JPH11136187A - Wavelength multiplex communication system and its fault relief method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wavelength multiplex communication system and its fault relief method where an optical output circuit is selected by a transmitter itself to continue communication on the occurrence of a fault in the optical output circuit, without the need for a standby transmission/reception system. SOLUTION: Each of transmitters 100, 200 has a function 90 of sending/ receiving a standby wavelength λ5 other than wavelength bands λ1-λ5 used for communication, and in the case that a fault is detected in the reception of any optical signal by a monitor circuit 10 of a receiver side transmitter, the information is sent to transmitter side devices 50, 60, 61, 8b, 62, 63 and the transmitter side devices 70, 80, 90 convert a signal with a fault into an optical signal with a standby quantity λ5 and transmit the converted signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wavelength division multiplexing communication system for converting a plurality of signals into lights having different wavelengths, multiplexing the signals, and performing wavelength division multiplexing communication via a transmission line, and a method for relieving a failure thereof, particularly a transmission apparatus. The failure relief of the optical output circuit.

[0002]

2. Description of the Related Art FIG. 2 is a functional block diagram showing an example of a conventional wavelength multiplex communication system of this kind. In FIG. 2, reference numerals 100 and 200 denote transmission devices, respectively. The transmission device 100 includes an optical transmitting unit 101a and an optical receiving unit 101b.
Is provided in the transmission device 200, and an optical receiving unit 201a and an optical transmitting unit 201b are provided, and bidirectional communication is performed via two transmission paths 8a and 8b.

[0003] Reference numeral 2 denotes an optical output circuit for converting an input electric signal into an optical signal of a predetermined wavelength (λ1 to λ4), and 3 a multiplexed optical signal from each optical output circuit 2. 4, a transmitting amplifier for amplifying the multiplexed optical signal, 5 a receiving optical amplifier for amplifying the optical signal transmitted via the transmission path, Reference numeral 6 denotes a demultiplexer for demultiplexing an optical signal, and 7 denotes a band-pass filter (BPF) having a different pass frequency band. The demultiplexer 6 and the BPF 7 separate optical signals of respective wavelengths, and separate the separated optical signals. Is converted into an electric signal by an optical / electric conversion unit (not shown).

Next, the operation will be described. Each signal input from the outside (four signals in FIG. 2) is
Are respectively predetermined wavelengths (λ1 to λ4 in FIG. 2).
Are converted into the four optical signals, and the four optical signals converted into the respective wavelengths λ1 to λ4 are multiplexed by the multiplexer 3, and the optical amplifier 4 amplifies the optical output power to transmit the optical signal 8a.
Sent to On the receiving side, after the optical multiplexed signal attenuated through the transmission line 8a is amplified by the receiving side amplifier 5, wavelength separation of λ1 to λ4 is performed by the demultiplexer 6 and the BPF 7, and each optical signal is electrically separated. The signal is converted into a signal and the signal is received. Also, the transmission device 200 to the transmission device 100
Communication to is performed in a similar manner.

However, in the wavelength division multiplexing communication system as shown in FIG. 2, for example, when a failure occurs in the optical output circuit of λ1, one of the four signals to be transmitted cannot be transmitted. Accordingly, in this type of wavelength division multiplexing communication system, as shown in FIG. 3, each of the transmission devices has a spare optical transmitting unit 102a, 202b and a spare optical receiving unit 102b,
202a and spare transmission paths 8-2a, 8-2
For example, when a failure occurs in the optical output circuit of λ1, a switching circuit (not shown) is operated manually, and the spare optical transmitting unit 102a, the transmission line 8-2a, and the spare optical receiving unit 202a are operated. To perform communication.

[0006]

The conventional wavelength division multiplexing communication system is configured as described above, and is provided with a spare transmitting and receiving system in preparation for the occurrence of a fault. And become expensive. Also, if a failure occurs, it is operated only by the spare transmission / reception system until it is recovered by replacing the package, etc., so if a further failure occurs in this spare transmission / reception system, it may cause a line failure, Since the wavelength to be used is specified for the optical output circuit of the wavelength division multiplexing communication system, the package of each wavelength must be kept for maintenance, and therefore, the failed optical output circuit cannot be replaced immediately. There were problems such as the occurrence of cases.

The present invention has been made to solve such a problem, and does not require a spare transmission / reception system. When a failure occurs in an optical output circuit, the transmission device switches the optical output circuit by itself to perform communication. To provide a wavelength division multiplexing communication system capable of continuing the operation and a method for remedying the failure.

[0008]

According to the present invention, there is provided a method for relieving a fault in a wavelength division multiplexing communication system, in which a plurality of signals are converted into optical signals having different wavelengths between transmission apparatuses and multiplexed to perform wavelength division multiplexing optical communication. In the method for relieving a failure in a wavelength division multiplexing communication system, each transmission device is provided with a function of transmitting and receiving a spare wavelength other than the wavelength used for communication, and a failure is detected in the reception of any optical signal in the receiving transmission device. In this case, this information is transmitted to the transmission-side transmission device, and the transmission-side transmission device converts a signal in which a failure has occurred into an optical signal of the spare wavelength and transmits the signal.

Further, each transmission device is provided with a function of transmitting and receiving a plurality of spare wavelengths other than the wavelength used for communication, and when a failure is detected in reception of any one of a plurality of optical signals by the reception-side transmission device, This information is transmitted to the transmission-side transmission device, and the transmission-side transmission device converts a plurality of failed signals into optical signals of the plurality of backup wavelengths and transmits the converted signals.

[0010] Further, each transmission device converts a plurality of signals into optical signals having different wavelengths, multiplexes them, and transmits a wavelength-division multiplexed optical signal to a transmission line, and a wavelength-division multiplexed light received from the transmission line. An optical receiving unit that splits a signal, and a spare optical transmitting unit and a spare optical receiving unit that are the same as the optical transmitting unit and the optical receiving unit are provided, and the optical transmitting unit and the optical receiving unit are provided between transmission devices. Are connected by a transmission line, and the spare optical transmitting unit and the spare optical receiving unit are connected by a spare transmission line. A function of transmitting and receiving a plurality of spare wavelengths other than the above, and a function of receiving the plurality of spare wavelengths in the optical receiving unit, and receiving any one of the plurality of optical signals in the optical receiving unit of the receiving-side transmission device. If a failure is detected in the transmission device, Transmits to the optical transmission unit, the optical transmission unit and transmits and converts the signal fails to light signals of the plurality of backup wavelength.

In a wavelength division multiplexing communication system according to the present invention, in a wavelength division multiplexing communication system for performing wavelength division multiplexing optical communication between transmission apparatuses, each transmission apparatus converts a plurality of signals into optical signals having different wavelengths and combines them. An optical transmission unit for transmitting a wavelength-division multiplexed optical signal to a transmission line, and a spare wavelength for converting any one of the plurality of signals to a spare wavelength other than the wavelength for converting the optical signal and for multiplexing with the wavelength-multiplexed optical signal A transmitting unit, an optical receiving unit that demultiplexes and outputs the wavelength multiplexed optical signal received from the transmission line, and a monitoring circuit that monitors each demultiplexed optical signal and detects a failed optical signal. When detecting that a failure has occurred in any of the optical signals, the control unit selects the optical signal of the spare wavelength as an output of the optical signal, and transmits information on the failed optical signal to the transmission-side transmission device. And from the receiving transmission device The signal has been said information, characterized in that the signal in question to operate the backup wavelength transmission unit and a switching means for converting the backup wavelength.

An optical transmitter for converting a plurality of signals into optical signals having different wavelengths, multiplexing the signals, and transmitting a wavelength-division multiplexed optical signal to a transmission line is provided in each transmission device. A spare wavelength transmitting unit for converting into a plurality of spare wavelengths other than the wavelength to be converted into the optical signal and multiplexing with the wavelength multiplexed optical signal, and an optical receiver for demultiplexing and outputting the wavelength multiplexed optical signal received from the transmission line And a monitoring circuit that monitors each of the split optical signals to detect a failed optical signal, and detects that a failure has occurred in any one of the plurality of optical signals, Control means for selecting an optical signal of the spare wavelength as an output and transmitting information of the optical signal in which a failure has occurred to the transmitting side transmitting apparatus, and the spare wavelength transmitting section based on the information transmitted from the receiving side transmitting apparatus. Operate the part and apply Characterized by comprising a switching means for converting the number of signals to each of the plurality of backup wavelength.

Further, each of the transmission devices further includes a spare optical transmitting unit same as the optical transmitting unit, and a spare optical receiving unit same as the optical receiving unit, and the spare optical transmitting unit and the spare optical transmitting unit. It is characterized by further comprising a spare transmission / reception system connected to the receiving unit via a spare transmission line.

In the wavelength division multiplexing communication system and the method for relieving a fault according to the present invention, the system itself switches to a spare wavelength and continues communication in response to a fault in the optical output circuit. There is no need to provide a transmission / reception system.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, 100 and 200 are transmission devices, respectively, and 8a and 8b are transmission lines, respectively. In each transmission device, reference numeral 2 denotes an electric signal input thereto at a predetermined wavelength (λ1
To λ4), an optical output circuit 3 converts the optical signal from each optical output circuit 2 into one wavelength multiplexed optical signal, and a multiplexed optical signal. , A receiving optical amplifier for amplifying an optical signal sent via a transmission path, 6 a demultiplexer for demultiplexing an optical signal, 7
Are band-pass filters (BPFs) having different pass frequency bands, which are the same as or correspond to the same reference numerals in FIG. 2. As in FIG. 2, these are optical transmission units 101 a and 201 b and optical reception units, respectively. 101b, 201
a is formed.

A monitoring circuit 10 monitors the state of the optical signal of each wavelength (that is, whether a normal optical signal is transmitted), and a band-pass filter (BPF) 20 extracts a spare wavelength λ5. , 30 are couplers for optically splitting the optical output from the BPF 20 into the number of transmission signals, and 40 is a BP
A selection circuit for switching and outputting the optical signal from the F7 or the optical signal from the coupler 30. Reference numeral 50 denotes a control circuit, and when an abnormality is detected in any of the optical wavelength signals by the monitoring circuit 10, the selection circuit 40 for the wavelength where the abnormality is detected is operated to select the optical signal from the coupler 30, and It outputs control information that informs the transmitting side which optical wavelength signal has an abnormality.

Reference numeral 60 denotes an electric / optical converter for converting control information from the control circuit 50 into an optical signal, 61 denotes a multiplexer for multiplexing this optical signal into a wavelength multiplexed optical signal used for communication, and 62 Is a demultiplexer for extracting an optical signal indicating control information from the wavelength-division multiplexed optical signal sent from the transmitting side, and 63 is for converting the optical signal of the demultiplexer 62 into an electric signal and outputting control information. It is an optical / electrical converter. Reference numeral 70 denotes a coupler for splitting an externally input electric signal, reference numeral 80 denotes a selection circuit for selecting one of a plurality of electric signals input according to control information from the reception side control circuit 50, and reference numeral 90 denotes a selection circuit. A spare wavelength λ other than the wavelengths λ1, λ2, λ3, λ4 used in normal communication with the electric signal selected by the circuit 80.
5 is an optical output circuit for conversion to 5.

In this specification, the optical output circuit is also referred to as a spare wavelength transmission unit, and the control described in this specification by the coupler 30, the selection circuit 40, the control circuit 50, the electric / optical conversion unit 60, and the multiplexer 61. The switching means referred to in this specification is constituted by the demultiplexer 62, the optical / electrical conversion unit 63, the coupler 70, and the selection circuit 80.

Next, the operation of the embodiment shown in FIG. 1 will be described. For example, on the receiving side of the transmission device 200, the received wavelength multiplexed optical signal is divided into each optical signal by the demultiplexer 6 and the BPF 7, and each optical signal is output to the selection circuit 40 and the monitoring circuit 10, and the monitoring circuit 10 Monitor each optical signal. The control circuit 50 collects the monitoring results of the monitoring circuit 10. If the monitoring circuit 10 detects an abnormality in any of the optical signals, the monitoring circuit 10 determines which optical wavelength signal has caused the abnormality and When an abnormality is detected in any of the optical signals, control information for notifying the transmitting side of which optical wavelength signal has an abnormality is generated, and the control information is transmitted to the electric / optical conversion unit 60.
The optical signal is converted into an optical signal and multiplexed into a wavelength multiplexed optical signal used for communication by the multiplexer 61. Then, the wavelength multiplexed optical signal to which the control information is multiplexed is transmitted to the optical receiver of the transmission device 100 via the transmission line 8b.

In the transmission device 100, an optical signal carrying control information is extracted by a demultiplexer 62 from the wavelength-division multiplexed optical signal input via the transmission line 8b, and is converted into an electric signal by an optical / electrical converter 63. And input to the selection circuit 80. As described above, each transmission signal from the outside branched by the coupler 70 is input to the selection circuit 80, and the selection circuit 80 removes the transmission signal in which the reception abnormality has occurred according to the transmitted control information as a spare. The signal is input to the optical output circuit 90, the transmission signal is converted into an optical signal of the backup wavelength λ5, multiplexed with the wavelength multiplexed optical signal transmitted by the multiplexer 3, and transmitted to the transmission device 200 via the transmission line 8a. .

The wavelength-division multiplexed optical signal transmitted to the transmission device 200 is separated into each optical signal by the demultiplexer 6 and each BPF. The BPF 20 is set to output an optical signal having the wavelength λ5. The output optical signal of wavelength λ5 is input to the selection circuit 40 via the coupler 30. Control circuit 5
0 switches the input of the selection circuit 40 of the optical signal in which the abnormality is detected to the input from the coupler 30 in accordance with the monitoring information from the monitoring circuit 10, and the optical signal in which the abnormality is detected becomes the spare wavelength λ5. The communication is performed, and the communication of the wavelength multiplexed optical signal can be continued.

In the embodiment shown in FIG. 1, the wavelengths used for signals are set to λ1 to λ4, and the spare wavelength is set to λ5. However, the wavelength used for signals is not limited to four. Alternatively, the configuration may be such that a plurality of auxiliary wavelengths are provided. Further, in the embodiment shown in FIG. 1, it is possible to cope with a failure of the optical output circuit 2, but it is not possible to cope with a failure of the transmission line. Therefore, it is also possible to adopt a configuration in which a spare transmission / reception system including a spare optical transmitter, a spare optical receiver, and a spare transmission line as shown in FIG. 3 is further provided.

[0023]

As described above, according to the wavelength division multiplexing communication system and the failure remedy method of the present invention, even if a failure occurs at any wavelength, the wavelength division multiplexer automatically switches to the spare wavelength to continue the communication. Until the package of the faulty wavelength is exchanged, the fault can be recovered without affecting the end user. In addition, since communication can be continued at the spare wavelength, there is an effect that the transmission device does not always need to have a spare optical output circuit for all wavelengths.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing an example of this type of conventional wavelength multiplex communication system.

FIG. 3 is a block diagram showing another example of this type of conventional wavelength multiplex communication system.

[Explanation of symbols]

 Reference Signs List 2 optical output circuit 3 multiplexer 4 transmitting amplifier 5 receiving optical amplifier 6 demultiplexer 7, 20 bandpass filter (BPF) 8a and 8b respectively transmission path 10 monitoring circuit 30 coupler 40 selection circuit 50 control circuit 60 electricity / Optical conversion unit 61 Multiplexer 62 Demultiplexer 63 Optical / electrical conversion unit 70 Coupler 80 Selection circuit 90 Optical output circuit 100 and 200 Transmission devices 101a, 201b Optical transmission units 101b, 201a Optical reception units

Claims (6)

[Claims] In a method for relieving a wavelength division multiplexing communication system in which a plurality of signals are converted into optical signals having different wavelengths and multiplexed between the transmission devices to perform wavelength division multiplexing optical communication, each transmission device is used for communication. A function of transmitting and receiving a spare wavelength other than the wavelength is provided, and if a failure is detected in the reception of any of the optical signals by the receiving-side transmission device, this information is transmitted to the transmitting-side transmission device. In the first aspect of the present invention, there is provided a method for relieving a failure in a wavelength division multiplexing communication system, wherein a signal in which a failure has occurred is converted into an optical signal having the backup wavelength and transmitted. 2. A failure remedy method for a wavelength division multiplexing communication system in which a plurality of signals are converted into optical signals having different wavelengths between the transmission devices and multiplexed to perform wavelength division multiplexing optical communication. A function of transmitting and receiving a plurality of spare wavelengths other than the wavelength is provided, and when a failure is detected in the reception of any one of the plurality of optical signals by the reception-side transmission device, this information is transmitted to the transmission-side transmission device. A method for relieving a failure in a wavelength division multiplexing communication system, wherein the transmission device converts a plurality of failed signals into optical signals of the plurality of backup wavelengths and transmits the converted signals. 3. An optical transmitter for converting a plurality of signals into optical signals having different wavelengths, combining the signals, and transmitting a wavelength-division multiplexed optical signal to a transmission line, a wavelength multiplexing signal received from the transmission line. An optical receiving unit that splits an optical signal, and a spare optical transmitting unit and a spare optical receiving unit that are the same as the optical transmitting unit and the optical receiving unit are provided, and the optical transmitting unit and the optical receiving unit are provided between transmission devices. Are connected by a transmission line, and the spare optical transmitting unit and the spare optical receiving unit are connected to each other by a spare transmission line. A function of transmitting and receiving a plurality of spare wavelengths other than a wavelength and a function of receiving the plurality of spare wavelengths in the optical receiving unit are provided, and an optical receiving unit of a receiving-side transmission device transmits any one of a plurality of optical signals. If a failure is detected in the reception, this information is A method for relieving a failure in a wavelength division multiplexing communication system, comprising transmitting to a transmission unit, the optical transmission unit converting a signal in which a failure has occurred into an optical signal having the plurality of spare wavelengths, and transmitting the signal. 4. A wavelength division multiplexing communication system for performing wavelength division multiplexing optical communication between transmission apparatuses, wherein each transmission apparatus converts a plurality of signals into optical signals having different wavelengths, multiplexes the signals, and multiplexes the signals into a transmission path. An optical transmitting unit that transmits a signal, a spare wavelength transmitting unit that converts any of the plurality of signals into a spare wavelength other than the wavelength that is converted into the optical signal, and multiplexes with the wavelength multiplexed optical signal, and is received from a transmission path. An optical receiver for demultiplexing and outputting the wavelength-division multiplexed optical signal, a monitoring circuit for monitoring each demultiplexed optical signal and detecting a failed optical signal, and a fault occurring in one of the optical signals. When it is detected that the optical signal of the spare wavelength is selected as the output of the optical signal, control means for transmitting the information of the optical signal in which the failure has occurred to the transmitting side transmitting apparatus, The spare wavelength transmission WDM communication system characterized in that a switching means parts by operating the converting an appropriate signal to the backup wavelength. 5. A wavelength division multiplexing communication system for performing wavelength division multiplexing optical communication between transmission apparatuses, wherein each transmission apparatus converts a plurality of signals into optical signals having different wavelengths, multiplexes the signals, and transmits the multiplexed optical signal to a transmission path. An optical transmission unit for transmitting a plurality of the plurality of signals to a plurality of spare wavelengths other than a wavelength for converting each of the plurality of signals to the optical signal, and a spare wavelength transmission unit for multiplexing the wavelength multiplexed optical signal; An optical receiver for demultiplexing and outputting a wavelength multiplexed optical signal received from a path, a monitoring circuit for monitoring each demultiplexed optical signal and detecting a failed optical signal, and any one of a plurality of optical signals When detecting that a failure has occurred, control means for selecting an optical signal of the spare wavelength as an output of each of the plurality of optical signals, and transmitting information of the failed optical signal to a transmission-side transmission device. , Sent from the receiving transmitter WDM communication system, characterized in that the said information, and a switching means for converting a plurality of signals in question by operating the spare wavelength transmission unit to the plurality of preliminary wavelengths. 6. Each of the transmission apparatuses further includes a spare optical transmitting unit that is the same as the optical transmitting unit, and a spare optical receiving unit that is the same as the optical receiving unit, and further includes the spare optical transmitting unit and the spare optical transmitting unit. 6. The wavelength division multiplexing communication system according to claim 4, further comprising a spare transmission / reception system connected to the optical receiving unit via a spare transmission line.