JPH03252232A - Monitor and control system for optical repeater - Google Patents

Abstract

PURPOSE:To monitor and control an optical relay in its inservice state by subjecting a control bit to specific modulation and using a generated carrier to optically transmit a monitor and control signal and extracting and demodulating the carrier after converting a part of a repeated optical signal to an electric signal. CONSTITUTION:One control bit added to n-bit data is so modulated that the continuity of '0' and that of '1' are repeated with a period TSV, and a generated frequency fSV is subjected to carrier amplitude deviation modulation to transmit the monitor and control (SV) signal. The optical signal passes an optical branching filter 9 and is synthesized with exciting light by an optical synthesizer 11 and is optically amplified by an Er-doped fiber 12 and passes optical branching filters 14 and 15 and is converted to an electric signal by a photoelectric transducer O/E 16, and the carrier is extracted by a BPF 18. DRIVs 19 and 20 and a shutter 26 are controlled by the SV signal obtained by demodulating this carrier in an SV circuit 25 to perform the loop back control and the current/ stand-by switching of an optical fiber section. Thus, the optical relay is monitored and controlled in its inservice state.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical repeater monitoring and control system, and relates to an optical repeater monitoring II that performs monitoring and control of an optical repeater that performs optical direct redundancy.
Adopt JI11 method.

In recent years, optical direct amplifiers have been developed that directly amplify signals using optical fibers doped with rare earth elements such as erbium ions. This optical direct amplifier has a simplified circuit,
It is particularly suitable for application to submarine type optical repeaters because it can be made smaller and consume less power, making the system highly reliable and economical.

[Conventional technology]

A conventional optical repeater converts an incoming optical signal into an electrical signal, performs equalization amplification, timing extraction, and discrimination/regeneration, and then converts it back into an optical signal and sends it out.

Conventional submarine optical repeaters are in operation (in-service)
As a transmission method for supervisory control signals, a parity violation is used in which the parity transmitted for each predetermined bit is changed from even parity to odd parity at a predetermined period, and this supervisory control signal is extracted during playback and sent to the optical repeater. Monitored υ control is performed.

[Problem to be solved by the invention]

Optical repeaters that perform optical direct amplification do not perform signal regeneration, so monitoring control signals cannot be obtained, and in-service monitoring of repeaters is not possible. There was a problem in that it was not possible to perform 1.

The present invention has been made in view of the above points, and an object of the present invention is to provide an optical repeater monitoring and control system capable of in-service monitoring and control of an optical direct amplification repeater.

(Means for Solving Problem 11) The optical repeater monitoring and controlling method of the present invention is an optical repeater monitoring and controlling method that monitors and controls an optical repeater that performs optical direct amplification, and includes data of a predetermined number of bits. A code in which a 1-bit control bit is added to the 111111 signal is optically transmitted, and a carrier signal generated by modulating the control bit with repeated O's and 1's at a constant period is used to transmit the monitoring 111111 signal and relay the optical signal. A part of the signal is converted into an electrical signal, the frequency components of the carrier signal are separated, and a monitoring III signal is obtained from the separated carrier signal to perform monitoring control.

(Function) In the present invention, a carrier signal of a predetermined frequency can be obtained by charging and converting a part of the optical signal relayed by an optical repeater that performs direct optical amplification, and by performing band separation. In-service monitoring of the optical repeater can be performed by obtaining the monitoring control signal transmitted using the optical repeater.

〔Example〕

FIG. 1 shows a block diagram of an embodiment of an optical repeater according to the present invention.

In the figure, the optical fiber 9 has a wavelength of, for example, 1.53 to 1.5.
A 5 μm optical signal comes in. Here, as shown in FIG. 2, this optical signal uses a code in which 1 bit of 1lJIO bit is added after n bits of data as a transmission code, and the control bit has a predetermined cycle T SV (for example, the data signal (including several thousand bits), repeated modulation of consecutive 0's and consecutive 1's is applied to provide a frequency component of fsv (=1/Tsv). Then, amplitude shift keying (ASK) is applied to the carrier of this frequency fsv, and a supervisory control signal is transmitted.

The optical signal entering the optical fiber 8 passes through the optical multiplexer 9, is multiplexed with the auxiliary light by the optical multiplexer 11, and is supplied to the erbium-doped fiber 12, where it is optically amplified. The optical signal optically amplified by the erbium-doped fiber 12 is outputted from the optical fiber 13, and is demultiplexed by the optical demultiplexer 14, 15 and supplied to the photoelectric converter (0/E) 16. The electrical signal photoelectrically converted here is automatic row 1! ilJ 1
11 circuit (AGC) 17 and a bandpass filter 18.

The gain 61111 voltage output by the AGC17 is supplied to the laser drive circuit (DRjV) 19.20, respectively, and the DRTV
19.20 respectively the main and -1 laser diodes 21.
22 respectively, this laser diode 21.22
The light intensity of each output laser beam is adjusted. The wavelength output by the laser diode 21 or 22 is, for example, 1.47 to 1.
, 49 μm excitation light is passed through the optical multiplexer 23 to the optical multiplexer 1.
1.

The bandpass filter 18 separates the carrier of frequency fsv from the electrical signal and supplies it to the supervisory control circuit (SV) 25 .

The supervisory control circuit 25 has the configuration shown in FIG.
An incoming carrier of frequency fsv is amplified by an amplifier 31, peak detected by a peak detector 32, and supplied to a comparator 33 to be converted into a rectangular wave and sent to a shift register 3.
4 and a monostable multivibrator (MM) 35. The MM 35 generates a shift pulse that falls after a predetermined period from the rise of the rectangular wave and supplies it to the shift register 34 . The shift register 34 is composed of D-type flip-flops connected in cascade, and the first stage 7 flip-flops latch the level of the rectangular wave from the inverter 33 at the falling edge of the shift clock, perform ASK demodulation, and output the obtained supervisory control signal. Each bit is shifted into the shift register 34 and stored.

All the pits of the supervisory control signal stored in the shift register 34 are decoded by the decoder 36, and a plurality of ll11
The m signal is output from terminals 371-371, and the shutter 26.m signal shown in FIG. Supplied to DRIV19.20 etc.

In the optical repeater, there is provided a downstream signal processing section 42 which has the same configuration as the upstream signal processing section and which is supplied with an optical signal from the optical fiber 40 and outputs it from the optical fiber 41. It mutually exchanges signals with the monitoring control circuit 25 of. The tm unit 43 supplies power supplied from a terminal 44 to each part in the repeater, and also supplies power to the next stage repeater from a terminal 45.

Returning to FIG. 1, the monitoring IQil) circuit 25 normally operates the DRIV 19, but stops the DRIV 19 in response to the monitoring control signal, and operates the DRIV 20 to switch the laser diodes 21 and 22.
4tc Adjust the drive current of each DRIV19.20.

In addition, loopback control is performed by opening the normally open shutter 26 and supplying the optical signal from the shutter 26 of the upstream signal processing unit to the optical multiplexer 9 in the downlink signal processing unit 42, and in the same way, the optical Performs working/standby switching of fiber section.

Furthermore, the monitoring 111111 signal is used to detect (monitor) the optical input level, optical output level, gain of the optical amplifier, drive current of each of the DRIVs 19 and 20, power of each of the laser diodes 21 and 22, and temperature.

In this way, a carrier signal of a predetermined frequency can be obtained by photoelectrically converting a part of the optical signal relayed by an optical repeater that performs direct optical amplification and separating the bands. Obtain the monitoring ll1w signal,
In-service monitoring and control of optical repeaters can be performed.

〔Effect of the invention〕

As described above, according to the optical repeater monitoring and control circuit of the present invention, it is possible to carry out in-service monitoring 1i1flD of optical repeaters that perform optical direct amplification, which was not possible in the past, and is practical. Above all, it is extremely useful.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of an optical repeater to which the method of the present invention is applied, FIG. 2 is a diagram showing the format of a transmission code, and FIG. 3 is a block diagram of a monitoring tlJ'llJ circuit. In the figure, 9.11.23 is an optical multiplexer, 12 is an erbium-doped fiber, 14.15 is an optical demultiplexer, 16 is a charging converter, 18 is a bandpass filter, 25 is a monitoring control circuit, and 26 is a shutter. shows.

Claims (1)

[Claims] A monitoring and control method for an optical repeater that monitors and controls an optical repeater that performs direct optical amplification, which optically transmits a code in which one control bit is added to a predetermined number of data bits, and A supervisory control signal is transmitted using a carrier signal generated by modulating control bits with repeated 0's and 1's at a constant period, and a part of the optical signal to be relayed is converted into an electrical signal to change the frequency of the carrier signal. A supervisory control system for an optical repeater, characterized in that components are separated (16, 18), and a supervisory control signal is obtained from the separated carrier signal to perform supervisory control (25).