TWI422173B - Optical transmission monitoring device - Google Patents

Description

Optical transmission monitoring device

The present invention relates to a method of propagating a pulse test light on an optical fiber transmission path provided between a first station and a second station, and monitoring the first station based on the rear side scattered light generated when the pulse test light propagates. A device for transmitting light between stations 2.

The optical fiber transmission system transmits and receives signal light via an optical fiber transmission path provided between the first station (for example, a base station) and the second station (for example, a user's home). Among them, a system in which a first station and a plurality of second stations are connected via a splitter via a fiber transmission path is called a PON (Passive Optical Network) system. In such an optical fiber transmission system, it is important to monitor the state of the optical fiber transmission path, and it is also important to monitor the signal transmission equipment installed in each of the first station and the second station.

Patent Document 1 discloses an invention intended to determine the cause of occurrence of some transmission abnormality in a fiber delivery system. In the invention disclosed in Patent Document 1, an optical switch and an optical transmission monitoring device are provided for a plurality of optical fiber transmission paths, and a plurality of optical fiber transmission paths are optically connected to the optical transmission monitoring device via optical switches in sequence. That is, a plurality of optical fiber transmission paths are sequentially monitored by the optical transmission monitoring device.

Advanced technical literature Patent literature

Patent Document 1: Japanese Patent Laid-Open No. Hei 5-199191

The inventors have conducted detailed research on the conventional optical transmission monitoring device and found the following problems. In other words, in the invention disclosed in Patent Document 1, when a transmission abnormality occurs in one of the plurality of optical fiber transmission paths, the optical transmission path for determining the abnormality is determined, and the cause of the transmission abnormality is sometimes determined. It takes a long time. For example, when it is assumed that the transmission path includes 2,000 optical fiber transmission paths and the test of one optical fiber transmission path takes 1 minute, a transmission abnormality occurs in one of the 2,000 optical fiber transmission paths until the optical fiber The transmission path is tested until the worst case requires 2000 minutes (33.3 hours), resulting in poor immediacy.

Further, after receiving an abnormality report from a user of the optical transmission system (for example, a user who is the user of the second station), it is also considered to perform a test for the optical fiber transmission path to the second station. However, at this time, it becomes a maintenance activity of the passive optical transmission system, and it takes time and cost to cope with the abnormality report or system maintenance from the user.

The present invention has been made to solve the above problems, and an object of the invention is to provide an optical transmission monitoring apparatus including a configuration for transmitting signal light in a fiber transmission path including a first station to a second station. The cause of the abnormality can be determined early when a transmission abnormality occurs on the path.

The optical transmission monitoring apparatus of the present invention causes the pulse test light to propagate in a transmission path unit of the one or more transmission units to be monitored, and to generate a backscattered light generated by the propagation of the light according to the pulse, Monitor the optical transmission of the monitored object. Here, one or more transmission path units respectively include a first station, a second station, and an optical fiber transmission path provided between the first station and the second station. The optical transmission monitoring device that selects each of the one or more transmission path units as a monitoring target candidate includes a monitoring unit, a measurement unit, an optical coupling unit, and a determination unit.

Specifically, the monitoring unit monitors the optical transmission status of each of the one or more transmission path units, and determines that any of the transmission path units is the monitoring target. In this case, the monitoring unit detects the presence or absence of a transmission abnormality in the monitoring target based on the transmission or reception of the signal light in the first station belonging to the transmission unit to be monitored. The measurement unit records the measurement data obtained from the one or more transmission path units of the transmission path unit to be monitored by the monitoring unit as the reference material of each of the one or more transmission path units. In this case, the measurement unit outputs pulse test light to the optical fiber transmission path belonging to the transmission path unit to be monitored, and receives the back scattered light generated in the optical fiber transmission path through which the pulse test light propagates, thereby obtaining the back scattered light. Time-varying data on the intensity. The optical coupling unit couples the pulse test light output from the measuring unit to the optical fiber transmission path belonging to the transmission path unit to be monitored by the monitoring unit, and generates a backscattered light coupling in the optical fiber transmission path through which the pulse test light propagates. In the measurement section. The determination unit determines that the cause of the abnormality of the transmission path unit in which the transmission is abnormal is detected by the monitoring unit. Further, the determination of the cause of the abnormality is performed based on the state of the transmission abnormality detected by the monitoring unit and the temporal change data of the intensity of the scattered light obtained by the measuring unit.

Further, the transmission abnormality to be monitored includes a situation in which the signal light cannot be propagated between the first station and the second station (hereinafter referred to as a transmission interruption), or an increase in the bit error rate of the signal light. Further, the cause of such a transmission abnormality includes a device abnormality such as a transmitter abnormality or a receiver abnormality in at least one of the first station side and the second station side, a disconnection of the optical fiber transmission path, and a loss in the optical fiber transmission path. Abnormal characteristics such as abnormalities and polarized wave anomalies.

In the optical transmission monitoring device of the present invention, the optical coupling unit includes an optical multiplexer/demultiplexer provided in correspondence with one or more transmission path units, and a switch unit.

Each of the optical multiplexer/demultiplexers includes a first port and a second port that are optically connected to the first station and the second station via respective fiber transmission paths, and includes pulse test light coupled to the corresponding fiber transmission path. And for extracting a measurement enthalpy for generating a backscattered light in a corresponding optical fiber transmission path through which the pulse test light propagates. Further, the switch unit has a structure for optically connecting any one of the measurement electrodes of the optical multiplexer/demultiplexer belonging to one or more transmission path units to the measurement unit, and the structure is controlled by an optical switch and a measurement control unit. And realized. Here, the light-on relationship includes a first input/output port that is provided corresponding to each of the measurement ports of the optical multiplexer/demultiplexer, and a second input/output port that is optically connected to the measurement unit. The measurement control unit is configured to optically connect the second input/output port 第 to the first input/output port corresponding to the measurement 埠 of the optical multiplexer/demultiplexer belonging to the transmission path unit to be monitored.

In the optical coupling unit having the above-described structure, the measurement control unit displays the wiring information of the first station (the first station and the optical fiber transmission path) The information on the relationship between the diameters and the information on the optical switch wiring (information indicating the correspondence between the optical fiber transmission path and the optical switch) is switched between the optical switches. However, the accuracy of the switching in the measurement control unit depends on the accuracy of the wiring information prepared in advance. In other words, when the prepared wiring information itself is incorrect, the pulse test light from the measuring unit may be transmitted to another transmission path unit that is different from the optical fiber transmission path corresponding to the first station that has detected the transmission abnormality by the monitoring unit. On the fiber transmission path. In addition, the optical transmission monitoring apparatus of the present invention may include a structure for automatically measuring the first station and the optical coupling unit that constitute one transmission path unit before the optical transmission between the first station and the second station is started.对应, and the corresponding relationship of the fiber transmission path.

Specifically, it can be realized by modifying the optical coupling portion having the configuration as described above. For example, each of the optical multiplexer/demultiplexer further includes a confirmation 用于 for extracting a portion of the signal light output from the corresponding first station. The optical open relationship includes a third input/output port that is provided corresponding to the confirmation of the optical multiplexer/demultiplexer, and a fourth input that is optically connected to any of the third input/output ports by the measurement control unit. Output 埠. Further, the switch unit further includes a signal detector that is optically coupled to the fourth input/output port and detects signal light from any of the first stations belonging to one or more transmission path units.

According to this configuration, the first input/output port of the optical switch is connected to the measurement port of the optical multiplexer/demultiplexer, the second input/output port is connected to the measurement unit, and the third input/output port is connected to the optical splitting/demultiplexer. For the purpose, the fourth input/output port is connected to the signal detector. The first and third input and output in the optical switch Since the corresponding correspondence is known, if the first station that has transmitted the signal is determined based on the detection result of the signal detector, the measurement of the first station and the optical multiplexer/demultiplexer that constitute one transmission path unit can be automatically constructed. And the correspondence between the fiber transmission paths.

Further, in the optical transmission monitoring apparatus of the present invention, the signal light propagation path of at least one of the one or more transmission path units may have a multi-branch structure. Specifically, one transmission path unit includes: a first station, which corresponds to a plurality of terminal stations of the second station, a splitter disposed between the first station and the plurality of terminal stations, and is disposed through the optical splitter. A multi-branch optical fiber transmission path corresponding to the optical fiber transmission path between the first station and the plurality of terminal stations. In this case, the optical transmission monitoring device transmits the pulse test light from the first station side toward the plurality of terminal stations on the multi-branch optical fiber transmission path in which the splitter is disposed, and monitors the scattered light after the propagation. Light transmission between the first station and a plurality of terminal stations.

Further, in the transmission path unit including the multi-branch optical fiber transmission path, the measurement unit receives the self-complex number at the first station before the start of optical transmission between the plurality of terminal stations and the first station. When the signal light transmitted by any of the terminal stations is transmitted, time-varying data of the intensity of the scattered light in the multi-branch optical fiber transmission path is obtained. The optical transmission monitoring device confirms the branch path of the terminal station connected to the transmission signal light in the branch path of the multi-branch optical fiber transmission path based on the temporal change data of the intensity of the scattered light obtained by the measurement unit. The light transmission between the first station and the terminal station that transmits the signal light is started.

In the optical transmission monitoring device (the optical transmission monitoring device of the present invention) having the above-described structure, the determination unit determines that the transmission path of the transmission abnormality is detected when the monitoring unit detects that the transmission of the optical transmission is abnormal. The cause of the abnormality of the unit is which of the signal light transmitting device failure in the first station, the signal light transmitting device failure in the second station, the fiber transmission path disconnection, and the loss of the optical fiber transmission path.

When the monitoring unit detects that the bit error rate in the optical transmission exceeds a certain value, the determination unit determines that the abnormal cause of the transmission path unit in which the transmission abnormality is detected is that the signal optical transmission device in the first station is malfunctioning, Which of the signal light transmission equipment failures in the second station and the loss of the optical fiber transmission path are abnormal.

Further, the measuring unit preferably outputs pulse test light having a wavelength longer than a wavelength of the signal light to the optical fiber transmission path belonging to the transmission path unit in which the transmission abnormality is detected. In this case, when the monitoring unit detects that the transmission of the interruption state of the optical transmission is abnormal, the determination unit determines that the abnormal cause of the transmission path unit in which the transmission abnormality is detected is that the signal optical transmission device in the first station is malfunctioning, and the second station The fault of the signal transmission equipment in Taichung, the disconnection of the optical fiber transmission path, the abnormality of the loss of the optical fiber transmission path, and the polarization wave abnormality of the optical fiber transmission path. Further, when the monitoring unit detects that the bit error rate in the optical transmission exceeds a certain value, the determination unit determines that the abnormal cause of the transmission path unit in which the transmission abnormality is detected is the signal light transmission in the first station. Which of the equipment failure, the signal light transmission equipment failure in the second station, the loss of the optical fiber transmission path, and the polarization wave abnormality of the optical fiber transmission path.

Furthermore, the optical transmission monitoring apparatus of the present invention preferably further includes: extracting, from the signal light output from the first station belonging to the one or more transmission path units, the power of the part of the signal light by the optical coupling unit Optical power meter for measurement. In this configuration, the determination unit determines that the measurement is based on the state of the transmission abnormality detected by the monitoring unit, the temporal change data of the intensity of the scattered light after the measurement by the measurement unit, and the measurement result of the optical power meter. The cause of the abnormality of the transmission path unit of the object.

According to the optical transmission monitoring apparatus of the present invention, when a transmission abnormality occurs in each of the one or more transmission path units to be monitored, the cause of the transmission abnormality can be determined early.

Hereinafter, each embodiment of the optical transmission monitoring apparatus of the present invention will be described in detail with reference to Figs. 1 to 13 . In the description of the drawings, the same components are denoted by the same reference numerals, and the description thereof will not be repeated.

(First embodiment)

Fig. 1 is a view showing the configuration of an optical transmission system including the optical transmission monitoring device of the first embodiment. The optical transmission system 1A shown in Fig. 1 includes N (one or more integers: 1, 2, ..., n, ...) transmission path units having the same structure, and optical transmission monitoring of the first embodiment. Device 2A. Furthermore, N is sometimes a value of around 2000. For example, the nth transmission unit includes a first station 11 _n , a second station 12 _n , and an optical fiber transmission path 13 _n provided between the first station 11 _n and the second station 12 _n as shown in FIG. 1 . Optical transmission is performed between the first station 11 _n and the second station 12 _n via the optical fiber transmission path 13 _n . The optical transmission monitoring apparatus 2A of the first embodiment monitors optical transmission in each of the N transmission path units that are to be monitored.

In the following description of the respective embodiments, when the same constituent elements belonging to each of the N transmission path units are indicated, the reference number subscript uses "N", and when only the specific transmission path unit is indicated, for example, When the components of the nth transmission path unit are used, "n" is used under the reference number. Specifically, the "first station 11 _N ", the "second station 12 _N ", and the "fiber transmission path 13 _N " indicate that all of the first stations, all the second stations, and all the optical fibers belonging to the N transmission path units are transmitted. path.

In each of the N transmission path units, a filter 14 _N is provided on the optical fiber transmission path 13 _N and on the second station 12 _N side (or directly in front of the second station 12 _N ). Further, an optical multiplexer/demultiplexer 15 _{N is} provided on the optical fiber transmission path 13 _N and on the first station 11 _N side. The optical multiplexer/demultiplexer 15 _N constitutes one of the optical coupling units in the optical transmission monitoring device 2A of the first embodiment, and includes the first optical connection with the first station 11 _N via the optical fiber transmission path 13 _N. port 15a, the second port 15b via an optical fiber transmission path 13 _N and 12 _N and optically connected to the second station, and the measurement for the test pulse light guided to the optical fiber transmission path 13 _N purposes port 15c.

In the optical transmission monitoring apparatus 2A of the first embodiment, all of the N transmission path units are used as monitoring target candidates, and when an abnormality is detected in the nth transmission path unit, for example, the abnormal cause of the nth transmission path unit is determined. . Therefore, the optical transmission monitoring device 2A includes the optical switch 20A, the measuring device 30, and the optical transmission abnormality determining device 50. The optical transmission abnormality determining device 50 includes an optical transmission monitoring unit 51, a measurement control unit 52, an optical transmission path test unit 53, a test data management unit 54, a wiring information management unit 55, an optical switch wiring information management unit 56, and a determination unit 57. Further, the optical switch 20A and the measurement control unit 52 constitute a switch unit.

The optical transmission monitoring unit 51 constitutes a monitoring unit that detects the transmission state of each of the N transmission path units based on the transmission or reception of the signal light in each of the first stations 11 _N. The measurement device 30, the measurement control unit 52, and the optical transmission path test unit 53 constitute a measurement unit, and the measurement data obtained from the transmission unit that is the target of the optical transmission monitoring unit 51 among the N transmission path units is used as the measurement data. It is recorded by the reference data of each of the N transmission path units. For example, when the nth transport path unit is to be monitored, the measurement unit outputs pulse test light to be propagated on the optical fiber transmission path 13 _n belonging to the nth transport path unit, and receives the optical fiber transmission path on the other hand. The backscattered light is generated in 13 _n , thereby obtaining temporal change data of the intensity of the backscattered light. Furthermore, the measurement control section 52 and the optical switch 20A constituting the switching unit, which based coupling light from the output of the pulse test measurement section to the optical fiber transmission path 13 _N each, on the other hand, the resulting optical fiber transmission line by each of the 13 _N The side scattered light is then coupled to the assay device 30. Further, the switch unit and the optical multiplexer/demultiplexer 15 _N constitute an optical coupling unit.

The first platform 11 _N optical fiber transmission line is intended to detect whether it is connected corresponding to the second station on the 12 _N 13 _N, and notifies the detection result to the optical transmission monitoring unit 51. Moreover, the transmission abnormality between the first station 11 _N and the second station 12 _N (the optical transmission is interrupted, or the bit error rate during optical transmission exceeds a certain value) is detected, and the detection result is notified. The light is transmitted to the monitoring unit 51. Furthermore, for the optical fiber transmission path connected to the second platform 13 _N 12 _N, if the optical fiber transmission line connected to the 13 _N, 13 _N then the situation is notified to the first station 1 via the optical fiber transmission line 11 _N. The optical transmission monitoring unit 51 receives the notification as described above from any of the first stations 11 _N , and determines the first station to which the notification is to be transmitted, for example, the nth transmission path unit to which the first station 11 _n belongs.

The optical switch 20A are connected to the optical multiplexer comprises a demultiplexer 15 _N of the first input-output port 210, and the second input-output port 220 is connected to the means 30 of measuring. The first input/output port 埠 and the second input/output port 该 of the optical switch 20A are controlled by the measurement control unit 52 to select any one of the optical multiplexer/demultiplexer 15 _N and the measuring device 30. Optically connected to each other.

The measuring device 30 outputs pulse test light to be propagated on the optical fiber transmission path 13 _N , and receives the rear side scattered light generated in the optical fiber transmission path 13 _N , thereby obtaining temporal change data of the intensity of the back scattered light. The measuring device 30 is preferably a device using an OTDR (Optical Time Domain Reflectometry).

The wavelength of the pulse test light outputted from the measuring device 30 is different from the wavelength of the signal light transmitted and received between the first station 11 _N and the second station 12 _N , and the optical fiber transmission path 13 _N can be detected earlier. The case where the bending time increases is preferably set to be longer than the wavelength of the signal light, and the wavelength which is increased by the bending is more likely to occur. For example, for a single-mode fiber of ITU-T G.625, when the bending radius is 15 mm, the bending loss at a wavelength of 1.31 μm is about 2.33 × 10 ^-2 dB/m, and the bending loss at a wavelength of 1.55 μm is 1.45 dB / Around m, the bending loss at a wavelength of 1.65 μm is about 4.77 dB/m. Therefore, even if the wavelength of 1.31 μm is smaller than the loss measurement accuracy of 0.01 dB of the OTDR and the bending loss increase cannot be detected, the fiber can be detected with a better sensitivity by using a pulse test light of a longer wavelength. The bending loss of the transmission path 13 _N. For example, when the wavelength of the signal light is 1.49 μm, it is preferable that the wavelength of the pulse test light is set to be 1.65 μm longer than the 1.49 μm by 100 nm or more.

The optical multiplexer/demultiplexer 15 _N disposed on the optical fiber transmission path 13 _N couples the pulse test light output from the measuring device 30 to the optical fiber transmission path 13 _N , and couples the rear side scattered light generated in the optical fiber transmission path 13 _N to the measurement. Device 30. Therefore, the optical multiplexer/demultiplexer 15 _N has at least the first port 15a, the second port 15b, and the measuring port 15c as described above.

The filter 14 _N provided on the optical fiber transmission path 13 _N selectively reflects the pulse test light output from the measuring device 30, and transmits and receives the signal light between the first station 11 _N and the second station 12 _N. Selectively through. Regarding the reflection of the pulse test light in the filter 14 _N , it is desirable to be significantly higher than the reflection of the pulse test light in the end face of the optical fiber, and it is preferable to substantially interrupt the pulse toward the second station 12 _N Test the incidence of light.

The optical transmission monitoring unit 51 detects the presence or absence of a transmission abnormality based on the state of transmission or reception of the signal light in each of the first stations 11 _N. More specifically, the optical transmission monitoring unit 51 and can not be connected to the light transmission to the first station abnormally 11 _N 13 _N via the optical fiber transmission path and the second platform 12 _N, 11 _N from the first station to acquire a first station 11 _N 12 _N second respective station identification information, the first station and the second station 11 _N 12 _N respective transmitting and receiving power specification information, and in the first station of the actual signal from the second station 12 _N 11 _N The light reception power is used as the second station connection signal, and the second station connection signal is transmitted to the determination unit 57.

On the other hand, the monitoring unit 51 in the optical transmission from the first station in the example 11 _N belonging to the first n transmission path unit _n. 11 of the first station 1 receives the optical transmission as expressed intention of the interrupt status notification, a notification to the and from the first transport platform 11 _n interrupt status acquired light of the first station and the second station 11 _n 12 _n respective identification information, the actual site of the first signal transmission power light 11 _n, and 11 _n from the first station The actual signal light reception power of the second station 12 _n is used as an optical transmission interruption signal, and the optical transmission interruption signal is transmitted to the determination unit 57.

Further, the optical transmission monitoring unit 51 receives the bit error rate (hereinafter referred to as "BER (Bit error rate)) indicating the optical transmission from the first station 11 _n belonging to the nth transmission path unit, and exceeds a certain value. At the time of the notification, the identification information of the first station 11 _n and the second station 12 _{n of the} BER abnormality is obtained from the first station 11 _n together with the notification, the actual signal light transmission power of the first station 11 _n , and the The actual signal light reception power of the second station 12 _n of the first station 11 _n is transmitted as an optical transmission BER abnormality signal, and the optical transmission BER abnormality signal is transmitted to the determination unit 57.

The measurement control unit 52 controls each of the optical switch 20A and the measurement device 30 in accordance with an instruction from the optical transmission path test unit 53. By controlling the measurement control unit 52 of, from the measurement pulse 30 of the test light introducing belonging to the n-th transmission path unit (monitoring target) of the optical fiber transmission path 13 is _n, and further, the measuring apparatus 30 to obtain the optical fiber transmission path 13 is _n Time-varying data of the intensity of the scattered light after the square is generated.

Further, the test data management unit 54 sets the temporal change data based on the temporal change data of the intensity of the backscattered light acquired by the measurement device 30 for each of the N transfer path units to be monitored. The reflection position and intensity information (measurement data) of the pulse test light in the filter 14 _N is memorized and managed as reference data relating to each of the second stations 12 _N. And, OLT wiring information management unit 55 and memory management for the 11 _N 13 _N a connection relationship of the first station and the optical fiber transmission path. SW light distribution information management unit 56 and memory management for the connection relation of each optical switch port 20A of the optical fiber transmission path 13 _N's.

The optical transmission path test unit 53 receives the test command from the determination unit 57. The test command includes a second station connection signal (a signal for notifying the start of optical transmission between the first station and the second station), an optical transmission interruption signal, or an optical transmission BER abnormality signal (a signal for notifying the transmission abnormality), and includes The identification information of each of the first station 11 _N and the second station 12 _N that have been signaled is notified of the signal of the first station 11 _n and the second station 12 _n (which belongs to the nth transmission path unit to be monitored). Upon receiving the test command, the optical transmission path test unit 53 instructs the measurement control unit 52 to start the test based on the information managed by the OLT wiring information management unit 55 and the optical SW wiring information management unit 56.

Further, for example, when the nth transmission path unit is determined as the monitoring target, the measurement control unit 52 controls the switching of the optical switch 20A so that the pulse test light is introduced from the measuring device 30 to the optical fiber transmission path 13 _n to be tested. At the same time, the measuring device 30 is controlled to obtain temporal change data of the intensity of the backscattered light caused by the pulsed test light outputted. Further, the optical transmission path test unit 53 analyzes the presence or absence of the reflection of the pulse test light of the filter 14 _{n based} on the temporal change data of the intensity of the backscattered light output from the measurement control unit 52.

When the optical transmission path from the test section 53 in the determining section 57 receives the n-th second station connected to the signal transmission path on the unit as a monitoring target, the position of the reflector of the optical filter 14 _n test pulses of light and the strength of The first station 11 _n and the second station 12 _{n are} associated with each other as reference data and stored in the test data management unit 54.

On the other hand, when the optical transmission path test unit 53 receives the optical transmission interruption signal or the optical transmission BER abnormality signal of the nth transmission path unit to be monitored from the determination unit 57, it is stored in the test data management unit 54. The reference data is checked whether the reflection of the pulse test light of the filter 14 _n is at the position of the reference data. Optical transmission path 53 to the test unit tests the reflected pulse of light of the optical filter 14 _n the case when the position reference data, the amount of increase in transmission loss by seeking the time of transmission of the optical fiber transmission path 13 _n starts. Then, the optical transmission path test unit 53 notifies the determination unit 57 of the result of the above.

The determination unit 57 receives the second station connection signal, the optical transmission interruption signal, or the optical transmission BER abnormality signal from the optical transmission monitoring unit 51 via the above operation.

Determination section 57 in the self optical transmission monitoring unit 51 receives on a monitoring target when the n-th transmission path unit of the second station connection signal according to the first station. 11 _n of the received power specification information and the first station in. 11 _n of 12 _n of the actual signal from the second power of the difference between the light receiving station obtains transmission loss optical fiber transmission line 13 _n of the boundaries, and the boundaries of the transmission loss as the first station by the optical fiber transmission path 13 _n and 11 _n are connected to the The network information of the second station 12 _n is memorized. Further, the determination unit 57 notifies the optical transmission path test unit 53 of the identification information of each of the first station 11 _n and the second station 12 _n and issues a test command for the optical fiber transmission path 13 _n .

On the other hand, when the optical transmission monitoring unit 51 receives the optical transmission interruption signal or the optical transmission BER abnormality signal of the nth transmission path unit to be monitored, the determination unit 57 is based on the first station 11 _n and the second station. 12 _n respective identification information, the first station the actual sum signal 11 _n of optical transmission power, the first station 11 _n of the sum from the trials on actual sum signal of the second station 12 _n of the light receiving power, and the optical transmission path test portion 53 of As a result, an abnormality of the transmission device of the first station 11 _n or the second station 12 _n or an analysis of the cause of the failure of the abnormality of the optical fiber transmission path 13 _n is performed.

Next, as an example, determination of the determination unit 57 when an optical transmission interruption signal or an optical transmission BER abnormality signal of the nth transmission path unit to be monitored among the N transmission path units is received will be described with reference to FIG. 2 to FIG. action. In addition, FIG. 2 to FIG. 5 are flowcharts for explaining the determination operation of the determination unit 57 included in the optical transmission monitoring device 2A of the first embodiment. Specifically, FIG. 2 is a flowchart for explaining the determination operation of the determination unit 57 when the optical transmission interruption signal is received. FIG. 3 is a flowchart for explaining the determination operation of the determination unit 57 when the optical transmission BER abnormality signal is received. FIG. 4 is a flowchart for explaining the determination operation of the determination unit 57 when the optical transmission interruption signal is received, particularly when the wavelength of the pulse test light is longer than the wavelength of the signal light by 100 nm or more. In addition, FIG. 5 is a flowchart for explaining the determination operation of the determination unit 57 when the optical transmission BER abnormality signal is received, particularly when the wavelength of the pulse test light is longer than the wavelength of the signal light by 100 nm or more.

The determination operation of the determination unit 57 when receiving the optical transmission interruption signal is as shown in FIG. 2. First, in step S11, if the actual signal light transmission power of the transmission device of the first station 11 _{n does} not reach the transmission specification, it is determined. The transmission device for the first station 11 _n has failed. Then in step S12, is not a specific position of the reflected test pulse light of the optical filter 14 _n if the sum, it is determined that the optical fiber transmission path 13 _n disconnected. Then in step S13, the overall increase in the amount of transmission loss of the time when the transfer of the optical fiber transmission path 13 _n since transmission loss is beyond the limit, it is determined that the optical fiber transmission path 13 _n is an abnormal loss. Moreover, then in step S14, the actual sum signal when the first station 11 _n of the sum from the second station 12 _n of the light receiving power of the first station receives specification 11 _n's, it is determined that the transmission 11 _n of the first station If the device fails, if it is not within the reception specification of the first station 11 _n , it is determined that the transmission device of the second station 12 _n has failed.

Receiving the light transmitted BER determination unit 57 of the abnormality signal based determination operation shown in FIG. 3, first at step S23, the overall increase in the amount of transmission loss of the time when the transfer of the optical fiber transmission line 13 _n is the transmission loss since the boundaries As described above, it is determined that the optical fiber transmission path 13 _n is a loss abnormality. Moreover, then in step S24, the real sum signal when the first station 11 _n of the sum from the second station 12 _n of the light receiving power of the first station receives specification 11 _n's, it is determined that the first station transmitting apparatus 11 _n of If a failure occurs, if it is not within the reception specification, it is determined that the transmission device of the second station 12 _n has failed.

Furthermore, the transmission power of the transmission device from the first station 11 _n is obtained by measuring the transmission power by the transmission device when the transmission is abnormal. The increase in the overall loss of the optical fiber transmission path 13 _n is obtained from the difference between the peak of the reflection in the filter 14 _n at the start of the transmission and the abnormality of the transmission. The transmission loss limit may be a value obtained by measuring the received power by the transmitting device of the second station 12 _{n at the start} of transmission and based on the difference between the value and the receiving specification of the device, or may be a preset value. Further, the actual signal light receiving power from the second station 12 _n can be obtained by measuring the received power by the transmitting device of the first station 11 _n when the transmission is abnormal.

The determination operation of the determination unit 57 when the optical transmission interruption signal is received when the wavelength of the pulse test light is longer than the wavelength of the signal light by 100 nm or more is as shown in FIG. 4 and the operation of FIG. 2 (step S11~) S14) corresponds to the operation and executes the operation including step S13A instead of step S13 (steps S11, 12, 13A, and S14), and steps S15 to S17 are executed. In step S13A, if the optical fiber transmission path 13 _n as a whole from the transmitting transmission loss began to increase, the process proceeds to step S15. In step S15, if the actual signal light receiving power from the second station 12 _{n in} the first station 11 _n and the total transmission loss (signal light wavelength conversion value) of the optical fiber transmission path 13 _{n are} not added to the second value When the transmission specification of the station 12 _n is determined, it is determined that the transmission device of the second station 12 _n has failed. Then in step S16, the real sum signal when the first station 11 _n of the sum from the second station 12 _n of the light receiving power of the first station receives specification 11 _n's, it is determined that the first station transmitting apparatus 11 _n of the occurrence malfunction. Moreover, then in step S17, the amount of increase (signal light wavelength conversion value) overall transmission loss at the time of when the transfer 13 _n of the optical fiber transmission path since transmission loss beyond the limit, it is determined that the optical fiber transmission path 13 _n is the loss abnormal, If it is not equal to or higher than the transmission loss limit, it is determined that the optical fiber transmission path 13 _n is a polarization abnormality.

The determination operation of the determination unit 57 when receiving the optical transmission BER abnormality signal when the wavelength of the pulse test light is longer than the wavelength of the signal light by 100 nm or more, as shown in FIG. 5, performs the operation corresponding to FIG. 4 ( In the operations of steps S13A and S14) (steps S23A and S24), steps S25 to S27 are executed again. In step S23A, if the optical fiber transmission path 13 _n as a whole from the transmitting transmission loss began to increase, the process proceeds to step S25. In step S25, the actual signal light receiving power from the second station 12 _{n in} the first station 11 _n and the total transmission loss (signal light wavelength conversion value) of the optical fiber transmission path 13 _{n are} not added to the second value. When the transmission specification of the station 12 _n is determined, it is determined that the transmission device of the second station 12 _n has failed. Then in step S26, the real sum signal when the first station 11 _n of the sum from the second station 12 _n of the light receiving power of the first station receives specification 11 _n's, it is determined that the first station transmitting apparatus 11 _n of the occurrence malfunction. Moreover, then in step S27, the amount of increase (signal light wavelength conversion value) overall transmission loss at the time of when the transfer 13 _n of the optical fiber transmission path since transmission loss beyond the limit, it is determined that the optical fiber transmission path 13 _n is the loss abnormal, If it is not equal to or higher than the transmission loss limit, it is determined that the optical fiber transmission path 13 _n is a polarization abnormality.

As described above, the optical transmission monitoring device 2A of the first embodiment of the present invention can determine the cause of the abnormality early when a transmission abnormality (optical transmission interruption or optical transmission BER abnormality) in the optical fiber transmission path occurs.

(Second embodiment)

Fig. 6 is a view showing a configuration of an optical transmission system 1B including the optical transmission monitoring device 2B of the second embodiment. The optical transmission monitoring device 2B shown in Fig. 6 monitors the optical transmission in the optical transmission system 1B. The optical transmission system 1B also includes N (one or more integers: 1, 2, ..., n, ...) transmission path units having the same structure, and the optical transmission monitoring device 2B of the second embodiment. For example, the nth transmission unit includes a first station 11 _n , a second station 12 _n , and an optical fiber transmission path 13 _n provided between the first station 11 _n and the second station 12 _n as shown in FIG. 6 . Optical transmission is performed between the first station 11 _n and the second station 12 _n via the optical fiber transmission path 13 _n . The optical transmission monitoring apparatus 2B of the second embodiment also monitors the optical transmission in each of the transmission path units to be monitored among the N transmission path units in order.

The first station 1 11 _N and 12 _N based on a second platform is provided by the optical fiber transmission path 13 _N optical signal transmission and reception between the first station 12 _N 11 _N and the second station.

Each of the N transmission path units is provided with a filter 14 _N on the optical fiber transmission path 13 _N and on the second station 12 _N side (or directly in front of the second station 12 _N ). Further, an optical multiplexer/demultiplexer 16 _{N is} provided on the optical fiber transmission path 13 _N and on the first station 11 _N side. The optical multiplexer/demultiplexer 16 _N constitutes one of the optical coupling units in the optical transmission monitoring device 2B of the second embodiment, and includes the first optical connection with the first station 11 _N via the optical fiber transmission path 13 _N. port 16a, the second port 16b is connected to the 16 _N stations of the second optically via an optical fiber transmission path 13 _N, for the test pulse light measured is introduced into the optical fiber transmission path 13 _N with the port 16c, and for extracting The confirmation of one of the signal lights output from the first station 11 _N is used for 16d.

In the optical transmission monitoring device 2B of the second embodiment, all of the N transmission path units are used as monitoring target candidates, and when, for example, the transmission abnormality is detected in the nth transmission path unit, the pulse test light is applied to the optical fiber transmission path _13n . The first station 11 _n side propagates toward the second station 12 _n side, and the cause of the transmission abnormality is determined based on the backscattered light generated when the pulse test light propagates. The optical transmission monitoring device 2B includes an optical switch 20B, a measuring device 30, an optical power meter 40, and a light transmission abnormality determining device 50. The optical transmission abnormality determining device 50 includes an optical transmission monitoring unit 51, a measurement control unit 52, an optical transmission path test unit 53, a test data management unit 54, an OLT wiring information management unit 55, an optical SW wiring information management unit 56, and a determination unit 57.

When compared with the configuration of the optical transmission monitoring device 2A of the first embodiment shown in FIG. 1, the optical transmission monitoring device 2B of the second embodiment shown in FIG. 6 differs in that: instead of the optical wave division The wave 15 _N (FIG. 1) includes an optical multiplexer 16 _N and includes an optical switch 20B instead of the optical switch 20A, and further includes an optical power meter 40.

The optical multiplexer/demultiplexer 16 _N introduces the pulse test light arriving from the optical switch 20B to the optical fiber transmission path 13 _N , and outputs the rear side scattered light generated in the optical fiber transmission path 13 _N to the optical switch 20B, and again, from the first The signal light that the station 11 _N reaches via the optical fiber transmission path 13 _N is output to the optical switch 20B. Therefore, the optical multiplexer/demultiplexer 16 _N has at least the first port 16a, the second port 16b, the measuring port 16c, and the confirmation port 16d as described above.

The optical switch 20B comprises: a first input-output port determination and optical multiplexer demultiplexer 16 _N of connecting only 16a optically port 210, the second input-output port 30 of the optical connection of the measuring device 220, and, with the optical multiplexer confirm the multiplexer 16 _N 4 O ports 230, and with the optical power meter 40 connected to the third input port with the output port optically connected to the 16d 240. The switching in the optical switch 20B is controlled by the measurement control unit 52. If the optical multiplexer/demultiplexer 16 _n belonging to the nth transmission path unit among the optical multiplexer/demultiplexer 16 _N is selected, the selected one is selected. The optical multiplexer/demultiplexer 16 _{n is} optically connected to the measuring device 30, and connects the corresponding 埠 of the first input/output port 210 to the second input/output port 220. Further, the optical switch controller 20B by the measurement control unit 52, 40 is optically connected to the optical power meter is the photosynthesis of the selected wave duplexer 16 _n, and the third input corresponding to the output port 230 to the fourth port The input/output port 220 is connected. With this configuration, the optical power meter 40 monitors the power of the signal light output from the first station 11 _n via the optical switch 20B and the optical fiber transmission path 13 _n .

The optical switch 20B comprises: a first input-output port determination and optical multiplexer demultiplexer 16 _N of connecting only 16a optically port 210, the second input-output port 30 of the optical connection of the measuring device 220, and, with the optical multiplexer confirm the multiplexer 16 _N 4 O ports 230, and with the optical power meter 40 connected to the third input port with the output port optically connected to the 16d 240. The switching in the optical switch 20B is controlled by the measurement control unit 52. If the optical multiplexer/demultiplexer 16 _n belonging to the nth transmission path unit among the optical multiplexer/demultiplexer 16 _N is selected, the selected one is selected. The optical multiplexer/demultiplexer 16 _{n is} optically connected to the measuring device 30, and connects the corresponding 埠 of the first input/output port 210 to the second input/output port 220. Further, the optical switch controller 20B by the measurement control unit 52, 40 is optically connected to the optical power meter is the photosynthesis of the selected wave duplexer 16 _n, and the third input corresponding to the output port 230 to the fourth port The input/output port 220 is connected. With this configuration, the optical power meter 40 monitors the power of the signal light output from the first station 11 _n via the optical fiber transmission path 13 _n connected via the optical switch 20B.

Further, when it is determined that the nth transmission path unit is to be monitored, the measurement control unit 52 controls each of the optical switch 20B, the measurement device 30, and the optical power meter 40 in accordance with an instruction from the optical transmission path test unit 53. At this time, the measurement control unit 52 acquires the monitoring result of the output signal optical power of the first station 11 _n of the optical power meter 40.

The optical transmission path test unit 53 receives a test command from the determination unit 57 regarding the nth transmission path unit to be monitored. The test command includes a second station connection signal, an optical transmission interruption signal, or an optical transmission BER abnormality signal, and includes identification information of each of the first station 11 _n and the second station 12 _n . The optical transmission path test unit 53 receives the monitoring result of the output signal optical power of the first station 11 _n of the optical power meter 40 from the measurement control unit 52, and transmits it to the determination unit 57.

In the second embodiment, the optical power meter 40 can monitor the first station 11 _{n even} when the signal light power of the first station 11 _n cannot be monitored for the nth transmission path unit to be monitored. The power of the output signal light. Using the monitoring result, the determination unit 57 can determine the cause of the transmission abnormality (light transmission interruption or optical transmission BER abnormality) in the optical fiber transmission path as in the case of the first embodiment.

(Third embodiment)

Fig. 7 is a view showing the configuration of an optical transmission system 1C including the optical transmission monitoring device 2C of the third embodiment. The optical transmission monitoring device 2C shown in Fig. 7 monitors the optical transmission in the optical transmission system 1C. The optical transmission system 1C also includes N (one or more integers: 1, 2, ..., n, ...) transmission path units having the same structure, and the optical transmission monitoring device 2C of the third embodiment. The optical transmission system 1C is a PON system, and the signal light propagation path of each transmission path unit has a multi-branch structure. For example, the n-th transfer unit 7, _n. 11 comprises a first station, the terminating station corresponding to the plurality of the second station 12 is _{n 12 n, 1, 12 n,} 2, 12 n, 3 ... ( Hereinafter, it is simply referred to as a second station _{n, M} (M is an integer of 2 or more), and a multi-branch optical fiber transmission path provided between the first station 11 _n and the plurality of second stations 12 _{n and M.} Moreover, multi-branch fiber having a transport path _n-separator 17, and comprises: provided on the optical fiber transmission path 17 between the first _n-1 to the separator station 11 _n 13 _n, are provided in the second separator 17 and a plurality of 2 _n A plurality of optical fiber transmission paths (branch lines) between the stations _{n, m} 18 _{n, 1} , 18 _{n, 2} , 18 _{n, 3} .... The optical transmission monitoring apparatus 2C of the third embodiment also monitors the optical transmission in each of the transmission path units to be monitored among the N transmission path units.

The first station 11 _N and the second station 12 _{N, M} transmit and receive signal light via the optical fiber transmission path 13 _N , the splitter 17 _{N ,} and the optical fiber transmission path 18 _N,m .

The optical transmission monitoring device 2C of the third embodiment has the same configuration as the optical transmission monitoring device 2A of the first embodiment, and the N transmission path units including the multi-branch optical fiber transmission path are candidates for monitoring, for example, The optical fiber transmission path 13 _n and the optical fiber transmission path 18 _{n, which are} the nth transmission path unit to be monitored, cause the pulse test light to propagate from the first station 11 _n side toward the second station 12 _{n and the M} side, and according to the The transmitted light is transmitted after the pulse test light propagates to monitor the light transmission.

The present third embodiment, to be the n-th transmission path unit monitoring target, the new connection to the optical fiber transmission line 18 _{n, m} (via the separator. 17 _n is connected to the optical fiber lines 13 is _n of the M optical fiber transmission line 18 is _n, The second station 12 _n,m of the mth optical fiber transmission path in _M transmits the signal light indicating the connection to the first station 11 _n . The first station 11 _n receives the signal light, and recognizes that the second station 12 _{n,m is} newly connected to the optical fiber transmission path 18 _n,m , and notifies the optical transmission monitoring unit 51 of the fact. The optical transmission monitoring unit 51 further notifies the determination unit 57 of this.

The optical transmission path test unit 53 receives, from the determination unit 57, information on the second station 12 _n,m of the nth transmission path unit to be monitored _{, which is} newly connected to the optical fiber transmission path 18 _n,m , and The measurement device 30 acquires the temporal change of the intensity of the scattered light, and analyzes the presence or absence of the reflection of the pulse test light of the filter 14 _{n, m} . At this time, the optical transmission path test unit 53 refers to the position and intensity of the reflection of the pulse test light stored in the filter of the second station, which is stored in the test data management unit 54, and the temporality of the intensity of the backscattered light. The change information confirms the existence of the path to the new second station 12 _{n, m} .

Further, when the optical transmission path test unit 53 only refers to the nth transmission path unit, when the presence of the path to the new second station 12 _n,m is confirmed, the new transmission is performed. The position and intensity of the reflection of the pulse test light of the filter 14 _{n, m} corresponding to the filter 12 _{n, m} of the second station 12 _{n, m} are stored in the test data as the reference data in association with the first station 11 _n and the second station 12 _{n, m} . In the management unit 54. Further, on the arrival of new confirmed the second station 12 _{n, m} of the presence of the path, beginning 12 _{n, m} of the transfer between the first station 11 _n of the second and the new site.

In the third embodiment, similarly to the case of the first embodiment, the determination unit 57 can determine the cause early when a transmission abnormality (optical transmission interruption or optical transmission BER abnormality) occurs in the optical fiber transmission path.

Further, in the third embodiment, when only the nth transmission path unit is involved, when the second station 12 _{m,m is} newly connected to the optical fiber transmission path 18 _n,m , the second station 12 _n can be performed _. The installation confirmation and performance check of the filter 14 _{n, m} corresponding to _m , and the transmission and reception of signal light between the first station 11 _n and the second station 12 _{n, m} after the confirmation.

Further, in the third embodiment, if only the nth transport path unit is involved _, the mounting positions of the filters 14 _{n and m} can be confirmed, so that the mounting positions of the filters 14 _{n and m} can be adjusted to be identifiable. The position of the reflection of each filter in the data of the temporal change of the intensity of the scattered light obtained by the measuring device 30 is obtained.

(Fourth embodiment)

In the optical coupling unit according to the first to third embodiments, the measurement control unit 52 records the wiring information of the first station recorded in the OLT wiring information management unit 55 in advance and is recorded in the optical SW wiring information management unit 56. In the light switch wiring information, the switch in the optical switches 20A, 20B is performed. However, the accuracy of the switching in the measurement control unit 52 depends on the accuracy of the wiring information prepared in advance. In other words, the wiring information recorded in the OLT wiring information management unit 55 and the optical SW wiring information management unit 56 is the information registered by the person who constructs the information, and there is a possibility that an input error and a human power delay occur. Therefore, when the wiring information registered in advance is incorrect in itself, the desired test cannot be performed on the transmission path unit determined by the monitoring unit. Further, as long as the wiring information is not registered in the OLT wiring information management unit 55 and the optical SW wiring information management unit 56, the test cannot be performed.

On the other hand, in the fourth embodiment, the first station and the optical coupling unit that constitute one transmission path unit are automatically constructed before the start of optical transmission between the first station and the second station.对应, and the corresponding relationship of the fiber transmission path. In addition, FIG. 8 is a view showing a configuration of the periphery of the optical coupling unit in the optical transmission monitoring device according to the fourth embodiment. Fig. 9 is a view showing the configuration of an optical transmission system including the optical transmission monitoring device 2D of the fourth embodiment. Fig. 10 is a view for explaining the logical structure of the OLT-light SW information management unit 500 in the optical transmission system 1D shown in Fig. 9.

The optical transmission system 1D shown in FIG. 9 includes N transmission units each having a multi-branch structure in the signal light propagation path, and an optical transmission monitoring device 2D according to the fourth embodiment. In the fourth embodiment, each of the transmission units of the optical transmission system 1D includes a multi-branch optical fiber transmission path which is the same as each of the transmission path units in the optical transmission system 1C shown in FIG. Further, part or all of the N transfer units of the optical transmission system 1D may have the same configuration as each of the transfer path units shown in FIGS. 1 and 6.

In the fourth embodiment, the optical coupling unit (including the optical multiplexer/demultiplexer and the switch unit) has the same configuration as that of the optical coupling unit shown in FIG. 6 except for the configuration of the switch unit. In addition, the switch part in the fourth embodiment is the same as the switch unit shown in FIG. 6 except that the signal detector 300 is included in place of the optical power meter 40 of the switch unit shown in FIG. 6. In other words, the optical coupling unit of the fourth embodiment includes the optical multiplexer/demultiplexer 16 _N and the switch unit which are respectively disposed on the optical fiber transmission path 13 _N belonging to the N transmission path units, as shown in FIG. 8 . The switch unit includes an optical switch 20C, a measurement control unit 52, and a signal detector 300.

Further, in the fourth embodiment, the optical transmission abnormality determining apparatus 50 of FIG. 9 is different from the optical transmission monitoring apparatuses 2A to 2C of the first to third embodiments described above in place of the OLT wiring information management unit 55 and the optical SW. The wiring information management unit 56 includes an OLT-light SW information management unit 500.

As described above, the configuration of the optical transmission monitoring device 2D of the fourth embodiment is not limited to the configuration of the optical coupling unit and the optical transmission abnormality determining device, and the optical transmission monitoring devices 2A to 2C of the first to third embodiments. The same is true, and the repeated description is omitted.

As shown in FIGS. 8 and 9, the optical multiplexer/demultiplexer 16 _N introduces the pulse test light arriving from the optical switch 20C to the optical fiber transmission path 13 _N , and outputs the rear side scattered light generated in the optical fiber transmission path 13 _N to The optical switch 20C outputs the signal light that has arrived from the first station 11 _N via the optical fiber transmission path 13 _N to the optical switch 20C. Therefore, the optical multiplexer/demultiplexer 16 _N constitutes one of the optical coupling units in the optical transmission monitoring device 2D of the fourth embodiment, and includes optically connected to the first station 11 _N via the optical fiber transmission path 13 _N. a connection port 16a, and a second port 16b optically connected to the plurality of second stations 16 _{N, M} via the optical fiber transmission path 13 _N for introducing pulse test light into the measurement port 16c of the optical fiber transmission path 13 _N , And a confirmation 埠 16d for extracting a part of the signal light output from the first station 11 _N.

Further, the optical switch 20C comprising: a first input-output port of the optical multiplexer demultiplexer measured 16 _N of connecting only 16a optically port of the second input-output port 30 is optically 210, the measuring device connected to the 220, and, with photosynthesis wave duplexer 16 _N 4 O confirm the port with the output ports of the third input port optically connected to the 16d 230, and the signal detector 300 of the optical connection 240. The switching in the optical switch 20C is controlled by the measurement control unit 52. If the optical multiplexer/demultiplexer 16 _n belonging to the nth transmission path unit among the optical multiplexer/demultiplexer 16 _N is selected, the selected one is selected. The optical multiplexer/demultiplexer 16 _{n is} optically connected to the measuring device 30, and connects the corresponding 埠 of the first input/output port 210 to the second input/output port 220. Further, the optical switch controller 20C by the measurement control unit 52, if it is selected of the photosynthetic wave duplexer 16 _n connected to the optical signal detector 300, then the third input corresponding to the output port 230 to the first port 4 input and output 埠 220. With this configuration, the signal detector 300 can detect the signal light output from the first station 11 _n via the optical switch 20C and the optical fiber transmission path 13 _n .

Next, the automatic construction operation of the OLT-light SW information management unit 500 before the light transmission between the first station 11 _N and the second station 12 _{N, M will be} described. In the following description _{, it is assumed} that optical transmission is started between the first station 11 _n belonging to the nth transmission path unit and the m second stations 12 _{n, m} .

First, the optical transmission monitoring unit 51 detects the first station transmits a new start signal of 11 _n, and the first determination unit 57 notifies the station 11 _n of the identification number. The determination unit 57 receives the notification, and controls the optical switch 20C and the signal detector 300 via the optical transmission path test unit 53 and the measurement control unit 52. Further, in the optical switch 20C, the measurement control unit 52 switches between the connection state of each of the third input/output ports 230 and the fourth input/output port 240, and confirms the detection result of the signal detector 300, while searching, detecting, and starting transmission. The first station 11 _n corresponds to the third input/output port 230. In the search, the third input/output port 230 of the UI number registered in the OLT-light SW information management unit 500 is outside the search target.

The measurement control unit 52 transmits the identification number of the first station 11 _n that has sent the new transmission start signal to the optical transmission monitoring unit 51 and the third of the optical switches 20C connected to the first station 11 _n . When the correspondence between the number of the input/output port 230 is detected, the determination unit 57 records the relationship between the detected identification number of the first station and the number of the third input/output port 230 in the OLT-light SW information management unit. 500 and managed. The logical structure of the OLT-light SW information management unit 500 is as shown in FIG. 10, for example. Further, the first input/output port 210 of the optical switch 20C (measurement 埠 16c to which each of the optical multiplexer/demultiplexer 16 _{N is} connected) and the third input/output 埠 230 of the optical switch 20C (with the optical multiplexer/demultiplexer connected thereto) 16 _N of respective confirmation port 16d) of the relationship of the system to satisfy the specific relationship of the optical multiplexer 16 _N measured by the respective ports of the multiplexer 16c and the port 16d is connected to the confirmation optical switch 20C. This specific relationship refers to, for example, the _number of the first input/output port 210 of the measurement port 16c to which the _n-th optical multiplexing/demultiplexing device 16 _n is connected, and the third input/output to which the confirmation pin 16d is connected. The number after 埠 230 is expressed by a specific calculation formula. Therefore, when the measurement control unit 52 detects the time number of the third input/output port 230, the 埠 number obtained by using the calculation formula having the detected 埠 number becomes the first input/output port 210. Since the corresponding number is used, the OLT-light SW information management unit 500 does not need to manage the correspondence between the first input/output port 210 and the third input/output port 230.

In addition, the optical transmission monitoring unit 51 newly new one of the first stations (the first station 11 ₁ to the first station 11 _n-1 , the first station 11 _n+1 to the first station 11 _N ) other than the management. When a signal indicating the start of transmission is sent, a new transmission start signal of the new first station is detected, and the identification number of the new first station is notified to the determination unit 57. The determination unit 57 that has received the notification sets the newly detected first station as the "first station of the new transmission start", and newly registers it in the OLT-light SW information management unit 500. Further, the time point of finding the third input/output port 230 corresponding to the new first station in the optical switch 20C is added to the management as the "detected OLT".

As described above, the determination unit 57 sends out the new time when the measurement control unit 52 detects the number of the third input/output port 230 corresponding to the first station that has sent the new transmission start signal. The relationship between the first station of the transmission start signal and the corresponding number of the third input/output port 230 of the optical switch 20C is sequentially recorded in the OLT-light SW information management unit 500 (see FIG. 10). Further, when the first station _N is removed, the determination unit 57 receives the notification from the optical transmission monitoring unit 51 that has detected the removal of the first station, and records it from the OLT-light SW. The relationship information in the information management unit 500 deletes information related to the removed first station.

The signal detector 300 is configured to monitor the signal light sent from the first station 11 _n connected via the optical switch 20C and the optical fiber transmission path 13 _n , and extract the signal in the transmission frame composed of the signal light. The identification number of the station 11 _n is notified to the measurement control unit 52. The determination unit 57 compares the identification number of the first station that has sent the new transmission start signal to the optical transmission monitoring unit 51, and the identification number extracted by the signal detector 300. As a result, if the identification number notified by the optical transmission monitoring unit 51 matches the identification number extracted by the signal detector 300, the determination unit 57 determines that the correct number of the third input/output port 230 in the optical switch 20C has been "detected. "." Further, as the signal detector 300, an ONU having a predetermined ONU (Optical Network Unit) identification number may be used. At this time, the optical connection path is established by the optical switch 20C, and the communication link between the first station and the ONU is established. Therefore, the optical transmission monitoring unit 51 confirms the communication link state between the first station and the ONU having the predetermined identification number. Thereby, the number of the third input/output port 230 in the optical switch 20C can be detected. In any of the means, it is possible to detect the corresponding number of the third input/output port 230 of the optical switch 20 while recognizing the first station that has sent the new transmission start signal, and thus even the plurality of first stations simultaneously In the case where a new transmission start signal is sent, the number of the third input/output port 230 of the optical switch 20C corresponding to each of the plurality of first stations can be accurately detected. For example, in the case of the initial OLT execution or the like, even if the first station of the plurality of power sources is turned on, the correct number can be detected (the third input/output port 230 of the optical switch 20C and the plural number) The corresponding number of each station of the first station).

In the optical transmission monitoring device 2D of the fourth embodiment, the first station and the corresponding number (the third input/output number 230 of the optical switch 20C) are registered in the OLT-light SW information management unit 500 as described above. The transmission path unit of the correspondence relationship can be a monitoring target. Therefore, for example, if the correspondence between the first station 11 _{n of} the nth transmission path unit and the _number of the third input/output port 230 is registered in the OLT-light SW information management unit 500, the nth transmission The monitoring operation of the path unit is performed in the same manner as in the first to third embodiments described above. However, the method of determining the number of the first input/output port 210 in the optical switch 20C for the pulse test light output from the measuring device 30 is different. In other words, when the first station 11 _n sends a signal to the optical transmission monitoring unit 51, the optical transmission monitoring unit 51 notifies the determination unit 57 of the identification number of the first station 11 _n . The determination unit 57 acquires the number of the third input/output port 230 corresponding to the first station 11 _n based on the correspondence relationship registered in the OLT-light SW information management unit 500, and based on the acquired number, and according to the optical switch In the structure of 20C, the corresponding number of the first input/output port 210 is obtained by calculation, and the pulse test light output from the measuring device 30 is coupled to the corresponding first input/output port 210 obtained by calculation.埠 number.

According to this configuration, the optical switch of the first input-output port 20C 210 are connected to optical multiplexer demultiplexer measured 16 _N purposes port 16c, the second input-output port 220 is connected to a measuring apparatus 30, a third input-output port 230, respectively, confirm connection to optical multiplexer demultiplexer 16 _N with the port, the fourth port 240 is connected to the input-output signal detector 300. Since the correspondence between the first and third input/output ports 210 and 230 in the optical switch 20C is known, if the first station that has transmitted the new transmission start signal is determined based on the detection result of the signal detector 300, the automatic construction can be automatically performed. The first station of one transmission path unit, the measurement 光 of the optical multiplexer/demultiplexer, and the correspondence relationship between the optical fiber transmission paths. Therefore, the optical transmission monitoring device 2D according to the fourth embodiment does not require the OLT wiring information management unit 55 and the optical SW wiring information management unit 56 in the first to third embodiments (the management unit 55 is not required). 56 login operation and management).

Further, based on the information recorded in the OLT-optical switch information management unit 500, it is possible to easily find the third input/output port 230 that is currently unavailable for monitoring due to the removal of the first station or the like. Thereby, it is possible to easily and accurately perform effective use such as recycling in the optical switch 20C.

(Fifth Embodiment)

FIG. 11 is a view showing a configuration of a periphery of an optical coupling unit in the optical transmission monitoring device according to the fifth embodiment. In addition, the optical transmission monitoring device of the fifth embodiment is substantially the same as the optical transmission monitoring device 2D (FIG. 9) of the fourth embodiment except for the optical switch 20D included in the optical coupling unit.

As shown in Fig. 11, the optical switch 20D in the fifth embodiment is different from the optical switch 20C in the fourth embodiment. In the optical switch 20D of the fifth embodiment, the second input/output port 220 (connected to the measuring device 30) and the fourth input/output port 240 (connected to the signal detector 300) are held at a fixed interval (Fig. 11). In a state in which three 埠 intervals can be configured, it is fixed to the head 250 which is movable in the direction indicated by the arrow A or B shown in the drawing. Corresponding to the structure of the head 250, the first input/output port 210 and the third input/output port 230 are alternately arranged every four.

According to the optical switch 20D of the fifth embodiment, when the fourth input/output port 240 is connected to any of the third input/output ports 230, the second input/output port 220 connected to the measuring device 30 is automatically connected to Corresponding to the first input/output port 210.

In addition to the 埠 switching mechanism and operation in the optical switch 20D, the OLT-light SW information management unit 500 is configured before the monitoring operation for each of the N transmission path units, and the fourth implementation The shape is the same. Further, the monitoring operation after the construction operation is the same as that of the optical transmission monitoring devices 2A to 2C of the first to third embodiments.

(Sixth embodiment)

FIG. 12 is a view showing a configuration of a periphery of an optical coupling unit in the optical transmission monitoring device according to the sixth embodiment. In the optical coupling unit according to the sixth embodiment, any one of the optical switches 20A to 20D in the first to fifth embodiments described above can be applied. However, in the sixth embodiment, the signal detector 300 and the optical power meter 40 are connected to the fourth input of the optical switches 20A to 20D via the switch 330 (SW) that performs switching control by the measurement control unit 52. Output 埠240.

Therefore, when the fourth input/output port 240 and the signal detector 300 are connected via the switch 330, the optical transmission monitoring device according to the sixth embodiment performs the same operation as the optical transmission monitoring device 2D (FIG. 9) of the fourth embodiment. . On the other hand, when the fourth input/output port 240 and the optical power meter 40 are connected via the switch 330, the structure of the optical transmission monitoring device of the sixth embodiment is the same as the fourth object except for the connection of the fourth input/output port 240. The optical transmission monitoring device 2D (Fig. 9) of the embodiment is the same. Further, this monitoring operation is the same as the monitoring operation of the optical transmission monitoring device 2B (FIG. 6) of the second embodiment.

(Seventh embodiment)

In the optical transmission monitoring apparatus according to the first to sixth embodiments, when the optical multiplexer/demultiplexer is connected to the first station and the optical fiber transmission path via the first and second ports, it is impossible to distinguish whether or not the first station is used. 2 light transmission between stations (cannot distinguish between current use/non-current use). Therefore, when the optical multiplexer/demultiplexer which is not in the current state of use, the optical fiber transmission path connected to the first station side of the optical multiplexer/demultiplexer, and the optical fiber transmission path on the second station side are removed, replaced, or re At the time of use, if such an operation is performed on the erroneous device, a situation in which the optical transmission is interrupted occurs. In actuality, in order to avoid such a situation, it is not possible to simply perform the fiber connection cancellation operation.

In the seventh embodiment, the optical transmission monitoring device according to the fourth to sixth embodiments (the optical transmission monitoring device according to the first to third embodiments described above) may further include the following structure: Simply find out the optical multiplexer/demultiplexer that is not in the current state of use, so as not to affect the light transmission in the current state of use, and can safely implement the removal, replacement, and reuse of such non-current equipment.

For example, the structure of the optical transmission monitoring device according to the seventh embodiment is the same as that of the optical transmission monitoring device 2D of the fourth embodiment, but the configuration of the periphery of the determination unit 57 is different. Specifically, as shown in the area (a) of FIG. 13, the determination unit 57 manages the OLT-light SW information management unit 500 in the same manner as the fourth embodiment, and further manages the communication status management unit 510.

In the seventh embodiment, the determination unit 57 automatically compiles the information before the start of the optical transmission between the first station and the second station in the same manner as the fourth embodiment (registered in the OLT-light SW information management unit 500). In the information related to the communication state between the first station and the second station managed by the communication status management unit 510 (OLT-ONU communication status), the third input in the optical switch is detected. Which one of the output ports 230 corresponds to the optical transmission path that is not used for the optical transmission between the first station and the second station, and registers the information in the communication status management unit 510. . Further, in the communication status management unit 510, as shown in the area (b) of FIG. 13, the detection result is sequentially registered. Further, the OLT-light SW information management unit 500 registers the relationship between the identification number of the first station and the number corresponding to the third input/output port 230 of the optical switch.

Further, the optical open relationship is set in the vicinity of the optical multiplexer/demultiplexer (the optical multiplexer/demultiplexer belonging to each of the N transmission path units), and the corresponding 埠 of the optical switch and the optical multiplexer/demultiplexer are about 5 m. One fiber optic cord is simply connected. Therefore, if the optical fiber cord between the optical switch and the optical multiplexer/demultiplexer is visually tracked based on the non-current use information of the optical switch registered in the communication status management unit 510, it is possible to easily find the photosynthetic state that is not in the current state of use. The wavelength demultiplexer and the optical fiber transmission path on the first station side of the optical multiplexer/demultiplexer and the optical fiber optical transmission path on the second station side. Furthermore, since the optical fiber cord between the optical switch and the optical multiplexer/demultiplexer is independent of the optical transmission between the first station and the second station, it can be pulled out from the optical switch at any time (without affecting the optical transmission). At this time, the target optical multiplexer/demultiplexer can also be found by a method such as illuminating the reference light from the side of the optical switch.

As described above, according to the optical transmission monitoring apparatus of the seventh embodiment, it is possible to perform operations such as removal, replacement, and reuse of the non-currently used equipment without affecting the light transmission in the current use state.

1A~1D. . . Optical transmission system

2A~2D. . . Optical transmission monitoring device

11. . . 1st station

12. . . 2nd station

13. . . Fiber transmission path

14. . . Filter

15,16. . . Photosynthetic wave splitter

17. . . Beam splitter

18. . . Fiber transmission path (branch path)

20A~20D. . . light switch

30. . . Measuring device

40. . . Optical power meter

50. . . Optical transmission abnormality determining device

51. . . Optical transmission monitoring department

52. . . Measurement control department

53. . . Optical transmission path test department

54. . . Test data management department

55. . . OLT wiring information management department

56. . . Optical SW wiring information management department

57. . . Judgment department

300. . . Signal detector

500. . . OLT-light SW information management department

510. . . Communication status management department

Fig. 1 is a view showing a configuration of an optical transmission system including the optical transmission monitoring device of the first embodiment;

2 is a flowchart (1) for explaining a determination operation of a determination unit included in the optical transmission monitoring device according to the first embodiment;

3 is a flowchart (2) for explaining a determination operation of a determination unit included in the optical transmission monitoring device according to the first embodiment;

4 is a flowchart (3) for explaining a determination operation of a determination unit included in the optical transmission monitoring device according to the first embodiment;

5 is a flowchart (4) for explaining a determination operation of a determination unit included in the optical transmission monitoring device according to the first embodiment;

Fig. 6 is a view showing a configuration of an optical transmission system including the optical transmission monitoring device of the second embodiment;

Fig. 7 is a view showing the configuration of an optical transmission system including the optical transmission monitoring device of the third embodiment;

FIG. 8 is a view showing a configuration of a periphery of an optical coupling unit in the optical transmission monitoring device according to the fourth embodiment;

FIG. 9 is a view showing a configuration of an optical transmission system including the optical transmission monitoring device of the fourth embodiment;

10 is a view for explaining a logical configuration of an OLT-light SW information management unit in the optical transmission system shown in FIG. 9;

FIG. 11 is a view showing a configuration of a periphery of an optical coupling unit in the optical transmission monitoring device according to the fifth embodiment;

FIG. 12 is a view showing a configuration of a periphery of an optical coupling unit in the optical transmission monitoring device according to the sixth embodiment; and

(a) and (b) of FIG. 13 are views showing a configuration of a periphery of a determination unit in the optical transmission monitoring device according to the seventh embodiment, and a logical structure for explaining the communication status management unit.

1A. . . Optical transmission system

2A. . . Optical transmission monitoring device

11 ₁ , 11 _n . . . 1st station

12 ₁ , 12 _n . . . 2nd station

13 ₁ , 13 _n . . . Fiber transmission path

14 ₁ , 14 _n . . . Filter

15 ₁ , 15 _n . . . Photosynthetic wave splitter

15a. . . First connection埠

15b. . . 2nd connection埠

15c. . . Measuring 埠

20A. . . light switch

30. . . Measuring device

50. . . Optical transmission abnormality determining device

51. . . Optical transmission monitoring department

52. . . Measurement control department

53. . . Optical transmission path test department

54. . . Test data management department

55. . . OLT wiring information management department

56. . . Optical SW wiring information management department

57. . . Judgment department

210. . . 1st input and output埠

220. . . 2nd input and output埠

Claims (8)

An optical transmission monitoring apparatus that monitors one or more transmission units including a first station, a second station, and an optical fiber transmission path provided between the first station and the second station, respectively In the transmission unit, the pulse test light is propagated from the first station side toward the second station side, and the light between the first station and the second station is monitored based on the backscattered light generated when the pulse test light propagates. And a monitoring unit that determines any one of the one or more transmission units as a monitoring target, and based on signal light in the first station belonging to the transmission unit that is the monitoring target The presence or absence of transmission or reception detects the presence or absence of a transmission abnormality in the transmission unit to be monitored; and the measurement unit obtains from the transmission unit of the one or more transmission units that is monitored by the monitoring unit. The measurement data is pre-recorded as the reference material of each of the one or more transmission units, and is And transmitting, by the optical fiber transmission path of the transmission unit of the monitoring object, pulse test light, and receiving the backscattered light in the optical fiber transmission path propagated by the pulse test light, thereby obtaining time variation data of the intensity of the backscattered light An optical coupling unit that couples pulse test light output from the measuring unit to an optical fiber transmission path belonging to a transmission unit to be monitored by the monitoring unit, and transmits the optical fiber transmission path in which the pulse test light propagates After the generation, the scattered light is coupled to the measuring unit; and a determination unit that determines a cause of an abnormality of the transmission unit that has transmitted the abnormality by the monitoring unit, and obtains a state of the transmission abnormality detected by the monitoring unit and acquires a backscattered light by the measurement unit. The temporal change data of the intensity determines the cause of the abnormality; the optical coupling unit includes an optical multiplexer/demultiplexer that is disposed on the optical fiber transmission path of the one or more transmission units, and each of which includes Corresponding optical fiber transmission paths are optically connected to the first port and the second port of the first station and the second station, respectively, and include optical coupling signals for coupling the pulse test to the corresponding fiber transmission path, and And a switch unit for extracting the above-mentioned optical multiplexed wave which belongs to the one or more transfer units respectively; and a switch unit for extracting the backscattered light generated in the corresponding optical fiber transmission path through which the pulse test light propagates; Any one of the measuring devices of the branching filter is optically connected to the measuring unit; and the switch unit includes an optical switch. a first input/output port that is provided corresponding to each of the measurement ports of the optical multiplexer/demultiplexer, and a second input/output port that is optically connected to the measurement unit; and a measurement control unit that is configured to use the second a first input/output port corresponding to the measurement 埠 of the optical multiplexer/demultiplexer belonging to the transmission unit to be monitored, which is optically connected to the first input/output port, and an input/output port 埠; each of the optical multiplexer/demultiplexer Further includes a confirmation 用于 for extracting a portion of the signal light output from the corresponding first station; the optical switch includes: a confirmation for each of the optical multiplexer/demultiplexer a third input/output port provided correspondingly and a fourth input/output port optically connected to the third input/output port by the measurement control unit; the switch unit further including a signal detector Optically connected to the fourth input/output port, and detecting signal light from any one of the first stations belonging to the one or more transmission units; the determining unit is connected to the first station and the second station Before the start of the optical transmission between the two, the first station and the optical coupling unit of the one or more of the one or more transmission units are automatically constructed based on the detection result of the signal detector. Corresponding relationship between the above optical fiber transmission paths. The optical transmission monitoring apparatus of claim 1, wherein at least one of the one or more transmission units includes: the first station; and a plurality of terminal stations corresponding to the second station; a splitter between the one station and the plurality of terminal stations; and a multi-branch optical fiber transmission path provided between the first station and the plurality of terminal stations via the splitter and corresponding to the optical fiber transmission path; The transmission monitoring device transmits the pulse test light from the first station side toward the plurality of terminal stations on the multi-branch optical fiber transmission path in which the splitter is disposed, and monitors the backscattered light generated during propagation. Optical transmission between the first station and the plurality of terminal stations. The optical transmission monitoring device of claim 2, wherein In the transmission unit including the multi-branch optical fiber transmission path, the measurement unit receives the plural number from the first station before the optical transmission between the plurality of terminal stations and the first station starts. When the signal light transmitted by any of the terminal stations is transmitted, temporal change data of the intensity of the backscattered light generated in the multi-branch optical fiber transmission path is obtained; the optical transmission monitoring device is obtained by the measurement unit After confirming the temporal change data of the intensity of the scattered light, it is confirmed that the branch station of the branch path of the multi-branch optical fiber transmission path is connected to the branch path of the terminal station that transmits the signal light, and then starts the first station and the terminal station that transmits the signal light. The light is transmitted between. The optical transmission monitoring apparatus according to any one of claims 1 to 3, wherein the determination unit determines that an abnormality of the transmission unit that detected the transmission abnormality is caused when the transmission unit detects that the transmission of the optical transmission is abnormal. The signal transmission device failure in the first station, the signal transmission device failure in the second station, the fiber transmission path disconnection, and the loss of the optical fiber transmission path are abnormal. The optical transmission monitoring apparatus according to any one of claims 1 to 3, wherein the determination unit determines that the transmission abnormality is detected when the monitoring unit detects that the transmission error rate of the bit error rate in the optical transmission exceeds a predetermined value The cause of the abnormality of the transmission unit is the failure of the signal light transmission device in the first station, the failure of the signal light transmission device in the second station, and the loss of the optical fiber transmission path. The optical transmission monitoring device of any one of claims 1 to 3, wherein The measurement unit outputs pulse test light having a wavelength longer than a wavelength of the signal light to the optical fiber transmission path of the transmission unit that has detected the transmission abnormality; and the determination unit detects that the optical transmission is interrupted by the monitoring unit. In the case of an abnormality, the cause of the abnormality of the transmission unit that has detected the transmission abnormality is that the signal optical transmission device in the first station is faulty, the signal optical transmission device in the second station is faulty, the optical fiber transmission path is disconnected, and the optical fiber transmission is performed. The abnormality of the path loss and the polarization wave abnormality of the above-mentioned optical fiber transmission path. The optical transmission monitoring apparatus according to any one of claims 1 to 3, wherein the measuring unit outputs pulse test light having a wavelength longer than a wavelength of the signal light to the optical fiber transmission path belonging to the transmission unit in which the transmission abnormality is detected; When the monitoring unit detects that the bit error rate in the optical transmission exceeds a certain value, the determination unit determines that the abnormal cause of the transmission unit that has detected the transmission abnormality is that the signal optical transmission device in the first station is malfunctioning. And a failure of the signal transmission device in the second station, an abnormality in loss of the optical fiber transmission path, and an abnormality in polarization of the optical fiber transmission path. The optical transmission monitoring apparatus according to any one of claims 1 to 3, further comprising: the signal light output from the first station belonging to the one or more transmission units, by the optical coupling unit Taking out a part of the power to measure the optical power meter; The determination unit determines that the transmission abnormality detected by the monitoring unit, the temporal change data of the intensity of the scattered light measured by the measurement unit, and the measurement result of the optical power meter are determined. The cause of the abnormality of the transfer unit that transmitted the exception.