurality of monitoring optical lines 105; an OTDR 110 which transmits first monitoring light for each of the plurality of monitoring optical lines 105, measures a reflected light intensity of the first monitoring light for each of the plurality of monitoring optical lines 105, transmits second monitoring light for a monitoring optical line in which a trouble has occurred, and measures a back-scattered light intensity of the second monitoring light produced in the monitoring optical line in which the trouble has occurred; a first identification unit 232 for identifying the monitoring optical line in which the trouble has occurred on the basis of the reflected light intensity of the first monitoring light; and a second identification unit 234 for identifying a position where the trouble has occurred on the basis of the back-scattered light intensity of the second monitoring light.

Description

  The present invention relates to an optical line monitoring system for monitoring an optical line, and a test apparatus, an optical line monitoring method, and a program used in such an optical line monitoring system.

  In communication networks such as the Internet and CATV (Common Antenna Television, Community Antenna Television), etc., in recent years, communication lines have become optical lines. As a result, it is possible to provide a higher-speed and higher-quality communication service than before.

  In such a communication network, when a failure such as disconnection occurs in the optical line, the communication service cannot be used in all the subscriber houses connected to the optical line. For this reason, it is necessary to monitor the state of the optical line using an OTDR (Optical Time Domain Reflectometer: optical pulse tester) or the like to detect an optical line failure at an early stage.

  For example, Patent Document 1 below discloses an optical line monitoring system using OTDR. In the optical line monitoring system described in Patent Document 1, an optical coupler is provided in the vicinity of the center side transmission device and a reflection unit is provided in the vicinity of the subscriber side transmission device for each of the plurality of optical lines. A configuration is adopted in which an optical pulse tester is connected. According to Patent Document 1, this optical line monitoring system can detect any failure in any of the plurality of optical fiber lines.

JP 2010-185762 A JP 2009-229082 A

  However, in the optical line monitoring system described in Patent Document 1, an optical coupler is provided in each of a plurality of optical fiber lines, and pulse test light is input from the optical coupler to the optical fiber line.

  In general, since the optical coupler has a relatively large insertion loss, in the optical line monitoring system described in Patent Document 1, the longer the optical fiber line length, the more the intensity of the backscattered light cannot be obtained. There is a possibility that the failure position in the fiber line cannot be accurately determined.

  In addition, like the optical pulse tester disclosed in Patent Document 2, the conventional optical pulse tester sends the pulse test light to the optical fiber line a plurality of times, thereby increasing the intensity of the backscattered light. By measuring multiple times and averaging these multiple measurement results, measurement data with the noise fluctuation canceled is obtained, and based on this measurement data, the fault location in the optical fiber line is specified. Yes.

  For this reason, in the conventional optical pulse tester, the process for detecting the failure cannot be performed continuously in a short cycle, and when a failure occurs in the optical fiber line, the failure can be detected quickly. Can not.

  As described above, in the conventional optical line monitoring system, when a failure occurs in the optical fiber line, the failure cannot be detected quickly and accurately.

  An object of the present invention is to realize an optical line monitoring system capable of detecting a failure of an optical line quickly and accurately.

  In order to solve the above-described problems, an optical line monitoring system according to the present invention is an optical line monitoring system that monitors a plurality of optical lines, and is a plurality of monitoring optical lines, each of which is the plurality of optical lines. A plurality of monitoring optical lines provided alongside each of the plurality of monitoring optical lines, a reflecting means provided at one end of each of the plurality of monitoring optical lines, and each of the plurality of monitoring optical lines. The first monitoring light is sent to the first measuring light to measure the intensity of the reflected light that is the first monitoring light reflected by the reflecting means, and the first measuring light is measured by the first measuring means. Based on the intensity, the first specifying means for specifying the faulty monitoring optical line, and the second monitoring light is sent to the faulty monitoring optical line, and the fault has occurred. After the second monitoring light generated at various points on the monitoring optical line A plurality of second measuring means for measuring the intensity of the scattered light; and a second specifying means for specifying the position where the failure has occurred based on the intensity measured by the second measuring means. For each of the monitoring optical lines, light for switching the connection destination of the monitoring optical line between an optical line from which the first monitoring light is transmitted and an optical line from which the second monitoring light is transmitted. A switch is further provided.

  According to the present invention, the processing for identifying the failed optical line is performed simultaneously on the plurality of optical lines, and only the failed optical line identified thereby has failed. Since the processing for specifying the position is performed, the optical line and the position where the failure has occurred can be specified in a short time.

  Further, according to the present invention, since an optical line dedicated for monitoring (monitoring optical line) is used, the optical line can be monitored without affecting the optical line for data communication.

  In particular, according to the present invention, when monitoring light is input to the monitoring optical line, insertion loss due to the optical coupler does not occur. Therefore, compared with the conventional configuration in which the monitoring light is input using the optical coupler, The accuracy of fault detection can be increased.

  Further, the optical line monitoring system according to the present invention is an optical line monitoring system for monitoring a plurality of optical lines, and is a plurality of monitoring optical lines, each provided alongside each of the plurality of optical lines. For each of the plurality of monitoring optical lines, reflection means provided at one end of each of the plurality of monitoring optical lines, and each of the plurality of monitoring optical lines, the first monitoring Based on the intensity measured by the first measuring means, the first measuring means for sending light and measuring the intensity of the reflected light that is the first monitoring light reflected by the reflecting means, First identifying means for identifying a faulty monitoring optical line, and second monitoring light is transmitted to the faulty monitoring optical line, and various parts of the faulty monitoring optical line are transmitted. Measuring the intensity of the backscattered light of the second monitoring light generated in step A second measuring unit; and a second specifying unit that specifies a position where a fault has occurred based on the intensity measured by the second measuring unit, and each of the plurality of monitoring optical lines includes: A first optical line connected to the optical line from which the first monitoring light is transmitted, and a second optical line connected to the optical line from which the second monitoring light is transmitted It is characterized by that.

  According to the present invention, the same effect as the above optical line monitoring system can be obtained.

  In the optical line monitoring system, the first specifying means specifies a monitoring optical line in which a failure has occurred based on the intensity obtained by one measurement by the first measuring means, and the first Preferably, the second specifying means specifies the position where the failure has occurred based on the intensity obtained by averaging a plurality of measurement results obtained by the second measuring means.

  According to this configuration, when a faulty monitoring optical line is identified, it is not necessary to perform the averaging process of a plurality of measurement results as in the conventional case, so that an optical line failure can be detected in a short time. can do. In particular, since the optical line failure is detected based on the measurement value of the intensity of the reflected light, the optical line failure can be accurately detected from one measurement data without the need for the above averaging. it can.

  In the optical line monitoring system, the first measurement unit is provided in a first measurement device, the second measurement unit is provided in a second measurement device, and measurement processing by the first measurement unit is performed. It is preferable that the measurement process by the second measurement unit can be executed in parallel with each other.

  According to this configuration, even when the measurement process by one measurement unit is being performed, the measurement process by the other measurement unit is started as long as the monitor light can be transmitted to the monitoring optical line. Therefore, the processing interval of each measurement process can be shortened.

  The optical line monitoring system further includes reference data registration means for registering the intensity measured by the first measurement means as reference data, wherein the first specifying means performs registration by the reference data registration means. It is preferable to identify the monitoring optical line in which the failure has occurred by comparing the intensity measured by the first measuring means after the break and the intensity registered as the reference data.

  According to this configuration, despite the simple processing of comparing the measurement data and the reference data, the measurement data and the reference data are highly accurate, so that an optical line failure can be detected with high accuracy. In particular, since the measurement data measured in advance is used as the reference data, it is possible to reduce the time and effort required for the user to make the presetting.

  The optical line monitoring system further includes notification means for notifying a user of the failure specified by the specifying means, wherein the notification means is a period from when the failure is detected until the failure is not detected. Is preferably notified to the user as fault information.

  According to this configuration, it is possible to notify the user of the duration of the failure that has occurred in the optical line, and the user can estimate the cause of the failure from this duration.

  Further, the optical line monitoring method according to the present invention is an optical line monitoring method for monitoring a plurality of optical lines, each of a plurality of monitoring optical lines each provided alongside each of the plurality of optical lines, The first monitoring light is sent to the monitoring optical line, and the intensity of the reflected light that is the first monitoring light reflected by the reflecting means provided at one end of the monitoring optical line is measured. And a first identifying step for identifying the faulty monitoring optical line based on the intensity measured in the first measuring step, and the faulty monitoring optical line. A second measuring step of transmitting the second monitoring light to measure the intensity of the backscattered light of the second monitoring light generated at various points of the monitoring optical line in which the failure has occurred; Based on the intensity measured in step 2, the location where the failure occurred is identified. A second specific step, and for each of the plurality of monitoring optical lines, a connection destination of the monitoring optical line, an optical line from which the first monitoring light is transmitted, and the second monitoring light line It further includes a switching step of switching between the optical line through which the light is transmitted.

  According to the present invention, the same effect as the above optical line monitoring system can be obtained.

  Further, the optical line monitoring method according to the present invention is an optical line monitoring method for monitoring a plurality of optical lines, each of a plurality of monitoring optical lines each provided alongside each of the plurality of optical lines, The first monitoring light is sent to the monitoring optical line, and the intensity of the reflected light that is the first monitoring light reflected by the reflecting means provided at one end of the monitoring optical line is measured. And a first identifying step for identifying the faulty monitoring optical line based on the intensity measured in the first measuring step, and the faulty monitoring optical line. A second measuring step of transmitting the second monitoring light to measure the intensity of the backscattered light of the second monitoring light generated at various points of the monitoring optical line in which the failure has occurred; Based on the intensity measured in step 2, the location where the failure occurred is identified. Each of the plurality of monitoring optical lines includes a first optical line connected to an optical line from which the first monitoring light is transmitted, and the second monitoring light. An optical line monitoring method comprising: a second optical line connected to the optical line from which the light is transmitted.

  According to the present invention, the same effect as the above optical line monitoring system can be obtained.

  A test apparatus according to the present invention is a test apparatus used in the optical line monitoring system, and includes the first specifying means and the second specifying means.

  According to the present invention, the same effect as the above optical line monitoring system can be obtained.

  The program according to the present invention is a program for causing a computer to function as the test apparatus, and causes the computer to function as the means included in the test apparatus.

  According to the present invention, when the computer executes the program, the computer can achieve the same effects as the test apparatus.

  According to the present invention, an optical coupler is not necessary for inputting the monitoring light to the monitoring optical line, and only the monitoring optical line in which the failure has occurred performs the process for specifying the failure occurrence position. Thus, it is possible to realize an optical line monitoring system capable of detecting a failure of an optical line quickly and accurately.

1 is a diagram illustrating an overall configuration of an optical line monitoring system according to Embodiment 1. FIG. 1 is a block diagram showing a functional configuration of a test apparatus according to Embodiment 1. FIG. 4 is a flowchart illustrating a procedure of failure detection processing by the test apparatus according to the first embodiment. 6 is a graph illustrating an example of measurement data used for failure detection processing by the test apparatus according to the first embodiment. 5 shows an output example of failure information by the test apparatus according to the first embodiment. 6 is a flowchart illustrating a procedure of failure location identification processing by the test apparatus according to the first embodiment. In the optical-line monitoring system which concerns on Embodiment 1, the state of an optical fiber selector and an optical switch when a fault location specific process is performed is shown. 6 is a graph showing an example of measurement data used for failure location identification processing by the test apparatus according to the first embodiment. It is a figure which shows the whole structure of the optical line monitoring system which concerns on Embodiment 2. FIG. It is a figure which shows the whole structure of the optical-line monitoring system which concerns on Embodiment 3. FIG.

Embodiment 1
Hereinafter, embodiments according to the present invention will be described with reference to the drawings. First, Embodiment 1 of the optical line monitoring system according to the present invention will be described.

(Outline of optical line monitoring system)
First, an outline of the optical line monitoring system 10 according to the first embodiment will be described. FIG. 1 is a diagram illustrating an overall configuration of an optical line monitoring system 10 according to the first embodiment. As shown in FIG. 1, the optical line monitoring system 10 includes a test apparatus 100, a monitoring optical line 105, an OTDR 110, an optical fiber selector 115, an optical splitter 120, an optical switch 125, and a filter 130.

  The optical line monitoring system 10 monitors a section between any transmission devices in which at least one (one core) optical line 20 is laid as a section to be monitored (hereinafter referred to as a “monitoring section”). Is. The monitoring section can be a part of the optical line or can be the whole part of the optical line. In particular, the optical line monitoring system 10 can monitor each monitoring target section of a plurality of optical lines.

(Optical line)
The optical line 20 is incorporated in a communication network such as the Internet or CATV, and bears a transmission function of various data in such a communication network. In the optical line 20, signal light modulated by various data is transmitted. For this reason, an optical fiber is used as the optical line 20.

  In the optical line 20, signal light (hereinafter referred to as “downlink signal light”) can be transmitted from the transmission device 30 </ b> A to the transmission device 30 </ b> B. Conversely, it is also possible to transmit signal light (hereinafter referred to as “upstream signal light”) from the transmission device 30B to the transmission device 30A. That is, the optical line 20 can perform bidirectional communication.

  For example, signal light having a wavelength of 1490 nm is used as downlink signal light, and signal light having a wavelength of 1310 nm is used as uplink signal light. In this way, by making the wavelength different between the downstream signal light and the upstream signal light, it becomes possible to simultaneously transmit the downstream signal light and the upstream signal light through one optical line 20.

(Monitoring optical line 105)
The monitoring optical line 105 is provided in each of the plurality of optical lines in order to detect a failure in each optical line. In this embodiment, a single optical fiber is used for the monitoring optical line 105, and the optical line is arranged in parallel with the optical line 20. The monitoring optical line 105 may be juxtaposed in one optical fiber cable together with the optical line 20. Therefore, if there is one air core (so-called dark fiber) in the existing optical fiber cable, it can be used as the monitoring optical line 105. As described above, since the monitoring optical line 105 and the optical line 20 are arranged in parallel, if an abnormality occurs in the optical line 20, an abnormality also occurs in the monitoring optical line 105 arranged in parallel. Therefore, the abnormality of the optical line 20 can be detected by detecting the abnormality of the monitoring optical line 105.

(OTDR110)
The OTDR 110 is a so-called optical pulse tester that transmits the monitoring light to the optical line 20 and measures the intensity of the return light generated by the monitoring light being scattered or reflected on the optical line 20.

  The OTDR 110 includes a light source such as a laser diode, and outputs monitoring light emitted from the light source from an input / output port. As the monitoring light, light having a wavelength different from that of the signal light (downstream signal light and upstream signal light) can be used. In the present embodiment, pulsed light having a wavelength of 1650 nm is used as monitoring light. However, in this embodiment, since the monitoring optical line 105 for transmitting the monitoring light is an optical line different from the optical line 20 for transmitting the signal light, the signal light (downstream signal light and upstream) is used as the monitoring light. Signal light) and light having the same wavelength can also be used.

  The OTDR 110 includes a light receiving element such as a photodiode. The light receiving element receives the return light input from the input / output port and generates an electric signal having a value corresponding to the intensity. The OTDR 110 samples the electric signal to generate time series data indicating the intensity of the return light at each time, and outputs the time series data to the outside (test apparatus 100).

  In the optical line monitoring system 10, the monitoring light output from the OTDR 110 can be transmitted to each of the plurality of monitoring optical lines 105 as described below. In response to this, the OTDR 110 can measure the intensity of return light (that is, reflected light or backscattered light) generated in each of the plurality of monitoring optical lines 105.

  In FIG. 1, a connection line indicated by a thin solid line indicates the optical line 20, a connection line indicated by a thick solid line indicates a transmission path of the monitoring light, and a connection line indicated by an arrow indicates a control line. Indicates the signal transmission path.

  In practice, a relay device such as a termination box may be provided on the optical line 20 or the monitoring optical line 105.

(Optical splitter 120, optical fiber selector 115, optical switch 125)
In particular, in the optical line monitoring system 10, the monitoring light (first monitoring light) output from the OTDR 110 can be sent to each of the plurality of monitoring optical lines 105 via the optical splitter 120. It has become.

  Specifically, the monitoring light output from the OTDR 110 is sent to the optical splitter 120. The optical splitter 120 splits this monitoring light into multiple branches. One of the plurality of monitoring lights generated thereby is transmitted to the monitoring optical line 105 in the monitoring section A, and the other is transmitted to the monitoring optical line 105 in the monitoring section B.

  In the optical line monitoring system 10, the monitoring light (second monitoring light) output from the OTDR 110 is selectively transmitted to any of the monitoring optical lines 105 via the optical fiber selector 115. Is also possible.

  Specifically, the monitoring light output from the OTDR 110 is sent to the optical fiber selector 115. In the optical fiber selector 115, one of the monitoring optical lines 105 is selected as an output destination by external control. Thereby, the optical fiber selector 115 outputs the monitoring light output from the OTDR 110 to the selected monitoring optical line 105.

  That is, there are a case where the monitoring light is transmitted from the optical splitter 120 and a case where the monitoring light is transmitted from the optical fiber selector 115 to each monitoring optical line 105. The switching of the monitoring light input path is realized by the optical switch 125.

(Filter 130)
The filter 130 is provided at each end of the plurality of monitoring optical lines 105. The filter 130 is configured to cut and reflect the monitoring light transmitted from the monitoring optical line 105.

  In the present embodiment, the filter 130 is used as an example of a reflection unit that reflects monitoring light. In particular, a fiber Bragg grating (FBG) that cuts the monitoring light (1650 nm) and highly reflects the monitoring light (1650 nm) is used as the filter 130. However, the reflecting means is not limited to the filter 130 as long as it has a function similar to that of the filter 130. In this embodiment, since the monitoring optical line 105 through which the monitoring light is transmitted is an optical line different from the optical line 20 through which the signal light is transmitted, the function of transmitting the signal light as a reflecting means is provided. It is also possible to use a non-existing one (for example, a metal mirror).

  As described above, the monitoring light is transmitted toward the end of each of the plurality of monitoring optical lines 105. For this reason, in each of the plurality of monitoring optical lines 105, the reflected light of the monitoring light by the filter 130 is generated.

  Here, the optical path lengths from the optical splitter 120 to the end of each of the plurality of monitoring optical lines 105 (that is, up to the filter 130) are different from each other to the extent that they can be discriminated at least by the resolution of the OTDR 110. For example, the length of the optical path to the end of the monitoring optical line 105 may be at least about 30 cm to 1 m and different from each other in the plurality of monitoring optical lines 105.

(Measurement with OTDR110)
The OTDR 110 receives the return light of the monitoring light. Then, the OTDR 110 generates measurement data indicating the intensity of the received return light, and outputs this measurement data to the test apparatus 100.

  The OTDR 110 can measure the intensity of the return light of each of the plurality of monitoring optical lines 105. In the following description, this measurement process performed by the OTDR 110 is referred to as “first measurement process”.

  The OTDR 110 can measure the intensity of the return light of the monitoring optical line 105 in the optical line where the failure has occurred. In the following description, this measurement process performed by the OTDR 110 is referred to as “second measurement process”.

  In the first measurement process, the OTDR 110 transmits monitoring light to each of the plurality of monitoring optical lines 105. The OTDR 110 receives the return light from each of the plurality of monitoring optical lines 105. The return light of each of the plurality of monitoring optical lines 105 reaches the OTDR 110 via the optical splitter 120. For this reason, the return light of each of the plurality of monitoring optical lines 105 is multiplexed by the optical splitter 120. The OTDR 110 receives the combined return light, generates measurement data indicating the intensity, and outputs the measurement data to the test apparatus 100.

  On the other hand, in the second measurement process, the OTDR 110 transmits monitoring light to the monitoring optical line 105 in which a failure has occurred. The OTDR 110 receives the return light of the monitoring light from the monitoring optical line 105 in which the failure has occurred. The OTDR 110 generates measurement data indicating the intensity of the return light, and outputs the measurement data to the test apparatus 100.

  Conventionally, when measuring the intensity of the return light of the optical line using the OTDR 110, the processing method can be used not only for the backscattered light but also for the reflected light in consideration of temporal fluctuation of the light intensity of the backscattered light. The averaging process was performed using a plurality of measurement results without changing the above. However, the inventor has found that when the reflection intensity is sufficiently larger than the Fresnel reflection by the filter 130 or the like, the temporal variation in the reflection intensity is very small and it is not necessary to perform an averaging process. Therefore, in the first measurement process, the OTDR 110 transmits the monitoring light only once, measures the intensity of the return light of the monitoring light only once, and outputs measurement data indicating the measurement result.

  On the other hand, the detection of the failure occurrence point in the optical line is performed mainly based on the intensity of the backscattered light included in the return light of the optical line. For this reason, in the second measurement process, the OTDR 110 transmits the monitoring light a plurality of times to measure the intensity of the return light of the monitoring light a plurality of times, and uses the plurality of measurement results to perform a noise averaging process. It is preferable to generate measurement data in which noise fluctuations are averaged. Alternatively, it is preferable to cause the test apparatus 100 to generate measurement data in which noise fluctuations are averaged by outputting the plurality of measurement results to the test apparatus 100 and causing the test apparatus 100 to perform noise averaging processing. .

(Test apparatus 100)
The test apparatus 100 is an apparatus that tests the optical line 20 based on the time series data output from the OTDR 110. For example, a so-called computer device such as a PC or a server is used for the test apparatus 100.

  The test apparatus 100 is connected to the OTDR 110 and can communicate with the OTDR 110. By performing this communication, the test apparatus 100 can instruct the OTDR 110 to perform the above-described measurement or receive time-series data output from the OTDR 110.

  The test apparatus 100 performs a failure detection process for detecting a failure in the optical line 20 (determining whether or not there is a failure) and a failure point specifying process for specifying the occurrence point when a failure in the optical line 20 is detected. can do.

  For example, when the OTDR 110 performs the first measurement process, the test apparatus 100 performs the failure detection process based on the measurement data received from the OTDR 110.

  Specifically, in the received measurement data, a peak of reflected light intensity occurs at a time corresponding to the optical path length up to the filter 130 (that is, up to the end of the monitoring section). In particular, in the measurement data, since the reflected lights of the plurality of monitoring optical paths 105 are combined, a peak of the intensity of each of the plurality of reflected lights occurs.

  When a failure such as a transmission line break occurs in the section up to the filter 130, the intensity of the reflected light generated by the filter 130 is weakened, and naturally, the peak value of the intensity of the reflected light is also weakened in the measurement data. . That is, a time change occurs in the peak value of the intensity of the reflected light in the measurement data according to the occurrence of the failure.

  Therefore, the test apparatus 100 according to the present embodiment can detect a failure in each optical line by monitoring a temporal change in the peak value of the intensity of each reflected light in the measurement data.

  On the other hand, when the OTDR 110 performs the second measurement process, the test apparatus 100 performs the failure location specifying process based on the measurement data received from the OTDR 110.

  Specifically, if there is no failure in the monitoring optical line 105, reflected light is generated by the filter 130. Therefore, the measurement data is reflected at a time corresponding to the optical path length to the filter 130. A light intensity peak occurs.

  However, if a failure occurs in the monitoring optical line 105, an abnormal phenomenon such as reflection occurs at the position where the failure occurs. Therefore, the measurement data includes the optical path length to the position where the failure occurs. An abnormal characteristic such as a reflection peak occurs at the corresponding time.

  Therefore, the test apparatus 100 according to the present embodiment can detect the failure position in the optical line based on the occurrence time of the abnormal characteristic in the measurement data.

  As described above, the test apparatus 100 can identify the optical line where the failure has occurred. In the following description, this specific processing by the test apparatus 100 is referred to as “failure detection processing”.

  In addition, the test apparatus 100 can identify the position where the failure occurs in the optical line where the failure has occurred. In the following description, this specifying process by the test apparatus 100 is referred to as “failure location specifying process”.

  Note that the test apparatus 100 is connected to an output device such as a display or a speaker. Thereby, when detecting a failure in the optical line 20, the test apparatus 100 can notify the user of this failure. Thereby, when detecting a failure in the optical line 20, the test apparatus 100 can notify the user of this failure.

  Next, the functional configuration of the test apparatus 100 according to the present embodiment will be described with reference to FIG. FIG. 2 is a block diagram illustrating a functional configuration of the test apparatus 100 according to the first embodiment. The test apparatus 100 includes a control unit 210, a measurement data acquisition unit 212, a reference data registration unit 214, a storage unit 216, a failure detection unit 230, and a notification unit 220.

(Control unit 210)
The control unit 210 controls each unit of the test apparatus 100 and controls the OTDR 110 through communication with the OTDR 110. For example, the control unit 210 transmits a control signal instructing execution of measurement to the OTDR 110.

  Further, the control unit 210 can switch the output destination of the optical fiber selector 115 to an arbitrary output destination by transmitting a control signal to the optical fiber selector 115.

  Further, the control unit 210 can switch the connection destination of the optical switch 125 by transmitting a control signal to an arbitrary optical switch 125.

(Measurement data acquisition unit 212)
The measurement data acquisition unit 212 acquires time-series data output from the OTDR 110 in the initial setting process, the failure detection process, and the failure location specifying process. This time-series data is hereinafter referred to as “measurement data”. Further, it is assumed that one measurement data includes a time series of the intensity of the return light generated by one pulse constituting the monitoring light.

(Reference data registration unit 214)
In the initial setting process, the reference data registration unit 214 uses the measurement data acquired by the measurement data acquisition unit 212 to specify the times tA and tB when the reflection peak occurs and the intensity hA and hB of the reflection peak. Then, the specified times tA and tB and the strengths hA and hB are stored in the storage unit 216 as reference data. Note that the times tA and tB at which the reflection peaks specified by the reference data registration unit 214 occur are hereinafter also referred to as “measurement points”.

  In this embodiment, as a method for specifying the times tA and tB when the reflection peak occurs and the intensities hA and hB of the reflection peak, the measurement data is displayed on the display as a waveform, and the times tA and tB and the intensities hA and hB and the user are displayed. Adopt the method of letting you specify. However, a method of automatically specifying the times tA and tB when the reflection peak occurs and the intensity hA and hB of the reflection peak from the measurement data using a known peak detection algorithm or the like may be employed.

(Fault detection unit 230)
The failure detection unit 230 includes a first specifying unit 232 and a second specifying unit 234.

  In the failure detection process, the first specifying unit 232 uses the values hA ′ and hB ′ of the measurement data acquired by the measurement data acquisition unit 212 at the times tA and tB as the reference data, and the intensity of the reflection peak stored in the storage unit 216. By comparing with hA and hB, the presence or absence of a failure in the optical line 20 is determined.

  In the fault location specifying process, the second specifying unit 234 specifies the fault location in the optical line 20 based on the time of abnormal characteristics such as a reflection peak in the measurement data acquired by the measurement data acquisition unit 212.

(Notification unit 220)
The notification unit 220 notifies the user that a failure has occurred in the optical line 20 by outputting failure information regarding the failure detected by the failure detection unit 230 in the failure detection process. For example, the notification unit 220 displays this failure information on the display. Further, the notification unit 220 can emit a warning sound from a speaker or transmit failure information to a predetermined terminal by e-mail or the like.

  Next, with reference to FIG. 3, the procedure of the initial setting process and the failure detection process by the test apparatus 100 will be described. FIG. 3 is a flowchart showing a procedure of initial setting processing and failure detection processing by the test apparatus 100.

(Initial setting process)
First, the control unit 210 instructs the OTDR 110 to perform measurement (step S302). In accordance with this instruction, the OTDR 110 performs transmission of monitoring light and measurement of return light, and outputs measurement data indicating the measurement result to the test apparatus 100. Then, the measurement data acquisition unit 212 acquires the measurement data output from the OTDR 110 (Step S304).

  The measurement data acquisition unit 212 passes the acquired measurement data to the reference data registration unit 214. The reference data registration unit 214 displays the measurement data as a waveform on the display (step S305), and allows the user to specify the times tA and tB when the reflection peak occurs and the reflection peak intensities hA and hB. When the times tA and tB and the strengths hA and hB are designated by the user, the reference data registration unit 214 stores the times tA and tB and the strengths hA and hB designated by the user in the storage unit 216 as reference data. (Hereinafter referred to as “registration”) (step S306).

(Fault detection processing)
When the initial setting process is completed, the test apparatus 100 instructs the OTDR 110 to perform measurement (step S308). In accordance with this instruction, the OTDR 110 repeatedly transmits monitoring light and measures return light, and sequentially outputs measurement data obtained by each measurement to the test apparatus 100. The failure detection process is realized by repeatedly executing the following steps.

  First, the measurement data acquisition unit 212 acquires measurement data output from the OTDR 110 (step S310). The measurement data acquisition unit 212 passes the acquired measurement data to the failure detection unit 230.

  The failure detection unit 230 extracts the values hA 'and hB' at the times tA and tB registered in step S306 from the measurement data acquired in step S310. Then, the extracted value hA ′ is compared with the intensity hA registered in step S306 (step S312), and it is determined whether or not the difference hA−hA ′ is equal to or larger than a predetermined threshold Th (step S314). . Similarly, the extracted value hB ′ is compared with hB registered in step S306 (step S312), and it is determined whether or not the difference hB−hB ′ is equal to or greater than a predetermined threshold Th (step S314).

  If it is determined in step S314 that the difference hA−hA ′ is greater than or equal to the threshold Th, the test apparatus 100 uses the time tA (measurement point) and the difference hA−hA ′ (level change amount) as fault information on the display. Display (step S315), and the process proceeds to step S316. Similarly, when it is determined in step S314 that the difference hB−hB ′ is greater than or equal to the threshold Th, the test apparatus 100 displays the time tB and the difference hB−hB ′ on the display as failure information (step S315). Then, the process proceeds to step S316. On the other hand, when it is determined in step S314 that the difference hA−hA ′ is less than the threshold value Th and the difference hB−hB ′ is less than the threshold value Th (step S314: No), the test apparatus 100 performs step S310. Return processing to.

  In step S316, the measurement data acquisition unit 212 acquires new measurement data output from the OTDR 110. The measurement data acquisition unit 212 passes the acquired new measurement data to the failure detection unit 230. The failure detection unit 214 determines whether there is a failure in the optical line 20 based on the new measurement data (steps S318 and S320).

  The comparison in step S318 and the determination in step S320 are the same as the comparison in step 312 and the determination in step 314, respectively. However, if it is determined in step 314 that only the difference hA−hA ′ is greater than or equal to the threshold Th, the determination in step 320 may be performed only for the difference hA−hA ′. Similarly, when it is determined in step 314 that only the difference hB−hB ′ is greater than or equal to the threshold Th, the determination in step 320 may be performed only for the difference hB−hB ′.

  When it is determined in step S314 that the difference hA−hA ′ is greater than or equal to the threshold Th (failure occurrence), and in step S320, it is determined that the difference hA−hA ′ is less than the threshold Th (failure recovery), the test apparatus 100 displays the time from failure occurrence to failure recovery on the display as failure information in addition to the time tA (measurement point) and the difference hA−hA ′ (level change amount) (step S328), and the process proceeds to step 310. return. Similarly, if it is determined in step S314 that the difference hB−hB ′ is greater than or equal to the threshold Th, and it is determined in step S320 that the difference hB−hB ′ is less than the threshold Th, the test apparatus 100 determines that the time tB In addition to the difference hB−hB ′, the time from failure occurrence to failure recovery is displayed on the display as failure information (step S328), and the process returns to step S310.

(Example of measurement data)
Next, an example of measurement data will be described with reference to FIG. FIG. 4 is a graph showing an example of measurement data output from the OTDR 110. In FIG. 4, the horizontal axis represents time (elapsed time since the monitoring light was transmitted), and the vertical axis represents the intensity of the return light.

  In FIG. 4, measurement data 402 indicated by a dotted line is an example of normal measurement data obtained in the initial setting process, and measurement data 404 indicated by a solid line is an example of abnormal measurement data obtained in the fault detection process. It is an example.

  Here, since the return lights of the plurality of monitoring optical paths 105 are combined by the optical splitter 120, each measurement data indicates the intensity of the combined return lights. However, in the optical line monitoring system 10, since the optical path lengths of the respective monitoring optical lines 105 are made different, the peak of the reflected light appears at different times in each measurement data.

  For example, in the example illustrated in FIG. 4, the measurement data 402 and 404 are generated in the monitoring optical path 105 in the monitoring section A at time tA corresponding to the optical path length of the monitoring optical path 105 in the monitoring section A. A peak of reflected light appears, and a peak of reflected light that appears in the monitoring optical line 105 in the monitoring section B appears at time tB according to the optical path length of the monitoring optical line 105 in the monitoring section B.

  As already described, the test apparatus 100 uses the reflection peak intensities hA and hB in the measurement data 402 obtained in the initial setting process and the values hA ′, tA and tB of the measurement data 404 obtained in the fault detection process. A failure in the optical line 20 is detected by comparing with hB ′.

  In the example shown in FIG. 4, the value hA ′ at the time tA of the measurement data 404 is substantially the same as the reflection peak intensity hA in the measurement data 402. From this, the test apparatus 100 can determine that “no failure has occurred” in the optical line 20 in the monitoring section A.

  On the other hand, in the example shown in FIG. 4, the value hB ′ at the time tB of the measurement data 404 is smaller than the intensity hB of the reflection peak in the measurement data 402. When the difference between the two is d = hB−hB ′ and the predetermined threshold Th is 1 dB, the test apparatus 100 determines that a failure has occurred in the optical line 20 in the monitoring section B when the difference d is 1 dB or more. It can be determined.

  As described above, the failure detection process in the optical line monitoring system 10 compares the intensity hA ′, hB ′ of the return light at the preset times tA, tB with the intensity hA, hB of the preset reflection peak. It is realized by. At this time, the intensities hA 'and hB' of the return light at times tA and tB are specified from one measurement data as described above. For this reason, each failure detection process is completed in a very short time. Thereby, since the failure detection process can be repeatedly executed at short intervals, it becomes possible to realize real-time monitoring of the optical line 20.

  Furthermore, as described above, the intensities hA 'and hB' of the return light at the times tA and tB do not change with each measurement. Therefore, each fault detection process is accurate despite being completed in a very short time.

(Example of failure information output)
FIG. 5 shows an example of failure information output by the test apparatus 100. A screen 500 illustrated in FIG. 5 is a screen displayed on a display connected to the test apparatus 100, and is a screen for notifying the user of a failure in the optical path. This screen 500 is provided with a measurement data display column 510 and a failure information notification column 520.

  In the measurement data display column 510, the measurement data acquired in the initial setting process and the measurement data acquired in the failure detection process are displayed as waveforms. Here, the measurement data acquired in the failure detection process is updated sequentially (for example, every time the test apparatus 100 acquires the measurement data). In the failure information notification column 520, failure information generated in the failure detection process is displayed. Here, the failure information is added each time a new failure is detected. With this screen 500, the user can grasp in real time the occurrence of a failure in the optical line 20.

  In the example shown in FIG. 5, the measurement data acquired in the initial setting process is displayed with a dotted line, and the measurement data acquired in the failure detection process is displayed with a solid line, but these are displayed in different colors. Also good. Thereby, the user can grasp | ascertain visually visually the fall degree of each reflection peak easily.

  In the example shown in FIG. 5, the measurement data display field 510 is provided with a reduced display field 512 and an enlarged display field 514. In the reduced display column 512, measurement data in a wide area (2 km area) is reduced and displayed, and in the enlarged display field 514, measurement data in a narrow area (13 m area) is enlarged and displayed. The user can grasp the general condition of the optical line 20 from the reduced display column 512 and can grasp the degree of reduction of each reflection peak from the enlarged display column 514. Further, the user can freely move the area to be displayed in the enlarged display field 515 by operating an input device such as a mouse or a keyboard.

  In the example illustrated in FIG. 5, the failure information notification column 520 includes, as failure information, the date when the failure was detected (“Alarm Date”) and the reflection having a reduced intensity among the times tA and tB at which reflection peaks occur. The time corresponding to the peak is converted to a distance (“Alarm Distance (m)”), and a message (“Message”) indicating the content of the failure is shown. In the failure information notification column 520, such failure information is added line by line every time a failure occurs. In addition, the message includes the time from the occurrence of the failure to the failure recovery (for example, “2739 ms” in the first line). Thereby, the user can estimate the failure reason. For example, if the time from failure occurrence to failure recovery is a few seconds, it is assumed that there has been a temporary insertion / removal of the optical connector, and if it is less than 1 second, it is assumed that there has been a temporary overbending of the fiber. Can do.

  In the example shown in FIG. 5, the optical path length is used as the fault information as the fault information in the fault information. Of course, the name of the fault position, the optical path identification information, etc. It is also possible to use information that makes it easy to specify the location of failure.

  When the test apparatus 100 detects a fault in the optical line 20, in addition to displaying such fault information, the test apparatus 100 emits an alert sound from the speaker, or sends such fault information to various communication lines (Internet line, telephone line, It is possible to transmit to other terminal devices via a dedicated line or the like.

(Fault location identification process)
Next, with reference to FIG. 6, the procedure of the fault location specifying process by the test apparatus 100 will be described. FIG. 6 is a flowchart showing a procedure of failure location identification processing by the test apparatus 100.

  First, the control unit 210 switches the output destination of the optical fiber selector 115 to the monitoring optical line 105 of the optical line identified as having failed in the failure detection process (step S602). Further, the control unit 210 switches the input of the optical switch 125 connected to the monitoring optical line 105 from the optical splitter 120 to the optical fiber selector 115 (step S604).

  Next, the control unit 210 instructs the OTDR 110 to perform the second measurement process (step S606). In accordance with this instruction, the OTDR 110 performs the second measurement process and outputs measurement data indicating the measurement result. In response to this, the measurement data acquisition unit 212 acquires the measurement data output from the OTDR 110 (step S608).

  At this time, it is preferable that the OTDR 110 repeats the second measurement process and outputs measurement data obtained in each measurement. In this case, the measurement data acquisition unit 212 acquires measurement data obtained from each measurement from the OTDR 110, and generates average measurement data obtained by averaging these measurement data.

  The fault detection unit 230 identifies the fault occurrence position in the optical line where the fault has occurred based on the time of the abnormal characteristic such as the reflection peak in the measurement data acquired in step S310 (step S610).

  When the OTDR 110 repeatedly performs the second measurement process in response to the instruction from the control unit 210 in step S606, the failure detection unit 230 causes an abnormality such as a reflection peak in the average measurement data generated by the measurement data acquisition unit 212. It is preferable to specify the position of the failure in the optical line where the failure has occurred based on the characteristic time.

  Furthermore, the test apparatus 100 determines whether or not the failure occurrence position has been identified in step S610 (step S612).

  If it is determined in step S612 that “the location where the failure has occurred can be identified” (step S612: Yes), the notification unit 220 outputs the failure information (step S614), and the test apparatus 100 identifies the failure location. End the process.

  On the other hand, when it is determined in step S612 that “the failure occurrence position could not be identified” (step S612: No), the notification unit 220 outputs a message indicating that the failure occurrence position could not be identified. (Step S616), the test apparatus 100 ends the failure location specifying process.

  FIG. 7 shows the states of the optical fiber selector 115 and the optical switch 125 when the fault location specifying process is performed in the optical line monitoring system 10 according to the first embodiment. In this example, it is specified by the failure detection process that a failure has occurred in the optical line 20 in the monitoring section B.

  For this reason, in the optical line monitoring system 10 in the state shown in FIG. 7 (state when the failure location specifying process is performed), the optical fiber is changed from the state shown in FIG. 1 (state when the failure detection process is performed). The output destination of the selector 115 is switched to the monitoring optical line 105 in the monitoring section B. The input of the optical switch 125 connected to the monitoring optical line 105 is switched from the optical splitter 120 to the optical fiber selector 115.

  As a result, in the optical line monitoring system 10, in the state shown in FIG. 1, the monitoring light (first monitoring light) output from the OTDR 110 passes through the optical fiber selector 115 and the optical splitter 120 for each monitoring. Although transmitted to the optical line 105, in the state shown in FIG. 7, the monitoring light (second monitoring light) output from the OTDR 110 is monitored in the monitoring section B via the optical fiber selector 115 and the optical switch 125. It will be transmitted only to the optical line 105 for work.

(Example of measurement data)
Next, an example of measurement data will be described with reference to FIG. FIG. 8 is a graph showing an example of measurement data output from the OTDR 110. In FIG. 8, the horizontal axis represents time (elapsed time since the monitoring light was transmitted), and the vertical axis represents the intensity of the return light.

  In FIG. 8, measurement data 802 indicated by a solid line is an example of normal measurement data obtained in the fault location specifying process, and measurement data 804 indicated by a dotted line is an abnormal measurement obtained in the fault location specifying process. It is an example of data.

  In FIG. 8, measurement data 802 indicated by a solid line indicates measurement data obtained when no failure occurs in the monitoring optical line 105, and measurement data 804 indicated by a dotted line indicates this monitoring optical line. Measurement data obtained when a failure occurs at 105 is shown.

  When there is no failure in the monitoring optical line 105, most of the monitoring light is reflected at the end of the monitoring optical line 105. Therefore, in the measurement data, the peak of the reflected light from the monitoring optical line 105 is It appears at a time corresponding to the optical path length to the end of the monitoring optical line 105.

  When a failure occurs in the monitoring optical line 105, most of the monitoring light is reflected or lost at the position of the failure. Therefore, in the measurement data, the abnormal characteristic of the return light from the monitoring optical line 105 is It will appear at a time corresponding to the optical path length to the obstacle position.

  For example, in the example shown in FIG. 8, when no failure occurs in the monitoring optical line 105, the peak of the reflected light from the monitoring optical line 105 in the measurement data 802 is the end of the monitoring optical line 105. It appears at time t2 according to the optical path length until.

  On the other hand, when a failure occurs in the monitoring optical line 105, in the measurement data 804, the peak of the reflected light from the monitoring optical line 105 appears at time t1 according to the optical path length to the failure position. Yes.

  The test apparatus 100 can easily determine the failure position based on the time from the time when the monitoring light is transmitted to the time when the peak of the reflected light occurs and the propagation speed (that is, the speed of light) of the monitoring light.

  When a failure occurs in the monitoring optical line 105, in the measurement data, the time corresponding to the optical path length to the failure position is not limited to the reflection peak, and other abnormal changes (for example, sudden drop) occur. In some cases. By storing the waveform pattern of each abnormal change in advance, the test apparatus 100 recognizes this as an obstacle even when an abnormal change in the intensity of the return light appears in the measurement data. The failure position can be obtained based on the occurrence time. In the example shown in FIG. 8, in each measurement data, the reflection peak 812 and the reflection peak 814 occur at a time earlier than the time t2, and the reflection peak 812 is due to the connector reflection of the optical fiber selector 115. The reflection peak 814 is due to connector reflection of a termination box (not shown) provided on the monitoring light transmission path. Therefore, the reflection peak 812 and the reflection peak 814 always appear in the measurement data regardless of whether or not a failure has occurred. However, the test apparatus 100 may use these waveform patterns, their occurrence times, or measurement data 802. And the like are stored in advance, so that they are not erroneously recognized as a failure occurrence location.

  As described above, the optical line monitoring system 10 according to the present embodiment performs the process for specifying the optical line in which the failure has occurred at the same time on the plurality of optical lines, and the optical line in which the failure is specified as a result. Therefore, since the process for specifying the position where the failure occurs is performed, the optical line and the position where the failure occurred can be specified in a short time.

  Further, according to the optical line monitoring system 10 of the present embodiment, since the optical line dedicated for monitoring (monitoring optical line) is used, the optical line can be monitored without affecting the communication optical line. it can.

  In particular, according to the optical line monitoring system 10 of the present embodiment, when the monitoring light is input to the monitoring optical line, there is no insertion loss due to the optical coupler. Therefore, the conventional monitoring light is input using the optical coupler. Compared with the configuration, the utilization efficiency of the monitoring light can be increased.

  Further, the optical line monitoring system 10 according to the present embodiment can detect a failure by a simple process of comparing the peak value of each reflected light with the reference data, so that the time required for one process can be shortened. Can be As a result, a plurality of measurements can be continuously performed at short intervals, so that real-time monitoring of a plurality of optical lines can be realized.

  In the optical line monitoring system 10 according to the present embodiment, since the optical path lengths to the end of the monitoring section (that is, the filter 130) are different from each other in the plurality of optical lines, the above peaks are obtained at different times. This makes it possible to easily determine the failure of each optical line.

  Further, the optical line monitoring system 10 of the present embodiment performs the failure determination based on the reflected light of the monitoring light generated by the filter 130 whose intensity hardly changes at every measurement, so that the higher accuracy can be obtained. Judgment can be made.

[Embodiment 2]
Hereinafter, a second embodiment of the optical line monitoring system according to the present invention will be described. In the second embodiment, an example in which a plurality of optical lines are monitored by an optical line monitoring system 12 having a configuration different from that of the optical line monitoring system 10 (first embodiment) will be described.

  In the optical line monitoring system 12 described in the second embodiment, points other than those described below are the same as those of the optical line monitoring system 10 described so far, and thus description thereof is omitted. Hereinafter, differences from the optical line monitoring system 10 described so far will be described.

  FIG. 9 is a diagram illustrating an overall configuration of the optical line monitoring system 12 according to the second embodiment.

  The optical line monitoring system 10 according to the first embodiment has a configuration including one OTDR 110 as shown in FIG. In contrast, the optical line monitoring system 12 according to the second embodiment has a configuration including two OTDRs 110 (OTDR 110A and OTDR 110B) as shown in FIG.

  In the second embodiment, the OTDR 110B performs a first measurement process, and the OTDR 110A performs a second measurement process.

  That is, the OTDR 110B functions as a first measuring unit by transmitting monitoring light (first monitoring light) to all optical lines and measuring the intensity of the return light.

  On the other hand, the OTDR 110A functions as a second measuring unit by sending monitoring light (second monitoring light) to the optical line where the failure has occurred and measuring the intensity of the return light.

  In response to this, the control unit 210 of the test apparatus 100 instructs the OTDR 110B to perform the first measurement process when performing the failure detection process. Naturally, the measurement data acquisition unit 212 of the test apparatus 100 acquires measurement data indicating the measurement result of the first measurement process from the OTDR 110B.

  Further, when the failure location specifying process is performed, the OTDR 110A is instructed to perform the second measurement process. Naturally, the measurement data acquisition unit 212 of the test apparatus 100 acquires measurement data indicating the measurement result of the second measurement process from the OTDR 110A.

  In the second embodiment, since the two OTDRs 110 perform the measurement process independently, for example, even when the OTDR 110A is performing the second measurement process, the OTDR 110B performs the next first measurement process. Can start. In particular, since the input of each of the plurality of monitoring optical lines 105 can be individually switched by the optical switch 125, for example, when the OTDR 110B performs the next first measurement process, the second measurement process ends. It is possible to prevent the monitoring light from being sent to the monitoring optical line 105 that has not been provided.

[Embodiment 3]
Hereinafter, Embodiment 3 of the optical line monitoring system according to the present invention will be described. In the third embodiment, an example in which a plurality of optical lines are monitored by an optical line monitoring system 14 having a different configuration from the optical line monitoring system 10 (first embodiment) and the optical line monitoring system 12 (second embodiment) will be described.

  Since the optical line monitoring system 14 described in the third embodiment is the same as the optical line monitoring system 10 described in the first embodiment except for the points described below, the description thereof is omitted. Hereinafter, differences from the optical line monitoring system 10 described in the first embodiment will be described.

  FIG. 10 is a diagram illustrating an overall configuration of the optical line monitoring system 14 according to the third embodiment.

  In the optical line monitoring system 10 of the first embodiment, as shown in FIG. 1, one monitoring optical line 105 is composed of one (one core) optical line. On the other hand, in the optical line monitoring system 14 of the third embodiment, as shown in FIG. 10, one monitoring optical line 105 includes two (two-core) optical lines (optical line 105a (first optical line). ) And an optical line 105b (second optical line)).

  Of the two optical lines, the optical line 105b is used for the first measurement process, and the optical line 105a is used for the second measurement process. Accordingly, each optical line 105b of the plurality of monitoring optical lines 105 is connected to the optical splitter 120, and each optical line 105a of the plurality of monitoring optical lines 105 is connected to the optical fiber selector 115. Has been. In the present embodiment, in the monitoring optical line 105, a filter 130 is provided toward each optical line 105b.

  Therefore, when the OTDR 110 performs the first measurement process, the monitoring light output from the OTDR 110 is transmitted to each optical line 105b via the optical splitter 120, and the OTDR 110 transmits the return light of the monitoring light from each optical line 105b. It will be received via the optical splitter 120.

  When the OTDR 110 performs the second measurement process, the monitoring light output from the OTDR 110 is transmitted to the optical line 105a of the optical line where the failure has occurred via the optical fiber selector 115, and the OTDR 110 The backscattered light of the monitoring light is received from the optical line 105a via the optical fiber selector 115.

  In the third embodiment, since the dedicated optical line is provided for each of the first measurement process and the second measurement process, it is not necessary to provide the optical switch 125. Thereby, the insertion loss of the optical switch 125 does not occur. Of course, the test apparatus 100 does not need to perform switching control of the optical switch 125. In many cases, an existing optical fiber cable has a plurality of air core wires instead of one. Therefore, when two optical fibers can be used as the monitoring optical line 105, the configuration of the third embodiment that does not require the optical switch 125 is effective.

  In the third embodiment, as in the second embodiment, a dedicated OTDR 110 may be provided for each of the first measurement process and the second measurement process. In this case, the first measurement process and the second measurement process can be performed in parallel by the two OTDRs 110.

(Program, storage medium)
Each function of the test apparatus 100 described in the above embodiments may be realized by hardware by a logic circuit formed on an integrated circuit (IC chip), or software using a CPU (Central Processing Unit). May be realized.

  For example, the test apparatus 100 includes a CPU that executes instructions of a program that realizes each function, a ROM that stores the program, a RAM that expands the program, and various storage devices (recording media) that store the program and various data. I have. Each function of the test apparatus 100 can be realized by the CPU reading out the programs stored in the various storage devices and executing the programs.

  Examples of the recording medium include tapes such as magnetic tapes and cassette tapes, magnetic disks such as floppy (registered trademark) disks / hard disks, and disks including optical disks such as CD-ROM / MO / MD / DVD / CD-R. IC cards (including memory cards) / optical cards, semiconductor memories such as mask ROM / EPROM / EEPROM / flash ROM, PLD (Programmable logic device), FPGA (Field Programmable Gate Array), etc. Logic circuits or the like can be used.

  Note that the program may be supplied to the test apparatus 100 via a communication network. The communication network only needs to be able to transmit at least the program to the test apparatus 100, and any type of communication network may be used. For example, the Internet, intranet, extranet, LAN, ISDN, VAN, CATV communication network, virtual private network, telephone line network, mobile communication network, satellite communication network, etc. can be used as the communication network. is there.

  Further, any kind of transmission medium for supplying the program to the test apparatus 100 may be used. For example, a wired medium such as IEEE1394, USB, power line carrier, cable TV line, telephone line, ADSL (Asymmetric Digital Subscriber Line) line may be used as the transmission medium. As transmission media, infrared rays such as IrDA and remote control, Bluetooth (registered trademark), IEEE80211 wireless, HDR (High Data Rate), NFC (Near Field Communication), DLNA, cellular phone network, satellite line, terrestrial digital network You may use the thing by radio | wireless.

(Supplementary information)
The embodiments according to the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  For example, in the embodiment, the OTDR 110 and the test apparatus 100 use different apparatuses, but instead, for example, the OTDR 110 having the function of the test apparatus 100 may be used. In this case, for example, in the embodiment in which two OTDRs 110 are provided, the first measurement process can be performed by one OTDR 110 and the second measurement process can be performed by the other OTDR 110 in parallel with this. .

  In each embodiment, an example in which two optical lines (monitoring sections) are monitored has been described. However, three or more optical lines (monitoring sections) can be monitored. When three or more optical lines (monitoring sections) are monitored, the monitoring optical path 105 may be provided for each optical line (monitoring section) as in the embodiments.

  The present invention can be suitably used as an optical line monitoring system related to an optical line incorporated in a communication network such as the Internet or a CATV system.

DESCRIPTION OF SYMBOLS 10 Optical line monitoring system 12 Optical line monitoring system 14 Optical line monitoring system 20 Optical line 100 Test apparatus 105 Monitoring optical line 110 OTDR (1st, 2nd measuring means)
115 Optical fiber selector 120 Optical splitter 125 Optical switch 130 Filter (reflection means)
210 Control unit 212 Measurement data acquisition unit 214 Reference data registration unit (reference data registration means)
216 Storage unit 220 Notification unit (notification means)
230 failure detection unit 232 first identification unit (first identification unit)
234 2nd specific part (2nd specific means)

Claims (10)

An optical line monitoring system for monitoring a plurality of optical lines,
A plurality of monitoring optical lines, each of which is attached to each of the plurality of optical lines;
Reflecting means provided at one end of each of the plurality of monitoring optical lines;
For each of the plurality of monitoring optical lines, the first monitoring light is transmitted to the monitoring optical line, and the intensity of the reflected light that is the first monitoring light reflected by the reflecting means is measured. First measuring means;
First identifying means for identifying a faulty monitoring optical line based on the intensity measured by the first measuring means;
Second monitoring light is transmitted to the monitoring optical line in which the failure has occurred, and the intensity of backscattered light of the second monitoring light that has occurred in various places on the monitoring optical line in which the failure has occurred is measured. Second measuring means to perform,
Based on the intensity measured by the second measuring means, the second specifying means for specifying the position where the failure occurred, and
For each of the plurality of monitoring optical lines, the connection destination of the monitoring optical line is an optical line from which the first monitoring light is transmitted, and an optical line from which the second monitoring light is transmitted. An optical line monitoring system characterized by further comprising an optical switch to be switched at. An optical line monitoring system for monitoring a plurality of optical lines,
A plurality of monitoring optical lines, each of which is attached to each of the plurality of optical lines;
Reflecting means provided at one end of each of the plurality of monitoring optical lines;
For each of the plurality of monitoring optical lines, the first monitoring light is transmitted to the monitoring optical line, and the intensity of the reflected light that is the first monitoring light reflected by the reflecting means is measured. First measuring means;
First identifying means for identifying a faulty monitoring optical line based on the intensity measured by the first measuring means;
Second monitoring light is transmitted to the monitoring optical line in which the failure has occurred, and the intensity of backscattered light of the second monitoring light that has occurred in various places on the monitoring optical line in which the failure has occurred is measured. Second measuring means to perform,
Based on the intensity measured by the second measuring means, the second specifying means for specifying the position where the failure occurred, and
Each of the plurality of monitoring optical lines is connected to a first optical line connected to the optical line from which the first monitoring light is transmitted, and to an optical line from which the second monitoring light is transmitted. An optical line monitoring system comprising: the second optical line. The first specifying means includes:
Based on the intensity obtained by one measurement by the first measuring means, the faulty monitoring optical line is identified,
The second specifying means includes:
The optical line according to claim 1 or 2, wherein a position where a fault has occurred is specified based on the intensity obtained by averaging a plurality of measurement results obtained by the second measuring means. Monitoring system. The first measuring means is provided in a first measuring device,
The second measuring means is provided in a second measuring device,
4. The light beam according to claim 1, wherein the measurement process by the first measurement unit and the measurement process by the second measurement unit can be performed in parallel with each other. 5. Road monitoring system. Reference data registration means for registering the intensity measured by the first measurement means as reference data,
The first specifying means includes:
By comparing the intensity measured by the first measuring means after registration by the reference data registering means with the intensity registered as the reference data, a monitoring beam in which a failure has occurred The optical path monitoring system according to any one of claims 1 to 4, wherein a path is specified. A notification means for notifying the user of the failure specified by the specifying means;
The notification means is
6. The optical line monitoring system according to claim 1, wherein a period from when the failure is detected to when the failure is not detected is notified to the user as failure information. 6. An optical line monitoring method for monitoring a plurality of optical lines,
For each of the plurality of monitoring optical lines that are provided alongside each of the plurality of optical lines, the first monitoring light is transmitted to the monitoring optical line, and is provided at one end of the monitoring optical line. A first measuring step of measuring the intensity of the reflected light that is the first monitoring light reflected by the reflecting means;
Based on the intensity measured in the first measurement step, a first identification step for identifying a monitoring optical line in which a failure has occurred;
Second monitoring light is transmitted to the monitoring optical line in which the failure has occurred, and the intensity of backscattered light of the second monitoring light that has occurred in various places on the monitoring optical line in which the failure has occurred is measured. A second measuring step,
A second specifying step of specifying a position where a failure has occurred based on the intensity measured in the second measuring step;
For each of the plurality of monitoring optical lines, the connection destination of the monitoring optical line is an optical line from which the first monitoring light is transmitted, and an optical line from which the second monitoring light is transmitted. The optical line monitoring method characterized by further including the switching process switched by. An optical line monitoring method for monitoring a plurality of optical lines,
For each of the plurality of monitoring optical lines that are provided alongside each of the plurality of optical lines, the first monitoring light is transmitted to the monitoring optical line, and is provided at one end of the monitoring optical line. A first measuring step of measuring the intensity of the reflected light that is the first monitoring light reflected by the reflecting means;
Based on the intensity measured in the first measurement step, a first identification step for identifying a monitoring optical line in which a failure has occurred;
Second monitoring light is transmitted to the monitoring optical line in which the failure has occurred, and the intensity of backscattered light of the second monitoring light that has occurred in various places on the monitoring optical line in which the failure has occurred is measured. A second measuring step,
A second specifying step of specifying a position where a failure has occurred based on the intensity measured in the second measuring step;
Each of the plurality of monitoring optical lines is connected to a first optical line connected to the optical line from which the first monitoring light is transmitted, and to an optical line from which the second monitoring light is transmitted. And a second optical line. An optical line monitoring method comprising: A test apparatus used in the optical line monitoring system according to claim 1 or 2,
A test apparatus comprising: the first specifying unit and the second specifying unit.   A program for causing a computer to function as the test apparatus according to claim 9, wherein the program causes the computer to function as each unit included in the test apparatus.

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