KR100342758B1 - Apparatus for automatically switching cable in a optical subscriber system - Google Patents

Abstract

The present invention relates to an optical subscriber line automatic switching device for automatically switching to an optical line section where a line failure has not occurred by dualizing an optical line section connecting between a telephone station and a subscriber side in an optical subscriber network system.

According to the present invention, when a failure occurs in a section in which an optical signal is transmitted in a section of a redundant optical beam, that is, when the voltage value for the monitoring signal reflected in the section in which the optical signal is transmitted is higher than a reference voltage value, the present signal is detected. The service continues to be provided in the transmitting optical path section, and if it is lower than the reference voltage value, it is determined that some trouble has occurred in the optical signal transmission line, and the optical signal is transmitted through another optical line by controlling the operation of the switch to switch the optical path. After the failure, the failure recovery is immediately performed on the failed optical path to make it available again, thereby shortening the recovery time and providing an uninterrupted service.

Description

Optical subscriber line automatic switching device {APPARATUS FOR AUTOMATICALLY SWITCHING CABLE IN A OPTICAL SUBSCRIBER SYSTEM}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical subscriber network system, and more particularly, to an optical subscriber line automatic switching device for automatically switching to an optical line section in which a line failure has not occurred by dualizing an optical line section connecting between a telephone station and a subscriber.

Currently, the optical subscriber network system is used to monitor communication failure by exchanging information by using overhead of communication protocol between telephone station optical communication transceiver and subscriber optical communication transceiver. There is no way to monitor or test for communication failures.

1 is a block diagram of a general distributed type / broadcasting optical subscriber network system.

The optical signal output from the telephone station side optical communication transceiver 110 is distributed by the optical splitters 120 to 123 inserted into the respective optical path sections 11 to 23 and input to the optical communication transceivers 130 to 138 located at the subscriber side. It is configured to be.

As mentioned above, the conventional optical subscriber network system shown in Fig. 1 recognizes the occurrence of the optical fiber failure by transmitting and receiving information using the overhead on the communication protocol between the telephone station and the subscriber.

Therefore, when the failure monitoring device that occurs on the optical path is not implemented, the failure of the optical subscriber line can be known only when the subscriber gives a failure signal, and the method using the overhead of the communication protocol is not only limited to the digital transmission method. It was not possible to monitor the performance of the track itself or to test it or to use it when the subscriber station was in the idle state.

In addition, even when performing a test for maintenance due to a line failure, it is impossible to know the fault section accurately. Therefore, conduct a test for detecting a fault section, perform a test for maintenance after detecting a fault section within the corresponding section. As a result, it takes a lot of time to not provide efficient services to subscribers, but also causes a great economic loss.

In addition, since the connection between the optical splitter and the optical path was disconnected for the maintenance test, the service through all the optical fiber sections connected to the optical splitter under test was stopped.

FIG. 2 is a block diagram illustrating an apparatus for monitoring and testing a line condition of an optical subscriber for solving the above problems, wherein the monitoring optical signal transmitter 200, the communication optical transmitter and receiver 210, and the optical circuit 220 are provided. , Demultiplexer 230, reflected light receiver 240, multiplex / demultiplexer 250, segmented light reflector 260, light distributor 270, longitudinal light reflector 280-300, subscriber Consists of the side light transmitting and receiving unit (310 ~ 330), the detailed operation description is made as follows.

The light source of the monitoring optical signal transmitter 200 is a continuous wave (CW), and emits a monitoring optical signal for monitoring the occurrence of failures in the optical path sections 201 to 207, and the optical transmitter / receiver 210 communicates. The optical signal is transmitted to the subscriber side and the communication optical signal transmitted from the subscriber side is received.

At this time, the wavelength band of the light source transmitted by the monitoring optical signal transmitter 200 uses a wavelength band different from the wavelength band used by the optical transmitter / receiver 210.

As shown in the figure, the optical circulation unit 220 outputs to the multiplexing / demultiplexing unit 250 through the port b when the monitoring optical signal is input from the monitoring optical signal generating unit 200 through the port a, As will be described later, the monitoring reflected optical signal transmitted from the multiplexing / demultiplexing unit 250 through the b port is provided to the demultiplexing unit 230 through the c port.

The multiplexing / demultiplexing unit 250 multiplexes the communication optical signal transmitted from the optical transmitting / receiving unit 210 of the telephone station side and transmits it to the section type optical reflecting unit 260, and is reflected with the communication optical signal transmitted from the subscriber side. The monitoring optical signal is transmitted by separating the monitoring optical signal transmitted to the optical circulation unit 220 and the optical signal for communication is transmitted to the optical transmission and reception unit 210 of the telephone station.

The section light reflecting unit 260 includes an optical fiber grating reflector 311, an asymmetric light splitter 312, and an antireflective output port 313 as shown in FIG. 3A.

That is, the interval type light reflection unit 260 is provided for each section, and when the monitoring optical signal and the communication optical signal are input from the multiplexing / demultiplexing unit 250, the optical fiber having the characteristic of reflection in a specific wavelength band in the monitoring wavelength band The asymmetric light splitter 312 and the asymmetric light splitter 312 that asymmetrically reflect the optical signals transmitted from the grating reflector 311 and the optical fiber grating reflector 312 are separated and output without being reflected. The non-reflective output port 313 is configured to.

At this time, the anti-reflective output port 313 is used as a connection port of the test measuring instrument in the line test of the line maintainer.

The pure communication wavelength band component not reflected by the section light reflecting unit 260 passes through the light distribution unit 270 and is transmitted to the terminal light reflecting units 280 to 282.

The vertical light reflection units 280 to 282 are installed on the subscriber side inlet terminal box or a conduit close to the subscriber side, and as shown in FIG. 3B, the optical signal for monitoring and communication transmitted through the optical distribution unit 270 is provided. The optical fiber grating reflector 321 reflecting the monitoring optical signal in the monitoring wavelength band and the non-reflective monitoring wavelength band and the communication wavelength component pass through the demultiplexer 322 so that the monitoring wavelength band component is Outgoing to the non-reflective output port 323, the communication signal is transmitted to the subscriber-side optical transmission and reception unit 290 ~ 292, the non-reflective output port 323 is used as a connection port for the line test when a line failure occurs.

On the other hand, the demultiplexer 230, as can be seen from the above, by demultiplexing for each wavelength of the reflected reflection signal transmitted through the c port of the optical circulator 220 to the reflected light receiving unit 240, reflected light The receiver 240 may receive a signal for each wavelength from the demultiplexer 230 and may monitor in real time the failure of a specific optical path section or an optical subscriber line.

And, when a failure is found and the maintenance test is performed, the line maintainer can connect the test meter to the non-reflective output ports 313 and 323 and perform the line maintenance work as described above without the need for the separation test of the optical line. In this case, the monitoring optical signal can be used without repairing the optical signal source.

However, the optical subscriber line monitoring and test apparatus described above takes considerable time in recognizing and recovering a failure section, and because the service is interrupted due to the maintenance test by the line maintainer, it is not only economically expensive but also indispensable service. There was a problem that is not provided.

The present invention has been made in order to solve the above problems, an object of the present invention is to duplicate the light beam section, when the occurrence of a line failure is automatically switched to another light beam section that does not cause a line failure, due to the maintenance test The present invention provides an optical subscriber line automatic switching device to prevent interruption of service.

In order to achieve the above object, the present invention is to detect the occurrence of a failure in the optical path section by the first and second monitoring optical signal reflected by generating a monitoring optical signal in the optical path section between the telephone station and the subscriber side In the optical subscriber line switching device for switching the line, the optical line between the telephone station side and the subscriber side has a redundant line structure, the apparatus for automatically switching to the optical path that does not cause the failure of the duplicated optical line A branching means for branching the monitoring optical signal at a predetermined ratio, and a first means for switching to an optical path in which no failure occurs when a failure occurs by the first and second monitoring reflection optical signals branched from the branching means and input. And first and second switch control means for providing a second switching control signal, and a failure is not generated according to the first and second switching control signals. First and second switches which are switched to the non-optical path.

1 is a general optical subscriber network configuration diagram,

Figure 2 is a block diagram of the optical subscriber network line monitoring and testing apparatus according to the prior art,

3 is a block diagram illustrating a detailed configuration of a light reflection unit illustrated in FIG. 2;

Figure 4 is a block diagram showing the configuration of the automatic subscriber line automatic switching device according to the present invention,

FIG. 5 is a detailed configuration diagram of the switch control unit shown in FIG. 4.

<Description of the symbols for the main parts of the drawings>

401: monitoring optical signal transmitter 402: optical transmitter and receiver

403: multiplexing / demultiplexing unit 404, 408, 409, 414, 415: optocoupler

405: section type optical switch 406: section type optical switch control unit

407: section light reflecting unit 410: terminal type optical switch control unit

411: termination type optical switch 412, 413: termination type light reflection part

416: optical communication transmitter and receiver 420-437: optical path

Hereinafter, with reference to the accompanying drawings will be described in detail the operation of the preferred embodiment according to the present invention.

Figure 4 is a block diagram showing the configuration of the automatic subscriber line automatic switching device according to a preferred embodiment of the present invention.

As shown in the figure, in the embodiment of the present invention, a 1 × 3 optical splitter is used, and on the telephone station side, a monitoring optical signal transmitter 401, an optical transmitter / receiver 402, an optical circuit 403, and a reflected light receiver 405, a multiplexing / demultiplexing unit 406, an optocoupler 407, a section type optical switch 408, a section type optical switch control unit 409 is provided, section section light reflecting section 410 , 411, optical distribution unit 412, optocouplers 413, 414, 421, 422, 429, 430, end type optical switch 415, 423, 431, end type optical switch control unit 416, 424, 432 , The longitudinal light reflecting units 417, 418, 425, 426, 433, 434 are installed, and the optocouplers 419, 427, 435 and the optical transmitting and receiving units 420, 428, 436 are installed on the subscriber side.

Each of the building blocks described above is connected by optical paths 501 to 537. At this time, reference numerals 506 to 535 denote duplicated optical path sections.

The detailed operation of the optical subscriber line automatic switching device according to the preferred embodiment of the present invention is as follows.

Here, since the same members as those for performing the optical subscriber line monitoring and testing shown in FIG. 2 are mentioned in the above-described operation description, they will be omitted below.

As can be seen from the above, the wavelength band component for monitoring is transmitted through the asymmetric optical splitter 312 by the reflection characteristic of the optical fiber grating reflector 311 of the section light reflecting section 260 shown in FIG. When the optical coupler 408 is input to the optical coupler 407 having 99 to 1 divergence characteristics, the optical coupler 407 multiplexes / demultiplexes 406 99% of the input monitoring optical reflection signal. Through the reflected light receiving unit 405, and the remaining 1% is transmitted to the section type optical switch control unit 409.

That is, the multiplexing / demultiplexing unit 406 demultiplexes 99% of the reflected reflection optical signal transmitted from the optical coupler 407 to the optical circulation unit 403, and the optical circulation unit 403 is again demultiplexing unit. In operation 404, the demultiplexer 404 demultiplexes the monitoring reflection signal transmitted from the light circulation unit 403 for each wavelength and transmits the signal to the reflected light receiver 405.

Then, the section type optical switch controller 409 detects whether or not a failure occurs in the optical path by the 1% reflected optical signal transmitted from the optical coupler 407 and controls the section type optical switch 408 according to the result. The optical signal for communication may be transferred to the communication optical transmitter / receiver 420, 428, 436 at the subscriber side by switching to the non-occurring optical path section.

Accordingly, the section light reflecting units 410 and 411 may receive an optical signal input through a light path section in which an obstacle does not occur due to the switching operation of the section light switch 408. It passes through the 414, 421, 422, 429, 430 and the termination optical switch (415, 423, 431) to the termination light reflection portion (417, 418, 425, 426, 433, 434).

That is, the optical distribution unit 412 distributes the optical signal input through the section type optical switch 408, and the respective optical couplers 413, 414, through the optical paths 510, 511, 519, 520, 528, 529. 421, 422, 429, and 430, and each of the optocouplers 413, 414, 421, 422, 429, and 430 passes through the optical paths 512, 513, 521, 522, 530, and 531, respectively. To the termination optical switches 415, 423, 431, and the termination optical switches 415, 423, 431 pass through the respective optical paths 514, 515, 523, 524, 532, 533. It passes to parts 417, 418, 425, 426, 433, 434.

The vertical light reflectors 417, 418, 425, 426, 433, and 434 transmit the wavelength reflected by the optical fiber grating reflector 321 to the telephone station as described above, and the remaining wavelength component is an unreflected monitoring wavelength. Only the pure communication wavelength component of the component and the communication wavelength component is passed to the optical coupler 419, 427, 435.

At this time, the monitoring reflected optical signal reflected and transmitted by the end type light reflection parts 417, 418, 425, 426, 433, 434 passes through the end type light switches 415, 423, 431. When the optical couplers 413, 414, 421, 422, 429, and 430 have branched portions, the optical couplers 413, 414, 421, 422, 429, and 430 transmit 99% of the reflected optical signals. Sectional light reflecting section 410, 411, section optical switch 408 and optical coupler 407, multiplexing / demultiplexing section 406, optical circulation section 403, demultiplexing section 404 via 412 Through the reflected light receiving unit 405 through.

The remaining 1% of the reflected optical signal is input to the end type optical switch controllers 416, 424, and 432 to detect whether a failure occurs and to control the end type optical switches 415, 423, and 431 according to the result. The optical signal for communication is transferred to the optical communication transceivers 420, 427, and 436 on the subscriber side through the optical coupler 419, 427, and 435 by automatically switching to the optical path section where no obstacle has occurred.

FIG. 5 is a detailed configuration diagram of the section type optical switch control unit 409 and the terminal type optical switch control unit 416, 424, and 432 shown in FIG. 4, and specific operations are performed as follows.

First, referring to the operation of the section optical switch controller 409, the band pass filter 409-1 of the section optical switch controller 406 reflects 1% of the reflection transmitted from the optical coupler 407. Only the monitoring signal of the corresponding wavelength is transmitted to the photodiode 409-2, and the photodiode 409-2 converts the monitoring signal transmitted from the band pass filter 409-1 into an electrical signal. It is provided to the comparator 409-3.

The comparator 409-3 is a light path state of a light path section currently transmitting a signal when the value provided by the photodiode 409-2 is equal to or greater than a predetermined voltage value, that is, when the voltage value of the monitoring signal is equal to or greater than the reference voltage value. Is determined to be good and continues to provide service, and if the value provided by the photodiode 409-2 is lower than or equal to a predetermined voltage value, that is, if the voltage value of the monitoring signal is lower than or equal to the reference voltage value, the signal is transmitted to the optical path to which the current signal is transmitted. It is determined that a failure has occurred, and the power is supplied to the section optical switch 408 so that the operation of the section optical switch 408 is changed to reverse the transmission ratio of the two beams so that a signal is transmitted through the other beam.

For example, if it is assumed that the flow of the monitoring and communication optical signal that has passed through the section optical switch 408 is transmitted to the subscriber through the optical paths 506 and 508, the flow of the monitoring signal is the section light reflection unit ( 410 and the longitudinal light reflectors 417, 425 and 433, and the non-reflected signals are output to the non-reflective output ports 313 and 323. The monitoring signal reflected from the longitudinal light reflecting units 417, 425, and 433 is branched from the optical coupler 407, and 99% of the multiplexing / demultiplexing unit 406, the optical circulation unit 403, and the demultiplexing unit 404 are used. ) Is input to the reflected light receiving unit 405, and the remaining 1% is input to the section type optical switch control unit 409 to detect a failure occurrence section and control the section type optical switch 408 according to the result.

In addition, the monitoring signal reflected from the end-type light reflection unit (417, 425, 432) is branched from the optical coupler (413, 421, 429) and outputs a part to the reflected light receiving unit 405, the rest of the end-type optical switch control unit Inputted to (416, 424, 432) to detect the failure occurrence section and controls the end-type optical switch (415, 423, 431) according to the result.

In this case, as shown in FIG. 5, when a failure occurs at point A of the optical path 506, the voltage sensed by the comparator 409-3 of the section type optical switch controller 409 is a reference voltage value. When a lower voltage is sensed, a predetermined voltage is applied to the section type optical switch 408 to switch the switching path to switch the optical path. That is, the switching path of the section type optical switch 408 is changed by the voltage supplied from the comparator 409-3 so that the optical signal is transmitted from the existing optical path 506 to the new optical path 507.

As the above-described light path 506 monitors the state of each light line in real time in the reflected light receiving unit 405 as described above, the failing light path can be immediately available after the automatic transfer. Leave it as is.

On the other hand, when a failure occurs at the point B of the optical path 524 after the automatic switching, there is no optical signal reflected from the longitudinal light reflecting section (417, 425, 433), the optical coupler (413, 421, 429) Through the end-type optical switch control unit 416, 424, 432 is no signal detected. Accordingly, the termination type optical switch controllers 416, 424, and 432 change a switching path for switching the optical transmission path by applying a predetermined voltage to the termination type optical switches 415, 423, and 431. That is, the switching paths of the termination type optical switches 415, 423, 431 according to the voltages provided by the comparators 416-2, 424-2, 432-2 of the termination type optical switch controllers 416, 424, 432 are It is changed and transferred from the existing optical path 524 to the new optical path 523 to change the flow of the current transmission light beam, and as described above, the faulty optical path after the automatic transfer can be immediately repaired and available again. Leave it as is.

In this case, the section type optical switch 408 or the end type optical switch 415, 423, 431 may be paralleled according to the control of the section type optical switch control unit 408 and the end type optical switch control unit 415, 423, 431. To cross or cross to parallel.

As described above, the optical subscriber line automatic switching device according to the present invention, there is no need to perform the maintenance test when the line failure occurs by automatically switching to the light ray section detected by the duplication of the line section by detecting the occurrence of the line failure. Therefore, it is possible to provide an uninterrupted service, and it is possible to provide an economical and efficient service since it is easy to recover after the failure of the optical path section.

Claims (4)

Optical subscriber line switching device which detects the occurrence of failure of the optical path section by switching the optical signal between the telephone station and the subscriber side by generating the optical signal for monitoring and reflecting it. To The optical path between the telephone station side and the subscriber side has a redundant line structure, The apparatus for automatically switching to the optical path of the failure of the redundant optical path, Branching means for branching the first and second monitoring optical signals at a predetermined ratio; A first and second switching control signals for providing a first and second switching control signal for switching to an optical path in which the failure has not occurred when a failure occurrence is detected by the first and second monitoring reflected optical signals branched from the branching means; Second switch control means; And a first switch and a second switch which are switched to the optical path in which the obstacle does not occur according to the first and second switching control signals. The method of claim 1, The first switch control means, A band pass filter for passing only a monitoring signal of a corresponding wavelength among the first monitoring optical signals transmitted from the branching means; A photodiode converting the first monitoring optical signal transmitted from the band pass filter into an electrical signal and providing a corresponding voltage value; And a comparator configured to compare the voltage value provided from the photodiode with a reference voltage value and provide a first switching control signal to the first switch when a failure is detected. The method of claim 1, The second switch control means A photodiode for converting the second monitoring optical signal transmitted from the branching means into an electrical signal and providing a corresponding voltage value; And a comparator configured to compare the voltage value provided from the photodiode with a reference voltage value and provide a second switching control signal to the second switch when a failure is detected. The method of claim 2 or 3, The comparator maintains the optical signal flow to the current optical path when the voltage value provided by the photodiode is higher than the reference voltage value, and transfers the current optical path when the voltage value provided by the photodiode is lower than the reference voltage value. Optical subscriber line automatic switching device, characterized in that for providing a voltage for the switch.