JPH03228437A - Optical submarine repeater - Google Patents

Abstract

PURPOSE:To exactly derive a distance between a repeater in the vicinity of a fault part and the fault part by measuring a voltage between a feeder and a housing by a voltage measuring circuit, providing its output to an input of a modulator, and modulating and transmitting a turn-back main signal. CONSTITUTION:This repeater is provided with a voltage measuring circuit 21 for measuring a voltage between feeders 7, 8 and a housing 11, a signal converter 22 for converting its output to a data signal being suitable for modulation of a main signal, a switch 23 interposed between its output and an input of reproducing repeaters RRP 1, 2, and a control circuit 24 for twisting back the main signal in accordance with a control signal superposed on the main signal, and also, connecting the output of the voltage measuring circuit 21 to an input of a modulator by controlling the switch 23. In such a way, in accordance with generation of a fault of an optical submarine cable, the main signal is turned back and transmitted to the repeater of the side of the fault part by transmitting a control signal, and also, the output of the voltage measuring circuit 21 is fetched by demodulating the main signal, and from a feeder voltage of the repeater, the fault part is derived exactly, based on an installation point of the repeater as a reference.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is used to connect an operating power supply in series through a power supply line in an optical submarine cable, and to perform regenerative relay of optical signals by being inserted in the middle of an optical submarine cable. This relates to an optical submarine repeater that receives power.

[Conventional technology]

FIG. 3 shows a block diagram of the main parts. The regenerative repeaters (hereinafter referred to as RRPs) 1 and 2 each have a 3R function and a modulator for outgoing and incoming paths. is regeneratively relayed to the same optical cable 4 and transmitted, and the optical signal from the optical cable 5 on the return route is regeneratively relayed and transmitted to the similar optical cable 6 by the RRP2. The power source is supplied in series through a power supply line 7 on the power supply side, and this power supply current is further sent to the next repeater via a power supply line 8 on the termination side.

Further, a control signal can be freely superimposed on the main signals in the optical cables 3 and 5, and a return path 9 or 1G is formed accordingly to transfer the signal from the optical cable 3 to the optical cable 6, or The signal from the optical cable 5 can be returned to the optical cable 4 and transmitted.

Note that all the circuits including RRP1 and 2 are housed in a watertight and pressure resistant casing 11.

Therefore, in the event of a failure such as a break in the optical submarine cable, repeaters on both sides of the failure site are determined from the return K of the main signal, and a power supply path is formed via the general seawater, so the direct current of the power supply line is The distance between the land terminal station and the faulty part is determined by the resistance measurement method, and the faulty part is searched for based on this distance.

[Problem to be solved by the invention]

However, the resistance value per unit length of the power supply line is only about 1/100 of the internal resistance value of the optical submarine repeater, and as the difference in locating the fault site increases, the wavelength of the optical signal has recently become longer. The interval between repeater insertions has increased accordingly, and due to these factors, it has become increasingly difficult to search for faulty locations.

[Failure to solve the problem]

In order to solve the above-mentioned problems, the present invention is constructed by the following means.

In other words, in the above-mentioned optical submarine repeater, there is a voltage measurement circuit that measures the voltage between the feeder line and the housing, a switch that is interposed between the output of this circuit and the input of the modulator, and a A control circuit is provided which loops back the main signal according to the control signal, controls the switch and connects the output of the voltage measurement circuit to the input of the modulator.

[Effect]

Therefore, in response to the occurrence of a fault in the optical submarine cable, the main signal is sent back to the repeater on the side of the fault site by sending a control signal, and the output of the voltage measurement circuit is extracted by demodulating the main signal. If you know the feed line voltage of the Todoroki repeater, this voltage is determined according to the distance between the Todoroki repeater and the fault location, so you can accurately determine the fault location based on the installation point of the Todoroki repeater. be able to.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to FIGS. 1 and 2 showing embodiments.

FIG. 1 is a block diagram of the main parts. In addition to the configuration shown in FIG. A signal converter (hereinafter referred to as 5Cv) 22 that converts the output of
A switch (hereinafter referred to as 5W) 23 is provided between the modulator (hereinafter referred to as MOD) input in RPl, 2, and
A control circuit (hereinafter referred to as CCT) 24 that responds to a control signal sent superimposed on the main signal from the optical cable 3 or 5
is provided, and according to the control signal, the CCT 24 forms the return path 9 or 10 and controls the 5W 23,
The output of MMC21 via 5Cv22 is connected to the input of MOD provided in RRP1,2.

Therefore, when a failure occurs in the optical submarine cables on the optical cables 4 and 5 side, a control signal is sent from the land terminal station on the power feeding side to form a return route 10, and the output of vMc21 via 5CV22 is transferred to RRP2. Give it to the MOD of
By modulating and transmitting the return main signal using the output of the MMC 21 and demodulating it at the land terminal station, the voltage between the power supply line 8 and the housing 11 can be determined.

Figure 2 is an explanatory diagram of the situation in which the distance to the fault location is determined based on the voltage measured as described above.
), an optical submarine cable (hereinafter referred to as "GTS") is connected between the land terminal station (hereinafter referred to as "GTS") 31 on the power feeding side and the GTS 32 on the termination side via optical submarine repeaters (hereinafter referred to as "LRP") 33 to 35.
A transmission line is formed by the cable) 36, and under normal conditions, as shown in the voltage distribution diagram (b), series power is supplied to the voltage VsK with the return path to the ground at the GTS 31,
In GT832, the power supply voltage is zero V.

On the other hand, if a fault occurs between LRPs 34 and 35, as indicated by As the voltage of LRP3 decreases to V, the supply voltage v1 correspondingly decreases to v3, while LRP3
5 is negative voltage v4, and the voltage of GTS32 is also negative voltage v5, and each voltage v2 and v4 is LRP
Distances t1 and 1.34 and 35 to the fault site.
It will be determined accordingly.

That is, the distance t! is the feed line 7.8 in the cable 36
When the resistance value of b shown by is Ro, it is given by the following equation.

2 Ll-(km)　　　　　　　...(1) R.

Also, t! Since the voltage v4 includes the voltage drop within the LRP 35, when this is set as vr, it is expressed by the following equation.

Therefore, using the voltage v2 or v4 measured by the VMC 21 of the LRP 34 or 35 closest to the faulty part, the distance to the faulty part based on the LRP 34 or 35 can be accurately determined, and the faulty part can be searched. It becomes easier.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the voltage between the power supply line and the housing is measured by a voltage measuring circuit, the output of this is applied to the input of the modulator, and the folded main signal is modulated. The distance between the repeater near the faulty part and the faulty part can be accurately determined, and it is especially effective when repeaters are installed at long intervals. Remarkable effects can be obtained in submarine repeaters.

[Brief explanation of drawings]

Fig. 1 and Fig. 2 show an embodiment of the present invention, Fig. 1 is a block diagram of the main part, Fig. 2 is an explanatory diagram of the situation in which the distance to the faulty part is calculated, and Fig. 3 shows a conventional example. FIG. 2 is a block diagram of main parts. 1.2...Regenerative repeater, 3-6...Optical cable, 7,8...Power line, 9.10...Return path,
11... Housing, 21... Voltage measurement circuit, 23...
...Switcher, 24...Control circuit.

Claims (1)

[Claims] In an optical submarine repeater that is equipped with a 3R function and a main signal loopback function, as well as a modulator that modulates the main signal, there is provided a voltage measurement circuit that measures the voltage between the feeder line and the housing, and an output of the measurement circuit. a switch interposed between the input of the modulator and a control signal superimposed on the main signal to loop back the main signal and control the switch to send the output of the voltage measurement circuit to the input of the modulator; An optical submarine repeater characterized in that it is provided with a control circuit for connection.