JPS61156930A - Supervising system for optical fiber relay transmission line - Google Patents

Abstract

PURPOSE:To simplify the constitution of a repeater by supervising a reflected wave of a supervisory optical pulse to supervise an optical repeater or a signal optical fiber cable. CONSTITUTION:A supervisory optical pulse is generated from a supervisory optical pulse generating/light emitting power output device 11 placed near an optical terminal station device 10 and the pulse is transmitted to a faulty location generator 21 placed near an optical repeater 20 via a supervisory optical fiber cable 101. When the repeater 20 is normal, a slightly reflected wave is returned from the generator 21 to a supervisory optical pulse generating/ photodetecting power device via the cable 101 and the pulse is outputted with a time delay in response to the length of the supervisory optical fiber cable 101. Similarly, the supervisory optical pulse outputs as a slightly reflected pulse from faulty point generators 31, 41 placed near the repeaters 30, 40 from a photodetector power output point 3. Thus, a fault detected by the optical relater in the optical fiber transmission line is located by the optical terminal station device by adding a simple device to the optical repeater.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a monitoring system for optical relay transmission lines using original fiber cables.

[Prior art]

Conventionally, in a source fiber transmission line consisting of a source fiber cable and an optical repeater, if the optical signal is interrupted or a malfunction occurs due to a failure in the repeater or a break in the optical fiber cable, each repeater is The interruption or occurrence of a monitoring signal having a frequency that distinguishes each built-in repeater is monitored at the receiving end, and the fault location or fault section is evaluated.

However, each repeater needs to have a circuit having a capability element such as a supervisory signal generator, and the structure of each repeater becomes complicated.

[Purpose of the invention]

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned drawbacks, an object of the present invention is to provide an optical fiber relay transmission line monitoring system in which a monitoring information signal for each repeater is generated by an optical switch, and the configuration of each repeater is simplified. be.

a plurality of optical repeaters that relay the original signal via a signal optical fiber cable, a monitoring optical pulse generator/light receiving power output device that sends out a monitoring optical pulse, and each of the optical repeater. and connected in series to the output end of the monitoring source pulse generator/light receiving power output device via a monitoring optical fiber cable, and depending on whether the optical repeater is normal or abnormal, the monitoring optical fiber cable and a failure point generating device that turns on and off the connection between the optical repeater and the optical repeater or the signal by monitoring the reflected wave of the monitoring optical pulse in the monitoring optical pulse generator/received light power output device. ] Next, embodiments of the present invention will be described in detail with reference to the drawings.

As shown in the 1d-year lock diagram, the electrical signal to be transmitted is input to the electrical signal input point 1 of the optical terminal equipment 10 (transmission side), converted to an optical signal, and the signal optical fiber cable 1
00 to the optical repeater 20, and then the signal is transmitted to the next optical repeater 30 via the signal optical fiber cable 200. Similarly, according to the signal optical fiber cable 300,
Signal fiber cable 40 via optical repeater 40
0 to the optical terminal equipment 50 (receiving side), converted into an electrical signal, and outputted from the electrical signal output point 2.

On the other hand, a monitoring optical pulse generator/light receiving power output device 11 placed near the optical terminal station [10 (transmission side) generates a monitoring optical pulse, and transmits the monitoring optical pulse through the monitoring optical fiber cable 101. Failure point generating device 21 placed near the optical repeater 20
If the optical repeater 20 is normal, a small amount of reflected waves from the failure point generating device 21 are returned to the monitoring optical pulse generator/light receiving power unit via the monitoring optical fiber cable 101, and the received light power is From the output point 3, the signal is output with a time delay depending on the length of the monitoring optical fiber cable 101. Similarly, the monitoring optical pulse causes a small number of reflected pulses to be output from the reception power output point 3 from the failure point generating device 31.41 placed near each optical repeater 30.40.

For example, when a failure occurs in the optical repeater 30, a failure occurrence signal from the optical repeater 30 is transmitted to the failure point generating device 31, the source switch that constitutes the failure point generating device 31 is disconnected, and the monitoring optical fiber cable is disconnected. Disconnect 201.301. As a result, the optical pulse receives a large reflection (the optical pulse is not transmitted to the monitoring optical fiber cable 301), generates a monitoring optical pulse, and is extracted from the received light power output point 3 of the received light power output device 11.

Fault-free optical repeater 30. The output waveforms of the received light power output points 3 and 3 when a fault is detected at
It is shown in FIG. 2(a) and FIG. 2(b). In FIG. 2(a), the first reflected pulse is the monitoring optical fiber cable 1
01, and the fifth reflected pulse is a reflection from the monitoring optical fiber termination point 4. Figure 2 (
The third reflected pulse in b) is a reflected pulse from the failure point generating device 31 near the optical repeater 3o that detected the occurrence of the failure.

〔Effect of the invention〕

According to the present invention, a fault detected in an optical repeater in an optical fiber transmission line can be located at an optical terminal equipment (transmission side) by adding a simple device to the optical repeater. Can provide monitoring methods.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 (a
) and (b) are waveform diagrams showing the operation in normal and abnormal conditions in FIG. 1. 1... Electric signal input point, 2... Electric signal output point, 3... Received light power output point, 4...
... Optical fiber termination point for monitoring, 10 ... Optical terminal equipment (transmission side), 20° 30.40 ... Optical repeater, 50 ... Optical terminal station Device (receiving side), 11
... Monitoring optical pulse generator/light receiving power output device, 2
1, 31, 41... Failure point generating device, 100.
200,300,400... Signal optical fiber cable, 101,201,301.401...
・Optical fiber cable for monitoring, 202,302.402
...Fault signal transmission path. /'!

Claims (1)

[Claims] An optical terminal device that converts an electrical signal into an optical signal and sends it out, a plurality of optical repeaters that relays the optical signal via a signal optical fiber cable, and a monitoring optical pulse generator that sends out a monitoring optical pulse.・Installed in the vicinity of each of the received light power output device and the optical repeater, and connected in series to the output end of the monitoring optical pulse generator and received light power output device via a monitoring optical fiber cable, a failure point generation device that turns on and off the connection between the monitoring optical fiber cables depending on whether the monitoring optical fiber cable is normal or abnormal; An optical fiber relay transmission line monitoring system characterized in that the optical repeater or the signal optical fiber cable is monitored by monitoring.