JP2018096788A - Active core determination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active core determination device capable of determining whether an optical fiber core is active or not without influencing communication and regardless of there is a cutoff filter or not and whether a transmission device for a user is on or off.SOLUTION: An active core determination device according to the present invention transmits a determination signal including a wavelength band (for example, 1630 nm or less and 1670 nm or more) passing through a light-shielding filter and a modulation frequency (for example, 270 Hz, 1 kHz or 2 kHz) different from communication light through a determination object optical fiber core toward a user side transmission device direction, and determines whether the core is active or not on the basis of presence or absence of reflection light.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to an optical access network that provides an FTTH (Fiber To The Home) service for connecting a station building and a user's house through an optical fiber, and has a network configuration having a branch by an optical branching element such as an optical splitter installed outside the station building When using (PON: Passive Optical Network), the present invention relates to a working core line discriminating apparatus that estimates whether an optical fiber core wire is working or not working at a user's home side from a branch point where an optical splitter is disposed.

In an optical access network that provides an FTTH (Fiber To The Home) service that connects an office building and a user's home via an optical fiber, a network configuration (PON: Passive) having a branching by an optical branching element such as an optical splitter installed outside the office building (Optical Network) may be used. In this case, the optical fiber core wire is determined by determining the presence or absence of the test light blocking filter provided on the user transmission device side of the optical fiber core wire on the user home side from the branch point where the optical splitter is disposed. Has been proposed (see, for example, Patent Documents 1 and 2).
The working core wire means an optical fiber core wire used by a specific user, and the non-working core wire means an optical fiber core wire not used by any user.

JP 2009-025052 A JP 2008-309958 A Japanese Patent Laying-Open No. 2015-132775

ONU detection tool, https: // www. nttrec. co. jp / product / category0203 / 11226100 (searched on November 25, 2016)

  However, when the cutoff filter is left in the non-working state, it is actually the non-working core wire, but in the conventional method of judging based on the presence or absence of the test light cutoff filter, it is determined as the working core wire. . In view of this, there has been proposed an apparatus that determines whether active or inactive by detecting uplink communication light emitted from a user transmission apparatus (see, for example, Non-Patent Document 1). In addition, by acquiring the communication connection status and MAC address of the user transmission device at the work site on the user's home side from the branch point where the optical splitter is placed, it can be used or not used regardless of the presence or absence of a blocking filter. An apparatus for determination has also been proposed (see, for example, Patent Document 3).

  However, even in these apparatuses, when the power of the user transmission apparatus is OFF, the upstream communication light is not emitted, so that the active core is determined to be non-active. Therefore, the present invention provides a working core discriminating apparatus capable of discriminating whether an optical fiber core is in use or not in use regardless of the presence of a cutoff filter and power ON / OFF of a user transmission apparatus without affecting communication. For the purpose.

  In order to achieve the above object, an active core wire discrimination device according to the present invention combines a determination signal that passes through a light shielding filter into an optical fiber core wire to be determined, and determines whether it is active or inactive depending on the presence or absence of reflected light. It was decided to distinguish.

Specifically, the active core identification device according to the present invention connects a user-side transmission device to an end portion of a user-side optical fiber core via a light-shielding filter that transmits a wavelength band of communication light. In a PON (Passive Optical Network) that provides an optical FTTH (Fiber To The Home) service, an active core discriminating device that determines whether the user side optical fiber core is active or not,
A determination signal incident means for entering a determination signal having a wavelength band that passes through the light shielding filter and a modulation frequency different from that of the communication light in an end direction for each of the user side optical fiber cores;
Reflected light detecting means for detecting reflected light reflected by the end portion of the user side optical fiber core wire, which is input by the determining signal incident means;
When the reflected light detection means does not detect the reflected light, the user side optical fiber core that has entered the determination signal is determined to be in use, and the reflected light detection means detects the reflected light, Determination means for determining that the user-side optical fiber core wire on which the determination signal is incident is inactive;
It is characterized by providing.

  If the optical fiber core is non-working, the user-side transmission device is not connected and is released, so the determination signal is Fresnel-reflected at the open end and returns to the working core discrimination device. On the other hand, when the optical fiber core is currently used and the user-side transmission device is connected, the determination signal is the connection between the optical fiber core and the user-side transmission device regardless of whether the power of the user-side transmission device is on or off. There is almost no reflection at the point. In other words, it is possible to determine whether it is active or not based on the presence or absence of reflected light. And since the signal for determination permeate | transmits a light shielding filter, even if the interruption | blocking filter is left, there is no influence.

  Accordingly, the present invention provides a working core wire discrimination device that can determine whether an optical fiber core wire is active or not, regardless of the presence of a cutoff filter and power ON / OFF of a user transmission device without affecting communication. be able to.

The active core wire discrimination device according to the present invention further comprises communication light detection means for detecting the communication light from the end side for each of the user side optical fiber core wires,
When the communication light detection means detects the communication light, the determination means determines that the user-side optical fiber core wire that has detected the communication light is in use, and the communication light detection means detects the communication light. If not detected, the determination signal incident means is caused to enter the user-side optical fiber core wire, and the reflected light detection means detects or does not detect the reflected light of the user-side optical fiber core wire. It is characterized by determining non-working or working.

  If the communication light detection means is installed, it can be easily determined that the optical fiber core to be determined is in use, and it is not necessary to input a determination signal again to the optical fiber core. Therefore, it is possible to eliminate the influence on the working communication.

The active core wire discriminating apparatus according to the present invention is a test light in which test light having a wavelength band blocked by the light shielding filter and a modulation frequency different from that of the communication light is incident in an end direction for each of the user side optical fiber core wires. Further comprising an incident means,
The reflected light detection means detects reflected test light in which the test light incident by the test light incident means is reflected by the light shielding filter,
The determination means calculates a difference between the light intensity of the reflected light detected by the reflected light detection means and the light intensity of the reflection test light, and detects the reflected light when the difference is larger than a predetermined threshold value. The reflected light is not detected when the difference is smaller than a predetermined threshold value.

  If there is a light shielding filter on the optical fiber core to be judged, if the loss is measured using the test light reflected by the light shielding filter, the optical fiber core is not affected by variations in line loss and input / output efficiency. It becomes possible to determine whether the line is currently used or not.

The determination signal incident means of the active core wire discrimination device according to the present invention comprises:
A bending portion that applies bending to the user-side optical fiber core that enters the determination signal;
A probe fiber that inputs and outputs light from the side of the user side optical fiber core wire in proximity to the bending of the user side optical fiber core wire provided by the bending portion;
And the determination signal is incident on the bending of the user-side optical fiber with the probe fiber,
The reflected light detecting means can receive the reflected light leaking from the bending of the user side optical fiber core wire with the probe fiber.

The determination signal incident means of the active core wire discrimination device according to the present invention comprises:
A bending portion that applies bending to the user-side optical fiber core that enters the determination signal;
A probe fiber that inputs and outputs light from the side of the user side optical fiber core wire in proximity to the bending of the user side optical fiber core wire provided by the bending portion;
And the determination signal is incident on the bending of the user-side optical fiber with the probe fiber,
The reflected light detection means may include a photodetector that receives the reflected light leaking from the bending of the user-side optical fiber core provided by the bending portion.

  The working core wire discriminating apparatus according to the present invention further includes a centering portion that adjusts a relative position between the bending of the user side optical fiber core wire and the probe fiber. It is possible to increase the coupling efficiency to receive the judgment signal and test light to the optical fiber core, and to receive the reflected light and communication light from the optical fiber core, and accurately determine whether the optical fiber core is active or not It becomes possible.

  The working core wire discrimination device according to the present invention uses, for example, a signal having a wavelength of 1630 nm or less or 1670 nm or more and a modulation frequency of 270 Hz, 1 kHz, or 2 kHz as the determination signal. Moreover, the working core wire discrimination apparatus according to the present invention sets, for example, the light intensity of the determination signal between −10 dBm and −30 dBm.

  It is an object of the present invention to provide an active core discriminating apparatus that can determine whether an optical fiber core is active or not, regardless of the presence or absence of a cutoff filter and power ON / OFF of a user transmission apparatus without affecting communication. it can.

It is a figure explaining the determination method of the working core wire discrimination | determination apparatus which concerns on this invention. It is a flowchart explaining operation | movement of the working core wire discrimination | determination apparatus based on this invention. It is a figure explaining the structure of the working core wire discrimination | determination apparatus which concerns on this invention. It is a figure explaining the structure of the working core wire discrimination | determination apparatus which concerns on this invention. It is a flowchart explaining operation | movement of the working core wire discrimination | determination apparatus based on this invention. It is a figure explaining the structure of the working core wire discrimination | determination apparatus which concerns on this invention. It is a figure explaining the structure of the working core wire discrimination | determination apparatus which concerns on this invention. It is a flowchart explaining operation | movement of the working core wire discrimination | determination apparatus based on this invention. It is a figure explaining the structure of the working core wire discrimination | determination apparatus which concerns on this invention. It is a figure explaining the structure of the working core wire discrimination | determination apparatus which concerns on this invention. It is a figure explaining the alignment part of the active core wire discrimination | determination apparatus which concerns on this invention.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments. In the present specification and drawings, the same reference numerals denote the same components.

  FIG. 1 is a diagram for explaining a determination method of an active core wire determination apparatus according to the present invention. The equipment situation on the user side of the optical fiber core is one of the four patterns (1) to (4) in FIG. (1) is the current work in which the user-side transmission device is connected to the optical fiber and the light-shielding filter is installed, and the user-side transmission device is turned on. (2) is the current work in which the user-side transmission device is connected to the optical fiber core and the light-shielding filter is installed, and the power supply of the user-side transmission device is in the OFF state. (3) is a non-working state in which the optical fiber core wire is released, and is a state in which the light shielding filter is left behind. (4) is a non-working where the optical fiber core wire is released, and the shading filter is also removed.

The working core wire discriminating apparatus according to the present invention discriminates these situations by the following two flows.
Flow 1: Search for upstream communication light from the user-side transmission device propagating through the determination target optical fiber using the communication light detection means. If the upstream communication light is detected, the pattern (1) is determined. If uplink communication light cannot be detected, it is one of patterns (2) to (4).
Flow 2: a determination signal having a wavelength band (for example, 1630 nm or less or 1670 nm or more) that transmits the light shielding filter through the optical fiber core to be determined and a modulation frequency (for example, 270 Hz, 1 kHz, or 2 kHz) that is different from communication light Send to the side transmission device. If the optical fiber core is an open end, the reflected light by Fresnel reflection returns, but if the user-side transmission device is connected, there is almost no reflected light by Fresnel reflection. Therefore, if the reflected light of the transmitted determination signal is detected, it can be determined as non-working according to the pattern (3) or (4). If there is no reflected light, the pattern (2) is determined as active.

(Embodiment 1)
The active core wire discrimination device according to the present embodiment connects a user side transmission device to an end portion of a user side optical fiber core wire through a light shielding filter that transmits a wavelength band of communication light, and uses the communication light to perform FTTH (Fiber). In a PON (Passive Optical Network) that provides a To The Home (Service), a working core discriminating device that determines whether each of the user side optical fiber cores is in use or not,
A determination signal incident means for entering a determination signal having a wavelength band that passes through the light shielding filter and a modulation frequency different from that of the communication light in an end direction for each of the user side optical fiber cores;
Reflected light detecting means for detecting reflected light reflected by the end portion of the user side optical fiber core wire, which is input by the determining signal incident means;
When the reflected light detection means does not detect the reflected light, the user side optical fiber core that has entered the determination signal is determined to be in use, and the reflected light detection means detects the reflected light, Determination means for determining that the user-side optical fiber core wire on which the determination signal is incident is inactive;
Is provided.

  FIG. 2 is a flowchart for explaining the operation of the working core line discrimination device of the present embodiment. Step S04 is an operation performed by the determination signal injection means. The determination signal incident means uses a light signal having a wavelength band (for example, 1630 nm or less or 1670 nm or more) that passes through the light shielding filter and a modulation frequency (for example, 270 Hz, 1 kHz, or 2 kHz) different from the communication light as a determination signal. The fiber core wire is sent in the direction of the user transmission device.

  Here, the light intensity of the determination signal reaching the user-side transmission device is such that it does not affect communication, and the light intensity of the reflected light reaching the reflected light detection means is equal to or higher than the minimum light receiving sensitivity of the reflected light detection means. Need to be. For example, the light intensity of the determination signal is desirably about −10 dBm to −30 dBm.

Step S05 is an operation performed by the reflected light detection means and the determination means. The reflected light detection means and the determination means determine whether or not the reflected light of the transmitted determination signal is detected. The reflected light detection means determines whether or not the reflected light is detected as follows.
The light intensity received by the reflected light detection means can be expressed by the following equation.
Pout = Pin + T + Ein−L + RL−Eout + T (Formula 1)
However,
Pout: light intensity received by the reflected light detection means Pin: light intensity transmitted from the determination signal incident means T: transmittance combined with an optical circulator, wavelength multiplexer / demultiplexer, etc. L: line loss (for one way)
R: reflectivity at the end of the optical fiber core Ein: input efficiency from the judgment signal incident means to the optical fiber core Eout: output efficiency from the optical fiber core to the reflected light detection means

  When a user-side transmission device is connected to the end of the optical fiber core, R = −50 dB to −35 dB. On the other hand, when the user-side transmission device is not connected to the end of the optical fiber core wire, R = about -14 dB due to Fresnel reflection. Since Pout differs by 21 dB to 36 dB depending on whether or not the user-side transmission device is connected to the end of the optical fiber core, the determination means determines whether it is active or not based on this difference. Specifically, it has a determination threshold value for Pout, and if Pout is smaller than the threshold value, it is determined that the active optical fiber is connected to the user side transmission apparatus (step S06). If Pout is larger than the threshold value, the user side is determined. It is determined that the non-working optical fiber is not connected to the transmission device (step S07).

(Example 1-1)
FIG. 3 is a diagram for explaining a working core line discriminating apparatus 301 which is an example of the present embodiment. The determination signal incident means of the active core wire discrimination device 301 is:
A bending portion 11 for bending the user-side optical fiber core line 50 on which the determination signal is incident;
A probe fiber 12 that inputs and outputs light from the side of the user side optical fiber core 50 in proximity to the bending of the user side optical fiber core wire 50 provided by the bending portion 11;
And the determination signal is incident on the bending of the user-side optical fiber 50 with the probe fiber 12,
The reflected light detecting means receives the reflected light leaking from the bending of the user side optical fiber core wire 50 with the probe fiber 12.

  The determination signal incident means includes a bending part 11, a probe fiber 12, an optical circulator 13, and a determination signal transmission part 14. The determination signal transmitter 14 outputs a determination signal, the optical circulator 13 couples the determination signal to the probe fiber 12, and the probe fiber 12 is determined to be bent formed on the user side optical fiber core 50 by the bending portion 11. The signal for use is incident.

  The reflected light detection means includes a bending portion 11, a probe fiber 12, an optical circulator 13, and a reflected light detection portion 15. The probe fiber 12 receives reflected light leaking from the bend formed on the user side optical fiber core 50 by the bending section 11, the optical circulator 13 couples the reflected light to the reflected light detection section 15, and the reflected light detection section 15 The presence or absence of reflected light is detected from the light intensity of the reflected light.

  The determination means includes a working core line determination processing unit 16. The working core line determination processing unit 16 is connected to the determination signal transmission unit 14 and the reflected light detection unit 15. The working core line discrimination processing unit 16 receives the transmission report that transmitted the determination signal from the determination signal transmission unit 14. The working core discrimination processing unit 16 receives the light intensity of the reflected light received from the reflected light detection unit 15 within a predetermined time from the transmission report, and determines whether the optical fiber core 50 is active or not according to the flow shown in FIG. Determine whether it is in use.

(Example 1-2)
FIG. 4 is a diagram for explaining a working core line discriminating apparatus 302 which is an example of the present embodiment. The determination signal incident means of the active core wire discrimination device 302 includes:
A bending portion 11 for bending the user-side optical fiber core line 50 on which the determination signal is incident;
A probe fiber 12 that inputs and outputs light from the side of the user side optical fiber core 50 in proximity to the bending of the user side optical fiber core wire 50 provided by the bending portion 11;
And the determination signal is incident on the bending of the user-side optical fiber 50 with the probe fiber 12,
The reflected light detection means includes
It has the photodetector 17 which receives the said reflected light leaking from the bending of the user side optical fiber core wire 50 which the bending part 11 provided.

  The determination signal incident means includes a bending portion 11, a probe fiber 12, and a determination signal transmission portion 14. The determination signal transmitter 14 outputs a determination signal and couples it to the probe fiber 12, and the probe fiber 12 makes the determination signal incident on the bend formed by the bending unit 11 on the user-side optical fiber core 50.

  The reflected light detection means includes a bending portion 11, a photodetector 17, and a reflected light detection portion 15. The photodetector 17 receives reflected light leaking from the bend formed on the user-side optical fiber 50 by the bending portion 11, and the reflected light detection portion 15 detects the presence or absence of reflected light from the light intensity of the reflected light received by the photodetector 17. To do.

  The determination means includes a working core line determination processing unit 16. The operation of the working cord determination processing unit 16 is the same as that described in FIG.

(Embodiment 2)
The active core detection device of the present embodiment further includes communication light detection means for detecting the communication light from the end side for each of the user side optical fiber cores with respect to the active core determination device of the first embodiment. ,
The determination means includes
When the communication light detection means detects the communication light, it is determined that the user side optical fiber core wire that has detected the communication light is in use, and when the communication light detection means does not detect the communication light, The determination signal incident means is made to enter the user side optical fiber core wire, and the reflected light detection means detects or does not detect the reflected light so that the user side optical fiber core wire is not used or used. judge.

  FIG. 5 is a flowchart for explaining the operation of the working core line discrimination device of the present embodiment. In the working core discriminating apparatus of the present embodiment, steps S01 to S03 are added to the operation of the working core discriminating apparatus of the first embodiment (the flowchart in FIG. 2).

  Step S01 is an operation performed by the communication light detection means. The communication light detecting means detects upstream communication light propagating through the user side optical fiber core. Examples of means for detecting upstream communication light include devices described in Non-Patent Document 1 and Patent Document 2. Step S02 is an operation performed by the determination means. When the communication light detection unit detects the uplink communication light propagating through the user side optical fiber core, the determination unit determines that the user side optical fiber core is in use (step S03). On the other hand, when the communication light detection unit cannot detect the upstream communication light propagating through the user side optical fiber core, the determination unit performs step S04 and subsequent steps described with reference to FIG. 2 to determine whether the user side optical fiber core wire is in use. Determine whether it is non-working.

(Example 2-1)
FIG. 6 is a diagram for explaining a working core line discrimination device 303 as an example of the present embodiment. The determination signal incident means of the active core wire discrimination device 303 is:
A bending portion 11 for bending the user-side optical fiber core line 50 on which the determination signal is incident;
A probe fiber 12 that inputs and outputs light from the side of the user side optical fiber core 50 in proximity to the bending of the user side optical fiber core wire 50 provided by the bending portion 11;
And the determination signal is incident on the bending of the user-side optical fiber 50 with the probe fiber 12,
The reflected light detecting means receives the reflected light leaking from the bending of the user side optical fiber core wire 50 with the probe fiber 12.

  The communication light detection means includes a bending part 11, a probe fiber 12, a wavelength multiplexer / demultiplexer 18, and a communication light detection part 19. The probe fiber 12 receives upstream communication light leaking from the bend formed on the user-side optical fiber core 50 by the bending section 11, and the wavelength multiplexer / demultiplexer 18 couples the communication light to the communication light detection section 19, The detection unit 19 detects the presence or absence of upstream communication light by means described in Non-Patent Document 1 and Patent Document 2. Since the communication light and the reflected light have different wavelength bands, the wavelength multiplexer / demultiplexer 18 can couple the communication light to the communication light detector 19 and couple the reflected light to the circulator 13.

  The determination signal incident means includes a bending section 11, a probe fiber 12, a wavelength multiplexer / demultiplexer 18, an optical circulator 13, and a determination signal transmission section 14. The determination signal transmitter 14 outputs a determination signal, the optical circulator 13 and the wavelength multiplexer / demultiplexer 18 couple the determination signal to the probe fiber 12, and the probe fiber 12 is bent at the user side optical fiber core wire. A determination signal is incident on the bend formed at 50.

  The reflected light detection means includes a bending part 11, a probe fiber 12, a wavelength multiplexer / demultiplexer 18, an optical circulator 13, and a reflected light detection part 15. The probe fiber 12 receives reflected light leaking from the bend formed on the user side optical fiber 50 by the bending portion 11, and the wavelength multiplexer / demultiplexer 18 and the optical circulator 13 couple the reflected light to the reflected light detection portion 15. The reflected light detector 15 detects the presence or absence of reflected light from the light intensity of the reflected light.

  The determination means includes a working core line determination processing unit 16. The working core line discrimination processing unit 16 is connected to the communication light detection unit 19, the determination signal transmission unit 14, and the reflected light detection unit 15. When receiving the detection report that the upstream communication light is detected from the communication light detection unit 19, the active core detection unit 16 determines that the user-side optical fiber core 50 is in use. When receiving a non-detection report that the upstream communication light has not been detected, the working core line determination processing unit 16 causes the determination signal transmission unit 14 to transmit a determination signal. In addition, the working core line discrimination processing unit 16 receives a transmission report in which the determination signal is transmitted from the determination signal transmission unit 14. The working core discrimination processing unit 16 receives the light intensity of the reflected light received from the reflected light detection unit 15 within a predetermined time from the transmission report, and determines whether the optical fiber core 50 is active or not according to the flow shown in FIG. Determine whether it is in use.

(Example 2-2)
FIG. 7 is a diagram for explaining a working core line discriminating apparatus 304 as an example of the present embodiment. The determination signal incident means of the active core wire discrimination device 304 is:
A bending portion 11 for bending the user-side optical fiber core line 50 on which the determination signal is incident;
A probe fiber 12 that inputs and outputs light from the side of the user side optical fiber core 50 in proximity to the bending of the user side optical fiber core wire 50 provided by the bending portion 11;
And the determination signal is incident on the bending of the user-side optical fiber 50 with the probe fiber 12,
The reflected light detection means includes
It has the photodetector 17 which receives the said reflected light leaking from the bending of the user side optical fiber core wire 50 which the bending part 11 provided.

The operation and configuration of the communication light detection means are the same as those described in Example 2-1 in FIG.
The determination signal incident means includes a bending section 11, a probe fiber 12, a wavelength multiplexer / demultiplexer 18, and a determination signal transmission section 14. The determination signal transmitter 14 outputs a determination signal, the wavelength multiplexer / demultiplexer 18 couples the determination signal to the probe fiber 12, and the probe fiber 12 is formed by the bending portion 11 on the user side optical fiber core 50. A judgment signal is incident on the bend.
The operation and configuration of the reflected light detection means are the same as those described in Example 1-2 in FIG.
The determination means includes a working core line determination processing unit 16. The operation of the working cord determination processing unit 16 is the same as that described in FIG.

(Embodiment 3)
The working core line discriminating apparatus according to the present embodiment is different from the working core line discriminating apparatus according to the second embodiment in the wavelength band blocked by the light-shielding filter in the end direction for each user-side optical fiber core line and the communication light. A test light incident means for injecting test light having a different modulation frequency from
The reflected light detection means detects reflected test light in which the test light incident by the test light incident means is reflected by the light shielding filter,
The determination means calculates a difference between the light intensity of the reflected light detected by the reflected light detection means and the light intensity of the reflection test light, and detects the reflected light when the difference is larger than a predetermined threshold value. When the difference is smaller than a predetermined threshold, the reflected light is not detected.

  FIG. 8 is a flowchart for explaining the operation of the active core wire discrimination device of the present embodiment. In the working core discriminating apparatus of this embodiment, step S03A is added to the operation of the working core discriminating apparatus of the second embodiment (the flowchart in FIG. 5).

  Step S03A is an operation of performing test light incident means and reflected light detection means. The test light incident means is a test light having a wavelength band (for example, 1650 nm band) blocked by a light-shielding filter installed on the user side optical fiber core and a modulation frequency (for example, 270 Hz, 1 kHz, or 2 kHz) different from the communication light. Is sent to the user side optical fiber in the direction of the user side transmission apparatus. Then, the reflected light detecting means receives the reflected test light, which is the test light reflected by the light shielding filter, and measures the light intensity.

The working core line discriminating apparatus according to the present embodiment receives test light reflected by the light shielding filter, and obtains Pout in the case of R≈0 in Expression 1. When Pout when the test light is incident is Pout1 [dB], and Pout when the determination signal is incident is Pout2 [dB],
Pout1-Pout2 ≒ R
Therefore, R can be obtained without depending on the values of L, Ein, and Eout. That is, the working core line discriminating apparatus according to the present embodiment can discriminate whether it is working or not working with high accuracy without being affected by variations in line loss and input / output efficiency as compared with the first and second embodiments.

For example, when the user side optical fiber is currently used (FIGS. 1 (1) and (2)),
Pout1-Pout2≈R = 35 dB to 50 dB,
When an open end and a light shielding filter are installed (FIG. 1 (3)),
Pout1-Pout2≈R = 14 dB,
When the open end and shading filter is not installed (Fig. 1 (4))
Pout1-Pout2≈0.
By setting the threshold value of Pout1-Pout2 used when determining whether the determination means is active or non-active to a value between 14 dB and 35 dB (for example, 20 dB), it is possible to determine whether it is active or non-active.

(Example 3-1)
FIG. 9 is a diagram for explaining a working core line determination device 305 as an example of the present embodiment. The test light incident means includes a bending portion 11, a probe fiber 12, a wavelength multiplexer / demultiplexer 18, an optical circulator 13, and a determination signal transmission portion 14. The determination signal transmission unit 14 outputs test light having a wavelength band (for example, 1650 nm band) blocked by the light shielding filter and a modulation frequency (for example, 270 Hz, 1 kHz, or 2 kHz) different from the communication light, and the optical circulator 13 and The wavelength multiplexer / demultiplexer 18 couples the test light to the probe fiber 12, and the probe fiber 12 makes the test light incident on the bend formed by the bending portion 11 on the user-side optical fiber core wire 50.
The communication light detection means, the determination signal incident means, the reflected light detection means, and the determination means are the same as those in the description of the working core line determination device 303 in FIG.

  That is, the structure of the working core wire discriminating device 305 is the same as that of the working core wire discriminating device 303 in FIG. 6, but the judgment signal transmitting unit 14 also transmits the test light, and the reflected light detecting unit 15 reflects the light. The test light is also detected, and the difference between the light intensity of the reflected light and the reflected test light is used when the active core determination unit 15 determines whether the user-side optical fiber core is active or not. Is different.

  9 is configured such that the determination signal transmission unit 14 can emit test light having a wavelength of 1650 nm in the configuration of the active core line determination apparatus 303 in FIG. The active core line discriminating apparatus 301, the active core line discriminating apparatus 302 in FIG. 4, and the active core line discriminating apparatus 304 in FIG. 7 can also have a structure capable of emitting test light having a wavelength of 1650 nm to the determination signal transmitter 14. .

(Embodiment 4)
FIG. 10 shows a working core line discrimination device 306 of the present embodiment. The working core discriminating device 306 further includes a centering unit 20 that adjusts the bending of the user-side optical fiber core 50 and the relative position of the probe fiber 12 with respect to the working core discriminating device 305 of the third embodiment.

  The working core discriminating device 306 includes an aligning unit 20 for aligning the probe fiber 12 at an optimum position so that the maximum input / output efficiency can be obtained by side input / output in bending of the user side optical fiber core 50. A control unit 21 is included.

  The determination signal transmission unit 14 causes test light or a determination signal to enter the bending of the target user-side optical fiber core wire 50 from the probe fiber 12. The reflected light reflected at the end of the user-side optical fiber core 50 or the reflected test light reflected by the light shielding filter is again received by the probe fiber 12, and the control unit 21 maximizes the received light power measured by the reflected light detector 15. Thus, the alignment unit 20 is driven to align the probe fiber 12. The upstream communication light of the user-side optical fiber core 50 is received by the probe fiber 12, the alignment unit 20 is driven so that the received light power measured by the control unit 21 by the communication light detection unit 19 is maximized, and the probe The fiber 12 may be aligned.

  FIG. 11 is a diagram for explaining the operation of the aligning unit 20. 11A is a top view seen from a direction perpendicular to the user-side optical fiber core 50 and the probe fiber 12, and FIG. 11B is seen from a direction parallel to the user-side optical fiber core 50. It is a side view. It is desirable that the aligning portion 20 can move the tip of the probe fiber 12 as shown in FIG. 11, and is desirably adjustable at least in the Y-axis and Z-axis directions. The aligning unit 20 is, for example, a micrometer when performing manual alignment, and is an ultrasonic actuator or piezoelectric actuator having a resolution of about 1 μm when performing automatic alignment.

  10 has a configuration in which the alignment unit 20 and the control unit 21 are added to the configuration of the active core discriminating device 305 in FIG. 9, but the active core discriminating device 301 in FIG. The working core line discriminating apparatus 302 of FIG. 4 and the working core line discriminating apparatus 304 of FIG. 7 can also be configured by adding the alignment unit 20 and the control unit 21.

(Effect of the invention)
The active core wire discrimination device described in the present embodiment has the following effects.
(1) Regardless of the presence or absence of the cutoff filter and the power transmission ON / OFF of the user transmission device, it is possible to determine whether the user-side optical fiber core is active or not.
(2) It is possible to determine whether the user-side optical fiber core wire is in use or not in use without cutting the connector or removing the connector.
(3) The working / non-working can be determined simply by bending the user-side optical fiber at the work site.
(4) Unlike Patent Documents 1 and 2, since it is not necessary to enter test light from the station side device, it is completed only at the work site.

11: Bending unit 12: Probe fiber 13: Optical circulator 14: Determination signal transmission unit 15: Reflected light detection unit 16: Working core line discrimination processing unit 17: Photo detector 18: Wavelength multiplexer / demultiplexer 19: Communication light detection unit 20 : Alignment unit 21: control unit 50: user side optical fiber core wires 301 to 306: active core wire discrimination device

Claims (8)

A user-side transmission device is connected to the end of the user-side optical fiber via a light-shielding filter that transmits the wavelength band of communication light, and a PON (Passive to provide FTTH (Fiber To The Home) service with the communication light. In an Optical Network), a working core wire discriminating device for determining whether the user side optical fiber core wire is in use or not,
A determination signal incident means for entering a determination signal having a wavelength band that passes through the light shielding filter and a modulation frequency different from that of the communication light in an end direction for each of the user side optical fiber cores;
Reflected light detecting means for detecting reflected light reflected by the end portion of the user side optical fiber core wire, which is input by the determining signal incident means;
When the reflected light detection means does not detect the reflected light, the user side optical fiber core that has entered the determination signal is determined to be in use, and the reflected light detection means detects the reflected light, Determination means for determining that the user-side optical fiber core wire on which the determination signal is incident is inactive;
An apparatus for discriminating a working core wire, comprising: Further comprising communication light detecting means for detecting the communication light from the end side for each of the user side optical fiber cores,
The determination means includes
When the communication light detection means detects the communication light, it is determined that the user side optical fiber core wire that has detected the communication light is in use, and when the communication light detection means does not detect the communication light, The determination signal incident means is made to enter the user side optical fiber core wire, and the reflected light detection means detects or does not detect the reflected light so that the user side optical fiber core wire is not used or used. The active core wire discrimination device according to claim 1, wherein the determination is performed. Test light incident means for injecting test light having a wavelength band cut off by the light shielding filter and a modulation frequency different from the communication light in the end direction for each of the user side optical fiber cores,
The reflected light detection means detects reflected test light in which the test light incident by the test light incident means is reflected by the light shielding filter,
The determination means calculates a difference between the light intensity of the reflected light detected by the reflected light detection means and the light intensity of the reflection test light, and detects the reflected light when the difference is larger than a predetermined threshold value. 3. The working core line discrimination device according to claim 1, wherein the reflected light is not detected when the difference is smaller than a predetermined threshold value. The determination signal incident means includes:
A bending portion that applies bending to the user-side optical fiber core that enters the determination signal;
A probe fiber that inputs and outputs light from the side of the user side optical fiber core wire in proximity to the bending of the user side optical fiber core wire provided by the bending portion;
And the determination signal is incident on the bending of the user-side optical fiber with the probe fiber,
4. The active core wire discrimination device according to claim 1, wherein the reflected light detection unit receives the reflected light leaking from the bending of the user side optical fiber core wire with the probe fiber. 5. . The determination signal incident means includes:
A bending portion that applies bending to the user-side optical fiber core that enters the determination signal;
A probe fiber that inputs and outputs light from the side of the user side optical fiber core wire in proximity to the bending of the user side optical fiber core wire provided by the bending portion;
And the determination signal is incident on the bending of the user-side optical fiber with the probe fiber,
The reflected light detection means includes
The working core wire discrimination device according to any one of claims 1 to 3, further comprising a photodetector that receives the reflected light leaking from the bending of the user side optical fiber core wire provided by the bending portion.   The working core wire discrimination device according to claim 4, further comprising a centering portion that adjusts a bending of the user side optical fiber core wire and a relative position between the probe fiber and the probe fiber.   7. The determination signal incident means uses a signal having a wavelength of 1630 nm or less or 1670 nm or more and a modulation frequency of 270 Hz, 1 kHz, or 2 kHz as the determination signal. Working cord discriminating device.   8. The working core wire discriminating apparatus according to claim 1, wherein the determination signal incident unit sets a light intensity of the determination signal between −10 dBm and −30 dBm. 9.

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