JPS59139746A - Monitoring system of repeater - Google Patents

Abstract

PURPOSE:To measure the working margin which is sent to the next stage by each terminal station at a receiving terminal station for monitoring by providing a control signal generating means at a transmitting terminal station and a means at each repeater to receive a control signal and to vary the level of a signal to be transmitted. CONSTITUTION:A transmitting terminal station equipment 1 is connected to a receiving terminal station equipment 2 via a control line 3, and plural repeaters REP1-REPn are provided to the line 3. An optical fiber 4 is used to connect among these repeaters and devices 1 and 2. A test signal generating circuit is provided to the device 1, and a control signal is sent to the repeater REP1. At the same time, an AGC circuit which varies the level to be transmitted in response to the control signal supplied from the device 1 is provided to each repeater together with a driving circuit, etc. Then the device 2 measures the working margin of the designated repeater of the next stage from the outputs of repeaters REP1-REPn and the level of the signal to be received which are designated by the device 1. Thus those repeaters are monitored.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention is directed to improving the operating margin of each of a plurality of repeaters provided via a transmission path between a transmitting terminal station device and a receiving terminal station device. This is related to the repeater monitoring method for measuring.

(b) Background of the Technology There is a transmission method in which various signals are sent and received between a transmitting terminal device and a receiving terminal device via a transmission path and a plurality of repeaters.

An embodiment of such a transmission system will be described using FIG. Note that the explanation will be made using an optical transmission method here.

FIG. 1 is a configuration diagram of an embodiment of an optical transmission system. In the figure, l is a transmitting terminal device, 2 is a receiving terminal device, 3 is a control line, 4 is a source fiber, and RE P 1 to RE
Pn is a repeater.

Now, for the transmitting terminal device L and the receiving M terminal device 2-ζ,
Suppose that predetermined information, such as an audio signal, is to be transmitted.

At this time, the transmitting terminal device 1 converts the information into electricity and sends it out to the original fiber 4. It is received by the receiving terminal device 2 via the electric relays REP to REPn. Incidentally, at this time, the repeater REP.

Here, the optical fibers 4 to REP nj are respectively
The optical signal received from the optical fiber is amplified, equalized, identified and regenerated, and then sent out to the optical fiber 4#.

Then, the receiving terminal device 21 receives the received/original signal. The above-mentioned information from the transmitting terminal device 1 can be obtained by electrically converting and amplifying, equalizing, identifying and reproducing the electrical signals obtained.

In such a system, repeaters REP to REPn
In order to know the characteristics such as the deterioration state of the repeaters REP, the operating margin of each of the repeaters REP to REPn, that is, the repeater RE
There is a need for a terminal device to be able to measure how much margin there is before PJ to REPn start to fail.

(c) Purpose of the Invention In view of the background of such technology, the present invention provides a method for calculating the operating margin of each of a plurality of repeaters provided between a transmitting terminal station device and a receiving terminal station device via a transmission path. The purpose of this invention is to provide a repeater monitoring method that can be measured at a receiving end station.

(a) Structure of the Invention In order to achieve the above object, the present invention provides a system having a plurality of repeaters provided between a transmitting terminal station device and a receiving terminal station device via a transmission path. a variable means for varying the level of the transmitted signal in response to a control signal from the transmitting end station device in each of the repeaters; and a variable means for transmitting the variable level of the transmitted signal to the receiving end station device. The transmitting end station device is provided with a transmitting means for transmitting a control signal for designating one repeater for operating the variable means, and the receiving end station device Measuring the operating margin of a repeater installed at the next stage of the specified repeater from the output of the transmitting means of the repeater specified by the specifying means of the device and the level of the received signal. This is a characteristic feature.

(e) Embodiments of the Invention Hereinafter, the repeater monitoring system provided by the present invention will be explained in detail with reference to the drawings.

FIG. 2 is a configuration diagram of an embodiment of a transmitting end station device according to the present invention. In the figure, parts with the same numbers as in Figure 1 indicate the same parts, 5 is a control circuit, 6 is a test signal generation circuit, 7 is a drive circuit, 8 is a light emitting element, IN
is an input terminal.

FIG. 3 is a configuration diagram of an embodiment of a repeater according to the present invention. In the figure, the same numbers as in FIG. 1 indicate the same parts, 9 is a light receiving element, 1O is an amplifier, 11 is an equalization amount, 12 is an identification circuit, 13 is a drive circuit, 1
4 is a light emitting element, 15 is an AGC circuit, 16 is a receiving circuit, 1
7 is a control circuit, 18 is a transmitting circuit, and 19 is a digital-to-analog converter/converter (hereinafter referred to as a D/A converter). In FIG. 1, 2o is a light receiving element, 21 is an amplifier, 22 is an equalization amount, 23 is an identification circuit, 24 is an AGC circuit,
25 is a control circuit, and 26 is an erroneous copy detection circuit.

Here, we will explain the case of measuring the operating margin of the repeater REPs shown in FIG. 1 as Example 1.

At this time, the control circuit 5 in the transmitting terminal device 1 communicates via the control line 3 with the repeater REP! At the same time, a control signal is sent to cause the source output to deteriorate, and the switch SW is switched to the test signal generation circuit 6 side. At this time, the test signal from the test signal generation circuit 6 is input to the drive circuit 71, and the drive circuit 7 drives the light emitting element 8 in response to the test signal.

Then, the optical signal from the light emitting element 8 is sent out through the optical fiber 41.

This optical signal is input to the repeater RFP via the original fiber 4 and the repeater RFP.

The converted signal is amplified by an amplifier 10ζ, and the amplified signal is equalized by an equalizer 11.

The output of the equalization amount 11 is then identified and reproduced by the identification circuit 12 and input to the drive circuit 13. The drive circuit 13 selects the light emitting element 1 in response to the output l of the identification circuit 12.
Drive 4.

At this time, in the repeater REP2, the receiving circuit 16f receives the control signal transmitted from the control device 5 of the transmitting terminal device 1 via the control line 3.

The control signal received by the receiving circuit 16 is transmitted to the control circuit 17.
And it will be deciphered. The control circuit 17 sends the control signal instruction (or the control amount thereof) to the transmitting circuit/18 and the D/A converter 19. The transmitting circuit 18 sends the attenuation amount of the optical output calculated from the control amount from the control circuit 17 to the control a3. In addition, the D/A converter 19 gradually lowers the bias voltage of the light emitting element 14 according to the control amount from the control circuit 17. Therefore, the level of the optical signal sent from the repeater RFP also decreases little by little. become.

The optical signal sent from the repeater R'E P 2 is transmitted to the original fiber and the repeaters RE P s to RE
It is received by the receiving terminal device 2 via Pn.

In the receiving terminal device 2, the original signal input from the optical fiber 4 is optically converted into electricity by the light receiving element 20 and amplified by the amplifier 21. The output of this amplifier 21 is
The signal is equalized by an equalization amount 22, and identified and reproduced by an identification circuit 23. The output of the identification circuit 23 is sent to an erroneous car detection circuit 26, where the erroneous car rate is monitored by a parity check, a code error check, and the like. Then, when the error rate of the output of the identification circuit 23 exceeds a specified value, the error rate detection circuit 26 notifies the control circuit 25 of this fact.

Note that the control circuit 25 connects the repeater REP via the control line 3.
The amount of attenuation from z is input.

Therefore, when the control circuit 25 receives from the error rate detection circuit 26 that the error rate of the output of the identification circuit 23 exceeds the specified value, the control circuit 25 calculates the amount of attenuation from the repeater REP2 at that time. It's crowded.

From this ζ, in the control circuit 25I, the repeater RE
The operating margin of Ps can be measured. That is, each repeater REP to REPn has an AGC circuit 15, but reduces the optical output level of the repeater that has been cut by fmi9 before the repeater under test. The operating margin of RFPn can be measured by setting the point in time when the AGC circuit is no longer able to follow the signal as the operating limit of the repeater to be measured.

Although the optical transmission system has been explained here as an example, the repeater monitoring system of the present invention can also be implemented using other electrical transmission systems.

(Effects of the Invention As explained in detail above, according to the repeater monitoring system of the present invention, a plurality of It is possible to measure the operating margin of each repeater.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of an embodiment of an optical transmission system;
Fig. 3 is a block diagram of an embodiment of a transmitting terminal device according to the present invention, Fig. 3 is a block diagram of an embodiment of a repeater according to the present invention, and Fig. 4 is a block diagram of an embodiment of a receiving terminal station according to the present invention. FIG. 2 is a configuration diagram of an embodiment. In the figure, 1 is a transmitting terminal device, 2 is a receiving terminal device, 3 is a control line, 4 is a source fiber, REPt to REPn are repeaters,
5, 17.25 is a control circuit, 6 is a test signal generation circuit, 7
, 13 is a drive circuit, 8.14 is a light emitting element, 9.20 is a light receiving element, 10.21 is an amplifier, 11.22 is an equalization amount, 1
2. ．． 23 is an identification circuit, 15.24 is an AGC circuit, 16
18 is the receiving circuit, 18 is the transmitting circuit, 19 is the iD/rAX converter, and 26 is the error rate detection circuit.

Claims (1)

[Claims] Between the transmitting end station device and the receiving end station device (via this transmission line, each of the plurality of repeaters of a system having a plurality of repeaters provided) (in response to the control signal from the transmitting end station device) and a variable means array t for varying the level of the signal to be sent out.
A transmitting means for transmitting a variable level of the transmitted signal to the receiving end station device is provided, and one repeater is designated in the transmitting end station device for controlling the varying means by operation. A specifying means for sending out a control signal is provided, and the receiving terminal device determines the specified value from the output of the transmitting means of the designated repeater and the level of the received signal. A repeater monitoring method characterized by measuring the operating margin of a repeater installed at the next stage of a designated repeater.