JP2002374188A - Wavelength multiplex communication system, and transmission line switching system for wavelength multiplex communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wavelength multiplex communication system, which enables rapid maintenance operation if a trouble occurs in an optical transmitter receiver, and to provide a transmission line switching system for the wavelength multiplex communication system. SOLUTION: Wavelength multiplex transmission devices, each being equipped with a plurality of optical transmitter receivers, a multiplexer, and a demultiplexer are provided for two systems, i.e., an in-use system and a standby system and switched and controlled by a redundant switching device in the transmission switching system. Each optical transmitter receiver is equipped with an integrated type optical transmission part, an optical reception part, a fault monitor part which monitors faults, and a transmission control part which controls the signal transmission of the optical transmission part. If a fault occurs in the optical reception part 15a of the in-use system, the fault monitor part 16a informs the redundant switching device 5 and transmission control part 17a of the fault, and the redundant switching device 5, having been informed of the fault, switches the path of a received light signal to the standby system; and the transmission control part 17a stops the signal transmission of the optical transmission part 14a and the redundant switching device 8, having recognized the signal stop from the optical transmission part 14a, switches the path of a transmitted light signal to the standby system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wavelength division multiplex communication system and a transmission line switching method in the wavelength division multiplex communication system, and more particularly to a wavelength division multiplex communication system and a wavelength division multiplex communication system capable of quick maintenance work when a failure occurs. The present invention relates to a transmission path switching method.

[0002]

2. Description of the Related Art A transmission line switching method in a conventional wavelength multiplex communication system will be described with reference to FIG.
In FIG. 2, it is assumed that a transmission optical signal of a communication device (not shown) on the client side connected to the redundant switching device 5 is connected to the optical coupler 51a, and a reception optical signal is connected to the optical SW 52a. Further, it is assumed that a transmission optical signal of a client-side communication device (not shown) connected to the redundancy switching device 6 is connected to the optical coupler 61a, and a reception optical signal is connected to the optical SW 62a.

An optical signal transmitted from a client communication device on the side of the redundant switching device 5 is branched into two by an optical coupler 51a and sent out to the optical transceivers 13a and 33a in parallel. The received optical signal of the client communication device is an optical SW5.
2a is used to select whether to receive from the active optical transceiver 13a or the standby optical transceiver 33a.

Similarly, a transmission optical signal of a client communication device on the opposite side is branched into two by an optical coupler 61a, and a reception optical signal is transmitted by an optical SW 62a to an active optical transceiver 23a or a standby optical transceiver. 43
a is selected.

Here, the active system is selected for both transmission and reception as viewed from the client communication device on the side of the redundant switching device 5, that is, the optical transceiver 13a and the optical transceiver 23a communicate via an optical signal of wavelength λa. It is assumed that

[0006]

In this system, if a failure such as a failure of the optical receiving circuit occurs in the optical receiving unit 15a of the optical transceiver 13a at a certain point in time, the failure monitoring unit 16a detects this. And notifies the optical SW 52a. The optical SW 52a notified of the occurrence of the failure converts the received optical signal into a standby system,
That is, it switches to the optical receiving unit 35a of the optical transceiver 33a. At this time, the optical signal of the wavelength λa is
From the viewpoint of the client communication device on the side, the transmission optical signal is divided into the working system (that is, the optical transceivers 13a and 23a), and the reception optical signal is divided into the protection system (that is, the optical transceivers 33a and 43a) for communication. become. In this case, the optical transceiver 13a is continuously operated in a state where a failure has occurred.

In the maintenance work, it is necessary to replace the failed optical transceiver 13a. However, the maintenance person on the wavelength multiplexing transmission apparatus 1 side needs the optical SW 62a on the opposite side to use either the active system or the standby system. I do not know if I have selected. Therefore, it is necessary to confirm whether the optical transceiver 13a can be removed as it is or whether the switching operation should be performed by the optical SW 62a. When it is determined that the switching operation is necessary, the optical transceiver 13a must be replaced after performing the switching operation artificially by the optical SW 62a.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a main object of the present invention is to provide a wavelength division multiplex communication system and a wavelength multiplex communication system capable of performing quick maintenance work when a failure occurs in an optical transceiver. An object of the present invention is to provide a transmission line switching method in a multiplex communication system.

[0009]

In order to achieve the above object, a wavelength division multiplexing transmission apparatus according to the present invention combines a plurality of optical transceivers for transmitting and receiving optical signals with optical signals from the plurality of optical transceivers. A wavelength division multiplexing transmission device comprising: a multiplexer for transmitting the multiplexed optical signal; and a demultiplexer for demultiplexing the multiplexed optical signal and distributing the multiplexed optical signal to each of the optical transceivers. An optical transmitting unit that sends out a signal to the multiplexer, an optical receiving unit that is formed integrally with the optical transmitting unit and receives a signal from the demultiplexer, and the optical transmitting unit or the optical receiving unit. A failure monitoring unit that monitors a failure, and at least a transmission control unit that performs control to stop signal transmission of the optical transmission unit based on a notification from the failure monitoring unit, in a case where a failure occurs in the optical reception unit. The signal transmission of the optical transmission unit is stopped.

[0010] The wavelength division multiplexing communication system of the present invention comprises:
In a wavelength division multiplexing communication system having two systems of wavelength division multiplex transmission systems, an active system and a protection system, and switching control of the wavelength division multiplex transmission device by a redundant switch, an integrated optical system is provided in each of the wavelength division multiplex transmission devices. A transmission / reception unit, a failure monitoring unit for monitoring a failure of the optical transmission unit or the light reception unit, and an optical transceiver including a transmission control unit for controlling signal transmission of the optical transmission unit; When a failure occurs in the optical receiving unit in the wavelength division multiplex transmission device of the system,
The path of the received optical signal is switched to the standby system by the redundant switching device that has received the notification from the failure monitoring unit, and the transmission of the optical transmission unit is stopped by the transmission control unit. The switching to the standby system is controlled.

A transmission switching system according to the present invention is a transmission switching system in a wavelength division multiplex communication system including two systems of wavelength division multiplex transmission devices, an active system and a protection system, and switching control of the wavelength division multiplex transmission device by a redundant switching device. In each of the wavelength division multiplexing transmission apparatuses, an integrated optical transmission unit and an optical reception unit, a failure monitoring unit that monitors a failure of the optical transmission unit or the optical reception unit, and a signal transmission of the optical transmission unit An optical transceiver comprising a transmission control unit for controlling the
When a failure occurs in the optical receiving unit in the working wavelength division multiplex transmission device, a failure monitoring unit notifies the transmission control unit of the occurrence of the failure, and based on the notification, the transmission control unit transmits the optical transmission The control for stopping the signal transmission of the unit is performed.

A transmission switching method according to the present invention is a transmission switching method in a wavelength division multiplexing communication system including two systems of wavelength division multiplex transmission devices, an active system and a protection system, and switching control of the wavelength division multiplex transmission device by a redundant switching device. In each of the wavelength division multiplexing transmission apparatuses, an integrated optical transmission unit and an optical reception unit, a failure monitoring unit that monitors a failure of the optical transmission unit or the optical reception unit, and a signal transmission of the optical transmission unit An optical transceiver comprising a transmission control unit for controlling the
When a failure occurs in the optical receiving unit in the working wavelength multiplex transmission apparatus, the failure monitoring unit notifies the redundant switching unit and the transmission control unit on the receiving side of the occurrence of the failure, and receives the notification. The redundant switching device on the receiving side switches the path of the received optical signal to the standby system, and the transmission control unit that has received the notification performs control to stop the signal transmission of the optical transmission unit, and the signal from the optical transmission unit. The transmission-side redundant switch that recognizes the stop switches the path of the transmission optical signal to the standby system.

As described above, according to the present invention, even when a failure occurs in an optical transceiver in a wavelength division multiplexing communication system including an optical transceiver integrated with a transmission and reception, the transmission path on the reception side and the transmission on the transmission side can be realized. By simultaneously switching the paths to the standby system, it is possible to prevent continuous operation in a state where a failure has occurred, and to quickly perform maintenance work when a failure occurs.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a preferred embodiment, a transmission line switching method in a wavelength division multiplex communication system according to the present invention is a wavelength division multiplex transmission system comprising a plurality of optical transceivers, a multiplexer and a demultiplexer. In the transmission switching system in which the apparatus is provided with two systems of an active system and a standby system and is switched and controlled by a redundant switching device, each optical transceiver has an integrated optical transmitting unit and optical receiving unit, an optical transmitting unit or A fault monitoring unit that monitors a fault in the optical receiving unit; and a transmission control unit that controls signal transmission of the optical transmitting unit. When a fault occurs in the optical receiving unit 15a in the active wavelength multiplex transmission device, The failure monitoring unit 16a includes the redundant switching unit 5 on the receiving side and the transmission control unit 1
7a notifies the occurrence of a failure, and the redundant switching unit 5 that has received the notification switches the path of the received optical signal to the standby system, and the transmission control unit 17a that has received the notification performs control to stop the signal transmission of the optical transmission unit 14a. The transmission-side redundant switch 8 recognizes the stop of the signal from the optical transmission unit 14a, and switches the path of the transmission optical signal to the standby system. And reception can be simultaneously switched to the standby system. This will be described below with reference to the drawings.

In FIG. 1, reference numerals 1 and 2 denote wavelength division multiplexing transmission devices, which are connected by transmission lines 7 and 8 (working system). The wavelength multiplexing transmission devices 3 and 4 are connected to transmission lines 9 and 10 respectively.
(Standby system) and redundant switching unit 5
The active system and the standby system are switched by means of (6) and (6).

The multiplexer 11 of the wavelength division multiplexing transmission apparatus 1 uses different wavelengths (λ) output from the optical transceivers 13a to 13n.
a to λn), and outputs one wavelength multiplexed optical signal to the transmission path 7. The demultiplexer 12 converts the wavelength multiplexed optical signal received via the transmission path 8 into The signal is demultiplexed into optical signals of wavelengths (λa to λn) and output to the optical transceivers 13a to 13n.

Each of the optical transceivers is of a transmission / reception integrated type. For example, in the optical transceiver 13a, the optical transmitter 14
a converts an optical signal of a predetermined format input from the optical coupler 51a into an optical signal of a specific wavelength (in this case, λa), and sends it to the multiplexer 11. Also, the optical receiving unit 15a
Converts an optical signal having a specific wavelength (in this case, λa) input from the demultiplexer 12 into an optical signal of a predetermined format, and transmits the optical signal to the optical SW 52a.

The optical transceiver 13a includes an optical transmitter 14
a and a failure monitoring unit 16a for monitoring the failure state of the optical receiving unit 15a. If the occurrence of a failure is detected, the occurrence of the failure is notified to the optical SW 52a, and the received optical signal is transmitted to the standby system. The mode is switched to the optical receiving unit 35a. At the same time, the failure monitoring unit 16a also notifies the transmission control unit 17a of the occurrence of the failure. When notified of the occurrence of the failure, the transmission control unit 17a instructs the optical transmission unit 14a to stop the transmission of the optical signal. Therefore, the failure monitoring unit 26a on the opposite side detects that the optical reception unit 25a has lost the optical input. Is done. This is the optical SW62a
And the switching to the standby system, that is, the optical receiving unit 45a is performed. As a result, the optical signal having the wavelength λa is communicated in the standby system (that is, the optical transceivers 33a and 43a) in both directions.

As described above, according to the present invention, when a failure occurs in an integrated optical transceiver for transmission and reception of a certain wavelength, it is possible to prevent continuous operation in a state where the failure has occurred and to prevent transmission and reception. Since there is no need to separately communicate between the active system and the standby system for reception, more rapid maintenance work can be performed.

[0020]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention;

In FIG. 1, reference numerals 1 and 2 denote wavelength division multiplex transmission devices, which are connected by transmission lines 7 and 8. Also,
The wavelength multiplex transmission devices 3 and 4 are connected by transmission lines 9 and 10. Here, the wavelength division multiplex transmission devices 1 and 2 and the transmission lines 7 and 8 are assumed to be working systems, and the wavelength division multiplex transmission devices 3 and 4 and the transmission lines 9 and 10 are assumed to be protection systems.

The wavelength division multiplex transmission apparatus 1 comprises a multiplexer 11, a demultiplexer 12, and a plurality of optical transceivers 13a to 13n. The other wavelength division multiplex transmission devices 2, 3, and 4 have the same configuration as shown in the figure.

The redundancy switches 5 and 6 are connected to the wavelength multiplex transmission devices 1 and 3 and the wavelength multiplex transmission devices 2 and 4, respectively, and have a function of switching between the working system and the standby system.

The redundant switching device 5 includes a plurality of optical couplers 51.
a to 51n and optical SWs (switches) 52a to 52n. The optical couplers 51a to 51n transmit optical signals of a predetermined format from a communication device (not shown) on the client side to the working system and the standby system. It branches and sends the same optical signal to both systems. In addition, the optical SWs 52a to 52n
Based on the failure information detected by the failure monitoring units 16a to 16n a to 13n, the active side and the standby side of the receiving side optical signal are switched. The redundant switching device 6 has the same configuration and function as the redundant switching device 5.

The multiplexer 11 of the wavelength division multiplexing transmission apparatus 1 uses different wavelengths (λ) output from the optical transceivers 13a to 13n.
The optical signals a to λn) are multiplexed, and one wavelength multiplexed optical signal is output to the transmission line 7. The demultiplexer 12 demultiplexes the wavelength multiplexed optical signal received via the transmission line 8 into optical signals of respective wavelengths (λa to λn) and outputs the optical signals to the optical transceivers 13a to 13n.

Each of the optical transceivers is of a transmission / reception integrated type. For example, in the optical transceiver 13a, the optical transmitter 1
4 a converts an optical signal of a predetermined format input from the optical coupler 51 a into an optical signal of a specific wavelength (in this case, λa), and sends it to the multiplexer 11. Also, the optical receiving unit 15
“a” converts an optical signal having a specific wavelength (in this case, λa) input from the demultiplexer 12 into an optical signal of a predetermined format, and transmits the optical signal to the optical SW 52a.

The optical transceiver 13a includes an optical transmitter 14a.
And a failure monitoring unit 16a that monitors the failure state of the optical receiving unit 15a. If the failure is detected, the failure is notified to the optical SW 52a and the transmission control unit 17a. The transmission control unit 17a has a function of issuing an instruction to stop transmission of an optical signal to the optical transmission unit 13a when notified of occurrence of a failure.

Next, the operation of this embodiment in FIG. 1 will be described in detail.

In FIG. 1, it is assumed that a transmission light signal of a communication device (not shown) on the client side connected to the redundant switching device 5 is connected to the optical coupler 51a, and a reception light signal is connected to the optical SW 52a. Further, it is assumed that a transmission optical signal of a client-side communication device (not shown) connected to the redundancy switching device 6 is connected to the optical coupler 61a, and a reception optical signal is connected to the optical SW 62a.

The transmission optical signal of the client communication device on the side of the redundant switching device 5 is split into two by an optical coupler 51a.
The data is transmitted to the optical transceivers 13a and 33a in parallel. Also,
The received optical signal of the client communication device is an optical SW 52a.
Thus, which of the active optical transceiver 13a and the standby optical transceiver 33a to receive is selected.

Similarly, the transmission optical signal of the client communication device on the opposite side is split into two by the optical coupler 61a, and the reception optical signal is switched by the optical SW 62a to the active optical transceiver 23a or the standby optical transceiver 23a. 43
a is selected.

Here, the active system is selected for both transmission and reception as viewed from the client communication device on the side of the redundant switching device 5, that is, the optical transceiver 13a and the optical transceiver 23a communicate via the optical signal of the wavelength λa. It is assumed that

In this system, at some point the optical transceiver 1
Assuming that a failure such as a failure of the optical receiving circuit has occurred in the optical receiving unit 15a of 3a, the failure monitoring unit 16a detects this and notifies the optical SW 52a. The optical SW 52a notified of the occurrence of the failure switches the received optical signal to the standby system, that is, the optical receiving unit 35a of the optical transceiver 33a. At this time, as for the optical signal of the wavelength λa, the transmission optical signal is viewed from the client communication device on the side of the redundant switching device 5, the transmission optical signal is used for the working system (that is, the optical transceivers 13 a and 23 a), and the reception optical signal is used for the protection system ( The communication is performed separately between the devices 33a and 43a).

However, in the present invention, the failure monitoring unit 16a notifies the optical SW 52a of the failure and also notifies the transmission control unit 17a of the occurrence of the failure. The transmission control unit 17a that has received the notification instructs the optical transmission unit 14a to stop transmitting the optical signal. As a result, the failure monitoring unit 26a on the opposite side detects that the optical receiving unit 25a has lost the optical input, and
Notify W62a. The optical SW 62a is a standby system,
Switching to the optical receiving unit 45a of the optical transceiver 43a is performed.
As a result, the optical signal having the wavelength λa is communicated in the standby system (that is, the optical transceivers 33a and 43a) in both directions.

As a result, in the maintenance work,
The failed optical transceiver 13a can be replaced immediately without checking the standby system or performing an artificial switching operation.

In this case, although the optical receiving unit 25a is in a state where the optical input is interrupted, it is not a failure of the optical receiving unit 25a itself. Therefore, the failure monitoring unit 26a does not notify the transmission control unit 27a of the occurrence of the failure. To Therefore, the optical transceiver 23a
Since the optical transmitting unit 24a keeps transmitting the optical signal, even if the optical transceiver 13a is replaced with a normal one, the optical receiving unit 15a enters the normal optical signal receiving state and the optical transmitting unit A normal optical signal is transmitted from 14a. As a result, the optical receiver 25a of the optical transceiver 23a also enters a normal optical signal receiving state, and it is possible to switch back to the active system artificially or to automatically switch back to the active system due to a failure in the standby system.

[0037]

As described above, according to the present invention,
When a failure occurs in a transmission / reception integrated optical transceiver of a certain wavelength, it prevents continuous operation with the failure still occurring, and separates transmission and reception into working and standby systems for communication. The maintenance work can be performed more quickly.

The reason is that the optical transmitter / receiver of the wavelength division multiplex transmission apparatus is provided with a means for stopping the signal transmission of the optical transmitter in response to a notification from the failure monitoring unit, so that when a failure occurs in the optical transmitter / receiver, the receiving side is stopped. This is because it is possible to switch the transmission line of the transmission side and the transmission line of the transmission side to the standby system at the same time.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a wavelength division multiplexing communication system and an optical signal transmission path according to the present invention.

FIG. 2 is a block diagram illustrating a configuration of a conventional wavelength division multiplexing communication system and an optical signal transmission path.

[Explanation of symbols]

1-4 wavelength multiplexing transmission device 5, 6 redundant switching device 7-10 transmission line 11, 21, 31, 42 multiplexer 12, 21, 32, 41 demultiplexer 13a-13n, 23a-23n, 33a-33n, 4
3a to 43n Optical transceivers 14a to 14n, 24a to 24n, 34a to 34n, 4
4a to 44n Optical transmission 15a to 15n, 25a to 25n, 35a to 35n, 4
5a to 45n Optical reception 16a to 16n, 26a to 26n, 36a to 36n, 4
6a to 46n Fault monitoring units 17a to 17n, 27a to 27n, 37a to 37n, 4
7a-47n Transmission controller 51a-51n, 61a-61n Optical coupler 52a-52n, 62a-62n Optical coupler

Claims (4)

[Claims] A plurality of optical transceivers for transmitting and receiving optical signals; a multiplexer for multiplexing and transmitting optical signals from the plurality of optical transceivers; and a multiplexer for demultiplexing the multiplexed optical signals. A wavelength division multiplexing transmission device having a demultiplexer for distributing the optical signal to each of the optical transceivers, wherein the optical transceiver has an optical transmitter for transmitting an optical signal to the multiplexer, and the optical transmitter is integrated with the optical transmitter. An optical receiving unit configured to receive a signal from the duplexer; a failure monitoring unit that monitors a failure of the optical transmitting unit or the optical receiving unit; and A transmission control unit for performing control to stop signal transmission of the unit, and when a failure occurs in the optical reception unit, the signal transmission of the optical transmission unit is stopped. apparatus. 2. A wavelength division multiplexing communication system comprising two systems of wavelength division multiplex transmission systems, an active system and a protection system, wherein the switching of said wavelength division multiplex transmission device is controlled by a redundancy switcher. An optical transmission / reception unit comprising: an integrated optical transmission unit and an optical reception unit; a failure monitoring unit that monitors a failure of the optical transmission unit or the optical reception unit; and a transmission control unit that controls signal transmission of the optical transmission unit. When a failure occurs in the optical receiving unit in the wavelength division multiplex transmission device of the active system, the path of the received optical signal is switched to the standby system by the redundant switching unit that has been notified from the failure monitoring unit. The wavelength division multiplexing communication system, wherein the switching is performed, the transmission control section stops the signal transmission of the optical transmission section, and the path of the transmission optical signal is switched to the standby system. 3. A transmission switching system in a wavelength division multiplexing communication system comprising two systems of a wavelength division multiplex transmission system, an active system and a protection system, and switching and controlling said wavelength division multiplex transmission device by a redundant switch. In the device, an integrated optical transmission unit and an optical reception unit, a failure monitoring unit that monitors a failure of the optical transmission unit or the optical reception unit, and a transmission control unit that controls signal transmission of the optical transmission unit When a failure occurs in the optical receiving unit in the working wavelength multiplex transmission apparatus, a failure monitoring unit notifies the transmission control unit of the occurrence of the failure, and based on the notification, A transmission switching method in a wavelength division multiplexing communication system, wherein a transmission control unit performs control to stop signal transmission of the optical transmission unit. 4. A transmission switching method in a wavelength division multiplexing communication system comprising two systems of wavelength division multiplex transmission systems, an active system and a protection system, and switching and controlling said wavelength division multiplex transmission device by a redundant switcher. In the device, an integrated optical transmission unit and an optical reception unit, a failure monitoring unit that monitors a failure of the optical transmission unit or the optical reception unit, and a transmission control unit that controls signal transmission of the optical transmission unit When a failure occurs in the optical receiving unit in the working wavelength multiplex transmission apparatus, the failure monitoring unit notifies the redundant switching unit on the receiving side and the transmission control unit of the occurrence of the failure. Receiving the notification, the receiving-side redundant switcher switches the path of the received optical signal to the standby system, the transmission control unit that receives the notification performs control to stop the signal transmission of the optical transmission unit, Said Redundancy switching machine recognizes the signal stop from the transmission unit transmitting side, the transmission switching system in the wavelength division multiplexing communication system, characterized by switching a path of the optical transmission signal to the auxiliary system.