JPH06244803A - Optical repeater - Google Patents

Abstract

PURPOSE:To make it possible to easily perform the release of a loop island phenomenon in an optical repeater provided with a function which is capable of performing the communication of data signals between opposing optical repeaters. CONSTITUTION:The signal line for an opposing line data signal 2 from an opposing repeater 13 to a gate circuit 9a is provided with an interruption circuit 10a interrupting or passing the opposing line data signal. A loop back signal detection circuit 6a detects a loop back signal from the control signal 5a extracted from a self-line data signal 1 and controls the interruption circuit 10a according to the loop back setting or the loop back release shown by this loop back signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical repeater, and more particularly to an optical repeater having a function of exchanging data signals between opposed optical repeaters.

[0002]

2. Description of the Related Art The structure of a conventional optical repeater is shown in FIGS. As shown in FIG. 2, the own repeater 12 is connected to the own line.
A case in which a and 12b are connected and the opposite repeaters 13a and 13b are connected to the opposite line corresponding to these will be described.

In FIG. 3, the own line data signal 1 is input to the optical receiving circuit 4a and converted into an electric signal by photoelectric conversion. The converted electric signal is equivalently amplified, and then the clock component is extracted, and the equivalent waveform after the previous equivalent amplification is punched out by the extracted clock to identify and reproduce the data signal.

The identified and reproduced own-line data signal 1 is sent to the opposite repeater 13 for loopback, but is also sent to the gate circuit 9a as it is. Since the own line data signal 1 is modulated by mark rate modulation or parity violation, the control signal 5a superimposed on the own line data signal 1 is extracted by the optical receiving circuit 4a,
Various command operations are enabled by sending to the monitoring control circuit 3a. The extracted control signal 5a is also sent to the opposite repeater 13 and input to the supervisory control circuit 3b.

In FIG. 4, the control signal 5a input to the supervisory control circuit 3a is input to the signal detection circuit 14a,
Therefore, the presence or absence of the control signal 5a is detected, and when the control signal 5a is present, the analog switch 16 is switched to the side where the control signal 5a passes. When the control signal 5b is sent from the counter repeater 13 to the supervisory control circuit 3a and the control signal 5a does not exist, the control signal 5b is input to the signal detection circuit 14b, and the presence or absence of the control signal 5b is detected there. However, when there is the control signal 5b, the analog switch 16 is switched to the side where the control signal 5b passes.

Here, the control signal 5a is the supervisory control circuit 3a.
If the control signal 5b is subsequently input to the monitoring control circuit 3a while being input to the monitor control circuit 3a, the control signal 5b is not passed by the analog switch 16 and the control signal 5a is continuously passed by the analog switch 16. Logic is organized in the gate circuit 17 so as to have high priority.

The control signals 5a and 5b output through the analog switch 16 are demodulated into the original baseband format signal 19 by passing through the command receiver 18, and after further waveform shaping, input to the decoder 20. It is configured to perform various monitoring operations.

By the way, the gate circuit 9a is inputted with the identified and reproduced own line data signal 1 and the opposite line data signal 2 sent from the opposite repeater 13, but a control signal for loopback setting. When 5a or 5b is sent, the supervisory control circuit 3a recognizes it and changes the loopback control voltage 8a so that the opposite line data signal 2 passes through the gate circuit 9a. Also, the loopback release control signal 5a or 5
When b is sent, the supervisory control circuit 3a recognizes it and changes the loopback control voltage 8a so that the own line data signal 1 passes through the gate circuit 9a. The signal output from the gate circuit 9a is converted into an optical signal by the electro-optical converter 11a, and then transmitted to the next optical repeater through the optical fiber.

[0009]

In the above-mentioned conventional optical repeater, the loopback setting is performed by the own repeaters 12a and 12b.
And the opposite repeaters 13a and 13b, a loop island phenomenon occurs, and the data signal modulated by parity violation or the like constantly rotates forever between the four optical repeaters. I will end up. In this case, the control signals 5a and 5b are always input to the monitoring control circuits 3a and 3b, and even if the loopback cancellation control signal 5a is sent to the monitoring control circuit 3a later, the cancellation cannot be recognized. Even if an optical repeater is used as an access point, there is a problem that the loop island cannot be released.

An object of the present invention is to solve such a problem by adding a simple structure.

[0011]

SUMMARY OF THE INVENTION According to the present invention, an optical receiving circuit for converting received light into an electric signal, identifying and reproducing the own line data signal, and extracting a control signal from the own line data signal, and a self repeater. Monitoring control circuit for performing a monitoring operation by receiving the control signal from the receiver and the control signal from the counter repeater, and the counter relay with the own line data signal which is discriminated and reproduced by the optical receiving circuit under the control of the monitor control circuit. An optical repeater that includes a gate circuit that can select and output the opposite line data signal that is output from the optical receiver, and that has a function of exchanging data signals between the optical repeaters that face each other. The signal line for the opposite line data signal from the opposite repeater to the gate circuit is provided with a cutoff circuit that cuts off or allows the opposite line data signal to be extracted from the own line data signal. Characterized in that a loop-back signal detecting circuit for controlling the cut-off circuit detects the loopback signal from said control signal.

Further, the loopback signal detection circuit is
When the loopback signal represents a loopback setting, the shutoff circuit is opened, and when the loopback signal represents a loopback release, the shutoff circuit is closed.

[0013]

1 is a block diagram showing an embodiment of the present invention, in which the same parts as those in FIG. 3 are designated by the same reference numerals. The own repeater 12 and the opposite repeater 13 are respectively provided with the optical receiving circuit 4a,
A loopback signal detection circuit 6a that receives the loopback signal from the 4b and identifies the setting and cancellation of the loopback,
6b, loopback signal detection circuit 6a,
The cutoff circuits 10a and 10b controllable by 6b are provided on the data signal line between the own repeater 12 and the opposite repeater 13.

The loopback signal detection circuit 6a can identify the control signal 5a when a loopback setting / cancellation command is superimposed on the own line data signal 1. That is, when the loopback setting control signal 5a is sent to the loopback signal detection circuit 6a and the supervisory control circuit 3a, the supervisory control circuit 3a identifies it and the opposite line data signal 2 passes through the gate circuit 9a. Thus, the loopback control voltage 8a is changed. At the same time, the loopback signal detection circuit 6a also discriminates this and opens the cutoff circuit 10a so that the cutoff circuit control voltage 7a
Change.

On the other hand, when the loopback release control signal 5a is sent to the loopback signal detection circuit 6a and the supervisory control circuit 3a, the supervisory control circuit 3a identifies it, and the own line data signal 1 becomes the gate circuit 9a. The loopback control voltage 8a is changed so as to pass at. At the same time, the loopback signal detection circuit 6a also identifies it,
The breaking circuit control voltage 7a is changed so as to close the breaking circuit 10a.

With such a structure, even if a loop island occurs, a command is superimposed on the own line data signal 1 and the loopback release control signal 5a is generated.
The shutoff circuit 10a can be closed by sending When the shutoff circuit 10a is closed, the data signal on which the command component circulated by the loop island is superimposed disappears from the loop, so that the loopback release control signal 5a can be identified by the supervisory control circuit 3a.

[0017]

As described above, according to the present invention, the cutoff circuit is provided on the line for exchanging the data signal between the own repeater and the opposite repeater, and the cutoff circuit is a loop for identifying the setting and cancellation of the loopback. Controlling with the back signal detection circuit has an effect that the loop island can be released.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a connection diagram of an optical repeater necessary for explaining the present invention and the prior art.

FIG. 3 is a main configuration diagram inside a conventional optical repeater.

FIG. 4 is a configuration diagram of the monitoring control circuit shown in FIG.

[Explanation of symbols]

 1 own line data signal 2 opposite line data signal 5a, 5b control signal 7a, 7b cutoff circuit control voltage 8a, 8b loopback control voltage 12, 12a, 12b own repeater 13, 13a, 13b opposite repeater 14a, 14b signal detection Circuits 15a, 15b Analog switch control voltage 19 Baseband format signal

Claims (2)

[Claims] 1. An optical receiving circuit for converting the received light into an electric signal, identifying and reproducing the own line data signal, and extracting a control signal from the own line data signal, and an opposition to the control signal from the own repeater. A supervisory control circuit that receives a control signal from a repeater to perform a supervisory operation, a self-line data signal that is discriminated and reproduced by the optical receiving circuit under the control of the supervisory control circuit, and an opposite line data output from an opposite repeater An optical repeater including a gate circuit capable of selecting and outputting a signal, and having a function of exchanging a data signal between opposed optical repeaters, from the opposite repeater to the gate circuit. A loopback signal is provided from the control signal extracted from the own line data signal by providing the opposite line data signal signal line with a blocking circuit that blocks or passes the opposite line data signal. An optical repeater, which is provided with a loopback signal detection circuit for detecting the current and controlling the cutoff circuit. 2. The optical repeater according to claim 1, wherein the loopback signal detection circuit opens the cutoff circuit when the loopback signal represents a loopback setting, and the loopback signal represents a loopback cancellation. An optical repeater characterized by controlling so that the interruption circuit is closed at a time.