KR20010064429A - A watching device of automatic laser shutdown for reverse optical link - Google Patents

Abstract

PURPOSE: An ALS(Automatic Laser Shutdown) device by a reverse optical link monitoring is provided to transmit a monitoring control signal, so as to speedily identify a fail generation part, and to simplify a process algorithm to improve a system reliability. CONSTITUTION: An optical signal generator(111) converts an electric data signal into an optical wavelength signal, and outputs the converted signal. A BA(Booster Amplifier)(118) amplifies the received optical wavelength data signal as an optimum level signal. An optical demultiplexer(112) applies the optical wavelength data signal to an optical cable to output the signal, and separates and extracts a monitoring control signal of another wavelength to output the monitoring control signal to another path. A control signal receiver(113) receives the outputted optical wavelength monitoring control signal, and converts the monitoring control signal into the electric data signal. Monitoring controllers(115,125) process the monitoring control signal, and identify whether the optical cable is down, then inform an NMS(Network Management System) of an identifying result.

Description

A WATCHING DEVICE OF AUTOMATIC LASER SHUTDOWN FOR REVERSE OPTICAL LINK}

In the optical communication system for transmitting an optical signal through the optical cable, the present invention provides a point of occurrence of a defect at the time of occurrence of a defect such as a cut or break of an optical cable line, or the removal and opening of an optical connector. Automatic Laser Shutdown (ALS) which detects and automatically cuts off the laser-generating light source at the corresponding point, and automatically recovers when the defect is removed. In particular, the optical transmission system operating environment and the type of optical transmission network Regardless, the automatic light blocking (ALS) can be executed and restored by the reverse optical link monitoring channel.

Skin and eyes that are easily exposed to installation and maintenance personnel from the laser, which is a high power light source, when cutting or cutting the optical fiber line or opening of the optical cable connector in the optical communication system To protect the system and to restore the performance of the system quickly.

The copper (Cu) communication line, which is a general line used for communication such as a telephone, is not only vulnerable to moisture but also has a high possibility of data distortion or loss due to external factors such as static electricity or a short circuit. Without the same problem, there is an advantage that the long-distance transmission of data with less power.

An optical communication system using the optical communication line as described above uses one optical communication optical fiber cable line to process and transmit communication data having a capacity equivalent to about 2,000 to 30,000 times or more of a regular copper (Cu) telephone line subscriber line. In addition, due to the ability to reduce the cost of the facility due to the ability to communicate more long-distance, the use is gradually increasing.

Therefore, the maintenance for the normal operation of the large-capacity optical communication line as described above is very important, in particular, the failure such as open or cut in the optical cable (Optical Cable), or open the connector for connecting the optical cable for maintenance In this case, the international safety standard (IEC 825-1, 2) prevents damage to the skin or eyes of maintenance personnel by a high power laser for transmitting an optical signal. It is enacted and applied.

Hereinafter, an automatic light source blocking device according to the prior art will be described with reference to the accompanying drawings.

1 is a configuration diagram of an automatic light source blocking device of an optical communication system according to the prior art, and FIG. 2 is a flowchart of an automatic light source blocking method according to the prior art.

Referring to the accompanying drawings, the light source blocking device according to the prior art will be described. A caller is subscribed, and has a plurality of channels for optical communication, and a first optical for transmitting an optical signal for each channel. NE (Network Element) 10,

A plurality of optical cables 15 to 19, 25 to 29, which are optical transmission lines for transmitting optical signals transmitted and received for each of a plurality of channels from the first optical end station 10;

An optical fiber amplifier (OFA) configured to receive, amplify, and output an optical signal interposed between the plurality of optical cables 15 to 19 and 25 to 29 and is weak in the transmission process is configured for each channel. For example, a plurality of optical relay stations (30, 40, 50, 60) consisting of the first to fourth optical relay station,

The called party is subscribed to, and comprises a second optical element (NE) network 20 having a plurality of channels for optical communication and transmitting and receiving optical signals for each channel.

The automatic light source blocking (ALS) sequence according to the above-described prior art configuration is that the corresponding optical cable lines 15 to 19, 25 to 29 connected to the respective optical repeaters 30, 40, 50, and 60 are cut off. Or the optical signal is not input from the optical amplifiers of the respective optical relay stations 30, 40, 50, and 60 because the optical cable connector is opened for maintenance and the connection is released. The first step (S1) of determining whether the LOS (Loss Of Signal) is continuously detected for a predetermined time, and

In the first step (S1), when the LOS signal is continuously detected for a predetermined time, the light source for generating the optical communication signal of the corresponding optical amplifier 32, 42, 52, 62 that outputs the optical signal is automatically cut off. A second step S2 of generating an Automatic Laser Shutdown (ALS) signal requesting

When the ALS request signal is received in the second step S2, a high power optical signal generation and transmission (Tx) laser light source of the corresponding optical amplifiers 32, 42, 52, and 62 is received. Determining whether there is a defect in the third step S3,

As a result of the determination in the third step S3, when there is no defect in the Tx light source for transmitting the high power optical signal, the Tx light source for operating the high power optical signal is operated. A fourth step S4 of controlling Automatic Laser Shutdown (ALS) to prevent

After the operation of the high power laser light source is stopped by the fourth step (S4), the step (S5) of generating an alarm for the LOS generation and the operation stop state of the laser light source.

Hereinafter, the operation of the configuration as described above will be described in detail with reference to the accompanying drawings.

Among the plurality of optical paths, in one embodiment, the optical path 17, which is a transmission line of a signal transmitted from the second optical relay station 40, has been cut or opened by an accident or the like, or by a maintenance operation personnel. When the connection of the optical cable connector is released and the connection is opened, the corresponding transmission optical amplifier 52 connected to the corresponding channel CH A of the third optical relay station 50 corresponds to that of the second optical relay station 40. A state in which an optical signal is not received from the transmitting optical amplifier 42, that is, a state of loss of signal (LOS) is sensed and applied to a control unit of a third optical relay station 50 not shown in the drawing. .

The control unit of the third optical relay station 50 determines whether the LOS signal lasts for a predetermined time defined by International Standards (ITU-T, G.958) (S1).

If the LOS signal continues for a predetermined time as described above, the control unit of the third optical relay station 50 receives an automatic laser shutdown (ALS) request signal for blocking the operation of the light source. (S2), and applies to the receiving optical amplifier 45 of the second optical relay station 40 via the optical cable 27.

The control unit, not shown in the drawing of the second optical relay station 40, receives the ALS signal applied from the control unit of the third optical relay station 50, analyzes the optical amplifier for transmission of the corresponding channel CH A. (42) The state is checked to determine whether the high power laser light source operates normally or is defective (S3).

As a result of the determination (S3), when there is no defect in the light source of the transmitting optical amplifier 42, the laser light source is shut down so as not to generate a laser light signal (Shut-Down) S4), the signal of the corresponding alarm content such as the place where the defect occurred, is sent to the Network Management System (NMS) of the optical system so that the maintenance operation personnel can immediately take necessary repair measures. Make sure

Therefore, when the maintenance operation personnel arrives at the site where the defect of the optical cable 17 occurs for repair and repair, the open part or the optical cable of the optical cable 17 is transmitted through a high power laser light source. The laser light source output from the connector portion of the connector does not damage the skin or eyes of the operator.

However, when the defect occurs in the optical path at the same time at the reverse point of the corresponding communication channel, the ALS request signal is not transmitted in the reverse direction, and thus the light source of high power cannot be blocked automatically. Not only that, there was a problem that the light source, which was stopped by the ALS request signal, could not be recovered automatically even when the operating personnel repaired the defective optical cable line.

As another prior art which partially solves the problems of the prior art, according to Patent Application No. 99-39416, when the optical cable is cut or broken or the optical connector is opened by the operator, transmission is performed. When the signal is transmitted from the side laser and the signal reflected from the cross section of the damaged optical cable is received at the transmitting side to confirm that the optical cable is cut or broken, and a plurality of the optical cables are broken or cut. In addition, ALS was performed to shut down the laser generator.

However, the above-described technique uses the optical signal as a signal in which the broken end surface of the optical cable is uneven or the optical signal is spread, that is, the optical cable breakage or the opening of the optical connector is reflected at a point where the span loss is large. The amount of detection of the reflected optical signal on the cut surface is so weak that the generated and transmitted side can receive it again, so that the breakage of the optical cable or the opening of the optical connector cannot be detected and the ALS cannot be executed at the same time.

As another embodiment of the prior art, there is a technology using a data communication channel (DCC) channel, which is a data channel, but this is based on the premise that a DCCr (DCC Receive) channel and a DCC-SV (DCC Supervising) channel are operating normally. If the optical cable is cut or broken or the optical connector is open, DCC channel for point-to-point communication will not work properly. there was.

According to the present invention, the data transmission wavelength of the communication signal and the wavelength of the failure monitoring are differently used, and the failure monitoring signal is transmitted to the reverse optical link monitoring channel opposite to the data signal transmission direction. It is an object of the present invention to provide an automatic light source cut-off device by reverse optical link monitoring that can not only accurately identify a fault occurrence section but also simplify the algorithm by providing a fault monitoring control section for each channel and optical cable section of the apparatus.

In order to achieve the above object, the present invention provides an optical signal generator for converting an electric data signal to be transmitted into a predetermined optical wavelength signal and outputting the optical signal, and an optical wavelength data signal applied from the optical signal generator. A transmission optical amplifier for amplifying the signal and a wavelength data signal applied from the transmission optical amplifier to the optical cable and output the same; An optical demultiplexer for outputting an optical signal, a control signal receiver for receiving an optical wavelength supervisory control signal output from the optical demultiplexer via another path, converting the signal into an electrical signal, and outputting the electric signal; To detect whether the optical cable is disconnected and notify the central management department. It characterized by an automatic light blocking device according to the reverse optical link monitoring constituted made up of a control unit.

According to another aspect of the present invention, an optical multiplexing unit receives and outputs an optical wavelength data signal applied from an optical cable and simultaneously outputs another optical wavelength signal applied in another path to the optical cable in a reverse direction, and the optical applied from the optical multiplexing unit. A reception optical amplifier for amplifying the wavelength data signal into an optical wavelength signal of an appropriate level; an optical signal receiver for converting and outputting an optical wavelength data signal applied from the reception optical amplifier; A control signal transmitter for converting the signal into an optical wavelength signal different from the optical wavelength of the data signal and outputting the signal to the optical multiplexer; Automatic light source blocking device by reverse optical link monitoring.

1 is a configuration diagram of an automatic light source blocking device of an optical communication system according to the prior art,

2 is a flowchart of a method for automatically shutting off a light source according to the prior art;

3 is a functional block diagram of an optical signal transmission system to which an automatic light source blocking device based on reverse optical link monitoring is added as an embodiment of the present invention;

4 is a functional configuration diagram for explaining the automatic light source blocking device by monitoring the reverse optical link.

** Explanation of symbols on the main parts of the drawing **

10,20: optical end station 15,16,17,18,19,25,26,27,28,29: optical cable

30, 40, 50, 60: optical relay station 111, 121: optical signal generator

32,42,52,62,35,45,55,65,118,138,128,129,139,119: amplifier

112,122,132,132 ': demultiplexer 113,133,133', 123: control signal receiver

114,134,134'124: control signal transmitter 115,125,135: supervisory control

116,126,136,136 ': Multiplexer 117,127: Optical signal receiver

Hereinafter, with reference to the accompanying drawings will be described an automatic light source blocking device by monitoring the reverse optical link according to the technique of the present invention.

FIG. 3 is a functional block diagram of an optical signal transmission system to which an automatic light source blocking device is added by reverse optical link monitoring as an embodiment of the present invention, and FIG. 4 is a view for explaining the automatic light source blocking device by reverse optical link monitoring. It is a functional diagram.

Referring to the accompanying drawings, as an embodiment of the present invention, the automatic light source blocking apparatus using the reverse optical link monitoring is configured for each channel to transmit data, thereby transmitting an electrical data signal to be transmitted. An optical signal generator 111 which converts and outputs an optical wavelength signal, as an embodiment, into an optical wavelength signal of 1550 nm and is formed of a laser diode;

In an embodiment, an optical signal having a wavelength of 1550 nm applied from the optical signal generator 111 is remote, and an optical signal having an appropriate level may be used to transmit the data signal through a long distance optical cable having a length of about 160 Km. A transmission optical amplifier 118 for amplifying and outputting

The data optical signal of 1550 nm wavelength applied from the transmission optical amplifier 118 is outputted to be transmitted through the 160 Km optical cable 15, and at the same time, other optical signals applied by the reverse optical link from the optical cable 15 are transmitted. An optical demultiplexer 112 for separating and extracting a wavelength signal, as an example, a 1310 nm optical wavelength signal, and outputting the reverse signal through a reverse path;

A control signal receiver 113 for converting and outputting a 1310 nm wavelength supervisory control optical signal received from the optical demultiplexer 112 into an electrical signal;

The control signal receiver 113 processes an applied control signal converted into an electrical signal to determine whether the optical cable 15 is cut or broken, and the result is shown in the accompanying drawings. In one embodiment of the first optical end station 10, which includes a monitoring control unit 115 for transmitting and displaying to a central management unit (NMS) (not shown), a specific channel transmitter is configured.

The transmitter of the above configuration is a transmitter for each channel of the first optical end station 10, a transmitter for each channel of the first to fourth optical relay stations 30, 40, 50, and 60, and each of the second optical end station 20. It has the same structure as the transmission unit for each channel.

As another feature of the present invention, the automatic light source blocking device by the reverse optical link monitoring shown in the figure receives and outputs a data signal applied as a 1550 nm optical wavelength signal from the optical cable 19, and simultaneously reverses the optical link. An optical multiplexer 126 that receives an optical signal having a different wavelength applied to the optical signal, and, in one embodiment, receives a monitoring control signal having a 1310 nm optical wavelength and outputs the optical signal to the optical cable 19 as an embodiment;

A reception optical amplifier 128 for amplifying a data optical signal having a wavelength of 1550 nm applied from the optical multiplexer 126 into an optical wavelength signal having an appropriate level;

An optical signal receiver 127 which receives an optical signal having a wavelength of 1550 nm and then converts the electrical signal into an electrical signal after being amplified from the reception optical amplifier 128;

A supervisory control unit 125 for generating and outputting a supervisory control signal as an electrical signal for determining whether the optical cable 19 is cut or broken;

In an embodiment, the control signal transmitter 124 converts the monitoring control signal received from the monitoring controller 125 into an optical wavelength signal of 1310 nm and outputs the signal to the optical multiplexer 126. As an embodiment, a specific channel receiver of the second optical end station 20 is configured.

The signal receiver has the same configuration as all the channel receivers of the second optical end station 20, the first to fourth optical relay stations 30, 40, 50, and 60 and all the channel receivers of the first optical end station 10. .

Hereinafter, an automatic light source blocking device by monitoring the reverse optical link having the above configuration will be described in detail with reference to the accompanying drawings.

The first optical station 10 and the second optical station 20 and the first to fourth optical relay station (30, 40, 50, 60) is a critical failure occurs in the device and the operating device in operation It is composed of a spare device that can operate in place of the replacement, the transfer to the spare device is switched to operate by the control of the central management unit (NMS) not shown in the figure.

The optical signal generator 111 of the first optical end station 10 converts an electrical data signal for each channel to be transmitted into an optical signal having a wavelength of 1550 nm, and transmits an optical amplifier (BA). Amplified by an optical wavelength signal of a suitable level (118), and then applied to the optical demultiplexer 112.

The optical demultiplexer 112 transmits the optical signal having a wavelength of 1550 nm to the first optical relay station 30 by applying it to the optical cable 25 having a length of 160 Km.

At the same time, the demultiplexer 112 or the corresponding demultiplexers 132 ′, 122, and 132 of the first optical end station 10 may be multiplexed units 136 of the first optical relay station 30 or a corresponding multiplexer having the same configuration. The monitoring control signal of 1310 nm wavelength is applied from (126, 116, 136 ') to the reverse optical link, and is separately extracted and applied to the corresponding control signal receivers 113, 133, 133' and 123, respectively.

The corresponding control signal receivers 113, 133, 133 'and 123 convert the monitoring control optical signal of 1310 nm wavelength applied to the reverse optical link into an electrical signal and then apply the control signal to the corresponding monitoring control unit 115, 135 and 125. The controllers 115, 135, and 125 analyze the applied signals, respectively, and determine whether the optical cables 15 to 19, 25 to 29 connected to the corresponding channels are cut or broken, and receive the corresponding signals. By notifying the NMS not shown, the operating personnel can immediately identify the failure area and take necessary action immediately.

In addition, an optical signal having a wavelength of 1550 nm, which is generated from the optical signal generating unit 111 and applied through corresponding optical cables 15 to 19, 25 to 29, having a length of 160 Km, is the corresponding multiplexer 136, 126, 136. ', 116, respectively, and are applied to the received optical amplifiers (PA: Post Amplifier) 128 or the corresponding optical amplifiers (138, 139, and 119), respectively, to be amplified to an appropriate level of optical signal. After that, it is applied to the optical signal receiver 127 and converted into an electric signal, or applied to the corresponding demultiplexer 132 and transmitted through the corresponding optical cable.

The monitoring control unit 125 has the same function and configuration as the monitoring control unit 115 and the monitoring control unit 135 of each optical relay station, and according to the embodiment, corresponding optical cables 15 to 19 and 25 to 160 Km long are provided. 29) generates a control monitoring signal that can determine whether the cut or break is applied to the control signal transmitter (124, 134, 134 ', 114).

The control signal transmitters 124, 134, 134 'and 114 respectively convert the supervisory control signals received from the corresponding monitoring controllers 125, 135, and 115 into optical signals having a wavelength of 1310 nm, respectively, and then the corresponding multiplexers 126, 136, 116, 136'. ) Is applied.

The corresponding multiplexers 126, 136, 116 and 136 'receive the signals from the corresponding demultiplexers 132', 112, 132 and 122 by applying signals to the corresponding 160 Km long optical cables 15 to 19, 25 to 29, and the corresponding control. The signal receivers 113, 133 ′, 133, and 123 are converted into electrical signals and then applied to the corresponding monitoring controllers 115, 135, and 125 to analyze whether the corresponding optical cable is cut or broken.

Therefore, according to the present invention having the above-described configuration, it is possible to identify failures, that is, cuts or breaks, of the optical cables formed in each section for each section, and to simplify the algorithm for processing.

The present invention as described above, by transmitting a supervisory control signal for identifying whether the optical cable for each section of the optical signal transmission system is disconnected or damaged through the reverse optical link, it is possible to easily and quickly identify the failure portion, The processing algorithm is very simple and there is an industrial use effect to improve the reliability of the system.

Claims (2)

An optical signal generator which converts the electrical data signal to be transmitted into a predetermined optical wavelength signal and outputs the converted optical data signal; A transmission optical amplifier for amplifying the optical wavelength data signal applied from the optical signal generator into an appropriate level signal; An optical demultiplexer which applies and outputs an optical wavelength data signal applied from the transmission optical amplifier to an optical cable and simultaneously extracts and outputs a monitoring control signal having a different optical wavelength applied in a reverse direction from the optical cable and outputs it to another path; A control signal receiver for receiving the optical wavelength monitoring control signal output from the optical demultiplexer through another path and converting the signal into an electrical signal; Automatic light source blocking device by reverse optical link monitoring, comprising: a monitoring control unit configured to process the monitoring control signal received from the control signal receiving unit to determine whether the optical cable is disconnected and notify the central management unit An optical multiplexer which receives and outputs an optical wavelength data signal applied from an optical cable and simultaneously outputs another optical wavelength signal applied to another optical path in a reverse direction to the optical cable; A reception optical amplifier for amplifying the optical wavelength data signal applied from the optical multiplexer into an optical wavelength signal having an appropriate level; An optical signal receiver for converting and outputting an optical wavelength data signal applied from the received optical amplifier into an electrical data signal; A control signal transmitter for converting the applied monitoring control signal into an optical wavelength signal different from the optical wavelength of the data signal and outputting the optical signal to the optical multiplexer; And a monitoring control unit for applying an electric signal for monitoring and controlling disconnection of the optical cable to the control signal transmission unit.