JPS59176937A - System for supervising optical relay transmission line - Google Patents

Abstract

PURPOSE:To detect a failure by modulating an optical signal for supervision in the same wavelength by a different frequency supplied from each optical repeater, and adding the resultant signal to an optical transmission section to supervise the optical transmission line. CONSTITUTION:An electric signal optical modulator (wavelength lambda1) 23 for supervision of an optical repeater 20 receives the signal of an electric signal generator 24 (frequency f1), modulates the signal optically and inputs it to an optical synthesizer 22, and the synthesized optical signal is transmitted to the optical transmission line 200 via an optical repeater 21. The modulator (wavelength lambda1) of an optical repeater 30 receives a signal (frequency f2) of a generator 34, inputs an optical signal for supervision in wavelength lambda1 modulated in the f2 to an optical synthesizer 32, an optical repeater 31 amplifies an optical signal of the transmission line 200 and the optical signal for supervision for use in the repeater 30 and transmits the amplified signal to a transmission line 300. Further, the signal is inputted to an optical branching device 42 of an optical terminal station device 40, the optical signal in wavelength lambda1 is separated and inputted to a receiver 43, where the signal is converted into an electric signal and the frequency is separated into frequencies f1 and f2. The supervision is attained by judging the receiving level of the electric signals and outputting a failure position information signal from an output point 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical relay transmission line monitoring system for a transmission line using an original fiber cable.

Conventionally, when repeating transmission using an optical repeater in a five-way fiber transmission line, if the transmission is interrupted due to a break in the optical fiber cable or a failure in the optical repeater, the signal transmitted through the original repeater is electrically converted. By adding an electrical signal of a predetermined frequency to the circuit section provided for each optical repeater, this monitoring electrical signal is monitored at the receiving end to determine the trouble point section.

However, it may be difficult to add electrical signals to each relay device. For example, a five-way repeater may directly amplify an optical signal and send it out as an optical signal from the main repeater without electrical conversion.

In such a case, the present invention modulates a monitoring optical signal of the same wavelength at a different frequency for each optical repeater and adds it to the original transmission section of the optical repeater, thereby preventing interference at the signal receiving end. The purpose of this invention is to provide an optical relay transmission line monitoring system that determines the section and monitors the original transmission line.

Is the optical relay transmission line monitoring method of the present invention based on a gold-based fiber cable between one end station device? Optical relay device through? A single wavelength that is common to each repeater and different from that of the information source signal is transmitted by electrical signals of different frequencies for each optical repeater of the optical repeater transmission line that is cascaded and transmits the information source signal. The monitoring optical signal is modulated, transmitted through the source fiber relay transmission line, received by one of the source terminal equipment, and demultiplexed into the information source signal and the monitoring source signal to separate the monitoring electrical signal. The main feature of the present invention is to detect a fault in the optical relay transmission line by monitoring its level.

Embodiments of the present invention will be described in detail with reference to five drawings.

In FIG. 1, which shows an actual example of the present invention, a source end station device (transmission side) 10 having an electrical signal input point ii is connected to an optical repeater 20 via the entire source fiber transmission line 100, The device 20 connects to the optical repeater 30 via the original 7-way fiber transmission line 200, and the 5-way repeater 30 connects to the original fiber transmission line 30.
It is connected to the former terminal device 40 via 01. The optical terminal device 40 has an electric signal J point 2 and a failure location report signal output point 3.

The electrical signal to be transmitted from [electrical input signal point] is the optical transmission that constitutes the original terminal equipment (transmission side) 10? 5 (wavelength λo
) 11! It is converted into an optical signal of seven wavelengths λ0 and sent to the optical fiber transmission line 100. Single fiber transmission line 10
The optical signal from 0 is input to the optical multiplexer 22 that constitutes the optical repeater 20 . on the other hand.

The monitoring electrical signal optical modulator (wavelength λ1) 23 configuring the same optical repeater 20 receives the electrical signal from the monitoring optical signal total monitoring electrical signal generator 24 (frequency f1), and performs )E modulation. and is input to the optical multiplexer 22. The combined optical signal is input to the optical repeater 21 and output to the f'L transmission line 200.

The optical repeater 30 includes a monitoring electrical signal optical modulator (
The wavelength λ1) 33 receives a monitoring electrical signal generator 34 (frequency fz) and inputs the monitoring optical signal of the wavelength λ1 modulated at five frequencies f2 into the optical multiplexer 32. Optical repeater 31i1. ．． The optical signal sent via the original fiber transmission line 200 and the original monitoring signal for the optical repeater 30 are fully amplified and sent to the original fiber transmission line 300. The original signal from the f-fiber transmission line 300 is input to the optical demultiplexer 42 that constitutes the single end station device (receiving side) 40t, and the original signal for monitoring with wavelength λ1 is separated and the original signal for monitoring is received. Vessel 4
3 and is converted into an electrical signal Ifl! ! and the frequency f
Is the level of the furnace t, which is separated into 1 and f2 and receives these electrical signals, lowered? It determines whether a failure has occurred and outputs it from output point 3 to perform a monitoring function. On the other hand, the optical signal of wavelength λ0 separated by the optical demultiplexer 42 is input to the optical receiver 41, converted into an electrical signal, and extracted from the electrical signal output point 2.

According to the present invention, without using original signals of different wavelengths for each repeater for monitoring, and at the repeater,
It is possible to realize an optical relay transmission line monitoring system in which the monitoring signal can be added instead of being connected entirely electrically.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an example of a persimmon according to the present invention. ■... Electric signal input point, 2... Electric signal output point. 3... Fault location information signal output point, lO...
... Optical terminal equipment (transmitting side), 20.30... Optical repeating equipment, 40... Optical terminal equipment (receiving side), 1
1... Optical transmission? :% (e length λ0), 21. 3
1...-optical repeater, 41...optical receiver,
22.32... Optical demultiplexer% 42...
Optical demultiplexer, 23.33... Monitoring electrical signal optical modulator (wavelength λ1) + 43... Monitoring optical signal receiver, 24.34... Monitoring Electric signal generator for use, 100°200.300... Original fiber transmission line.

Claims (1)

[Claims] Optical repeater between optical terminal equipment via original fiber cable? By using a monitoring electric signal of a different frequency for each optical repeater of the optical repeater transmission line that is cascaded and transmits the tV# information polarized light signal, a signal of a single wavelength common to each repeater and different from the information optical signal is transmitted. Modulating the monitoring source signal, transmitting it through the optical fiber relay transmission line, receiving it at one end of the source terminal device, demultiplexing the information optical signal and the monitoring optical signal, and separating the monitoring electrical signal. An optical relay transmission line monitoring system characterized in that a failure of the optical relay transmission line is detected by monitoring the level thereof.