JPH02202129A - Submarine relay system - Google Patents

Abstract

PURPOSE:To clearly recognize a part where a submarine cable is cut by finding what order of conductor is cut and soaked in seawater starting from a longest one by detecting the value of a current that flows. CONSTITUTION:The conductor 51 is connected with the conductors 52 and 53 via the seawater on the plane of cut point F1 of the submarine cable 1, and a loop circuit is formed between a voltage supply circuit 4 and a current detection circuit 7 via the conductors 52 and 53, resistors 61 and 62. Here, when the resistance values R of the resistors 61 and 62 are decided so as to neglect the resistance value of the conductors 51-53, and the seawater, the synthetic resistance value of the resistors 61 and 62 goes to R/2, and the current detection circuit 7 detects a current I1 as shown in I1=V/(R/2)=2V/R. Where, V is shown as a voltage supplied from the voltage supply circuit 4. In such a way, it is possible to clearly judge the position of a faulty point in the submarine cable based on the voltage supplied to the conductor and the resistor and the current that flows on them.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a submarine relay system.

[Conventional technology]

Conventionally, a so-called loopback method has been adopted as a means of fault point evaluation in this type of submarine relay system.

FIG. 4 is a block diagram showing an example of a conventional submarine relay system. The transmission line in which the failure occurred is taken offline, and a unique pulse pattern assigned to each submarine repeater 3a3b, ~3e, 3f, ~ is sent from the terminal station 10, and the upstream submarine repeater specified by this pattern is Connect the output and downstream submarine repeater input. As a result, the uplink signal is looped back to the downlink and returns to the terminal station 10 again.

The terminal station 10 sequentially loops back from the submarine repeater 3a at the front, compares the transmitted signal and the received signal, and searches for a faulty section. In this example shown in FIG. 4, the transmission signal can be received normally when looped back from submarine repeater 3e to submarine repeater 3j, but it cannot be received normally when the pulse pattern assigned to submarine repeater 3f is sent. Can not. Therefore, it is determined that the faulty section is the section between submarine repeaters 3f and 31.

[Problem to be solved by the invention]

In the above-mentioned conventional loopback method of fault searching, it is possible to determine the faulty section, but it is not possible to determine where the fault is located between adjacent submarine repeaters. Therefore, when making repairs, it is necessary to drag the cable from the submarine repeater in the faulty section and search for the point of fault. However, recently, the relay interval has become longer, and in particular, in optical submarine relay systems, the interval is about to reach n00K, so there is a drawback that the work of searching for a fault point is extremely inefficient.

[Means to solve the problem]

The submarine relay system of the present invention includes a submarine cable and submarine repeaters connected to both ends of the submarine cable, and the submarine cable has a length that is separate from the signal line and power supply line between the two submarine repeaters. The first line is gradually shorter than 1/2 of the length of the signal line or power supply line. Each submarine repeater is provided with a voltage supply circuit that supplies voltage to the longest first conductor, and a voltage supply circuit that supplies voltage to the longest conductor, and a voltage supply circuit that supplies voltage to the second conductor through a resistor having the same resistance value. It is characterized by comprising a current detection circuit connected to one end of the n-th conductor.

〔Example〕

Next, the present invention will be explained with reference to FIGS. 1 to 3.

FIG. 1 is a block diagram showing one embodiment of the submarine relay system of the present invention, and FIGS. 2 and 3 show the first embodiment when the submarine cable in FIG. 1 is cut. FIG. 3 is a block diagram showing a second example.

As shown in FIG. 1, this embodiment consists of a submarine cable 1 and submarine repeaters 3A and 3B connected to both ends of the submarine cable 1. The submarine cable 1 includes a signal line and a power supply line 2 (length is L) and a voltage supply conductor 51 whose length Ll is slightly shorter than L/2.

Progressively shorter conductors 52.53.54. ．． 55°56
．． 57.58, submarine repeater 3A.

3B is a voltage supply circuit 4 that supplies voltage to the conductor 51, and resistors 61, 62, 63, 64° 65, 66, 6.
A current detection circuit 7 is connected to each conductor 52, 53, 54, 55゜56, 57, 58 through a conductor 52, 53, 54, 55゜56. It is connected to circuit 7.

Next, the operation of this embodiment will be explained with reference to FIGS. 2 and 3.

2 and 3, the submarine cable 1 in FIG. 1 is located at F1. It shows a state where it is cut at F2.

First, in Fig. 2, the cut point F of the submarine cable 1 is
, conductor 51 connects conductors 52 and 53 through seawater.
, and the voltage supply circuit 4 is connected to the conductor 51 . seawater, conductor 5
2.53. A loop circuit is formed between the resistor 361 and the current detection circuit 7 via resistors 361 and 62. Here, the conductors 51, ~5
3 and a resistor 61. so that the resistance value of seawater can be ignored.
When the resistance value R of the resistors 61 and 62 is determined, the combined resistance value of the resistors 61 and 62 becomes R/2, and the current detection circuit 7 detects the current 1 shown in equation (1).

I + =V/ (R/2)=2V/R・・・・・・
(1) Here, ■ is the voltage supplied from the voltage supply circuit 4.

In addition, in FIG. 3, since the conductors 51 and 56 are immersed in seawater, the resistors 61 and 62°63.64.65
The combined resistance value is R15.

Therefore, the current detection circuit 7 detects the current I2 shown in equation (2).

I2=V/(R15)=5V/R・・・・・・・・・
- (2) In this way, in this embodiment, by detecting the flowing current value, it is possible to know which conductor from the longest one is cut and immersed in seawater, so each conductor 52,
By determining the length of ~58 in advance, it is possible to clearly know where the submarine cable is broken.

[Effects of the Invention] As explained above, according to the present invention, there is an effect that the position value of the fault point of the submarine cable can be clearly determined based on the voltage supplied to the conductor and the resistor and the current flowing.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the submarine relay system of the present invention, and FIGS. 2 and 3 show the first embodiment when the submarine cable in FIG. 1 is cut. A block diagram showing the second example. FIG. 4 is a block diagram showing an example of a conventional submarine relay system. 1... Submarine cable, 2... Signal line and power supply line,
3A, 3B... submarine repeater, 4... voltage supply circuit,
5], ~58...Conductor, 61, ~67...Resistor,
7... Current detection circuit.

Claims (1)

[Claims] It consists of a submarine cable and a submarine repeater connected to both ends of the submarine cable, and the submarine cable has a length that is equal to the length of the signal line or the feeder line, in addition to the signal line and feeder line between the two submarine repeaters. The first step is shorter than 1/2 of the length,
Each submarine repeater is provided with a voltage supply circuit that supplies voltage to the longest first conductor, and a voltage supply circuit that supplies voltage to the longest conductor, and a voltage supply circuit that supplies voltage to the second conductor through a resistor having the same resistance value. A submarine relay system comprising a current detection circuit connected to one end of an n-th conductor.