JP2013032988A - Optical fiber line core determination device and determination method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber line core determination device capable of enhancing the determination accuracy of a core in an optical fiber line as a working target.SOLUTION: An optical fiber line connecting between an OLT 11 with an ONU 17 in an optical fiber line network has a monitor point which is formed to extract a part of a transmission optical signal to input the same to a core determination device 14. The core determination device 14 measures the timing when a signal frame passes through the monitor point on the basis of a result of the extraction of the optical signal at the monitor point and stores the same. The core determination device 14 obtains device time and a piece of device information owned by the ONU 17 or OLT 11 from the frame to obtain a piece of information on a distance between the monitor point and the ONU and a piece of information on an ONU proper ID and measures the length of the optical fiber line from the monitor point to the far-end of the optical fiber line. The core determination device 14 compares the distance information between the monitor point and the ONU and the length of the measured optical fiber line to collate a reflection point in the optical fiber line and a piece of ONU information on the far-end of the optical fiber line. In the analysis, the optical fiber line is given a reversible loss to obtain a piece of core information of the optical fiber line on the basis of the variation in the measured data of the optical fiber line length generated before and after the loss is given and the ONU information which coincides with the measured line length in the collation.

Description

  The present invention relates to an optical communication network (optical line network) constructed by an optical line made of an optical fiber, and in particular, an optical line core for specifying a target core line from among optical line cores of a branching optical line network. The present invention relates to a determination device and a core wire determination method.

  With the recent expansion of Internet users and the spread of broadband applications such as videophone and video distribution, communication networks using optical lines are also used for access networks. In such an optical line network (hereinafter referred to as an optical line network), in order to make an economical construction, a transmission optical signal is branched by an optical splitter in the middle of the optical line network and installed in a communication company building. A branch type (PON: Passive Optical Network) optical line network that connects a plurality of user-side transmission devices ONU (Optical Network Unit) to one indoor transmission device OLT (Optical Line Terminal) is widely used. Yes.

  By the way, when it is necessary to change the route of the branched optical line network, the optical line is switched at the connection point of the optical line such as an outdoor manhole. In general, an identification tag or the like that describes facility information on an optical line core is attached to a connection point of the optical line. However, assuming that there is a mistake in attaching the identification tag, etc., the worker at the outdoor switching point identifies the core wire while checking the target core wire while contacting the operator of the telecommunications carrier building ( Judgment). This confirmation procedure consists of (1) adding bending loss to the optical fiber core, which is considered to be an object by outdoor workers, and (2) monitoring the occurrence of optical line loss by the operator of the telecommunications carrier building, 3) Check whether or not the optical fiber core line in which loss has been confirmed matches the line length of the optical line to be switched, and (4) It is judged that there is, and the outside worker is notified that it is the correct target core wire.

“Optical media network operation technology to support expanding optical access network”, NTT Technology Journal 2006.12, P58-61

  However, at the connection points of multi-fiber optical fiber cables in recent years, it becomes a working environment for handling high-density optical fiber cores. There was a risk of attaching identification tags to the wires. Once the identification tag is attached to the wrong optical fiber core, it is impossible to confirm whether the optical fiber core is correct from the information only at the connection point at the work site.

  One of the information for identifying the optical fiber core line is the line length, and an optical pulse test is generally used to confirm the line length. In this optical pulse test, pulse light is incident on the optical line, and the loss time in the longitudinal direction of the optical line and the far end of the optical line are detected by measuring the return time and power of scattered light and reflected light. However, in order to confirm whether or not the far end position of the optical fiber core line read from the waveform obtained by the optical pulse test is the original length, it is necessary to compare with the equipment data stored in advance. There is.

  However, when a new optical line is installed, a storage length of an arbitrary length is provided at the connection part of the optical line, so in constructing equipment data, it is difficult to obtain an accurate optical line length and the accuracy is high. Building and operating a good optical line length database requires very large operational costs, such as constantly updating data as subscribers increase and decrease. Further, when data is input, a human error such as data input error occurs.

In general, when scattered light or reflected light is measured by an optical pulse test, if there is a large amount of reflection in the optical line, multiple reflections that reciprocate between the reflection points will occur. In some cases, reflection occurs at a long distance and erroneous measurement is performed.
The present invention has been made paying attention to the above-mentioned circumstances, and the ONU information and the optical line length information connected to the corresponding optical line core wire are also compared with the core line determination performed by the conventional loss occurrence monitor. An object of the present invention is to provide an optical fiber core determination device and a determination method thereof that can be confirmed at the same time and can increase the accuracy of identification (determination) of the optical fiber core to be worked.

In order to solve the above-described problems, the optical line core wire determination device according to the present invention is configured in the following manner.
(1) Used in an optical line network that connects a site-side transmission apparatus OLT (Optical Line Terminal) and a plurality of user-side transmission apparatuses ONU (Optical Network Unit) via an optical line, and provides a monitoring point in the middle of the optical line An optical line core determination device that extracts a part of an optical signal transmitted at the monitor point and analyzes the extracted optical signal to acquire information for determining the core of the optical line, Recording means for measuring and recording the timing at which a signal frame passes through a monitor point from the extraction result of the optical signal transmitted from the OLT to the ONU or from the ONU to the OLT at a point, and transmission between the OLT and the ONU Line information extraction means for acquiring distance information between the monitoring point and the ONU and ONU unique identification information by acquiring the device time and device information of the ONU or OLT from the signal frame, Optical line length measuring means for measuring the optical line length from the monitoring point to the far end of the optical line, distance information between the monitoring point and ONU obtained by the line information extracting means, and the optical line length Comparing the length of the optical line obtained by the measuring means with an analyzing means for collating the reflection point in the optical line with the ONU information at the far end of the optical line, the analyzing means is reversible to the optical line. The optical fiber core information is obtained from the change in the optical line length measurement data that occurs before and after the loss is given and the ONU information that matches the measurement line length.

  (2) In the configuration of (1), an optical filter that generates a reflected wave is arranged at the input / output unit of the ONU, and the peak of the reflected waveform of the optical filter is obtained by a technique that uses polarization modulation by applying a side pressure to the optical line. It is set as the aspect which confirms the core wire used as object by giving the phenomenon from which a value fluctuates.

(3) In the configuration of (1) or (2), an optical coupler is used for extracting the optical signal.
(4) In the configuration of (1) or (2), the optical signal is extracted by bending the optical fiber constituting the optical line and generating a radiation mode from the optical fiber core to the cladding by macro bending. And a means for obtaining leaked light.

(5) In any one of the constitutions (1) to (4), an optical switch is used for switching the input / output ports of the line information extracting means and the optical line length measuring means.
(6) In any one of the constitutions (1) to (4), an optical branching coupler is used for switching the input / output ports of the line information extracting means and the optical line length measuring means.

  (7) In the configuration of (6), the optical branch coupler transmits the test light having the first wavelength to the optical line length measuring means side, and the first optical line length extracting means side transmits the first light to the optical line length measuring means side. It is assumed that a WDM (Wavelength Division Multiplexing) coupler having a characteristic of transmitting test light having a second wavelength shorter than the wavelength is used.

Moreover, the optical line core wire determination method according to the present invention is configured in the following manner.
(8) Used in an optical line network that connects a site-side transmission device OLT (Optical Line Terminal) and a plurality of user-side transmission devices ONU (Optical Network Unit) by an optical line, and provides a monitor point in the middle of the optical line An optical line core line determination method for extracting a part of an optical signal transmitted at the monitor point and analyzing the extracted optical signal to obtain information for determining the core line of the optical line, From the extraction result of the optical signal transmitted from the OLT to the ONU or from the ONU to the OLT at a point, the timing at which the signal frame passes through the monitor point is measured and recorded, and the transmission signal frame between the OLT and the ONU is recorded. By acquiring the device time and device information that the ONU or OLT has, the distance information between the monitor point and the ONU and the ONU unique identification information are acquired, and from the monitor point to the far end of the optical line The optical line length of the optical line is measured, and the distance information between the acquired monitor point and the ONU is compared with the measured optical line length, so that the reflection point in the optical line and the ONU at the far end of the optical line are compared. Information is collated, and by giving a reversible loss to the optical line, the change in the optical line length measurement data that occurs before and after applying the loss, and the ONU information that is collated with the measurement line length It is set as the aspect which acquires the core line information of an optical line.

  According to the above configuration, it is possible to simultaneously check the ONU information and the optical line length information connected to the corresponding optical fiber as compared with the conventional determination of the optical fiber that has been performed by monitoring the occurrence of loss. It is possible to provide an optical line core determination device and a determination method thereof that can increase the accuracy of identification (determination) of the optical fiber core.

It is a block diagram which shows the structure of the communication system with which the optical line core wire determination apparatus which concerns on one Embodiment of this invention is used. It is a block diagram which shows the specific structure of the optical line core wire determination apparatus shown in FIG. It is a figure which shows the relationship between the signal which the optical line core wire determination apparatus shown in FIG. 1 measures, and timing. It is a figure which shows the example of the acquisition data of the optical line core wire determination apparatus shown in FIG. It is a figure which shows the measurement data and the apparatus information display example which the optical fiber core wire determination apparatus shown in FIG. 1 acquired.

Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiment described below is an example of the configuration of the present invention, and the present invention is not limited to the following embodiment.
(First embodiment)
FIG. 1 is a block diagram showing a configuration of a communication system in which a cord determination device according to an embodiment of the present invention is used.

  In FIG. 1, an OLT 11 installed in a telecommunications carrier building and a plurality of ONUs (# 1 to # 8 in the figure) 17 installed in a user's house are not shown in detail, but the optical line 1 It comprises a base or a plurality of optical splitters, and a connector for connecting the optical line or a connecting part such as fusion. FIG. 1 shows an example in which optical splitters 12 and 15 are arranged outdoors in a communication carrier building.

  The optical signal transmitted from the OLT 11 is equally branched by the optical splitter 12 and distributed to each optical line connected to the lower portion of the optical splitter 12. In the middle of the optical line connecting the OLT 11 and the ONU 17, an optical coupler 13 that slightly leaks an optical signal transmitted between the OLT 11 and the ONU 17 is set in advance as a monitoring point. Ports connected to the optical coupler 13 and the OLT 11 or the ONU 17 are called communication ports 131 and 132, and ports connecting the core determination device 14 are called test ports 133 and 134. A core determination device 14 is connected to the test ports 133 and 134 of the optical coupler 13.

  FIG. 2 is a block diagram showing a specific configuration of the core wire determination device 14. In FIG. 2, the core wire determination device 14 includes an optical input / output port 140 that receives signal light between the OLT 11 and the ONU 17 from the optical monitoring point or transmits test light to the optical monitoring point. A line information extracting unit 142 and an optical line length measuring unit 143 are selectively connected to the optical input / output port 140 by an optical switch 141. The line information extraction unit 142 receives communication light transmitted through the optical line through the input port, and extracts apparatus information included in the transmission frame and a counter value included in the apparatus. The optical line length measurement unit 143 includes an optical port for inputting and outputting test light, and measures the optical pulse response of the optical line.

  First, a method for acquiring distance information between the monitor point and the ONU 17 from the transmission system by the line information extraction unit 142 will be described. At the monitor point in the optical coupler 13 to which an optical signal from the OLT 11 or the ONU 17 that transmits through the optical line is input, a part of the optical power leaks. This leaked light is guided from the optical input / output port of the core wire determination device 14 to the line information extracting unit 142, converted into an electrical signal by the leaked light receiving unit 1421, and the signal analysis unit 1422 analyzes the converted signal. The distance information between the monitor point and the ONU 17 and the ONU unique identification information are acquired.

  A method for acquiring the distance information and the ONU unique identification information will be described. In EPON (Ethernet (registered trademark) PON), MPCP (Multi point control protocol) for controlling a plurality of ONUs 17 for one OLT 11 is used, and the ONU signal is transmitted from the optical splitter 15 to the optical path ahead. In order to share, each ONU 17 controls the signal transmission timing so that collision of signals transmitted from different ONUs 17 does not occur.

The signal transmission delay time between the OLT 11 and the ONU 17 required for the transmission timing control is acquired by the OLT 11. A method for acquiring the signal transmission delay time will be described with reference to a time chart shown in FIG.
In E-PON, the OLT 11 periodically performs a Discovery process in order to register a new ONU 17. The OLT 11 transmits a Discovery Gate including its own local timing t0, and the ONU 17 sets the received t0 in its own counter. Thereafter, a register request including ONU unique identification information and transmission timing t ′ 1 is transmitted to the OLT 11 at the signal transmission timing in the ONU 17.

  Here, the leakage light receiving unit 1421 detects the Discovery Gate and Register Request at the monitor point from the leaked light, and the signal analysis unit 1422 uses the time (Abs time) when the above signal is measured as the absolute time τ1, Recorded as τ2, and the time Tα required for transmission of the optical signal between the monitor point and the ONU device is obtained from the equation (1).

2Tα = (τ2-τ1)-(t'1-t0) (1)
Here, “MPCP timestamp” embedded in the transmission frame can be acquired as a binary value as a counter value in the apparatus. Further, when the round trip time (t′1−t0) is obtained from the counter value, the time count per bit is reflected in the difference between “MPCP timestamp” of the Discovery Gate frame and “MPCP timestamp” of the Register Request frame.

  FIG. 4 shows an example of a capture packet. The capture timing “Abs Timestamp: 542.092856770” and “MPCP timestamp = 992861107” were obtained in the Discovery Gate frame of OLT → ONU stream. On the other hand, the MAC address “xx: xx: xx: xx: 01: 01” and the capture timing “Abs Timestamp: 543.007258310” and “MPCP timestamp = 1050004859” are registered as ONU unique identification information from the Register Request transmitted from the ONU. was gotten. Therefore, (τ2−τ1) is 0.914401540 [s], and the difference of “MPCP timestamp” is 57143752. The MAC address of the corresponding device is “xx: xx: xx: xx: 01: 01”. In E-PON, 16 ns per 1-bit counter is defined in the IEEE Std 802.3ah standardization standard, t'1-t0 is 0.914300032 [s], and the round trip time from the monitoring point to ONU is 0.000101508 [s] Obtained. The distance L in the optical line is obtained by L = T × c / n (c: speed of light, n: refractive index in optical fiber).

  In FIG. 2, an optical line length measuring unit 143 measures the distance between the monitoring point and the ONU at the monitoring point, and includes a light source 1431 that emits pulsed light, a light receiving unit 1432 that converts an optical signal into an electrical signal, An optical coupler 1430 that transmits test light from the light source 1431 to the optical line and couples a signal returning from the optical line to the light receiving unit 1432 is provided. Light incident on the optical line from the light source 1431 is Rayleigh scattered in the measured line. The Fresnel reflection is generated, and the generated signal is received by the light receiving unit 1432 after a delay corresponding to the distance between the generated point in the optical line length and the apparatus. The A / D converter 1433 samples the received light signal power in a time-sharing manner, and the controller 1434 analyzes the temporal change in the received light power.

In order to connect the core determining device 14 and the optical line to be measured (optical fiber), the core determining device 14 is appropriately connected to the test port of the optical coupler 13 of FIG. taking measurement.
FIG. 5 shows the relationship between response light time and power change. In the return light from the optical line, weak Rayleigh scattered light is gradually attenuated according to the line loss, and a large Fresnel reflection occurs at the optical splitters 12 and 15 and the far end of the optical line, so that the reflected power increases rapidly. In the PON optical line, optical pulse test light is also distributed to each branch line by the optical splitters 12 and 15, and a reflection peak is obtained at a point corresponding to the lower length of each branch line.

  In FIG. 2, the analysis unit 144 stores in the data storage unit 1441 the optical line measurement data obtained by the optical line length measurement unit 143 and the distance information between the monitor point obtained by the above-described line information extraction unit 142 and the ONU. The data comparison unit 1442 performs data comparison using these stored data, and the equipment determination unit 1443 determines the optical fiber core to be operated from the comparison result. The comparison / determination process is appropriately displayed on the display unit 145.

  In the optical fiber determination device 14 having the above configuration, the optical line is determined based on the optical line measurement data obtained by the optical line length measurement unit 143 and the distance information between the monitor point and the ONU obtained by the line information extraction unit 142 described above. A method for determining an optical fiber core to be worked out (hereinafter referred to as a corresponding core wire) from a large number of core wires to be configured will be described below.

  Prior to entering the site, field workers who perform switching work to change the route of the optical network will display the ONU MAC address and the identification tag display information to be attached to the core as the user information to connect to the core. Know in advance. After that, the worker at the job site registers the corresponding core wire using the facility identification tag ascertained in advance.

  On the other hand, at the optical monitoring point in the optical coupler 13 in the communication carrier building, the core line determination device 14 obtains distance information between the monitoring point and the ONU, ONU unique identification information, and optical line measurement data. In the telecommunications carrier building, before the field work for outdoor switching work is started, the distance between the core wire determination device 14 and the ONU 17, ONU 17 is connected by connecting the core wire determination device 14 to the test ports 133 and 134. Get the MAC address and waveform data.

  Next, the site worker gives a loss such as bending to the optical line that is registered as the core. For optical measurement, for example, the test light uses a wavelength longer than the communication light band (1260 to 1625 nm) such as 1650 nm, and an optical filter 16 that blocks only the test light is installed immediately before the ONU 17. Since the loss due to bending to the optical line is large only in the long wavelength, even if the OLT 11 and the ONU 17 are in the communication state, it is possible to specify the corresponding core wire without affecting it.

  The worker who operates the core wire determination device 14 in the telecommunications carrier building and the local worker below the off-site light splitter 15 proceed with the work while communicating with the mobile phone etc. about the progress status etc. Is assumed. In addition, the local worker acquires in advance information about the ONU 17 connected to the optical fiber core to be worked on, for example, “xx-xx-xx-xx-xx-01”.

  Since the loss of the optical fiber core line increases when the local worker bends the optical line, the operator who operates the optical fiber determination device 14 in the telecommunications carrier building displays the core wire determination device 14. The waveform shown in FIG. 5 is observed. As a result, when the reflection corresponding to “xx-xx-xx-xx-xx-01”, which has been confirmed in advance, falls, it can be confirmed that it is definitely the corresponding core wire. If they do not match, the optical line bent by an off-site local worker is not the relevant core line for which the original work is planned, so it is written on the identification tag attached as a mark to the local optical line core line. This information is incorrect, and a worker outside the office only needs to find an optical line in which a waveform change occurs in the optical line core that matches the user apparatus MAC address to be worked on.

  As described above, according to the present embodiment, the optical line network connecting the OLT 11 and the ONU 17 includes the monitor point that leaks the optical signal transmitted in the middle of the optical line network. The ONU 17 or OLT 11 apparatus has a recording timing of a transmission optical signal transmitted to the ONU 17 or from the ONU 17 to the OLT 11 passing through the monitor point and has frame information described in a transmission signal between the OLT 11 and the ONU 17. By analyzing the counter value and the device information, the distance information between the monitoring point and the ONU 17 and the ONU unique identification information are acquired, thereby realizing the line information extraction function (142).

  Further, the optical line length between the ONU 17 and the monitor point extracted from the optical line measurement data by the optical line length measurement function (143), the monitor point obtained by the above-described line information extraction function (142), and the ONU 17 By comparing the distance information between them, a system for comparing the reflection point in the optical line with the ONU information at the far end of the optical line is realized.

  Also, the loss of reversibility is given to the optical line, the optical line length is measured before and after the loss is caused, the measurement data is changed, and the ONU information collated with the changed measurement line length is used as a key. Even when an erroneous identification tag is attached to the route core, a means for confirming whether or not the optical fiber is the correct optical fiber from information only at the connection point at the work site is realized.

According to the above configuration, it is possible to simultaneously check the ONU information and the optical line length information connected to the corresponding optical fiber as compared with the conventional determination of the optical fiber that has been performed by monitoring the occurrence of loss. The accuracy of specifying (determining) the optical fiber core can be improved.
Conventionally, collation with optical measurement data has a storage length of arbitrary length, so a difference of several tens to several hundreds of meters may have occurred in determining whether they match, but according to this method, Collation can be performed with high accuracy. In addition, in order to directly measure the optical fiber core for both measurement and data acquisition, if this information is recorded in association with each other, human errors such as data input errors cannot occur.

  In general, when an optical pulse test is performed, ghost reflection may occur at a position longer than the far end of the optical line due to multiple reflections that reciprocate a reflection point such as a connector in the optical line, and it may be difficult to determine. By using the present invention, it is possible to reliably determine which reflection point is the far end of the optical line in the measurement waveform.

  In the above embodiment, the means for acquiring the leaked light of the optical signal at the monitor point is not a means using an optical coupler, but a bend is applied to the optical fiber constituting the optical line, and the optical fiber by macrobending. A means for generating a radiation mode from the core to the clad to obtain leaked light may be used.

  In addition, in order to confirm the corresponding core wire of the local worker and the operator in the telecommunications carrier building, a phenomenon that the peak value of the reflected waveform of the optical filter 16 fluctuates on the display of the core wire determination device 14. Therefore, instead of the method of bending the lower cores of the optical splitters 12 and 15 as described above, the reflection is performed by a method using polarization modulation by applying a side pressure to the optical fiber. The peak value may be varied.

  Further, an optical branching coupler may be used for the optical switch 141 that switches the input / output ports of the line information extraction unit 142 and the optical line length measurement unit 143 included in the core determination device 14. Further, in order to reduce the branching loss when the optical branching coupler is used, the optical line length measurement unit 143 side transmits test light having a wavelength longer than 1625 nm, for example, and the other line information extraction unit 142 side transmits the test light. A WDM (Wavelength Division Multiplexing) coupler having a characteristic of transmitting a short wavelength of 1625 nm or less may be used.

  Moreover, the core wire determination device 14 is always installed in a telecommunications carrier building, and the optical input / output port 140 of the core wire determination device 14 is installed in a plurality of optical lines (when there are a plurality of OLTs in FIG. 1). The optical coupler 13 is connected to an optical switch (not shown) arbitrarily connected to each optical coupler 13, and the control and determination result of the core wire determination device 14 and the optical switch is transmitted only to a local worker via a mobile phone or a data network. It is good also as a system directly controlled by.

  In addition, the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some configurations may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different example embodiments may be combined as appropriate.

  DESCRIPTION OF SYMBOLS 11 ... OLT, 17 ... ONU (# 1- # 8 in a figure), 12, 15 ... Optical splitter, 13 ... Optical coupler, 131, 132 ... Communication port, 14 ... Core wire determination apparatus, 133, 134 ... Test port, DESCRIPTION OF SYMBOLS 140 ... Optical input / output port, 141 ... Optical switch, 142 ... Line information extraction part, 143 ... Optical line length measurement part, 1421 ... Leakage light receiving part, 1422 ... Signal analysis part, 1431 ... Light source, 1432 ... Light receiving part, 1430 ... Optical coupler, 1433 ... A / D converter, 1434 ... Control device.

Claims (8)

Used in an optical line network that connects an indoor transmission device OLT (Optical Line Terminal) and a plurality of user-side transmission devices ONU (Optical Network Unit) by an optical line, and a monitor point is provided in the middle of the optical line Extracting a part of an optical signal transmitted at a point, analyzing the extracted optical signal and obtaining information for determining the core of the optical line,
Recording means for measuring and recording the timing at which a signal frame passes the monitor point from the extraction result of the optical signal transmitted from the OLT to the ONU or from the ONU to the OLT at the monitor point;
Line information extraction means for acquiring distance information between the monitoring point and the ONU and ONU unique identification information by acquiring device time and device information of the ONU or OLT from a transmission signal frame between the OLT and the ONU ,
An optical line length measuring means for measuring an optical line length from the monitor point to the far end of the optical line;
By comparing the distance information between the monitoring point obtained by the line information extracting means and the ONU with the optical line length obtained by the optical line length measuring means, the reflection point and the optical line in the optical line are compared. Analyzing means for collating with the far-end ONU information,
The analyzing means gives a reversible loss to the optical line, so that the change in the optical line length measurement data that occurs before and after the loss is applied, and the ONU information that matches the measurement line length are used for the optical line. An optical-line core-line determination device characterized by acquiring core-line information.   By providing a phenomenon in which the peak value of the reflected waveform of the optical filter fluctuates by a method using polarization modulation by applying a side pressure to the optical line by arranging an optical filter that generates a reflected wave at the input / output unit of the ONU The optical fiber core wire determination device according to claim 1, wherein the optical fiber core wire is confirmed.   3. The optical line core determining device according to claim 1, wherein an optical coupler is used for extracting the optical signal.   The optical signal is extracted by using means for obtaining leakage light by bending the optical fiber constituting the optical line and generating a radiation mode from the optical fiber core to the cladding by macro bending. The optical line core wire determination apparatus according to claim 1 or 2.   5. The optical line core determining device according to claim 1, wherein an optical switch is used for switching input / output ports of the line information extracting unit and the optical line length measuring unit.   5. The optical fiber core line judging device according to claim 1, wherein an optical branching coupler is used for switching the input / output port of each of the line information extracting unit and the optical line length measuring unit.   The optical branching coupler transmits test light having a first wavelength to the optical line length measuring means side, and test light having a second wavelength shorter than the first wavelength to the other line information extracting means side. 7. The optical fiber core determining device according to claim 6, wherein a WDM (Wavelength Division Multiplexing) coupler having a characteristic of transmitting light is used. Used in an optical line network that connects an indoor transmission device OLT (Optical Line Terminal) and a plurality of user-side transmission devices ONU (Optical Network Unit) by an optical line, and a monitor point is provided in the middle of the optical line Extracting a part of an optical signal transmitted at a point, analyzing the extracted optical signal and obtaining information for determining the core of the optical line,
From the extraction result of the optical signal transmitted from the OLT to the ONU or from the ONU to the OLT at the monitor point, the timing at which the signal frame passes the monitor point is measured and recorded,
By acquiring the device time and device information of the ONU or OLT from the transmission signal frame between the OLT and the ONU, the distance information between the monitor point and the ONU and the ONU unique identification information are acquired,
Measure the optical line length from the monitor point to the far end of the optical line,
By comparing the distance information between the acquired monitor point and the ONU and the measured optical line length, the reflection point in the optical line and the ONU information at the far end of the optical line are collated,
By providing a reversible loss to the optical line, the optical line information of the optical line is obtained from the change in the optical line length measurement data that occurs before and after applying the loss, and the ONU information that matches the measurement line length. A method for determining an optical fiber core wire, comprising:

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