KR100278443B1 - Automatic output cutoff and recovery device for optical transmission network - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission output automatic interruption and recovery device for automatically blocking and restoring an optical transmission output due to a transmission failure such as cutting of an optical path in an optical communication transmission network. A circulator having three input / output terminals is adopted, and a circulator having three input / output terminals for bidirectional communication is used as an input terminal of the preamplifier of the receiving stage. Retransmit to the transmitter through the transmitter, and transmit the retransmitted transmission optical signal to the monitoring optical receiver through the transmitter circulator to measure the signal strength or determine the presence or absence of the signal. Automatically shuts down and automatically operates the optical amplifier in case of transmission failure recovery.

Description

Automatic shutdown and recovery system of sending power in optical transmission network

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission output automatic interruption and recovery apparatus for automatically interrupting and restoring an optical transmission output due to a transmission failure such as an optical fiber cut in an optical communication transmission network.

A general configuration diagram of an optical transmission network, as shown in FIG. 1, includes a first transmitter 10 and a second transmitter 15 including optical transmitters 11, 17, and optical receivers 12, 16, respectively. It is composed of Each of the optical transmitters 11 and 17 includes optical transmitters 11-1 and 17-1 including laser diodes for generating optical signals, and post optical amplifiers 11-2 and 17-2 for long distance transmission. . Each optical receiver 12, 16 comprises pre-optical amplifiers 12-1, 16-1 for amplifying the received optical signal, and optical receivers 12-2, 16-2 for converting the optical signal into an electrical signal. do. In the end station, the optical transmission network has a network structure for transmitting an optical signal to one optical fiber and receiving an optical signal to another optical fiber.

2 is a block diagram of an optical transmission network that performs automatic transmission output blocking and recovery according to the related art.

The first transmission device 20 is composed of a transmitting end 21 and the receiving end 22. The transmitting end 21 includes an optical transmitting end 21-1 and a monitoring controller 21-2 for monitoring the optical transmitting end 21-1, and the receiving end 22 includes the optical receiving end 22-1 and the optical receiving end ( And a monitoring controller 22-2 for monitoring 22-2, wherein the two monitoring controllers 21-2 and 22-2 exchange control information with each other.

The second transmission device 25 is composed of a receiving end 26 and a transmitting end 27. The receiving end 26 includes a monitoring controller 26-2 for monitoring the optical receiving end 26-1 and the optical receiving end 26-1, and the transmitting end 27 includes the optical transmitting end 27-1 and the optical transmitting end ( 27-1), a monitoring controller 27-2 for monitoring, and the two monitoring controllers 26-2 and 27-2 exchange control information with each other.

The first transmission device 20 and the second transmission device 25 have various monitoring / control functions and a function of automatically cutting off the optical output of the optical amplifier of the optical transmitter when the transmission network is disconnected (Auto Power ShutDown, hereinafter referred to as APSD). It is provided.

In the conventional optical transmission network, when the optical path is disconnected due to the cutting of the optical cable or other reasons, as shown in FIG. 2, the optical transmitting end 21-1 of the first transmitting device 20 and the optical receiving end of the second transmitting device 25 are used. When the transmission path between 26-1 is cut, the optical transmitting end 21-1 of the first transmission device 20 cuts off the optical output to be transmitted to the second transmission device 25 or keeps it below a certain level. This protects the eyes or skin of the person repairing the light path.

The process of blocking the optical output of the optical transmitter for this is as follows. First, an optical splitter (a kind of tap coupler, not shown) of the second transmission device 25 distributes a predetermined ratio of the received optical signal and transmits it to the receiving end 26. The optical receiving end 26-1 of the receiving end 26 receives the optical signal distributed by the optical splitter and converts it into an electrical signal. The monitoring control unit 26-2 monitors the output electrical signal of the light receiving end 26-1, and when the received optical signal is below a predetermined value, the monitoring signal 26-2 is regarded as a loss of the optical signal due to cutting and so on, and the control signal informing that the abnormal state is optical monitoring. It transmits to the first transmission device 20 using a channel. In this case, the optical monitoring channel uses a specific channel of a section overhead (SOH) for the purpose of monitoring / controlling the optical signal.

At this time, the first transmission device 20 continuously monitors the optical monitoring channel among the optical signals, and in the event of loss of the optical signal, cuts off the optical output of the transmitter 21 or maintains it below a certain level.

Similarly, in the recovery process of releasing the light output block, when the optical signal received from the optical receiver 26-1 enters a predetermined level, the control signal for notifying the normal signal is regarded as a normal signal to the first transmission device 20. send. The first transmission device 20 restores the optical output of the optical transmitter 21-1 to a normal state.

Such a conventional optical transmitting and receiving device requires a separate monitoring / controlling device to automatically block the light output, and there is a problem that depends on specific software for operating the device.

Accordingly, the present invention has been made to meet the above necessity and to solve the problem, the object of the present invention is to adopt a two-way communication optical element (circulator) of the transmitting / receiving end, whether the loss of the signal carried from the receiving end in the transmitting end The present invention provides a system for automatically blocking and restoring a transmission output in an optical transmission network that automatically detects a transmission failure due to the detection of a transmission line, and automatically cuts off the transmission optical output when the transmission failure occurs.

The present invention for achieving the above object, in the optical transmission network including a transmitting end having an optical transmitter and a post optical amplifier and a receiving end having an optical receiver and a pre-optical amplifier, transmission between the corresponding transmitting end and the corresponding receiving end due to the truncation of the transmission path An apparatus for automatically blocking and recovering a transmission light output in the event of a failure,

The transmitting end comprises: first input / output means for transmitting a transmission optical signal to the receiving end and receiving the retransmission from the receiving end; And monitoring control means for determining whether the retransmitted optical signal is lost, and if there is a loss, blocking the transmission light output, and if there is no loss, controlling the normal transmission light output.

The receiving end may include second input / output means for branching a part of the received optical signal and retransmitting the received optical signal to the corresponding transmitting end; And means for monitoring the reception state using the remaining part of the received optical signal, and controlling the optical receiver and the pre-optical amplifier according to the result.

1 is a configuration diagram of a general optical transmission network,

2 is a block diagram of an optical transmission network that performs automatic transmission output blocking and recovery according to the related art;

3 is a block diagram of an optical transmission network that automatically cuts and restores transmission power according to the present invention.

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

300,350: transmitter 310,390: transmitter

311,391: Optical transmitter 312,392: Post optical amplifier

330,370: Receiver 335,375: Optical Receiver

332,372: pre-op amp 333,334,373,374: tap coupler

313,331,371,393: Circulator 314,336,376,394: Monitoring optical receiver

315,337,377,395: supervisory controller

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

3 is a block diagram of an optical transmission network that automatically cuts and restores transmission power according to the present invention.

In the optical transmission network composed of the first transmission device 300 and the second transmission device 350, each transmission device includes a transmitting end (310, 390) and a receiving end (330, 370). The transmitting end 310 and the transmitting end 390 have the same configuration. The receiving end 330 and the receiving end 370 have the same configuration.

The transmitting end 310 of the first transmission device 300 includes an optical transmitter 311 for generating an optical signal to be transmitted, a post amplifier 312, a circulator 313, and amplification for amplifying the optical signal for long distance transmission. A molten light receiver 314 and a monitoring controller 315.

Here, the optical transmitter 311 is composed of a laser diode for generating an optical signal and a peripheral circuit thereof.

The circulator 313 has an input / output structure for bidirectional communication, and is a device in which a unique output terminal is determined according to an input direction of an optical signal. For example, as shown in FIG. 4, the optical signal input to terminal 1 of the circulator is always output to terminal 2, and the optical signal input to terminal 3 is necessarily output to terminal 1. . That is, the first matched output terminal is determined by rotating clockwise of the input port. The circulator 313 transmits the output of the post amplifier 312 to the second transmission device 350 and provides a signal output from the receiving end 370 of the second transmission device 350 to the monitoring optical receiver 314. do.

The monitoring optical receiver 314 receives the optical signal transmitted through the circulator 313 and detects the loss thereof and provides the monitoring signal to the monitoring controller 315.

The monitoring controller 315 controls whether the optical signal is generated or the optical signal output strength of the optical transmitter 311 according to the detection signal of the monitoring optical receiver 314.

The receiver 330 of the first transmission device 300 includes a circulator 331 for bidirectional communication, a preamplifier 332 for amplifying the received optical signal, first and second dividers 333 and 334, and an optical receiver 335 ), A monitoring optical receiver 336, and a monitoring controller 337.

The circulator 331 has a three-terminal input / output structure for bidirectional communication and is a device in which a unique output terminal is determined according to an input direction of an optical signal. The circulator 331 provides an optical signal received from the transmitting end 390 of the second transmission device 350 to the preamplifier 332, amplified by the preamplifier 332 and by the first divider 333. The divided signal is output to the transmitter 390 again.

The first divider 333 and the second divider 334 distribute the optical signals output from the preamplifier 332 to the two optical fibers at a predetermined ratio (eg, 99: 1). One (99%) of the optical signals distributed by the first divider 333 is transmitted to the second divider 334, and the other (1%) is provided to the transmitting end 390 of the second transmitting device 350. Each is transmitted to the circulator 331 to monitor the state of the transmission path. One of the optical signals (99%) distributed by the second divider 334 is transmitted to the optical receiver 335 and converted into an electrical signal, and the other (1%) is transmitted to the monitoring optical receiver 336, respectively.

The monitoring optical receiver 336 receives the optical signal distributed through the second distributor 334, detects the light intensity, etc., and provides the optical signal to the monitoring controller 337, and the monitoring controller 337 provides the optical receiver 335. ) And the pre-op amp 332 and the like.

In addition, the monitoring controller 337 of the transmitting end 310 and the monitoring controller 315 of the receiving end 330 may exchange information for control.

The transmitting end 390 of the second transmitting device 350 is composed of an optical transmitter 391, a post amplifier 392, a circulator 393, a monitoring optical receiver 394, a monitoring controller 395, and a receiving end 370. ) Includes a circulator 371, a preamplifier 372, first and second distributors 373 and 374, an optical receiver 375, a monitoring optical receiver 376, and a monitoring controller 377. Each component of the second transmission device 350 performs the same function and operation as the corresponding component of the first transmission device 300.

3, a process for automatically blocking and restoring the optical output of a transmitting end in a transmission network consisting of two optical transmission devices will be described.

① Automatic output light cutoff process

At the transmitting end 310 of the first transmission device 300, the optical signal generated from the optical transmitter 310 is amplified by the post amplifier 312, and the optical signal is transmitted through the circulator 313 to the second transmission device. Is sent to 350. The weak optical signal input to the receiving end 370 of the second transmission device 350 is input to the pre-op amp 372 through the circulator 371. The preamplifier 372 performs normal amplification when the input signal is normal, and outputs a predetermined value or less when the input signal is a predetermined value or less. The gain control of the pre-optical amplifier 372 follows a control scheme by the monitoring optical receiver 376 and the monitoring controller 377 of the receiver, which are normally performed.

The output light of the pre-optical amplifier 372 feeds back the 1% optical signal distributed by the first optical splitter 373 to the circulator 371, and the 99% optical signal is optically transmitted through the second optical splitter 374. The receiver 375 is distributed to the monitoring optical receiver 376 and transmitted.

At this time, the 1% optical signal input to the circulator 371 is retransmitted to the transmitting end 310 of the first transmission device 300 again. That is, bidirectional communication is performed through one optical path.

Now, the optical signal retransmitted from the receiving end 370 of the second transmitting device 350 is input to the monitoring optical receiver 314 through the circulator 313 at the transmitting end 310 of the first transmitting device 300. . The monitoring optical receiver 314 determines whether the received optical signal is input at a predetermined reference value (or whether the optical signal is present). If the determination result is less than the reference value (or there is no optical signal), it is regarded as loss of the optical signal due to truncation or the like, and outputs an abnormal control signal for blocking transmission to the monitoring controller 315.

Then, the monitoring controller 315 controls the optical transmitter 310 and the post fluorescent amplifier 312 according to the abnormal control signal to block the optical output of the transmitting end 310 or to maintain the optical output of the transmitting end 310 or less.

② Auto output light off process of transmitter

When the optical signal loss due to the truncation or the like is restored, bidirectional communication is performed again through one optical path, and in the monitoring optical receiver 314 of the first transmission device 300, the receiving end 370 of the second transmission device 350 is performed. It receives a normal optical signal from the. When the normal optical signal is continuously received for a predetermined time or more, a control signal indicating that the signal is normal is sent to the monitoring controller 315. The monitoring controller 315 controls the optical transmitter 311 and the post optical amplifier 312 according to a normal control signal to release the light output blocking of the transmitting end 310.

As described above, for APSD in the optical transmission network, additional circuits and complicated algorithms have to be implemented in order to use a specific overhead. However, the present invention employs a circulator and a monitoring optical receiver for a receiver. By receiving the feedback input of the optical signal transmitted back to determine whether or not the optical signal, it is possible to block or limit the transmission light output by cutting the transmission path.

Claims (5)

In the optical transmission network including a transmitter having an optical transmitter and a post optical amplifier and a receiver having an optical receiver and a pre-op amplifier, the transmission optical output is automatically cut off in case of a transmission failure between the transmitter and the receiver due to the truncation of the transmission path. Device for recovering, The transmitting end comprises: first input / output means for transmitting a transmission optical signal to the receiving end and receiving the retransmission from the receiving end; And A monitoring control means for determining whether the retransmitted optical signal is lost, controlling to transmit a transmission light output if there is a loss, and to send a normal transmission light output if there is no loss, The receiving end may include second input / output means for branching a part of the received optical signal and retransmitting the received optical signal to the corresponding transmitting end; And And means for monitoring the reception state using the remaining portion of the received optical signal, and controlling the optical receiver and the pre-optical amplifier according to the result. The apparatus of claim 1, wherein the first input and output means is a circulator connected to an output terminal of the post optical amplifier and bidirectionally communicating with the receiving terminal. The method according to claim 1, wherein the monitoring control means determines the presence of the retransmitted optical signal, cuts off the transmission of the transmission optical signal when there is no signal, and outputs the transmission optical signal when there is a signal. Automatic transmission block and recovery device in optical transmission network. The method of claim 1, wherein the monitoring control means, A monitoring optical receiver for detecting the intensity of the retransmitted optical signal; And The detection signal is compared with a predetermined reference value, and if it is less than this, an abnormal control signal for transmission blocking is generated, and if the reference value is exceeded for a predetermined time, a normal control signal for release is generated, and according to the control signal, And an controller for controlling an output of the optical transmitter and / or the post amplifier. 2. The apparatus of claim 1, wherein the second input / output means comprises: a circulator connected to an input of the pre-optical amplifier for bidirectional communication with the transmitter; And And a splitter connected to an output terminal of the preamplifier, for splitting a part of the amplified received optical signal and providing it to one end of the circulator.