JP2013243496A - Duplex device and duplex method of optical transmission line - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the uplink test signal light without entering it by means of a lower optical branch coupler.SOLUTION: A test signal is obtained by demultiplexing the uplink signal light by means of a lower optical branch coupler 201, and converting the wavelength of the uplink signal light thus obtained into the test signal wavelength. Since the optical path length difference can be determined from the uplink signal light and the test signal light multiplexed by an upper optical branch coupler 202, it is not required to enter the test signal light from the lower optical branch coupler, and a 2-input 1-output or 1-input 2-output optical branch coupler can be utilized as the lower optical branch coupler 201.

Description

  The present invention relates to an optical transmission line duplexing technique for forming a temporary detour at the time of switching an optical transmission line in a troubled transfer work of the optical transmission line.

As a conventional optical transmission path duplexing technique, there are a system in which all signal transmission in a detour is performed as an optical signal and a system in which it is temporarily converted into an electrical signal (for example, see Non-Patent Document 1 and Non-Patent Document 2).
In these systems, the test signal light for detecting the optical path length difference between the main line and the detour needs to be incident from the upper or lower optical branching coupler. Therefore, both the upper optical branch coupler and the lower optical branch coupler are two-input / two-output optical branch couplers. Here, as the upper optical branching coupler, it is possible to use the optical branching coupler already installed in the communication equipment building for the test use, but the lower optical branching coupler is not installed in the existing equipment, A temporary optical branching coupler based on the direction input / output technology (for example, Non-Patent Document 3) is required.

  However, the optical branching coupler using the side light input / output technology that is currently being realized is a branch with 2 downstream inputs and 1 output and 1 upstream input and 2 outputs, and the incident end of the upstream test signal light cannot be obtained. There is a problem that it cannot be used as a two-input / two-output optical branching coupler required for duplexing optical transmission lines.

Higashi et al .: Basic study on optical access media switching system -Service uninterrupted optical media switching system-, IEICE Technical OFT2008-52, pp.27-31, 2008 Tanaka et al .: Improving the reliability of optical fiber switching technology without service interruption, Science technique OFT2010-18, pp.11-16, 2010. Nado et al., High-performance optical fiber side-incidence method, 2011 IEICE General Conference Proceedings, p324, 2011 Elmic Corporation, PDH 4-bit, 6-bit high-speed programmable delay line: http://www.elmec.co.jp/programmable.html

  As described above, the optical branching coupler using the side light input / output technology that is currently being realized is a 2-input / 1-output or 1-input / 2-output branch, and an incident end of the upstream test signal light is obtained. Therefore, it cannot be used as a 2-input / 2-output optical branching coupler required for duplexing the optical transmission line.

  The present invention has been made in order to solve the above-described problem. The upstream test signal light can be obtained without the upstream test signal light being incident on the lower optical branching coupler. An object of the present invention is to provide an optical transmission line duplexing apparatus and a duplexing method thereof that can duplex an optical transmission path by using a 1-output or 1-input / 2-output optical branching coupler.

In order to solve the above-described problems, a duplexer for an optical transmission line according to the present invention is configured in the following manner.
(1) Upper detour used in an optical transmission apparatus in which the opposite station-side transmission apparatus and subscriber-side transmission apparatus transmit and receive signal light via the working optical fiber and are interposed at any two locations in the working optical fiber Forming a detour between the optical branching coupler for the lower part and the optical branching coupler for the lower part of the bypass, and in the optical transmission line duplexer for duplexing the communication, respectively connected to the branch ends of the upper and lower bypass optical branching couplers, Wavelengths of the upstream signal light of the upstream wavelength emitted from the subscriber side transmission device, the downstream signal light of the downstream wavelength emitted from the station side transmission device, and the test signal light of the test wavelength emitted from the test signal generator A pair of wavelength division multiplexing couplers for multiplexing and demultiplexing, an upstream optical signal-electric converter formed between the pair of wavelength division multiplexing couplers for converting the upstream optical signal into an upstream electrical signal, and the upstream electrical signal are provided. Uplink signal variable delay device that delays the time, an uplink signal electro-optical converter that converts the uplink electrical signal into signal light, an uplink signal light transmission means that includes an uplink signal light blocking switch that outputs and stops the uplink signal light, and A downlink signal light-electric converter formed between the pair of wavelength division multiplexing couplers for converting the downlink signal light into an electrical signal, a downlink signal variable delay device for delaying the downlink electrical signal for a set time, and the downlink electrical signal Formed between a pair of wavelength division multiplexing couplers, a downlink signal light-to-light converter for converting to downlink signal light, a downlink signal light transmission means including a downlink signal light blocking switch for outputting and stopping the downlink signal light, and A test signal variable delay device that takes in an electrical signal converted by an upstream signal light-electric converter as a test electrical signal and delays it for a set time, and converts the test electrical signal into a test signal light In other words, test signal electro-optical conversion means for converting to the test wavelength, test signal light transmission means including a test signal light cutoff switch for outputting and stopping the test signal light, and the test branched by the upper optical branching coupler An optical path length detector that receives the signal light and the upstream signal light, detects the presence or absence of an optical path length difference between the working optical fiber and the bypass optical fiber, and monitors the presence or absence of the optical path length difference and the test signal Control for controlling the delay time of the variable delay device and setting the delay time set in the test signal variable delay device when the difference in optical path length is detected in the uplink signal variable delay device and the downlink signal variable delay device It is set as the aspect which comprises a vessel.

  (2) In (1), the optical path length difference detector is a two-input / two-output optical switch in which transmission signal light of upstream signal light and test signal light that has passed through the upper optical branching coupler is provided to one input terminal And taking the transmission signal light output from one output end of the two-input / two-output optical switch, selecting the wavelength of the test signal light, and sending the selected test signal light to the other of the two-input / two-output optical switch. A test signal wavelength selection filter to be output to the input terminal of the optical signal and a transmission signal light output from the other output terminal of the two-input / two-output optical switch to convert the test signal light and the upstream signal light into electrical signals Clock signal recovery for extracting a clock from a test signal / upstream signal optical-electrical converter and a transmission signal output from the test signal / upstream optical signal-electrical converter and detecting an error at the time of extraction ; And a color detector, a manner for detecting the presence or absence of the optical path length difference from the detection result of the clock data recovery error detector.

(3) In (1), the test signal electro-optical conversion means converts the test electric signal delayed by the test signal variable delay device into test signal light of the test wavelength. It is set as the aspect provided with.
(4) In (1), the optical path length is provided in the new optical fiber when the working optical fiber is replaced with a new optical fiber, and converts the upstream signal light into the test wavelength. The detector receives the test signal light from the new optical fiber branched by the upper optical branching coupler and the test signal light from the bypass transmission path, and an optical path length difference between the new optical fiber and the bypass transmission path The controller monitors the presence or absence of the optical path length difference to control the delay time of the test signal variable delay device, and the test signal variable delay when the optical path length difference is detected is detected. In this aspect, the upstream signal variable delay device and the downstream signal variable delay device are set by subtracting the conversion delay time of the wavelength converter from the delay time set in the device.

Moreover, the duplexing method of the optical transmission line according to the present invention is configured in the following manner.
(5) Upper detour used in an optical transmission apparatus in which the opposite station-side transmission apparatus and subscriber-side transmission apparatus transmit and receive signal light via the working optical fiber and are interposed at any two locations in the working optical fiber In the optical transmission path duplexing method in which a detour is formed between the optical branching coupler for lower use and the optical branching coupler for lower detouring to duplex communication, a pair of wavelength divisions are made at the branching ends of the upper and lower detouring optical branching couplers, respectively. Multiplex couplers are connected, the upstream signal light of the upstream wavelength emitted from the subscriber side transmission apparatus, the downstream signal light of the downstream wavelength emitted from the station side transmission apparatus, and the test wavelength emitted from the test signal generator An upstream optical signal-to-electric converter that converts the upstream optical signal into an upstream electrical signal between the pair of wavelength division multiplexing couplers, and the upstream electrical signal Upstream signal optical transmission line comprising an upstream signal variable delay device that delays by a fixed time, an upstream signal electro-optical converter that converts the upstream electrical signal into signal light, an upstream signal light blocking switch that outputs and stops the upstream signal light, and A downstream signal light-electric converter for converting the downstream signal light into an electrical signal between the pair of wavelength division multiplexing couplers, a downstream signal variable delay device for delaying the downstream electrical signal for a set time, and the downstream electrical signal Forming a downstream signal light transmission path including a downstream signal light blocking switch that outputs and stops the downstream signal light, and between the pair of wavelength division multiplexing couplers, A test signal variable delay device that takes the electrical signal converted by the upstream signal light-electric converter as a test electrical signal and delays it for a set time, and converts the test electrical signal into a test signal light. Test signal electro-optical conversion means for converting to the test wavelength, a test signal light transmission line comprising a test signal light cut-off switch for outputting and stopping the test signal light, and the test branched by the upper optical branch coupler The signal light and the upstream signal light are received and compared to detect the presence or absence of an optical path length difference between the working optical fiber and the bypass optical fiber, and the presence or absence of the optical path length difference is monitored to The delay time is controlled, and the delay time set in the test signal variable delay device when the difference in optical path length is detected is set in the uplink signal variable delay device and the downlink signal variable delay device.

  (6) In (5), when the working optical fiber is replaced with a new optical fiber, a wavelength converter for converting the upstream signal light into the test wavelength is disposed in the new optical fiber, and the upper optical branching coupler Detecting the presence or absence of an optical path length difference between the new optical fiber and the detour transmission path from the test signal light from the new optical fiber and the test signal light from the detour transmission path branched at To control the delay time of the test signal variable delay device, and the conversion delay time of the wavelength converter is determined from the delay time set in the test signal variable delay device when the difference in optical path length is detected. It is set as the aspect which deducts and sets to the said upstream signal variable delay device and the downstream signal variable delay device.

  The duplexer of the optical transmission line of the present invention demultiplexes the upstream signal light by the lower optical branching coupler, and obtains the test signal by converting the wavelength of the upstream signal light obtained to the wave test signal wavelength. And In this case, the conversion of the wavelength of the upstream signal light to the wavelength of the test signal light may be light-to-light conversion, or once the upstream signal light is converted into a test electrical signal and processed by an electrical circuit. In addition, the electrical signal may be converted to a test signal light wavelength. Thereby, the optical path length difference can be detected from the upstream signal light and the test signal light combined in the upper optical branching coupler. In this way, since the test signal light does not need to be incident from the lower optical branch coupler as in the prior art in order to obtain the test signal light from the upstream signal light, the lower optical branch coupler has a two-input / two-output optical branch coupler. Therefore, it is possible to use a 2-input / 1-output or 1-input / 2-output optical branching coupler.

  Therefore, according to the present invention, it is possible to obtain the upstream test signal light without entering the upstream test signal light by the lower optical branching coupler, and for the lower optical branching, two inputs / one output or one input / two outputs. It is possible to provide an optical transmission line duplexing apparatus and a duplexing method thereof that can duplex an optical transmission path by using the optical branching coupler.

1 is a block diagram illustrating an internal configuration of a duplexer for an optical transmission line according to the present invention and a detour component that is one of its components. FIG. FIG. 2 is a block diagram illustrating the flow of signal light and test light when detecting a difference in optical path length during communication using an active optical fiber in the initial state of a duplex configuration in the apparatus shown in FIG. 1. It is a flowchart which shows the control procedure of the controller in the initial state of FIG. FIG. 2 is a block diagram illustrating the flow of signal light and test light when detecting a difference in optical path length during communication using a bypass component in the apparatus illustrated in FIG. 1. It is a flowchart which shows the control procedure of the controller in the initial state of FIG. FIG. 5 is a block diagram showing an internal configuration of an upstream signal wavelength converter that is one of the components of the apparatus shown in FIG. 4. It is a block diagram which shows the internal structure of the optical path length difference detector which is one of the components of the apparatus shown in FIG.

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.
FIG. 1 is a block diagram showing the internal configuration of an optical transmission line duplexing apparatus according to the present invention and a detour constructer which is one of its components. In FIG. 1, the downstream signal light having the wavelength λ _Down transmitted from the station-side transmission apparatus 100 is branched by the upper optical branching coupler 202 having two inputs and two outputs, both upstream and downstream, respectively. The optical fiber 103 is divided. The downstream signal light of wavelength λ _Down propagated through the upper bypass optical fiber 103 is demultiplexed by an upper WDM (Wavelength Division Multiplexing) coupler 1 and incident on the downstream signal light-electrical converter 10, where It is converted into an electrical signal. The converted downstream electrical signal is delayed for a set time by the downstream signal variable delay device 30 and input to the downstream signal electro-optical converter 20, where it is converted again into downstream signal light having the wavelength λ _Down . The signal light having the wavelength λ _Down passes through the downstream signal light cut-off switch 60, and then is combined by the lower WDM coupler 2 and passes through the lower bypass optical fiber 104 and has 2 downstream inputs and 1 output and 1 upstream input and 2 outputs. The lower optical branching coupler 201 _combines the downstream signal light having the wavelength λ _Down propagated through the working optical fiber 102 and reaches the subscriber side transmission apparatus 101.

The upstream signal light having the wavelength λ _Up transmitted from the subscriber-side transmission apparatus 101 is branched by the lower optical branching coupler 201 and divided into the working optical fiber 102 and the lower bypass optical fiber 104. The upstream signal light of wavelength λ _Up propagated through the lower bypass optical fiber 104 is demultiplexed by the lower WDM coupler 2 and incident on the upstream signal light-electrical converter 11 where it is converted into an electrical signal. The converted upstream electrical signal is supplied to the upstream signal variable delay unit 31.

The upstream signal supplied to the upstream signal variable delay device 31 is delayed for a set time and then converted again into upstream signal light having the wavelength λ _Up by the upstream signal electro-optical converter 21. The upstream signal light having the wavelength λ _Up passes through the upstream signal light blocking switch 61 and is then combined by the upper WDM coupler 2, and passes through the upper bypass optical fiber 103 and passes through the working optical fiber 102 by the upper optical branching coupler 202. The propagated upstream signal light having the wavelength λ _Up is combined and reaches the optical path length difference detector 41 and the station-side transmission device 100.

On the other hand, the upstream electrical signal obtained by the upstream signal optical-electrical converter 11 is also supplied to the test signal variable delay device 32 to be used for generating a test signal. This test signal detects whether or not the signal propagation times of the working optical fiber 102 and the detour route constituted by the upper detour optical fiber 103, the lower detour optical fiber 104, and the detour constructer 1000 match. And is generated by converting the upstream signal light to an electrical signal by the upstream signal light-electrical converter 11. This test signal is delayed for a set time by the test signal variable delay device 32 and then converted into test signal light having the wavelength λ _Sense by the test signal electro-optical converter 22. The test signal light having the wavelength λ _Sense passes through the test signal light cutoff switch 62, and is then combined by the upper WDM coupler 1 and reaches the optical path length difference detector 41 through the upper bypass optical fiber 103.

As the configuration of the upstream signal variable delay device 31, the downstream signal variable delay device 32, and the test signal variable delay device 33, a semiconductor delay line or the like can be used (see, for example, Non-Patent Document 4).
Since the controller 50 can confirm the presence or absence of the optical path length difference detected by the optical path length difference detector 41 through the detection signal line 51, the delay time of the test signal variable delay unit 32 is set by the variable delay control line 52. The delay times of the downstream signal variable delay device 30 and the upstream signal variable delay device 31 are set using the delay time when the optical path length difference coincides. Thereby, duplexing of the optical transmission path between the station side transmission apparatus 100 and the subscriber side transmission apparatus 101 is realized.

In the above configuration, with respect to the control processing for detecting the presence or absence of the optical path length difference between the working optical fiber 102 and the detour route in the initial state where the duplex configuration is provided by providing the detour route in the optical transmission path, This will be described with reference to FIGS.
FIG. 2 shows an upstream signal light and a test signal light when an optical path length difference between the working optical fiber 102 and the detour route is detected during communication on the route on the working optical fiber 102 side in an initial state where the duplex configuration is established. It is a block diagram which shows the flow. FIG. 3 is a flowchart showing the control procedure of the controller 50 in the initial state.

  First, in the controller 50, when a bypass route is provided in the optical transmission line and an instruction to start optical path length control of the bypass route is given in the initial state in which the duplication configuration has been incorporated (step S11), FIG. The upstream signal light blocking switch 61 and the downstream signal light blocking switch 60 are turned on to block upstream signal light and downstream signal light, and the test signal light blocking switch 62 is turned off to output test signal light (step S12). As a result, the test signal light generated from the upstream signal light and the upstream signal light flowing through the working optical fiber 102 are sent to the optical path length difference detector 41 through the upper optical branching coupler 202.

Here, when measuring the presence or absence of the optical path length difference while maintaining communication with the working optical fiber 102, the upstream signal light 2000 of the wavelength λ _Up and the test signal of the wavelength λ _Sense propagated through the working optical fiber 102. The light 2001 is simultaneously received by the optical path length difference detector 41 to detect the presence or absence of the optical path length difference. In this detection, if the signal propagation times of the working optical fiber 102 and the detour route match, the upstream signal light of wavelength λ _Up and the test signal light of wavelength λ _Sense match. On the other hand, if the optical path lengths do not match, both signal waveform patterns do not match. Using this principle, the optical path length difference detector 41 detects both signal waveform patterns, detects the presence / absence of an optical path length difference by determining whether the detected patterns match, and notifies the controller 50 of the result. To do.

  The controller 50 receives the detection result of the optical path length difference from the optical path length difference detector 41 and determines whether there is an optical path length difference (step S13). If there is a difference in optical path length, the delay time of the test signal variable delay device 32 is changed to search for a state in which there is no optical path length difference (step S14). If there is no difference in optical path length, the same delay time is set in the downlink signal variable delay device 30 and the uplink signal variable delay device 31 as the delay time set in the test signal variable delay device 32 (step S15). Subsequently, the upstream signal light blocking switch 61 and the downstream signal light blocking switch 60 are both turned off to output the upstream signal light and the downstream signal light, and the test signal light blocking switch 62 is turned on to stop the output of the test signal light. (Step S16), the control process in the initial state is completed.

  With the above control processing, when the optical transmission line is duplexed after the optical path length difference measurement, the set delay time of the test signal variable delay device 33 is set in the upstream signal variable delay device 31 and the downstream signal variable delay device 32. Even in the detour route, there is no difference in optical path length from the working optical fiber 102, and duplication of the transmission path can be completely established.

  Next, after adjusting and matching the optical path lengths of the route of the working optical fiber 102 and the detour route by the control processing of FIG. 3, the state after switching the communication light from the working optical fiber route to the detour route, that is, FIG. 4 and FIG. 5 are used for control processing for detecting the presence or absence of an optical path length difference between the detour route and the newly installed new optical fiber 105 in a state where communication is being performed on the route on the side of the detour constructer. The description will be given with reference.

  FIG. 4 shows whether or not there is a difference in optical path length between the bypass route and the newly laid new optical fiber 105 in a state where the transmission path is duplexed and communication is being performed using the route on the side of the bypass component 1000. It is a block diagram which shows the flow of the upstream signal light and test signal light at the time of making length match. FIG. 5 is a flowchart showing a control procedure for matching the optical path lengths of the bypass route of the controller 50 and the newly laid new optical fiber 105.

First, when the communication is maintained by the upper bypass optical fiber 103, the lower bypass optical fiber 104, and the detour constructer 1000, that is, when communication is being performed on the detour route, When measuring the optical path length difference from the detour route, the upstream signal light wavelength converter 71 is inserted into the new optical fiber 105, and the wavelength λ _Up upstream signal light 2000 branched to the new optical fiber 105 is tested for the wavelength λ _Sense . It is configured to convert to signal light 2001 ′.

FIG. 6 is a block diagram illustrating an internal configuration example of the upstream signal light wavelength converter 71. In FIG. 6, the upstream signal light 2000 is converted into an electrical signal by the upstream signal light-electrical converter 72, and then converted into the test signal light 2001 ′ having the wavelength λ _Sense by the test signal electrical-optical converter 73.

  In the above configuration, first, when the controller 50 is instructed to start optical path length control for the new optical fiber 105 (step S21), the upstream signal light blocking switch 61, the downstream signal light blocking switch 60 and the test shown in FIG. All the signal light cutoff switches 62 are turned off, and all of the upstream signal light, downstream signal light, and test signal light are transmitted (step S22). As a result, when the communication is maintained by the upper detour optical fiber 103, the lower detour optical fiber 104, and the detour constructer 1000, that is, when communication is performed by the detour route, the upstream signal light wavelength converter 71 The generated test signal light 2001 ′ is received by the optical path length difference detector 41 through the upper optical branching coupler 202. In addition, the test path light 2001 generated by being converted from the upstream signal light 2000 in the detour constituent device 1000 is also received by the optical path length difference detector 41 through the upper optical branching coupler 202. The optical path length difference detector 41 detects the presence or absence of an optical path length difference by comparing the received lights of these test signal lights 2001 and 2001 '.

Here, if the signal propagation times of the new optical fiber 105 and the detour route match, the signal waveform patterns of the test signal lights 2001 and 2001 ′ having the wavelength λ _Sense combined through the two paths match. If the optical path lengths do not match, the signal waveform patterns of the two are destroyed. Using this principle, the optical path length difference detector 41 detects the presence or absence of an optical path length difference from the state of this signal waveform pattern.

  The controller 50 receives the detection result of the optical path length difference from the optical path length difference detector 41, and determines whether or not there is an optical path length difference (step S23). If there is an optical path length difference, the delay time of the test signal variable delay device 32 is changed to search for a state without an optical path length difference (step S24). When there is no optical path length difference, the delay time measured in advance of the signal light wavelength converter 71 inserted in the new optical fiber 105 is subtracted from the delay time set in the test signal variable delay device 32, The same delay time is set for the downstream signal variable delay device 30 and the upstream signal variable delay device 31 (step S25). Subsequently, the test signal light cutoff switch 62 is turned on to stop the output of the test signal light (step S26), and the series of control processing is completed.

FIG. 7 is a block diagram illustrating an internal configuration example of the optical path length difference detector 41. In FIG. 7, the upstream signal light 2000 having the wavelength λ _Up and the test signal light 2001 having the wavelength λ _Sense that have passed through the upper optical branching coupler 202 are sent to one input (input 1) of the 2-input × 2-output optical switch 45. .

The 2-input × 2-output optical switch 45 has two types of states: a straight state (input 1 → output 1, input 2 → output 2), and a cross state (input 1 → output 2, input 2 → output 1). Can be set to In the straight state, both the upstream signal light 2000 having the wavelength λ _Up and the test signal light 2001 having the wavelength λ _Sense reach the test signal / upstream signal light-electrical converter 44. In the crossed state, the input 1 is sent to the test signal wavelength selection filter 43 via the output 2, where only the test signal light 2001 having the test signal wavelength λ _Sense is selected, and the signal light-electrical converter 44 again is selected. The test signal / upstream signal optical-electrical converter 44 is reached through the input 2 and the output 1.

  The test signal / upstream signal optical-electrical converter 44 converts the test signal into an electrical signal and sends it to a clock data recovery (CDR) error detector 42. The clock data recovery (CDR) error detector 42 extracts a clock from a transmission signal and detects an error at the time of extraction, and detects the presence or absence of an optical path length difference based on the detection result of the presence or absence of the error. To do.

  The optical path length difference detector 41 having the above configuration can be applied to both cases of FIGS. 2 and 4 by appropriately selecting the optical switch to be configured. That is, when the optical path length difference is detected during communication using the working optical fiber shown in FIG. 2, the 2-input × 2-output optical switch 45 is set in a straight state, and communication is performed using the bypass circuit configuration unit shown in FIG. In the case of detecting the optical path length difference, it is applicable to the detection of the optical path length difference by setting the 2-input × 2-output optical switch 45 to the cross state.

As described above, according to the present invention, since it is not necessary to supply a test signal from the lower optical branching coupler 201, it is possible to greatly relax the conditions of the optical branching coupler that can be used as the lower optical branching coupler 201. Become.
This makes it possible to use an optical branching coupler using a 2-input / 1-output or 1-input / 2-output side optical input / output technology that could not be applied conventionally. In addition, since a detour route can be created at an arbitrary place, it is possible to expand an application area of optical line switching work in trouble relocation work or the like using an optical transmission line duplexing device.

  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 1 ... Upper WDM coupler 2 ... Lower WDM coupler 10 ... Downstream signal light-electrical converter 11 ... Upward new word Udaka-electrical converter 20 ... Downstream signal electrical-optical converter 21 ... Upstream signal electrical-optical converter 22 ... Test signal Electric-to-optical converter 30 ... Downlink signal variable delay 31 ... Uplink signal variable delay 32 ... Test signal variable delay 41 ... Optical path length difference detector 42 ... CDR error detector 43 ... Test signal wavelength selection filter 44 ... Test signal -Upstream signal light-electric converter 45 ... 2 input x 2 output optical switch 50 ... Controller 51 ... Detection signal line 52 ... Variable delay device control line 60 ... Downstream signal light cutoff switch 61 ... Upstream signal light cutoff switch 62 ... Test Signal light cut-off switch 71 ... Uplink signal light wavelength converter 72 ... Uplink signal light-electric converter 73 ... Test signal electric-optical converter 100 ... Station side transmission device 101 ... Subscriber side transmission device 102 ... Current use Fiber 103 ... Upper bypass optical fiber 104 ... Lower bypass optical fiber 105 ... New optical fiber 201 ... Lower optical branch coupler 202 ... Upper optical branch coupler 1000 ... Bypass component 2000 ... Upstream signal light 2001, 2001 '... Test signal light

Claims (6)

Upper detour optical branching used in an optical transmission apparatus in which the opposite station side transmission apparatus and subscriber side transmission apparatus transmit and receive signal light via the working optical fiber and are interposed at any two locations in the working optical fiber In the optical transmission line duplication device that forms a detour between the coupler and the lower detour optical branching coupler, and duplexes the communication,
Respectively connected to the branch ends of the upper and lower bypass optical branching couplers, the upstream signal light of the upstream wavelength emitted from the subscriber side transmission device, the downstream signal light of the downstream wavelength emitted from the station side transmission device, And a pair of wavelength division multiplex couplers for multiplexing and demultiplexing the wavelength of the test signal light of the test wavelength emitted from the test signal generator,
An upstream signal optical-electrical converter formed between the pair of wavelength division multiplexing couplers for converting the upstream optical signal into an upstream electrical signal, an upstream signal variable delay device for delaying the upstream electrical signal for a set time, and the upstream electrical signal An upstream signal light transmission means comprising an upstream signal electrical-to-optical converter that converts the upstream signal light into a signal light, and an upstream signal light blocking switch that outputs and stops the upstream signal light;
A downlink signal light-electric converter formed between the pair of wavelength division multiplexing couplers for converting the downlink signal light into an electrical signal, a downlink signal variable delay device for delaying the downlink electrical signal for a set time, and the downlink electrical signal Downstream signal light transmission means comprising a downstream signal electro-optical converter for converting into downstream signal light, a downstream signal light blocking switch for outputting and stopping the downstream signal light, and
A test signal variable delay device that is formed between the pair of wavelength division multiplex couplers, takes an electrical signal converted by the upstream optical signal-electrical converter as a test electrical signal, and delays a set time, and the test electrical signal is a test signal. Test signal electro-optical conversion means for converting to light and converting to the test wavelength, test signal light transmission means comprising a test signal light cutoff switch for outputting and stopping the test signal light,
An optical path length difference detector that receives the test signal light and the upstream signal light branched by the upper optical branching coupler, and detects the presence or absence of an optical path length difference between the working optical fiber and the bypass optical fiber;
The presence or absence of the optical path length difference is monitored to control the delay time of the test signal variable delay device, and the delay time set in the test signal variable delay device when the optical path length difference is detected is detected as the upstream signal. And a controller for setting the variable delay unit and the downlink signal variable delay unit. The optical path length difference detector is
A two-input / two-output optical switch in which the transmission signal light of the upstream signal light and the test signal light that has passed through the upper optical branching coupler is applied to one input terminal;
The transmission signal light output from one output terminal of the two-input / two-output optical switch is taken in, the wavelength of the test signal light is selected, and the selected test signal light is input to the other input of the two-input / two-output optical switch. Test signal wavelength selection filter to be output to the end,
A test signal / upstream signal light-electrical converter that takes in transmission signal light output from the other output terminal of the two-input / two-output optical switch and converts the test signal light and the upstream signal light into electrical signals;
A clock data recovery error detector that extracts a clock from a transmission signal output from the test signal / upstream signal optical-electrical converter and detects an error at the time of extraction;
2. The optical transmission line duplex device according to claim 1, wherein the presence or absence of the optical path length difference is detected from a detection result of the clock data recovery error detector.   The test signal electro-optical conversion means includes a test signal electro-optical converter that converts the test electric signal delayed by the test signal variable delay device into test signal light having the test wavelength. Item 2. The optical transmission line duplex device according to Item 1. Provided in the new optical fiber when the working optical fiber is replaced with a new optical fiber, comprising a wavelength converter for converting the upstream signal light into the test wavelength;
The optical path length detector receives test signal light from the new optical fiber branched by the upper optical branching coupler and test signal light from the detour transmission path, and connects the new optical fiber and the detour transmission path. Detect the presence or absence of optical path length difference,
The controller monitors the presence or absence of the optical path length difference to control the delay time of the test signal variable delay device, and sets a delay set in the test signal variable delay device when the optical path length difference is detected. 2. The optical transmission line duplexing apparatus according to claim 1, wherein a subtracting delay time of the wavelength converter is subtracted from the time to set in the upstream signal variable delay device and the downstream signal variable delay device. Upper detour optical branching used in an optical transmission apparatus in which the opposite station side transmission apparatus and subscriber side transmission apparatus transmit and receive signal light via the working optical fiber and are interposed at any two locations in the working optical fiber In the optical transmission path duplexing method in which a bypass is formed between the coupler and the lower bypass optical branching coupler, and the communication is duplexed.
A pair of wavelength division multiplex couplers are connected to the branch ends of the upper and lower bypass optical branching couplers, respectively, and upstream signal light of the upstream wavelength emitted from the subscriber side transmission device and emitted from the station side transmission device The wavelength of the downstream signal light of the downstream wavelength and the test signal light of the test wavelength emitted from the test signal generator are multiplexed and demultiplexed,
Between the pair of wavelength division multiplexing couplers, an upstream optical signal-electric converter that converts the upstream optical signal into an upstream electrical signal, an upstream signal variable delay device that delays the upstream electrical signal for a set time, and the upstream electrical signal as a signal An upstream signal light-transmission path including an upstream signal light-to-light converter that converts the upstream signal light into light, and an upstream signal light blocking switch that outputs and stops the upstream signal light;
Between the pair of wavelength division multiplexing couplers, a downstream signal light-electric converter that converts the downstream signal light into an electrical signal, a downstream signal variable delay device that delays the downstream electrical signal for a set time, and the downstream electrical signal as a downstream signal Forming a downstream signal light transmission path comprising a downstream signal light-to-light converter for converting into light, a downstream signal light blocking switch for outputting and stopping the downstream signal light,
A test signal variable delay device for taking an electrical signal converted by the upstream signal light-electric converter as a test electrical signal between the pair of wavelength division multiplex couplers and delaying it for a set time, and converting the test electrical signal into a test signal light A test signal electro-optical converting means for converting and converting to the test wavelength, and forming a test signal light transmission line including a test signal light cut-off switch for outputting and stopping the test signal light,
Receiving and comparing the test signal light and the upstream signal light branched by the upper optical branching coupler to detect the presence or absence of an optical path length difference between the working optical fiber and the bypass optical fiber,
The presence or absence of the optical path length difference is monitored to control the delay time of the test signal variable delay device, and the delay time set in the test signal variable delay device when the optical path length difference is detected is detected as the upstream signal. A duplexing method for optical transmission lines, characterized by being set in a variable delay unit and a downstream signal variable delay unit. A wavelength converter for converting the upstream signal light into the test wavelength in the new optical fiber when the current optical fiber is replaced with a new optical fiber;
Detecting the presence or absence of optical path length difference between the new optical fiber and the detour transmission path from the test signal light from the new optical fiber branched by the upper optical branching coupler and the test signal light from the detour transmission path;
Monitoring the presence / absence of the optical path length difference to control the delay time of the test signal variable delay unit, and from the delay time set in the test signal variable delay unit when the optical path length difference is detected, the wavelength conversion 6. The method for duplicating an optical transmission line according to claim 5, wherein the uplink signal variable delay device and the downlink signal variable delay device are set by subtracting the conversion delay time of the optical device.

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