JPS5966238A - Optical fiber relay transmission line monitor - Google Patents

Abstract

PURPOSE:To detect a failure of an optical fiber, by outputting monitor optical signals having different wavelengths at each optical repeater and detecting the presence of a monitor optical signal from each optical repeater or the strength of its receiving level at the receiving side. CONSTITUTION:An electric signal inputted to a terminal 1 is converted into an optical signal having a wavelength lambda0 at an optical transmitter 11 in an optical terminal device 10 and transmitted into an optical fiber transmission line 100. The optical main signal from the transmission line 100 is synthesized 22 optically with a monitor optical signal having a wavelength lambda1 from a monitor optical signal generator 23 at the optical repeater 20, waveform-shaped at the optical repeater 21 and transmitted to an optical fiber transmission line 200. The optical signal on the transmission line 200 is synthesized 32 with the monitor optical signal 33 having lambda2 of wavelength similarly at the optical repeater 30, waveform- shaped 31 and inputted to an optical terminal station device 40 via a transmission line 300. An optical branching filter 42 of the device 40 branches the monitor optical signals having wavelengths lambda1 and lambda2, which are inputted to a monitor optical signal receiver 43 to discriminate the presence of the monitor optical signal and the result is outputted from a terminal 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to optical fiber cable communication, and more particularly to a monitoring device for an optical fiber relay transmission line that transmits signals between optical terminal devices via an optical fiber cable and an optical relay device.

Conventionally, when signal transmission is interrupted due to a disconnection of a single fiber transmission line, an electrical oscillator built into each repeater transmits a successor monitoring signal to the original fiber for a predetermined period for each repeater. Copper i1 twisted in the transmission line! (
5.・There is a method of detecting between reception and ends and determining whether there is a fault.

However, the intervening wire is affected by the guidance, and the cut of the original fiber itself cannot be detected.
・ :' The purpose and object of the present invention is to provide a monitoring system for an optical fiber transmission line that can detect failures in the optical fiber in the optical fiber transmission system.

According to the present invention: 1. Signal transmission between optical terminal equipment is carried out entirely optically, via fiber cables and optical repeaters. Monitoring light that outputs signals, @ signal transmitter, and receiving side 9. The optical terminal station tIi includes an optical signal input to the optical terminal station tIi, and a monitoring optical signal receiver that receives the monitoring optical signal from each optical repeater and detects a fault in the transmission path. A relay transmission line monitoring method is obtained.

Therefore, the present invention uses a monitoring optical signal receiver to detect the presence or absence of a monitoring optical signal from each optical repeater, or to detect the strength and weakness of the received level, thereby detecting a fault in an optical fiber transmission line, and monitoring the original fiber transmission line. can do.

Next, embodiments of the present invention will be described in detail with reference to the drawings.

The figure is a block diagram showing an embodiment of the present invention. An optical terminal equipment (sending side) 10 having all electrical signal input terminals 1 is connected to an optical repeater 20 via an original fiber transmission line 100 and an optical repeater 20.
is connected to the optical repeater 30 via the optical fiber transmission line 200,
The optical repeater 30 is connected to an optical terminal device (reception side) 40 via an optical fiber transmission line 300. Optical terminal device 40
has an electric signal output terminal 2 and a fault position information signal output terminal 3.

To explain the block diagram in more detail, the electrical signal input to the electrical input signal terminal 1 is converted into an original signal of wavelength λ0 by the optical transmitter in the 5-source terminal equipment 10, and then sent to the optical 7-Iber transmission line 100. sent to.

The optical main signal from the optical fiber transmission line 100 is input to the optical combiner 22 in the optical repeater 20. Furthermore, the original signal for monitoring with wavelength λ1 from the optical signal transmitter 23 for monitoring is also input to the optical multiplexer 22, and the combined optical signal is waveform-shaped by the all-optical repeater 21 and sent to the optical fiber transmission line 200. The optical main signal from the optical fiber transmission line 200 is input to the optical multiplexer 32 built in the i-relay device 30 . The optical multiplexer 32 also receives a monitoring optical signal of wavelength λ2 from a monitoring source signal transmitter 33. By this optical multiplexer 32, the wavelength λ0. λ
1. The optical signal of λ2 is multiplexed, and the optically synthesized wave is subjected to equalization and waveform shaping at the source repeater and sent to the source fiber transmission line 300. The optical signal transmitted through the optical fiber transmission line 300 is input to the optical demultiplexer 42 in the optical terminal equipment 40 and separated, and only the original monitoring signals with wavelengths λl and λ2 are sent to the original monitoring signal receiver 43. to check whether each monitoring optical signal is being received or not, or if it is being received but the reception level has decreased. On the other hand, the main optical signal of wavelength λ0 is input to the optical receiver 41 and taken out from the electrical signal output terminal 2.

Therefore, 5. For example, if a failure such as a disconnection occurs in the optical fiber transmission line 200, in addition to there being no output from the electrical signal output terminal 2 of the optical terminal equipment 4o, the source signal for monitoring at wavelength λ1 is Fault location information signal output terminal 3 of terminal device 4o
I can't get it.

It turns out that the problem is in the optical fiber transmission line 200.

Also, failures such as disconnections in the optical fiber transmission line 100 can be avoided.

Although the monitoring optical signals of the wavelengths λ1 and λ2 can be detected, this disconnection can be determined by the fact that no output can be detected from the electrical signal output terminal 2. In addition, optical 7 Aiba transmission line 30
A failure such as a disconnection at 0 can be determined by the button indicating that neither the monitoring optical signal nor the output from the electrical signal output terminal 2 can be detected.

As explained above, by monitoring optical repeaters using optical signals of different wavelengths for monitoring, faulty sections of optical fiber transmission lines can be easily detected.

[Brief explanation of the drawing]

The figure is a block diagram showing an embodiment of an optical fiber relay transmission line according to the present invention. 1... Electrical signal input terminal, 2... Electrical signal output terminal, 3... Fault position information signal output terminal, 10... Optical terminal equipment (transmission Side C 11...
. . . forward @ device (wavelength λ0), 20 . . . optical repeater, 21. 31 . . . original repeater, 22. '3
2... Optical multiplexer, 23... Monitoring optical signal transmitter (wavelength λ1), 30... Optical relay i
it, 33... Monitoring optical signal transmitter (wavelength λ2
), 40... Optical terminal equipment (receiving side C41...
...Optical receiver, 43... Monitoring optical signal reception g
i, 10012001300... Original fiber transmission line.

Claims (1)

[Scope of Claims] In an optical fiber relay transmission line that transmits signals between optical terminal equipment via an original fiber cable and an optical repeater, ζ Send optical signals for monitoring of different waves to different areas, such as monitoring signals, winding signals, tower signals and so on. Input to the receiving side optical terminal equipment. An optical fiber and relay transmission line monitoring device including a monitoring optical signal receiver for receiving the above-mentioned optical signals, congratulatory light, and Hayabusa from each optical repeater and detecting a fault in the transmission line.