JPH06338940A - Subscriber's optical line monitoring system - Google Patents

Abstract

PURPOSE:To easily divide responsibility between the sides of a carrier and a user at the time of generating a fault and to unnecessitate to require excessive power supply to the side of the user by realizing the turning-back of an optical signal outside of a customer station line terminating equipment by an optical transmission line turning-back equipment. CONSTITUTION:This system is constituted of the optical transmission line turning-back equipment 2 operating by the feeding from a terminal station equipment by being composed of a demultiplexer 4 separating a part of an optical signal received from the customer station line terminating equipment, an input interruption detecting circuit 6, a turning-back control signal detecting circuit 7, an optical switch 9 inputting the output of the detecting circuit 7 and the output of the input interruption detecting circuit 6 by way of an AND gate 8 and the like, and the station inside line terminating equipment 3 sending a turning-back control signal. Then, the customer station line terminating equipment 1 sends an operation stoppage signal and a turning-back requiring signal at the time of input power source interruption and the station-inside line terminating equipment sends the turning-back control signal for executing the turning- back operation of the optical transmission line turning-back equipment 2 the time of receiving the turning-back requiring signal from the customer station line terminating equipment 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for monitoring an optical subscriber line using an optical fiber, and an optical subscriber for realizing fault monitoring of the optical subscriber line when a home line terminating device is not in use. It relates to a track monitoring system.

[0002]

2. Description of the Related Art A conventional optical subscriber line monitoring system, as shown in FIG.
The optical signal from the intra-office line terminating device 21 is not folded back while the power is being supplied to the home line terminating device 25, and when the power is cut off, the intra-office line terminating device 21 monitors the output signal from the own device. It was a method to do. In FIG. 4, reference numeral 22 denotes a line supervisory signal generation unit that receives an electrical downlink signal and generates a line supervisory signal.
The electric signal from 2 is converted into an optical signal by the electric / optical conversion unit 23, and is supplied to the optical folding unit 26 in the home line terminating device 25 via the downstream optical subscriber line 24.

In this case, when the power is input to the optical return section 26, the optical signal from the downstream optical subscriber line 24 is optical / optical.
Although it proceeds to the electrical conversion unit 27 side, the optical signal is returned to the upstream subscriber line 32 when the power is cut off. Then, when the power switch 28 is turned off, the power-off detection unit 29 detects that fact, and the power-off signal generated by the power-off signal generation unit 30 based on this is converted into an electrical upstream signal as a power-off signal. After being inserted and transmitted to the inside of the office via the electric / optical conversion unit 31 and the optical folding unit 26, the optical folding unit 26 is set to the folded state.

Further, a failure in the in-home line terminating device 25 or the upstream optical subscriber line 32 is detected by the input disconnection detecting section 36 in the in-house line terminating device 21. Three
Reference numeral 3 denotes an optical / electrical converter that converts an optical signal from the upstream optical subscriber line 32 into an electric signal. Then, in the intra-office line terminating device 21, the power cut-off signal detection unit 34 detects the power cut-off signal, and depending on whether the line supervisory signal included in the return optical signal is detected by the line supervisory signal detection unit 35,
Whether or not a failure has occurred in the downstream optical subscriber lines 32, 24 is monitored. The above optical subscriber line monitoring system is described in, for example, Japanese Patent Laid-Open No. 2-58461.

[0005]

In this conventional optical subscriber line monitoring system, since the optical loopback unit is provided in the home line terminating device, the normality of the operation of the optical loopback unit is that of the home line terminating device. Affected by normality of movement. Therefore, there is a problem that it becomes difficult to demarcate the responsibility between the carrier side and the user side when this home line terminating device is installed by the user. In addition, in a normal use state, it is necessary to keep the light folding section in an operating state, and there is a problem that an extra power supply must be requested to the user side.

The present invention has been made in order to solve such a problem. When a failure occurs, the demarcation of responsibility between the carrier side and the user side becomes easy, and it is not necessary to request the user side to supply extra power. The purpose is to obtain an optical subscriber line monitoring system.

[0007]

The optical subscriber line monitoring system of the present invention is installed near a home line terminating device and separates a part of an optical signal received from the home line terminating device side. And an input disconnection detection circuit that receives the output of the demultiplexer, a loopback control signal detection circuit, and an optical input that outputs the output of the loopback control signal detection circuit and the output of the input disconnection detection circuit through an AND gate. An optical transmission line loopback device composed of a switch and operated by power supply from a terminal device, a home line terminating device having a function of transmitting an operation stop signal and a loopback request signal when the input power is cut off, and the above loopback request signal Constituting an intra-station line terminating device for transmitting a loopback control signal for executing the loopback operation of the optical transmission line loopback device when received from the line terminal device A.

[0008]

In the present invention, the in-home line terminating device sends out the operation stop signal and the loopback request signal when the input power is cut off, the optical transmission line loopback device operates by the power supply from the terminal device, and the in-office line termination device loops back. When the request signal is received from the home line terminating device, a loopback control signal for executing the loopback operation of the optical transmission line loopback device is transmitted.

[0009]

The present invention will be described below with reference to the drawings. 1 is a block diagram showing an embodiment of an optical subscriber line monitoring system according to the present invention, FIG. 2 is a time chart used for explaining the operation of FIG. 1, and FIG. 3 is a configuration example of the optical transmission line loopback device in FIG. It is a block diagram. In FIG. 1, 1
Is a home line terminating device having a function of sending an operation stop signal and a loopback request signal when the input power is cut off.

Reference numeral 2 is an optical transmission line folding device installed near the home line terminating device 1 and operated by power supply from a terminal device. The optical transmission line folding device 2 is, as shown in FIG. The demultiplexer 4 that separates a part of the signal received from the device 1 side, the input disconnection detection circuit 6 that receives one output of the demultiplexer 4, and the output of this input disconnection detection circuit 6 and folding control An optical switch 9 for inputting the output of the signal detection circuit 7 through an AND gate 8 and the optical switch 9
And the other output of the demultiplexer 4 are combined, and a part of the optical signals from the multiplexer 5 and the intra-station line terminating device 3 side for separating the multiplexed output to the intra-station line terminating device 3 side are separated. The demultiplexed output is composed of a loopback control signal detection circuit 7 and a demultiplexer 10 for sending the output to the optical switch 9.

Reference numeral 3 denotes an intra-station line terminating device which sends a loop-back control signal c for executing the loop-back operation of the optical transmission line loop-back device 2 when the loop-back request signal b is received from the home-line line terminating device 1. This is an operation stop signal sent from the terminating device 1. In the time chart shown in FIG. 2, time t ₁ indicates the home line terminating device, the power supply is shut down, and the operation stop signal is started to be transmitted, time t ₂ is detected by the internal line terminating device, and time t ₃ is the return request signal. Start of transmission, time t ₄ starts detection of loopback request signal and return control signal of intra-office line termination device, time t ₅ stops operation of home line termination device, time t ₆ detects return control signal of optical transmission line loopback device, loopback operation Indicates the start.

The operation of the embodiment shown in FIG. 1 will be described below with reference to FIGS. First, as shown in FIG. 2, the in-home line terminating device 1 in FIG. 1 sends a return request signal b to the in-office line terminating device 3 with a slight delay when the power is turned off. When this return request signal b is detected, the intra-station line termination device 3 sends a return control signal c to the optical transmission line return device 2. After detecting the loopback control signal c, the optical transmission line loopback device 2 executes loopback of the optical signal to the intra-office line terminating device 3. Then, the intra-station line terminating device 3 monitors the returned optical signal and detects a failure in the transmission path.

Next, as shown in FIG. 3, the optical transmission line loopback device 2 separates a part of the optical signal received from the home line terminating device 1 side by the demultiplexer 4 and outputs it by the input disconnection detection circuit 6. Monitor for signal input. Further, a part of the optical signal from the intra-station line terminating device 3 side is separated by the demultiplexer 10, and the loopback control signal detection circuit 7 detects the loopback control signal c. Then, when the optical input from the home line terminating device 3 side is disconnected at the time of detecting the loopback control signal, the optical switch 9 folds back the optical signal on the local line terminating device 3 side.

From these operations, the optical transmission line loopback device 2 detects the loopback control signal c from the intra-office line termination device 3 when the power of the home line termination device 1 is cut off, and the operation of the home line termination device 1 is completed. The optical signal wrapping operation is executed at the time when the optical signal is stopped. Further, when the power of the in-home line terminating device 1 is input, the optical input disconnection detection state in the optical transmission line loopback device 2 is released, and the loopback of the optical signal is also automatically released.

[0015]

As described above, according to the present invention, the optical signal return outside the in-home line terminating device is realized by the optical transmission line return device, so that the responsibility demarcation on the carrier side and the user side is easy when a failure occurs. In addition, there is an effect that it is not necessary to request extra power supply to the user side.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an optical subscriber line monitoring system according to the present invention.

FIG. 2 is a time chart used to explain the operation of FIG.

FIG. 3 is a block diagram showing a configuration example of an optical transmission line loopback device in FIG.

FIG. 4 is a block diagram showing an example of a conventional optical subscriber line monitoring system.

[Explanation of symbols]

 1 Home Line Termination Device 2 Optical Transmission Line Folding Device 3 Intra-Station Line Termination Device 4 Demultiplexer 5 Multiplexer 6 Input Loss Detection Circuit 7 Foldback Control Signal Detection Circuit 8 AND Gate 9 Optical Switch 10 Demultiplexer

[Procedure amendment]

[Submission date] May 12, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

[0007]

The optical subscriber line monitoring system of the present invention is installed near a home line terminating device and separates a part of an optical signal received from the home line terminating device side. And an input disconnection detection circuit that receives the output of the demultiplexer, a loopback control signal detection circuit, and an optical input that outputs the output of the loopback control signal detection circuit and the output of the input disconnection detection circuit through an AND gate. An optical transmission line loopback device composed of a switch and operated by power supply from a terminal device, a home line terminating device having a function of transmitting an operation stop signal and a loopback request signal when the input power is cut off, and the above loopback request signal Constituting an intra-station line terminating device for transmitting a loopback control signal for executing the loopback operation of the optical transmission line loopback device when received from the line terminal device A. In addition, the optical transmission line folding device
The device receives the optical signal from the home line terminating device and receives the first output signal.
The first demultiplexer for separating the force and the second output,
Input the first output of the duplexer to the input of the home line termination device
From the input disconnection detection circuit that detects disconnection and the internal line termination device
To receive the optical signal of the first optical signal and separate it into a first output and a second output.
Input the second demultiplexer and the first output of this second demultiplexer
The loopback control signal from the intra-office line termination device
The loopback control signal detection circuit and the second output of the second duplexer.
Input power and always use this input as the first switching output
It is sent to the internal line termination device and used as the detection signal of the input disconnection detection circuit.
The detection signal from the loopback control signal detection circuit is output together.
The second output of the second duplexer as the second switching output
Optical switch to output and the second output of the first demultiplexer
And the second switching output of the optical switch is input and multiplexed.
A multiplexer that transmits the multiplexed optical signal to the intra-station line terminal
It is composed of

Claims (1)

[Claims] 1. A demultiplexer installed near a home line terminating device for separating a part of an optical signal received from the home line terminating device, and an input disconnection detection using an output of the demultiplexer as an input. Optical transmission comprising a circuit, a loopback control signal detection circuit, and an optical switch for inputting the output of the loopback control signal detection circuit and the output of the input disconnection detection circuit via an AND gate A line loopback device, a home line terminating device having a function of transmitting an operation stop signal and a loopback request signal when the input power is cut off, and a light transmission line loopback device of the optical transmission line loopback device when the loopback request signal is received from the home line line termination device. An optical subscriber line monitoring system comprising an intra-station line terminating device for transmitting a loopback control signal for executing a loopback operation.