JPH05218909A - Optical communication equipment - Google Patents

Abstract

(57) [Abstract] [Object] An optical communication device for performing communication using an optical cable, wherein an optical multiplexer / demultiplexer is connected to the optical cable through an electric signal-optical signal converter, and the converter and the optical multiplexer are connected. An optical communication in which a loopback switching unit is provided between the separation unit and an individual maintenance management unit that receives a loopback start / cancel command from the overall maintenance management device controls the loopback switching unit to perform a loopback test. An object of the present invention is to enable a device to receive an instruction from the overall maintenance management device even during a loopback operation and restore the loopback state to a normal communication state. [Constitution] The individual maintenance management unit returns the loopback switching unit to release the loopback state after a lapse of a certain time from the loopback start command, or directly receives the electric signal from the electric signal-optical signal conversion unit to perform the whole operation. A loopback release command from the maintenance management device is detected and the loopback state is released.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical communication device, and more particularly to an optical communication device for performing communication using an optical cable.

The above-mentioned optical communication device FLM (Fiber Lo)
A switching center system including an op multiplexer) is shown in FIG. 3, where a large switching center CO-A and a small switching center C
OB to CO-D are interconnected, and the large exchange CO-A has a switch EX1 and a channel bank CHBK1.
And, for example, three optical communication devices FLM1 to FLM3, which constantly monitor devices SV1 and SV2.
The operation is remotely monitored by (including the printer 11, the display 12, the arithmetic unit main body 13 and the like).

Similarly, the small exchanges CO-B to CO-D similarly exchanges EX2 to EX4, channel banks CHBK2 to CHBK4, and optical communication devices FLM4 to FL, respectively.
M6 and the monitoring device S in each.
Remotely monitored by V1.

In such a switching center system, the switching centers CO-A and CO-B are interconnected with the optical communication devices FLM1 and FLM4 by an optical fiber 1-1, and the switching centers CO-A and CO-C. And the optical communication devices FLM2 and FLM5 are interconnected by an optical fiber 1-2, and the switching center CO-A and the switching center CO-D are connected to the optical fiber 1-.
3, the optical communication devices FLM3 and FLM6 are interconnected.

Each optical communication device FLM (general term) has a signal from an exchange within each exchange (based on the SONET standard).
It is designed to multiplex a signal called DS1 with a 1.5 MHz signal, convert this signal into an optical signal (for example, an optical signal called 150 MHz EO3), and send it to the opposite exchange, and vice versa. These optical communication devices FLM separate the optical signal received from the game and deliver it to the exchange.

In each of these exchanges, it is necessary to maintain and manage whether or not the multiplexing / demultiplexing operation of the optical communication device FLM is normally performed.

[0007]

2. Description of the Related Art FIG. 4 shows a diagram in which the above-mentioned optical communication device FLM is arranged so as to face each other by an optical fiber 1 (generic name). In this example, the optical communication device FLM1 of the exchange CO-A is shown.
And the optical communication device FLM4 of the exchange CO-B face each other. In each optical communication device FLM, the optical communication device FLM is used.
An electrical signal-optical signal converter 2 is connected to an optical cable 1 connecting between 1-4, and further this electrical signal-optical signal converter 2
A multiplexing / demultiplexing unit 4 is connected to the via a loopback switching unit 3.

Also, the loopback switching unit 3 and the multiplexing /
An individual maintenance management unit 5 is connected to the separation unit 4, and the overall maintenance management device 6 is connected to one of the individual maintenance management units 5 (in this example, the individual maintenance management unit 5 of the optical communication device FLM1). Has been done.

In a normal operation of such an optical communication device FLM, as shown in FIG.
The electrical signal from K (generic) is, for example, the optical communication device FLM1.
Is multiplexed by the multiplexing / demultiplexing unit 4, is directly passed through the loopback switching unit 3, is converted into an optical signal by the conversion unit 2, and is transmitted from the optical fiber 1 to the conversion unit 2 of the optical communication apparatus FLM 4 facing the optical fiber. Here, it is converted into an electric signal, further passed through the loopback switching unit 3 and separated by the multiplexing / demultiplexing unit 4, and then sent to the channel bank CHBK of the optical communication device FLM4.

When performing maintenance and management of each optical communication device FLM, the overall maintenance management device 6 receives the optical communication device FLM from the multiplexing / demultiplexing unit 4 via the individual maintenance management unit 5.
Optical communication device FL which obtains the maintenance management information of 1 and opposes
The maintenance management information of M4 is also obtained by the individual maintenance management unit 5 via the optical cable 1. The format of the optical signal in this case is determined by the standard, and data and maintenance management information are included in it.

On the other hand, such an optical communication device FLM1-4
When a part of the communication between the two is cut off, it is necessary to find the faulty part and repair it.In that case, before the operator directly touches the device to find the faulty part, whichever optical communication In order to distinguish whether it exists in the device FLM or the optical cable 1,
The overall maintenance management device 6 gives a loopback start command to the individual maintenance management units 5 of the two optical communication devices FLM1 and 4, whereby the loopback switching unit 3 is switched to the loopback state as shown by the dotted line, and the multiplex Separation / separation unit 4
The electric signal from is looped back by the loopback switching unit 3 and again demultiplexed by the multiplexing / demultiplexing unit 4,
By comparing the input signal and the output signal in the multiplexer / demultiplexer 4, it is possible to determine whether or not there is a failure in each optical communication device FLM.

[0012]

As described above, in the conventional optical communication apparatus, it is possible to determine whether the optical communication apparatus of the own station is a failure or the optical fiber 1 is a failure. For example, if the individual maintenance management unit 5 controls the loopback switching unit 3 in a loopback manner as illustrated in order to detect a failure in the optical communication apparatus FLM4, the optical signal from the opposing optical communication apparatus FLM1 cannot be received.

This means that the optical communication device FLM4 is transferred from the overall maintenance management device 6 to the optical communication device FLM1 and the optical cable 1.
After creating the loopback state by the loopback start instruction received via the optical communication device FLM4, the optical communication device FLM4 cannot receive the information from the overall maintenance management device 6, and thus the loopback state is returned to the original state. There was a problem that I could not do it.

Therefore, according to the present invention, an optical signal is transmitted to an optical cable.
An optical multiplexing / demultiplexing unit is connected via an optical signal converting unit, a loopback switching unit is provided between the converting unit and the optical multiplexing / demultiplexing unit, and a loopback start / cancel command from the overall maintenance management device is provided. In the optical communication device in which the individual maintenance management unit that has received the instruction controls the loopback switching unit to perform the loopback test, it is possible to receive a command from the overall maintenance management device even during the loopback operation, and based on the loopback state. The purpose is to return it so that a normal communication state can be obtained.

[0015]

FIG. 1 shows the principle of an optical communication device according to the present invention. In the present invention, an individual maintenance management unit 5 in each optical communication device is connected to an overall maintenance management device 6. After a lapse of a fixed time from the loopback start command, the loopback switching unit 3 is switched to release the loopback state.

Further, in the present invention, the maintenance management unit 5
However, the electric signal output from the electric signal-optical signal conversion unit 2 is directly received, a loopback cancellation command from the overall maintenance management device 6 is detected, and the loopback switching unit 3 is switched to cancel the loopback state. You can also do it.

In the figure, the overall maintenance management device 6 is indicated by a dotted line when the local maintenance management device 6 is provided in the own station and the overall maintenance management device 6 is provided in another station. This is because the individual maintenance management unit 5 can be directly controlled in the former case, whereas the individual maintenance management unit 5 is controlled in the latter case via the optical cable 1.

[0018]

Therefore, in the optical communication device according to the present invention, the individual maintenance management unit 5 automatically loops back after a certain time has elapsed from the loopback start command even if the loopback cancellation command from the opposite optical communication device cannot be received. The state can be canceled and the normal communication state can be restored.

The loopback state can also be canceled by inputting the data electric signal from the electric signal-optical signal converter 2 and detecting a loopback cancellation command from the general maintenance management device 6 of another station. It is possible to return to the normal communication state.

[0020]

FIG. 2 shows a concrete example of an optical communication apparatus FLM according to the present invention. In the figure, the same parts as those in FIG. Then, the case where the overall maintenance management device 6 is not connected to the individual maintenance management unit 5 like the optical communication device FLM4 shown in FIG. 4 is shown.

Further, the loopback switching unit 3 has a switch S.
It is composed of W1 and SW2, and these switches S
Switching between W1 and SW2 is controlled by the individual maintenance management unit 5.

Further, in this embodiment, the optical fiber 1 (150M
Hz) and a low-speed interface unit LIF connected to the high-speed interface unit HIF. The low-speed interface unit LIF includes a multiplexing / separation unit (LG # 1) 45. The multiplexer / separator (LG # 2) 46 and the multiplexer / separator (LG # 2)
3) 47, and each of these multiplexing / separating units 45 to 47 multiplexes the signal DS1 from the channel bank (see FIG. 3) by 4 channels into a signal of 6 MHz, or It operates as an interface for one channel of DS3, and the above 6 MHz data for 7 channels or 45 MHz data for 1 channel is sent to the high speed interface HIF respectively.

In the high-speed interface unit HIF, the multiplexing / demultiplexing units 42 to 44 are connected to the multiplexing / demultiplexing units 45 to 47 of the low-speed interface unit LIF, respectively.
It is multiplexed with the STS-1 signal (50MHz) according to
The signals multiplexed as data of 50 MHz and output as channels CH # 1 to CH # 3 are further multiplexed in the multiplexing / separation unit 41 and multiplexed as signals of STS-3 signals (150 MHz) in SONET. The signal is converted into an optical signal by the electric signal-optical signal conversion unit 2 via the loopback switching unit 3 and transmitted from the optical cable 1 to the opposing optical communication device at a speed of 150 MHz.

Then, the optical cable 1, the conversion unit 2, the loopback switching unit 3, the multiplexing / multiplexing
When the individual maintenance management unit 5 receives the maintenance management information via the separation unit 41, the individual maintenance management unit 5 controls the switching unit 3 to switch the switches SW1 and SW2 as shown in the drawing to create a loopback state.

The DS1 signal (or DS3 signal) generated from the DS1 signal generator 51 is multiplexed by the multiplexing / separating units 45 to 47 of the low speed interface unit LIF and sent to the high speed interface unit HIF. The multiplexing / demultiplexing units 42 to 44 and the multiplexing / demultiplexing unit 41 multiplex, but since the loopback switching unit 3 loops back as shown in the figure, this time, the multiplexing / demultiplexing unit 41 separates each. The original DS1 signal is returned to the data tick device 52 via the multiplexing / demultiplexing units 42 to 44 and the multiplexing / demultiplexing units 45 to 47 of the low-speed interface unit LIF.

Therefore, in the data tick device 52, DS1
It is possible to tick whether the signal (or DS3 signal) is correctly looped back, that is, whether the operation of the optical communication device FLM is normally performed.

After such a loopback operation is performed, that is, when a predetermined time has elapsed from the loopback start command from the overall maintenance management device 6, the individual maintenance management unit 5 switches the switches SW1 and SW2 of the switching unit 3. Can be returned to the position opposite to the position shown in the figure, and the normal communication state can be restored.

Alternatively, the individual maintenance management unit 5 converts the optical signal from the optical fiber 1 into an electrical signal by the conversion unit 2 and then directly inputs the electrical signal to the overall maintenance management device 6
The loopback state can be released by detecting the loopback release command from the same as described above and returning the switching unit 3 to the position opposite to the illustrated position.

Needless to say, in the optical communication device to which the overall maintenance management device 6 is directly connected, the individual maintenance management unit 5 directly executes the command from the overall maintenance management device 6, so that there is no problem.

[0030]

As described above, according to the optical communication device of the present invention, the individual maintenance management unit returns the loopback switching unit to release the loopback state after a certain time has elapsed from the loopback start command, or Alternatively, since the electric signal from the electric signal-optical signal converter is directly received and the loopback release command from the overall maintenance management device is detected to release the loopback state, the overall maintenance management device is directly connected. Even in an optical communication device of an exchange that does not exist, the loopback start-release operation can be accurately performed, which can be useful for improving the performance of the optical communication device.

[Brief description of drawings]

FIG. 1 is a block diagram showing in principle an optical communication device according to the present invention.

FIG. 2 is a block diagram showing an embodiment of an optical communication device according to the present invention.

FIG. 3 is a block diagram showing an exchange system including an optical communication device to which the present invention and a conventional example are applied.

FIG. 4 is a block diagram showing a conventional technique.

[Explanation of symbols]

 1 Optical Fiber 2 Electric Signal-Optical Signal Converter 3 Loopback Switch 4 Multiplexing / Demultiplexing 5 Individual Maintenance Management Unit 6 Overall Maintenance Management Device In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] 1. An optical multiplexer / demultiplexer (4) is connected to an optical cable (1) through an electrical signal-optical signal converter (2), and the converter (2) and the optical multiplexer / demultiplexer (4) are connected. An individual maintenance management unit that has a loopback switching unit (3) between it and 4) and receives a loopback start / release command from the overall maintenance management unit (6).
In the optical communication device in which (5) controls the loopback switching unit (3) to perform a loopback test, the individual maintenance management unit (5) switches the loopback after a certain time has elapsed from the loopback start command. An optical communication device characterized by switching the part (3) to release the loopback state. 2. The individual maintenance management unit (5) receives the electrical signal directly, detects the loopback cancellation command from the overall maintenance management device (6), and switches the loopback switching unit (3). 2. The optical communication device according to claim 1, wherein the loopback state is released by releasing the loopback state.