JPS60229434A - Remote supervisory system of operation margin - Google Patents

Abstract

PURPOSE:To decide the deterioration of a reception board and to confirm the operating margin by superimposing a superposing signal on an identification voltage of an identification reproducing circuit in an optical communication line to fluctuate slightly the identification voltage. CONSTITUTION:A reception signal in which transmission distortion is equalized by an equalizing circuit 14 is identified and reproducted by an identification and reproducing circuit 16. If the error rate obtained at a terminal station is deteriorated more than preceding error rate as a result of the measurement of the error rate by reflecting the terminal station and an intermediate relay station, a control signal is transmitted to a supervisory device S-SV of the corresponding intermediate relay station from the supervisory device M-SV of the terminal station so as to turn on the switch of the station in order to section the cause. A signal having a peak value of, e.g., nearly 10% of the peak value of the equalizing waveform from the circuit 14 is transmitted from a superimposing signal generating circuit 19 to the circuit 16. Then the identification voltage of the circuit 16 is fluctuated by nearly 10% to a specified DC voltage. Then if the measured error rate is deteriorated further, it is discriminated that the cause exists in the reception board and if not deteriorated, it is discriminated that the cause exists in other parts.

Description

[Detailed Description of the Invention] (a) Technical Field of the Invention The present invention relates to an operational margin remote monitoring system, particularly in an optical communication line in which a terminal station and m intermediate relay stations are connected by optical fiber cables. This invention relates to a remote operating margin monitoring system for monitoring the operating margin of an optical repeater from a terminal station.

(b) Conventional technology and problems FIG. 1 is for explaining the remote monitoring system.

In the figure, 1 and 12 indicate terminal equipment, 2 indicates terminal monitoring equipment, and 3
, 5, . . . 10 are intermediate relay station devices, 4, 6, . . . 11 are intermediate relay station monitoring devices, and 31 to 36 are repeaters, respectively.

In addition, the part that includes the terminal station equipment and the terminal station monitoring equipment (hereinafter abbreviated as M-SV) is included in the terminal station, and the part that includes the intermediate relay station equipment and the intermediate relay station monitoring equipment (hereinafter abbreviated as 5-SV) This part is called an intermediate relay station.

In FIG. 1, an optical signal from a terminal station device 1 is transmitted to an intermediate relay station device 3. After being relayed by repeaters 31, 33, 35, . . . in p. The received optical signal is then converted into an electrical signal by an optical/electrical conversion circuit (not shown), and the original data is extracted.

On the other hand, the optical signal sent from the terminal station device 12 is relayed in the reverse direction to the intermediate relay station devices 10 . . . 5 and 3, and the original data is extracted at the terminal station device 1.

In such a system configuration, each intermediate relay station is often unmanned, so the operation of these intermediate relay stations must be constantly monitored from the terminal station.

For this reason, M-5V 2 is installed at the terminal station, and 5V is installed at each intermediate relay station.
-5V 4. 6...11 are provided, each with terminal equipment 1.
M-SV
2 and each 5-SV with another line.

Then, data indicating the operating state of each intermediate relay station device is 5-3V.4. 6... terminal station (7) l'1-5
V2 automatically collected.

Therefore, if it is determined that a device failure has occurred at an intermediate relay station, a maintenance person from the terminal station goes to the failed station and repairs the failed part.

Of course 5-5V from M-SV 2 3. It is possible to control the intermediate relay devices 3, 5, and obtain data on the operating status of the intermediate relay devices 3, 5, and so on.

For example, if you want to obtain data on the error rate of a line looped back between terminal station l and repeaters 31 and 32 using M-SV 2, use h-8V
5 which received the control signal sent from 2 via the side line.
-3V 4 sets the loop back state.

Therefore, the data sent from the terminal station 1 is relayed by repeaters 31 and 32 and received again, and the error rate is measured.

If the error rate becomes worse than before in this measurement, there is a problem in that it is not possible to determine whether the deterioration is due to deterioration of the repeater in the intermediate relay station equipment or whether the deterioration is due to a problem with the transmitter or line. .

(C1 Purpose of the Invention The present invention has been made in view of the above-mentioned problems of the prior art. It is an object of the present invention to provide an operating margin remote monitoring system that can distinguish whether the repeater is in use or not, and can also monitor the operating margin of a repeater receiving panel.

(d) Structure of the Invention The object of the above invention is to superimpose a signal with a predetermined amplitude on the threshold voltage for identification when identifying an equalized received waveform in an optical communication line including an optical repeater. This is achieved by providing a remote operating margin monitoring system that monitors the operating margin of the optical repeater.

+e) Embodiment of the invention FIG. 2 shows an example of a block of a repeater receiving board in which the invention is implemented.

Note that the repeater is composed of a receiving board and a transmitting board, and the transmitting board is not shown.

In the figure, 11 is an optical/electrical conversion circuit, 12 is an automatic gain control circuit, 13 is an amplifier circuit, 14 is an equalization circuit, 15 is a timing extraction circuit, 16 is an identification regeneration circuit, and 17 is a signal 18 is a waveform shaping circuit, 19 is a superimposed signal generating circuit, 23 is a switch circuit, and 20.degree. and 21 are terminals, respectively.

In the figure, an optical signal applied to a terminal 21 through an optical fiber cable is converted into an electrical signal by an optical/electrical conversion circuit 11. After the converted electrical signal is amplified by an amplifier circuit 13, a portion of the signal is equalized by an equalizer circuit 14 to equalize the distortion of the transmission path, and is applied to an identification/reproduction circuit 16.

The remaining amplified part is timing extraction time 1 yen! At step 15, a timing component is extracted and this timing component is applied to the identification and reproduction circuit.

Therefore, the received signal whose distortion has been equalized is identified and reproduced by the identification and reproduction circuit 16. This reproduced signal is applied to a waveform shaping circuit 18 together with the timing component that has passed through the signal disconnection detection circuit 17, where the waveform is shaped and sent from a terminal 20 to a repeater transmission board (not shown).

Incidentally, the automatic gain control circuit 12 applies a DC voltage corresponding to the peak value of the output of the equalization circuit 13 to the terminal 22, and adjusts the bias voltage of the optical/electrical conversion circuit 11 so that this peak value becomes constant. Controls the gain of the amplifier circuit 13.

Also, when the reception level is lower than the standard and the timing extraction circuit 15 does not operate normally, the signal disconnection detection circuit 17 detects this and sends this detection output to the M-S of the terminal station via 5-SV.
Send to V.

Now, as a result of measuring the error rate by looping back between the terminal station and the intermediate relay station as described above, if the error rate data obtained at the terminal station is worse than the previously obtained error rate data, the cause In order to determine whether or not the repeater receiver board is connected, switch 2 of that station is sent from M-SV 2 of the terminal station to 5-SV of the corresponding intermediate repeater station.
A control signal is sent through the side line to turn on the switch 3.

5-SV turns on the switch 23 designated by the received control signal. As a result, a signal having a peak value of, for example, about 10% of the peak value of the equalized waveform outputted from the equi-northern circuit B14 is transmitted from the superimposed signal generation circuit 19 to the identification and reproducing circuit 1.
6 is sent out.

Therefore, the identification voltage of the identification reproducing circuit 14 is obtained by superimposing the above-mentioned signal on a predetermined DC voltage, and the identification voltage varies by about 10% with respect to this DC voltage. Now, if the error rate measured at the terminal station deteriorates further, the receiver board, especially the optical/electrical conversion circuit 1
There is a high possibility that the avalanche photodiode used in the system has deteriorated, and if the error rate does not deteriorate, it will be isolated from other parts, not the receiver.

The timing to superimpose the superimposed signal on the identification voltage is not limited to when an abnormality occurs, but by doing so during normal operation, it is possible to know the operating margin of the receiving board itself.

FIG. 4 shows a more specific example of the identification/reproduction circuit 16.

In the figure, an equalized waveform is applied to a terminal a of an identification reproducing circuit 16, and a superimposed signal from a superimposed signal generation circuit 19 is applied to a terminal through a switch circuit 23.

(f) As described in detail, according to the present invention, by superimposing a superimposed signal on the identification voltage of the identification reproducing circuit and slightly varying the identification voltage, it is possible to determine the deterioration of the receiver and check the operating margin. .

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the remote monitoring system, FIG. 2 is an embodiment of the present invention, and FIG. 3 is a more specific block diagram of the identification reproducing circuit. In the figure, 11 is an optical/electrical conversion circuit, 12 is an automatic gain control circuit, 13 is an amplifier circuit, 14 is an equalization circuit, 15 is a timing extraction circuit, 16 is an identification regeneration circuit, and 17 is a signal 18 is a waveform shaping circuit, 19 is a superimposed signal generation circuit, 20 and 21 are terminals, and 22 is a switch circuit. Akira 1 Figure 2 Suko 3 Concave

Claims (1)

[Claims] In an optical communication line including an optical repeater, when identifying an equalized received waveform, a signal with a predetermined amplitude is superimposed on the identification threshold voltage to monitor the operating margin of the optical repeater. This is a remote monitoring system with operating margins.