JP3292178B2 - Optical communication network equipment, optical transmission system and optical communication network - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical communication network, an optical communication network / node configuration, and a method for transmitting information on operation, management, and maintenance of the optical communication network.

[0002]

2. Description of the Related Art The use of optical communication makes it possible to increase the capacity of a single optical transmission line due to the wide bandwidth of light. However, if photoelectric conversion is performed on all the optical signals at a node on the way that is not related to the target node of the signal, the device becomes large and the cost increases. Therefore, an optical communication network that switches an optical signal as light has been receiving attention. By using an optical switch, it is possible to switch a large-capacity optical signal in a lump as it is, to perform network reorganization and recovery from a failure.

Therefore, conventionally, an optical communication network node device as shown in FIG. 9 (ECOC'93: European Confernece on Optical C
ommunication) Proceeding Volume 2, TuP5.
3. , P. 153, 1993).
FIG. 9 shows a block diagram of the node configuration, and FIG. 1 shows a configuration example of an optical switch network 901 used in the node.
0 is shown. In FIG. 9, reference numeral 900 denotes an optical cross-connect.
Represents a node. 905 to 910 are optical transmission lines connected to other nodes. 902 is SDH (Synchronous Digita)
l Hierarchy; CCITT Blue Book Recommendation G.707,
G.708, G.709) path digital cross-connect system, 903 and 904 are SDH transmission frame terminators (Optical Line Terminators and Multiplex).
ers).

In FIG. 10, reference numerals 1001 to 1024 denote L.
An 8 × 8 matrix optical switch composed of iNbO3, 1101 to 1164 are input terminals of an optical switch network, and 1201 to 1264 are output terminals of the optical switch network. An optical switch network can be configured by connecting the matrix optical switches 1001 to 1024 as shown in FIG.

[0005] In an optical cross-connect network, an electric signal is converted into an optical signal at a certain node and transmitted to an optical transmission line. The optical signals transmitted through the optical transmission lines 906 and 907 are switched as they are by the optical switch network 901, and the optical transmission lines 909 and 91 connected to other nodes.
0 is transmitted. As described above, in the node 900, the transmitted optical signal is switched to an optical signal without being converted into an electric signal and is transmitted to another node, so that a large-capacity optical signal can be switched collectively. It is possible to edit the net efficiently. In addition, since it is not necessary to switch a large-capacity optical signal by time-division demultiplexing, there is an advantage that the node device can be downsized.

[0006]

With the prior art described above, large-capacity optical signals can be switched at once, efficient network editing can be performed, and the node device can be downsized. is there. However, due to an increase in data communication, tolerance to network transmission path failures and node failures has become increasingly important. Particularly in the case of data communication networks, high-speed disaster recovery is required (Wu et al., Fiber Network Service Survivability, Artec House (Wu, Fibe)).
r NetworkService Survivability, Artech House),
A high-speed failure recovery is also required for a network using an optical cross-connect system, which performs data communication on a trunk network, (see page 6).

In a network using an optical cross-connect system, as shown in FIG. 9, optical signals transmitted through the optical transmission lines 906 and 907 pass through the node 900 as light. Transmission lines 906, 90
7 cannot be detected. Therefore, it is necessary to detect the failure of the optical signal at the terminal point where the optical signal is converted into the electric signal, and start the failure recovery operation from the terminal point.
The number of nodes that communicate information related to failure recovery increases, and the failure recovery time increases. Also, in the node 900 that passes light, the optical signal, the optical transmission line, the optical switch, and the like cannot be constantly monitored, and when a network failure occurs, the point of failure cannot be immediately determined. Such an efficient failure recovery cannot be performed, and the preparation amount of the spare optical transmission line increases.

[0008]

According to a first aspect of the present invention, there is provided an optical communication network apparatus comprising a first optical receiving means, a second optical receiving means, an optical function circuit means, an input terminal and a first optical receiving means. When an optical transmission line having an output end and a second output end is connected to the input end and a mixed light of light having a wavelength belonging to the first group and light having a wavelength belonging to the second group is input to the input end. First light separating means for outputting light having a wavelength belonging to the first group to the first output terminal and outputting light having a wavelength belonging to the second group to the second output terminal; An optical transmission line having an output end of the first and second output ends, and an optical transmission line connected to the input end to split light input to the input end into the first output end and the second output end; A second light separating means for outputting, and an information processing means for processing information on operation, management and maintenance of the network, A first output terminal of the first light separating unit is connected to an input terminal of the second light separating unit, and a first output terminal of the second light separating unit is connected to an input terminal of the optical function circuit unit. A second output end of the first optical splitting means is connected to an input end of the first optical receiving means, and a second output end of the second optical splitting means is connected to the second optical receiving means. Means, an output end of the first light receiving means is connected to an input end of the information processing means, and an output end of the second light receiving means is connected to an input end of the information processing means. The optical function circuit means is connected to the information processing means.

A second aspect of the present invention is an optical communication network device, comprising: a first optical receiving means, a second optical receiving means, an optical function circuit means, an input terminal, a first output terminal, and a second output terminal. An optical transmission line is connected to the input terminal, and when the mixed light of the light of the wavelength belonging to the first group and the light of the wavelength belonging to the second group is input to the input terminal, the optical transmission line belongs to the first group. First light separating means for outputting light having a wavelength to the first output end and outputting light having a wavelength belonging to the second group to the second output end; an input end; a first output end; And an optical transmission line connected to the input terminal and transmitting the light input to the input terminal to the first terminal.
And a second output terminal which branches and outputs the output terminal and the second output terminal.
And an optical transmission line having a first input terminal, a second input terminal, and an output terminal, an optical transmission line connected to the output terminal, and an input light to the first input terminal and the second input terminal. Optical superimposing means for outputting light superimposed on input light to the output terminal to the output end, optical transmitting means, and information processing means for processing information relating to operation, management, and maintenance of the network; A first output end of the light splitting means is connected to an input end of the second light splitting means, a first output end of the second light splitting means is connected to an input end of the optical function circuit means, The second output end of the first light splitting means is connected to the input end of the first light receiving means, and the second output end of the second light splitting means is connected to the second light receiving means. An output end of the first light receiving means is connected to an input end of the information processing means; The output end of the communication means is connected to the input end of the information processing means, the output end of the information processing means is connected to the input end of the light transmission means, and the output end of the light transmission means is the second end of the superposition means. , An output terminal of the optical function means is connected to a first input terminal of the optical superimposing means, and the optical function circuit means is connected to the information processing means.

A third invention is an optical transmission system for network operation, management, and maintenance information, wherein an optical signal of a wavelength belonging to a first group is transmitted to a second optical communication network device by using an optical transmission line. In an optical transmission system of network operation, management, and maintenance information from a first optical communication network device to a second optical communication network device for transmission, the first optical communication network device operates and manages the network. And generating an optical signal having a wavelength belonging to a second group having maintenance information, and transmitting the optical signal obtained by superimposing the optical signal belonging to the second group and the optical signal having the wavelength belonging to the first group on the optical transmission line. The second optical communication network device transmits the optical signal belonging to the first group and the optical signal belonging to the second group from the superimposed optical signal transmitted. Separated into The operation, management, and maintenance of the network are performed by receiving the optical signals belonging to the first group using a first optical receiving unit and receiving the optical signals belonging to the second group using a second optical receiving unit. It is characterized by obtaining information.

A fourth aspect of the present invention is an optical communication network, which mainly transmits information by using an optical signal of a wavelength belonging to the first group, and is composed of a plurality of nodes connected by an optical transmission line. In a communication network, when a node that outputs an optical signal is a transmitting node, and a node that is connected adjacent to the transmitting node by an optical transmission line and that receives the optical signal is a receiving node, the transmitting node is a first group. The optical signal having the wavelength belonging to the optical signal and the optical signal having the wavelength belonging to the second group are superimposed and transmitted to the receiving node.
The superimposed optical signal is separated into an optical signal having a wavelength belonging to the first group and an optical signal having a wavelength belonging to the second group, and the transmission is performed by monitoring the optical signal having a wavelength belonging to the second group. A failure in an optical transmission path between a node and the receiving node is detected.

Hereinafter, the operation of the present invention will be described.

According to the first invention, WDM (Wavelength Division Multiplexing and Demultiplexing) inserted before an optical signal is input to the optical function circuit means.
ultiplexing) The coupler has a different wavelength from the main signal.
An optical signal (hereinafter referred to as OAM signal light, abbreviated as OAM signal light) modulated in advance with information of network operation, management, and maintenance superimposed.
AM: Operation, Administration, and Maintenance)
Can be separated and extracted, and disconnection of the optical transmission path can be detected. Further, a failure of the main signal can be detected by the optical splitter. When these two detections are confirmed, not the failure of the optical transmitter sending the information signal, but the optical transmission path,
Alternatively, it can be confirmed that a failure has occurred in the node. Therefore, a failure recovery operation can be performed at the node closest to the failure occurrence point, and a failure recovery method in which only the failure section is bypassed because the failure point is known is possible, and a high-speed failure recovery is possible. Recovery is possible. Further, since only the failure section is bypassed, the number of spare optical transmission lines prepared for recovery from the failure can be reduced, and a failure recovery system can be constructed economically.

According to the second aspect of the present invention, a WDM coupler inserted before an optical signal is input to the optical function circuit means separates and extracts a pre-superimposed OAM signal light having a different wavelength from the main signal. And the disconnection of the optical transmission line can be detected. Further, a failure of the main signal can be detected by the optical splitter. When these two detections are confirmed, not the failure of the optical transmitter sending the information signal, but the optical transmission path,
Or it can be convinced that it is a node failure. Also, an optical coupler arranged after the optical function circuit means can superimpose an optical signal of a different wavelength from the main signal modulated with the control information for recovery from the failure, and control the other nodes for recovery from the failure. Transfer of information can be performed. Therefore, a failure recovery operation can be performed by sending a control message from a node closest to the failure location to another node, and a failure recovery method in which only the failure section is bypassed because the failure location is known. And fast failure recovery is possible. or,
Since only the failed section is bypassed, the number of spare optical transmission lines prepared for recovery from the failure can be reduced, and a failure recovery system can be constructed economically.

According to the third invention, before the optical signal is inputted to the optical function circuit means, a means for separating the wavelength such as a WDM coupler is inserted so that the signal is superimposed on a wavelength different from the wavelength of the main signal in advance. The OAM signal light can be separated and extracted, and by partially tapping and monitoring the optical level of the main signal light, at the node closest to the optical transmission line where the failure has occurred, It can be recognized that a failure has occurred in the optical transmission path. Therefore, the failure recovery operation can be started from the node closest to the optical transmission line where the failure has occurred, and high-speed failure recovery can be performed.

In the fourth invention, information relating to network operation, maintenance, and management is superimposed at the transmitting node using an optical coupler, and separated at the receiving node using a WDM coupler. When the transmission / reception system of the OAM signal is reliable, the disconnection state of the optical transmission line can be determined only by checking the light receiving level of the separated OAM signal light.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to examples.

In the following description, as an example, the wavelength of an optical signal for main communication (hereinafter, referred to as main signal light) is 1.
The wavelength of an optical signal (hereinafter, referred to as OAM signal light) used for communication for operation, maintenance, monitoring, and management of a network is 1.55 μm. Also, in the following description,
The optical transmitter can be configured using a DFB laser diode. In the following description, the optical receiver is an APD
(Avalanche photodiode). In the following description of the embodiment, in an optical communication network composed of a plurality of nodes having an optical switch network, an electric signal is converted into an optical signal at a certain node, sent out to an optical transmission line, and the optical When an optical signal passes through the switch network as it is and is converted into an electrical signal at a certain node at the end, a section that is electrically terminated is called an optical path, and failure recovery of the optical path will be considered.

An embodiment of the first invention will be described with reference to FIG.

FIG. 1 is a block diagram showing a first embodiment of the first invention. In FIG. 1, 101 is an optical transmission line,
105 is an optical receiver (first optical receiving means), 106 is an optical receiver (second optical receiving means), 104 is an optical switch network (optical function circuit means), and 103 is an optical switch network 1
A directional coupling type optical coupler (second optical separation unit) in which the ratio of the optical power output to the input terminal of the optical receiver 04 and the optical power output to the input terminal of the optical receiver 106 is 95: 5. A WDM coupler (first optical splitter) that outputs light having a wavelength of .31 μm to the input end of the optical coupler 103 and outputs light (OAM signal light) having a wavelength of 1.55 μm to an output end connected to the optical receiver 105. Means) is an optical communication network node (optical communication network device). 107
Is an information processing device (information processing means) that processes signals obtained from the optical receivers 105 and 106, and can use a workstation. As the optical switch network 104,
As shown in FIG. 10, 8 was fabricated using LiNbO3.
A 64 × 64 optical switch network made by combining a plurality of × 8 matrix optical switches (Shiragaki et al., ECOC'93: European Confernece on
Optical Communication) Proceeding Volume 2, T
(see pages 5.3 and 153). Although a plurality of optical transmission lines are input / output to / from the optical switch network 104, only one input optical transmission line and one output optical transmission line are shown in the figure for convenience of explanation. In the optical transmission line, for example, SDH (Synchronous Digital Hierar
chy: CCITT Blue Book Recommendation G.707, G.708,
G.709) can be used to transmit an optical signal.

The optical signal transmitted from the optical transmission line 101 is input to the optical switch network 104. When the WDM coupler 102, the optical coupler 103, and the optical receivers 105 and 106 are not connected, Even if the optical transmission line 101 is broken, there is nothing to detect the breakage, so that the node 108 cannot recognize the failure of the optical transmission line 101. When the WDM coupler 102 is not used and only the optical coupler 103 is inserted, monitoring of the optical power by the optical receiver 106 indicates that a failure has occurred in the main signal light. Since it is not known whether a failure has occurred, it takes time to find out where the failure has occurred, and the failure recovery time is delayed. For example, it is necessary to perform communication between adjacent nodes to find out to which node the main signal light is coming.
A main signal (1.31 μm) for monitoring between adjacent nodes
The optical signal having a wavelength of 1.55 μm (O
AM signal light), the OAM signal light is superimposed on the main signal light and transmitted by the WDM coupler at the upstream node in advance, and the WDM coupler 102 of the downstream adjacent node 108 is transmitted.
Is used to separate the OAM signal light, the failure of the OAM signal light can be recognized by the node (node 108 in this case) immediately downstream of the failure point. In the receiving node 108, when a failure occurs in the optical transmission line through which the signal is transmitted, the optical power of the main signal light is attenuated, and
Since the AM signal light is also attenuated at the same time, if the optical power is attenuated, it is considered that a failure has occurred in the optical transmission line. However, in this method, since the state of the main signal light is not directly observed, it cannot be confirmed whether or not the optical transmission line 101 has really failed. For example, there is a possibility that an optical transmitter for transmitting an optical signal for monitoring may fail.

Therefore, as in the present invention, the optical coupler 103
Is inserted between the optical switch network 104 and the WDM coupler 102, since the optical coupler 103 monitors the optical power of the main signal light, it can be confirmed whether there is really a problem with the main signal light. Observation of the reception failure of the OAM signal light by the optical receiver 105 and the reception failure of the main signal light by the optical receiver 106 has caused a failure in the optical transmission line 101 or the nodes and repeaters connected thereto. Can be determined.
Therefore, a failure recovery operation can be performed so as to bypass a section of the optical transmission path 101 where a failure has occurred. By bypassing only the section where a failure occurs, not from the node where the optical signal is electrically terminated, but from a node adjacent to the section where the failure occurs, the OAM ( The number of times of communication of (operation, maintenance, and management) information can be reduced, and high-speed failure recovery can be performed. In addition, since a detour is formed so as to detour only the faulted section, and a section where no fault occurs is used as it is, the number of optical transmission lines used as the detour can be reduced, and a spare prepared for recovery from the fault can be prepared. The preparation amount of the optical transmission line can be reduced, and the cost can be reduced.

In this case, an example of performing a high-speed failure recovery using the configuration of the node 108 will be described with reference to FIG. In FIG. 2, reference numerals 201 and 202 denote nodes;
Reference numeral 6 denotes an optical switch network, which can be the same as 104 in FIG. Although only one optical transmission line is input to the node 108 in FIG. 1 for convenience of explanation,
Node 202 receives two optical transmission lines,
The configuration is basically the same as that of the node 108 in FIG. 20
Reference numerals 6 and 207 denote optical transmitters for transmitting a monitoring optical signal (1.55 μm), and reference numerals 204 and 205 denote optical couplers having a 1: 1 coupling ratio for superimposing the monitoring optical signal on the main signal (1.31 μm). It is. 212 to 215 are optical receivers. 217-
Reference numeral 221 denotes an optical transmission line, and the optical transmission line 220 and the optical transmission line 2
An optical signal having the same contents is transmitted to 21. Optical signals having the same contents are also transmitted to the optical transmission lines 217 and 218. This is to form a detour when a failure occurs in one of the optical transmission lines. 20
8 and 209 output 1.31 μm light toward the optical switch network, and output 1.55 μm light to the optical receivers 214 and 21.
5 is a WDM coupler that outputs the signal to the direction 5. 210, 21
1 branches and outputs 5% of the light to the optical receivers 212 and 213, and outputs 95% to the optical switch network 216.
It is an optical coupler that splits% light. By switching the optical switch network 216 to the node 202, the optical transmission line 219 can be connected to either of the optical transmission lines 217 and 218. Although not shown in FIG. 2, a node (referred to as a node A) is connected to the end of the optical transmission line 219, and performs an electrical termination of the main signal light. Normally, it is assumed that the optical transmission line 218 and the optical transmission line 219 are connected, and the main signal light passes from the optical transmission line 218 to the optical transmission line 219.

Now, assuming that a failure has occurred in the optical transmission line 218, the node 202 recognizes that a failure has occurred in the optical transmission line 218 by a change in the reception level of the optical receiver 215 and the optical receiver 212. . Therefore, it is possible to switch between the optical transmission line 217 and the optical transmission line 219 where no failure has occurred without waiting for a failure notification from the node A terminating the main signal light. Since the communication time for notification of a failure from the node A to the node 202 can be saved, high-speed failure recovery can be performed. In particular, if there are more optical signals passing between the node 202 and the node A, the nodes that should communicate with each other after recognizing the failure at the electrically terminated node and then performing the failure recovery operation However, if the present invention in which the detour is performed only in the faulty section is applied, the number of nodes to be communicated is small, and the effect of omitting the communication time is increased.

In the optical receiver 105 and the optical receiver 106, monitoring can be performed based on the optical power level of the received signal, and monitoring can be performed based on the error rate of the received signal.

Thus, before the optical function circuit means, WD
By inserting the M coupler 102 and the optical coupler 103 and monitoring both the optical power level of the main signal and the optical power level of the supervisory signal light, the node adjacent to the downstream of the point of failure becomes upstream of the own node. It is possible to reliably recognize a failure in the optical transmission path connected to the optical transmission line. Therefore, high-speed failure recovery can be performed by, for example, starting a failure recovery operation from the node. Also, the amount of preparation for the number of spare optical transmission lines can be reduced, and the cost of the network can be reduced.

In this embodiment, a WDM coupler for separating an optical signal having a wavelength of 1.31 μm from an optical signal having a wavelength of 1.55 μm is used.
The present invention is not limited to this wavelength band, and can be applied to a WDM coupler that separates the wavelengths into arbitrary wavelength bands.

Next, an embodiment of the second invention will be described with reference to FIG.

FIG. 3 is a block diagram showing an embodiment of the second invention. In FIG. 3, reference numeral 301 denotes an optical communication network node (optical communication network device); and 309, an optical transmitter (optical transmitting means) for transmitting a monitoring optical signal having a wavelength of 1.55 μm. Reference numeral 104 denotes an optical switch network (optical function circuit means). Reference numeral 107 denotes a workstation (an information processing unit that processes information related to network operation, management, and maintenance). 305 is the optical transmitter 30
9 is an optical coupler (optical superimposing means) for superimposing the monitoring optical signal from the optical switch 9 and the main signal light from the optical switch network 104 at a coupling ratio of 1: 1. 103 is an optical receiver 1 for 5% of the input light.
An optical coupler (second optical separation means) for outputting to the optical switch network 104 and outputting 95% of the input light to the optical switch network 104
102 outputs 1.31 μm light of the input light to the optical coupler 103 and outputs 1.55 μm light to the optical receiver 105.
Is a WDM coupler (first light separating means) for outputting the light to the side. 105 is an optical receiver (first optical receiving means), 106
Denotes an optical receiver (second optical receiving means). The second invention has a configuration according to the first invention, in which a device (optical coupler 305 and optical transmitter 309) for superimposing the OAM signal light on the optical signal output from the optical switch network 104 is added.

The second invention has the effect of the first invention (the effect that the failure recovery operation can be started from the node closest to the failure point, the failure can be recovered at a high speed, and the preparation amount of the spare optical transmission line can be reduced). In addition to the above, there are the following effects. When a failure recovery method is used in which an identifier of a failed optical transmission line is reported to a terminal node and a failure recovery operation is performed, a failure location can be immediately determined, and a portion corresponding to the first invention is provided. Can be immediately transmitted to another adjacent node. By transmitting the information of the failed optical transmission line to the adjacent node a plurality of times, the information can be transmitted to the terminal node. Therefore, it is possible to recognize a failure point without inquiring the failure point by polling or the like from the end node. Therefore, high-speed failure recovery can be performed. Further, when failure recovery is detected, information on the identifier of the failed optical transmission line,
Since the information on the spare optical transmission line used for the recovery from the failure can be transferred to the adjacent node involved in the recovery from the failure, the failure detection method is used instead of the failure recovery method of transferring the identifier of the failed optical transmission line to the terminal node. A method of causing a failure recovery operation from the node that has performed the operation can be performed by sending a message to another node. Even in such a case, even in a node where an optical signal passes as it is, a disconnection of an optical transmission line connected to the node can be reliably detected, and a failure recovery operation can be performed from the node. Is possible.

Next, an embodiment of the third invention will be described with reference to FIG.

FIG. 2 is a block diagram showing an embodiment of the third invention. The description of each block is as described in the embodiment of the first invention. Normally, it is assumed that the optical transmission line 218 is a working optical transmission line and the optical transmission line 218 and the optical transmission line 219 are connected.

If the optical couplers 204, 210, 211
If none of the WDM couplers 208 and 209 are used, the optical signal passes through the optical switch network 302 as an optical signal, such as a command to change the switch state in the optical switch network 302. Network operation,
Information related to maintenance and management (hereinafter referred to as OAM information) cannot be transmitted to other nodes.

However, in the optical communication network device of the present invention, the OAM information from the information processing device 107 is transmitted to the main signal light (1.31 μm:
(1.55 μm: wavelength belonging to the second group), which is different from the wavelength of the second group, and by superimposing the light on the optical couplers 204 and 205,
OAM signals can be transmitted in addition to the main signal. Node 2
02, the WDM couplers 208 and 209 that separate the wavelengths of 1.55 μm and 1.31 μm use the 1.55 μm
OAM signal light having a wavelength of Therefore, reception of the OAM signal light (reception using the first optical reception means)
Thus, it is possible to obtain OAM information modulated on the OAM signal light, and obtain information on whether the OAM signal light is normally transmitted through the optical transmission line. However, with this alone, when a failure occurs in the optical transmission line 218, the node 202 cannot distinguish the failure from the optical transmitter that sends out the OAM signal light, and so on.
After detecting a failure in the node where the optical signal is terminated, switching for bypass is performed after receiving control information for failure recovery from the node in which the optical signal is terminated. However, by monitoring the optical power of the main optical signal with the optical receiver 212 as in the present invention, it is possible to be certain that the optical transmission path 218 is faulty. Therefore, after the occurrence of the failure in the optical transmission line 218, the node 202
Without waiting for an instruction from the terminal node, the optical transmission path 21
7 and the optical transmission line 219 can be connected to form a detour of the optical transmission line 218, and high-speed failure recovery is possible.

Next, an embodiment of the fourth invention will be described with reference to FIG.

FIG. 4 is a block diagram showing an embodiment of the fourth invention. In FIG. 4, a node 401 is a node (transmission node), and a node 402 is a node (reception node).
Represents 1.3 1 μm as the wavelength used for the main signal light
(A wavelength belonging to the first group), and 1.
A wavelength of 55 μm (wavelength belonging to the second group) is used. 40
Reference numerals 5 to 407 denote optical transmission lines, 403 denotes an optical transmitter for transmitting light having a wavelength of 1.55 μm, and 404 denotes an optical receiver. 40
Reference numerals 8 and 411 denote optical switch networks, which can be the same as the optical switch network 104 in FIG. 409 and 410 are WDM
A coupler which is the same as the coupler 102 in FIG. 1 can be used. An optical switch network 408 is connected to the input terminal for coupling 1.31 μm of the WDM coupler 409, and an optical transmitter 403 is connected to the input terminal for coupling 1.55 μm. WDM coupler 410
The optical receiver 404 is connected to an output terminal for separating and outputting light of 1.55 μm, and an optical switch network 411 is connected to an output terminal for separating and outputting light of 1.31 μm. . The main signal light output from the optical switch network 408 is an optical signal having a wavelength of 1.31 μm, which is superimposed on the monitoring optical signal output from the optical transmitter 403 by the WDM coupler 409 and the optical signal. The signal is input to the transmission path 406. At the receiving node, 1.55 μm light is input to the optical receiver 404 using the WDM coupler 410, and 1.31.
The main signal light of μm is input to the optical switch network 411.

Accordingly, in the receiving node, when a failure occurs in the optical transmission line through which the signal is transmitted, the optical power of the main signal light is attenuated and the monitoring optical signal is also attenuated at the same time. If only the optical power is monitored, it is possible to recognize a failure in the optical transmission line 406, perform the recovery without having to search for the optical transmission line in which the failure has occurred, and perform high-speed failure recovery. It can be performed. Since the main signal light is not monitored at the node that passes as it is, it cannot be determined whether the main signal light has actually failed. However, the OAM information communication system has high reliability and almost no trouble occurs. If not considered, as in the present invention,
The monitoring of the main signal light is omitted, and the optical receiver 404 is used for 1.
Since only the optical power of the wavelength of 55 μm is monitored, the cost can be reduced.

In FIG. 4, the node 401 is a transmitting node, and the node 402 is a receiving node.
01 can be a receiving node, and the node 402 can be a transmitting node. The nodes 401 and 402 represent a part of the network. In the entire network, for example, the nodes are connected in a mesh shape as shown in FIG.

In this embodiment, the case of a mesh network has been described.
It is obvious that the fourth invention can be applied to a star network.

An embodiment of the fifth invention will be described with reference to FIG. 3 (for the description of FIG. 3, refer to the embodiment of the second invention).

The fifth invention can be realized by connecting the nodes having the configuration shown in FIG. 3 in a mesh. W
The OAM signal light can be received by the DM coupler 102, and the main signal light can be monitored by the optical coupler 103. As described in detail in the embodiment of the second invention, a failure of the optical transmission line 101 connected upstream of the node 301 can be detected by the node 301 by these two monitoring operations. Failure recovery operation can be performed, and high-speed failure recovery is possible. In addition, since the failed optical transmission line can be immediately determined, the recovery from the failure bypassing only the failed section can be performed, and the number of spare optical transmission lines prepared for the recovery from the failure can be reduced. As the monitoring by the optical receiver 105, monitoring of a bit error rate by parity check and monitoring of a light receiving level can be considered.

An embodiment of the sixth invention will be described.

According to a sixth aspect, in the fifth aspect, the monitoring of the optical signal is limited to monitoring based on the optical power (light receiving level) of the optical signal. With this limitation, there is an effect that the fifth invention can be implemented at low cost by using an inexpensive optical receiver that only needs to detect the light receiving level.

An embodiment of the seventh invention will be described with reference to FIG.

FIG. 6 is a block diagram showing an embodiment of the seventh invention. In FIG. 6, reference numerals 601 to 605 denote nodes of the optical communication network ("a plurality of nodes" in the claims).
It is. Each node has the node configuration shown in FIG. 3 (for an explanation of the configuration in FIG. 3, refer to the embodiment of the second invention). At the node 601, the electrical signal to be transmitted is converted into an optical signal, and the destination is switched as it is at the nodes 602 and 603, and arrives at the node 604. At the node 604, the optical signal is converted into an electric signal. By using the configuration shown in FIG.
A wavelength of 55 μm can be superimposed, separated and extracted. Each node can detect the failure of the OAM signal light by the WDM coupler 102 and the optical receiver 105 in FIG. 3, and can detect the failure of the main signal light by the optical coupler 103 and the optical receiver 106. It is. By detecting these two disconnections, each node can recognize a failure in the optical transmission line to which the optical signal is input (optical transmission line failure detecting means for detecting the disconnection of the optical signal). For example, when the optical transmission line 607 between the node 602 and the node 603 is disconnected as shown in FIG. 6, the node 603 can recognize a failure in the optical transmission line 607 to which an optical signal is input. Therefore, it is possible to cause a failure recovery operation starting from the node 603. Since no failure has occurred in the section between the node 601 and the node 602 and the section between the node 603 and the node 604, this optical transmission line can be used as it is. Therefore, in order to form a detour via the node 605, the optical transmission line 60
8 and the optical transmission path 610 are connected to form a part of a detour. Information that such switching is performed when a failure occurs in the optical transmission line 607 is stored in the memory of the information processing unit 107 in FIG.

On the other hand, by using the OAM signal light having a wavelength of 1.55 μm (the optical transmitter 309 in FIG. 3), the identifier of the optical transmission line in which a failure has occurred and the identifier of the optical transmission line 610 used in the detour path have been identified. Can be transferred to the node 605 (means for exchanging information regarding operation, management, and maintenance of the network with other nodes). If a failure occurs in the optical transmission line 607 in advance, the node 605
The information processing apparatus of the node is provided with information that the optical transmission path 609 is connected to the node. Therefore, when the information that a failure has occurred in the optical transmission line 607 is received from the node 603, the optical transmission line 610 and the optical transmission line 609 are connected. Similarly, information that a failure has occurred in the optical transmission line 607 and information that the optical transmission line 609 is used as a detour are also transmitted to the node 602. The node 602 connects the optical transmission line 609 and the optical transmission line 606 when information indicating that the optical transmission line 609 is used as a bypass when a failure occurs in the optical transmission line 607 is transmitted. The optical switch network is switched so that the optical transmission line 606 and the optical transmission line 609 are connected when the information is received. Therefore, only the section where the failure has occurred (the section between the nodes 602 and 603) is
5 and a section where no other failure occurs (a section between the nodes 601 and 602 and a section between the nodes 603 and 604) can be used as it is.

FIG. 7 shows a detour form in which a detour is performed in an electrically terminated section (between the ends of an optical path) without using a method of detouring only in a section where a failure has occurred. Optical transmission line 60
7, a failure is detected at the electrical termination node 604, and the nodes 702, 701, and 60
By sequentially accessing “1”, a detour is formed. When this method is used, the number of nodes involved in the failure recovery is four in the case of FIG. In the case of FIG. 6, since only three nodes are involved in the recovery from the failure, the case of FIG. 6 (the seventh invention) shortens the time involved in transmitting and processing the information of the recovery from the failure in total. FIGS. 6 and 7 show a case where four nodes pass through the nodes 601 to 604 in the active system. However, if the number of passing nodes increases, failures in the cases of FIG. 6 and FIG. The difference in the number of involved nodes is even greater. In the failure recovery method in the case of FIG. 6, the number of nodes required to bypass the failure section is equal to the number of nodes (in FIG. 6, one node is bypassed, but usually at most two nodes or three nodes).
This is because it is related to the failure recovery which can be sufficiently recovered by the detour around the node). However, in the method of FIG. 7, the failure recovery is related to the number of nodes included between the end points of the optical signal. Similarly, in the case of FIG. 6, two optical transmission lines 609 and 610 are to be prepared, whereas in the case of FIG.
03 to three optical transmission paths 705, and FIG. 6 (seventh invention) requires less preparation of a spare optical transmission path for failure recovery. As with the number of nodes involved in recovery from failure, if the number of nodes existing between electrical termination points is large, the method of FIG. 6 does not depend on the number of nodes between electrical termination points. On the other hand, the method of FIG. 7 increases as the number of nodes increases, depending on the number of nodes between electrical termination points. Therefore, if the number of nodes involved in a failure is large, the effect of the seventh invention (high-speed failure recovery and saving of the number of spare optical transmission paths) is further enhanced.

In summary, by using the method of detouring only the faulty section as shown in FIG. 6, the number of nodes involved in fault recovery can be reduced, and high-speed fault recovery is possible. In addition, since the number of spare optical transmission lines to be prepared can be reduced, a failure recovery system can be constructed economically.

An embodiment of the eighth invention will be described with reference to FIG.

In FIG. 8, reference numerals 801 to 807 denote nodes of the optical communication network, and each node has the configuration shown in FIG. 3 (for FIG. 3, refer to the embodiment of the second invention). Reference numerals 809 to 816 denote optical transmission lines, and each node is connected as shown in FIG. Now, consider a case where a node failure has occurred in the node 803 as shown in FIG.

When a failure occurs in the node 803, the node 8
In No. 04, a fault is detected in both the main signal light and the monitoring signal light. However, with this detection alone, it is impossible to determine whether a failure has occurred in the optical transmission line 811 or the node 803. However, when the node 803 does not function, the optical transmission line 811 cannot be used. It may be determined that the optical transmission line 811 has substantially failed. Therefore, from node 804 to node 80
7, the information that a failure has occurred in the optical transmission line 811 is transferred, and the optical switch network of the node 804 is switched so as to connect the optical transmission line 812 and the optical transmission line 816. On the other hand, when a failure occurs in the node 803 in the node 807, the monitoring 1..
It is detected that the light receiving level of the 55 μm optical signal has dropped. Therefore, in the node 807, the optical transmission paths (the optical transmission path 815 and the optical transmission path 81
1: In the claims, a fault in "a plurality of optical transmission lines connected to a certain node" is recognized. In this case, a node failure of the node 803 or the optical transmission line 811
It is considered that one of the double failures of the optical transmission line 815 has occurred. In any case, a detour must be formed to avoid node 803. If such a situation is detected in advance, the optical transmission lines 816 and 8
14 and connect the information to node 8
Since the transfer to the node 06 is stored in the information processing means of the node 807, those operations are performed by the node 807. Also, when a failure is detected in both the optical transmission line 811 and the optical transmission line 815, the node 806 is switched to connect the optical transmission lines 814 and 813, and the information is transferred to the node 802. That means node 80
6 are stored in the information processing means 6 and their operations are performed in the node 806.

Since information for connecting the optical transmission line 809 and the optical transmission line 813 is stored in the information processing means of the node 802, the node 802 connects the optical transmission line 809 and the optical transmission line 813 to each other. Switch the optical switch network to connect. By the above operation, the path (the optical transmission path 809 and the optical transmission path 812) of the optical signal in which no failure has occurred is used as it is, and the node (node 803) in which the failure has been confirmed in the optical transmission path of the plurality of paths is used. Failure recovery can be performed by detouring without passing.

According to the present invention, FIG.
Similar to the comparison between the failure recovery methods of FIG. 7 and FIG. 7, the section where no failure occurs is used as it is and only the failed section is bypassed, so that the number of nodes involved in failure recovery can be reduced. Therefore, the communication volume between the nodes can be reduced, so that high-speed failure recovery is possible, and the number of spare optical transmission lines prepared for the failure can be reduced.

An embodiment of the ninth invention will be described.

The ninth invention is used in the embodiment of the seventh invention. That is, when a node obtains information related to failure recovery, the switching operation of the optical switch network of that node and the information transmitted to other nodes are determined in advance. By pre-determining such a method, the information processing means in each node does not need to execute a complicated algorithm such as a detour search, so that it is possible to perform a failure recovery without requiring a long time for detour formation. . Therefore, high-speed failure recovery can be performed.

An embodiment of the tenth invention will be described with reference to FIG.

FIG. 7 shows an optical communication network. 60
2, 603, 701, and 702 are optical communication network nodes having the configuration of FIG. 9 (for the configuration of FIG. 9, refer to the related art). An optical communication network node 601 has two optical signal terminating devices 904 in FIG. 9 and transmits the same optical signal. In order to supply the same signal to the two optical signal termination devices, an electric branching device may be used. Reference numeral 604 denotes an optical communication network node having the same configuration as the node 202 in FIG. 2 (for the description of the configuration in FIG. 2, refer to the embodiment of the first invention). Reference numeral 604 denotes the node 202 in FIG. 2 in which the optical transmission line 608 in FIG. 7 is connected instead of the optical transmission line 217, and the optical transmission line 705 in FIG. Node 60
4, an optical receiver for terminating the main signal light is connected to the end of the optical transmission line 407 in FIG.

In the node 602, the optical transmission line 606 and the optical transmission line 607 are connected using an optical switch network. In the node 603, the optical transmission line 607 and the optical transmission line 608 are connected in advance using an optical switch circuit network. Thus, the nodes 601, 602, 6
03, the section of the node 604 forms a section (first path) in which an optical signal is transmitted as it is and the transmission content does not change. In the node 701, the optical transmission path 703 and the optical transmission path 704 are connected in advance using an optical switch network.
In the node 702, the optical transmission line 704 and the optical transmission line 705 are connected in advance using an optical switch network. As a result, in the section between the node 601, the node 701, the node 702, and the node 604, an optical signal is transmitted as it is as light, and a section (second path) where the transmission content does not change is formed. At the node 601 (the first node in the section), one of the optical signals having the same content (the first optical signal) is transmitted to the optical transmission line 606 (the first path), and the other (the second optical signal) is transmitted. Is transmitted to the optical transmission path 703 (toward the second path). Node 60
In 4, any of the optical signal passing through the optical transmission path 608 and the optical signal passing through the optical transmission path 705 can be input to the optical receiver that terminates the main signal of the node 604. Therefore, if the bit error rate of the optical receiver terminating the main signal increases and the reception state becomes abnormal, switching to reception of the other signal can recover the failure. For example, it is assumed that an optical signal (first optical signal) passing through a first path using the optical transmission path 607 is being received at the node 604. When a failure occurs in the optical transmission line 607, all the reception values of the node 604 become 0 (assuming that the transmission signal is digital), which indicates that a failure has occurred in the transmission of the optical signal. Therefore, the optical switch network of the node 604 is switched, and the optical signal from the optical transmission line 705 (second
The failure is recovered by switching to receive the optical signal.

The use of the present invention has the following effects. Recovery of the failure can be performed only by detecting the reception failure of the main signal light at the node 604 terminating the optical signal and switching the optical switch network at the node 604, and exchanging control information with other nodes. Therefore, it is possible to perform the failure recovery at high speed. Also, the intermediate nodes include an optical switch network, and an optical transmission line is connected to the node. Therefore, when it is necessary to change the route prepared in advance, the optical switch network is switched to be flexible. Changes can be made.

The present invention is not limited to this embodiment. For example, in the embodiment, the configuration of the node 202 in FIG.
At 04, the main signal light is monitored by the optical coupler 103 using the configuration of FIG. 1 to detect disconnection of the first optical signal and disconnection of the second optical signal, and switch the optical signal to be received. It is also possible. Even if the first optical signal and the second optical signal use different wavelengths, the first optical signal and the second optical signal are routed at intermediate nodes such that the first optical signal and the second optical signal arrive at the node 604 via different paths. The present invention can be applied if is performed.

As described above, the first to tenth aspects of the present invention have been described in detail with reference to the embodiments. However, the present invention is not limited to these embodiments.

For example, in the embodiments, there is an invention in which an optical splitter or a WDM coupler is used as the light separating means. However, the present invention can be applied even if a polarization controller and a polarization splitter are used as the light separating means. In this case, the main signal is deflected by TE,
The optical signal for transmitting the AM information is polarization multiplexed and transmitted using TM deflection, each block is connected by a polarization maintaining fiber, and only the TM polarized light is extracted to obtain OAM information. As the polarization controller, an apparatus that controls the fiber by applying pressure to the fiber to change the polarization can be used. As the polarization splitter, for example, a crystal having birefringence such as LiNbO3 can be used.

In the embodiment, a WDM coupler for separating the wavelengths of 1.31 μm and 1.55 μm is used as the light separating means (WDM coupler). However, the wavelength used for the main signal light and the wavelength for the OAM signal light are used. W that can separate the wavelength
The present invention can be applied to any DM coupler.

In the embodiment, 1.31 is used as the main signal light.
Although a wavelength of 1.5 μm and a wavelength of 1.55 μm were used as OAM signal light, if there is an optical coupler capable of separating wavelengths,
The present invention is applicable even if different wavelength bands are used for each.

In the embodiment, one wavelength is used as the main signal. However, the present invention can be applied even when the main signal is wavelength division multiplexed.

In the embodiment, the space division optical switch network is used as the optical switch network. However, the present invention can be applied to the case where a wavelength division optical switch network for exchanging an optical transmission line for each wavelength is used. it can. In this case, for example, a wavelength of 1.31 μm can be used as the OAM signal light, and a 1.55 μm band is used as the main signal light as the main signal light, and the 1.55 μm band is wavelength division multiplexed at, for example, 1 nm intervals. Can be used.

The optical coupler used as the optical demultiplexing means or the optical superimposing means has a branching ratio of 95: 5 or 1: 1. 95: 5 if the value is branched so that it can be received by the means.
The present invention is applicable even if the ratio is not 1: 1.

In the embodiment, the optical switch network is used as the optical function circuit means, but the optical branching device, the star coupler, the W
The present invention can be applied even when a passive optical element such as a DM coupler or an isolator is used. Also, as an optical function circuit means,
The present invention can be applied to a configuration in which an optical component such as an optical splitter and a WDM coupler is added to an optical switch network. Further, the present invention can be applied to a case where the optical function circuit means includes an optical receiver and an optical transmitter for a main signal. The present invention can be applied even if an optical amplifier such as an Er-doped fiber or a semiconductor optical amplifier is used as the optical function circuit means.

Also, as the optical function circuit means, the optical function terminating device and the switch network means (exchanger, cross-connect device) for switching the electric signal are used. The present invention can also be applied to the case where a "device" is used. Also, as an optical function circuit means,
The present invention can be applied to a device including an optical signal termination device and a repeater for regenerating and relaying an electric signal. Further, the present invention can be applied even if an optical circuit network in which an input terminal and an output terminal are simply connected by an optical fiber is used as the optical function circuit means.
In addition, the present invention is also applicable to a case where an optical functional circuit means in which an optical superimposing means, a light separating means or another optical functional circuit means is connected to a stage preceding or succeeding another optical functional circuit means as the optical functional circuit means. Applicable. Further, the present invention is applicable even if a configuration including a wavelength division multiplexing optical switch network or a time division multiplexing switch network is used as the optical function circuit means.

As the optical switch used in the optical switch network, an optical switch made of LiNbO3 was used. However, an optical switch such as a mechanical optical switch, a semiconductor optical switch, and a quartz optical switch is used. The present invention can be applied even using the optical switch network described above.

Although the optical switch network 102 as described in the first embodiment of the present invention is used as the optical switch network, a switch network having an arbitrary switch network configuration and an arbitrary number of input / output ports can be used. Even if used, the present invention can be applied.

Although the description has been made with respect to the failure recovery in the section where the optical signal is electrically terminated, the present invention is applicable to a section where the content of the transmitted signal does not change even if the optical signal is electrically terminated and relayed halfway. Is self-evident.

In the embodiment of the present invention, an optical switch network is used in which the optical signal is switched in each node while the optical signal remains light. However, the optical signal is once converted into an electric signal, converted into an optical signal again, and then converted into an optical signal. The present invention can be applied to a case where an optical signal is switched by input to a switch network.

Although the workstation is used as the information processing means, the present invention is applicable to any personal computer, DSP (Digital Signal Processor), LSI, etc. as long as it can process OAM information of an optical communication network. it can.

In the embodiment, only a limited topology with a limited number of nodes has been described. However, it is obvious that the present invention can be applied to a network having a different number of nodes from the embodiment and a different topology. is there.

[0076]

When the present invention is applied, a part of the main signal light is tapped to monitor its light level, or a light having a different wavelength from the main signal light for insertion and separation between adjacent nodes. O
By monitoring the AM signal, it is possible to detect the disconnection of the connected optical transmission line at the node where the optical signal passes as light. Therefore, since it is possible to start the failure recovery operation from the node closest to the failure point,
By bypassing only the failure section, high-speed failure recovery becomes possible. Further, by using a method of bypassing only the faulty section, the number of optical transmission lines prepared for the fault can be reduced, and a low-cost network can be configured. In addition, by storing a bypass setting pattern for an optical transmission line failure in advance in the information processing device of each node, a bypass can be formed without performing a bypass search, so that failure recovery can be performed at high speed. It is possible.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing one embodiment of the first invention and the like.

FIG. 3 is a block diagram showing one embodiment of the second invention and the like.

FIG. 4 is a block diagram showing one embodiment of the fourth invention and the like.

FIG. 5 is a block diagram showing an embodiment of the fourth invention.

FIG. 6 is a block diagram showing one embodiment of the seventh invention and the like.

FIG. 7 is a block diagram for explaining an embodiment of the seventh invention, the tenth invention and the like.

FIG. 8 is a block diagram showing one embodiment of the eighth invention and the like.

FIG. 9 is a diagram for explaining a conventional example.

FIG. 10 is a diagram for explaining a conventional example.

[Explanation of symbols]

Reference Signs List 101 optical transmission line 102 WDM coupler (first optical separating means) 103 optical coupler (second optical separating means) 104 optical switch network (optical functional circuit means) 105 optical receiver (first optical receiving means) 106 Optical receiver (second optical receiving unit) 107 Information processing device (information processing unit) 108 Optical communication network node (optical communication network device) 201 Optical communication network node (first optical communication network device) 202 Optical communication network node (Second optical communication network device) 203, 216 Optical switch network (optical functional circuit means) 204, 205 Optical coupler (optical superimposing means) 206, 207 Optical transmitter (optical transmitting means) 208, 209 WDM coupler (optical) Separating means) 210, 211 Optical coupler (optical separating means) 211-215 Optical receiver 217- 21 Optical Transmission Path 301 Optical Communication Network Node (Optical Communication Network Device) 305 Optical Coupler (Optical Superimposing Means) 306 Optical Transmission Path 309 Optical Transmitter (Optical Transmitting Means) 401 Optical Communication Network Node (Transmission Node) 402 Optical Communication Network Node (Reception node) 403 Optical transmitter 404 Optical receiver 405-407 Optical transmission line 408, 411 Optical switch network 403-405 Optical communication network node 601-605 Optical communication network node 606-610 Optical transmission path 701, 702 Communication network Nodes 703 to 705 Optical transmission lines 801 to 807 Optical communication network nodes 809 to 816 Optical transmission lines 901 Optical switch networks 1001 8 × 8 matrix optical switches

Continuation of front page (56) References JP-A-63-193750 (JP, A) JP-A-5-260541 (JP, A) JP-A-7-183871 (JP, A) JP-A-3-214936 (JP) , A) JP-A-3-258038 (JP, A) Shiragaki, Hemi, Fujiwara, "Proposal and examination of a method for realizing operation, management and maintenance (OAM) functions in optical networks", IEICE (58) Field surveyed (Int.Cl. ⁷ , DB name) H04Q 3/52 H04Q 11/00-11/08 H04B 10/08 H04J 14/00 H04J 14/02 H04M 3/32

Claims (3)

(57) [Claims] 1. An optical transmission line having first optical receiving means, second optical receiving means, optical function circuit means, an input terminal, a first output terminal, and a second output terminal. When the mixed light of the light of the wavelength belonging to the first group and the light of the wavelength belonging to the second group is inputted to the input end, the light having the wavelength belonging to the first group is outputted to the first output end. First light separating means for outputting light having a wavelength belonging to the second group to the second output end;
An optical transmission line having an input end, a first output end, and a second output end is connected to the input end, and transmits light input to the input end to the first output end and the second output end. A second light separating means for branching and outputting information, and an information processing means for processing information relating to operation, management and maintenance of the network, wherein a first output terminal of the first light separating means is And a first output terminal of the second light separating unit is connected to an input terminal of the optical function circuit unit, and a second output terminal of the first light separating unit is connected to an input terminal of the second light separating unit. An end is connected to an input end of the first optical receiving unit, a second output end of the second optical separating unit is connected to an input end of the second optical receiving unit, and the first optical receiving unit is connected to the first optical receiving unit. An output end of the means is connected to an input end of the information processing means, and an output end of the second light receiving means is connected to the information processing means. Is connected to the input terminal, an optical communication network system is the optical function circuit means and being connected to said information processing means. 2. An optical transmission line having first optical receiving means, second optical receiving means, optical function circuit means, an input terminal, a first output terminal, and a second output terminal. When the mixed light of the light of the wavelength belonging to the first group and the light of the wavelength belonging to the second group is inputted to the input end, the light having the wavelength belonging to the first group is outputted to the first output end. First light separating means for outputting light having a wavelength belonging to the second group to the second output end;
An optical transmission line having an input end, a first output end, and a second output end is connected to the input end, and transmits light input to the input end to the first output end and the second output end. A second light separating means for branching and outputting the light, and an optical transmission line having a first input terminal, a second input terminal, and an output terminal connected to the output terminal, and an input to the first input terminal. Optical superimposing means for outputting light obtained by superimposing light and input light to the second input end to the output end; optical transmitting means; and information processing means for processing information relating to network operation, management and maintenance And the first
The first output end of the light separation means is connected to the input end of the second light separation means, and the first output end of the second light separation means is connected to the input end of the optical function circuit means. , The first
The second output end of the light separating means is connected to the input end of the first light receiving means, and the second output end of the second light separating means is connected to the input end of the second light receiving means. Connected, an output end of the first light receiving means is connected to an input end of the information processing means, an output end of the second light receiving means is connected to an input end of the information processing means, An output end of the means is connected to an input end of the light transmitting means, an output end of the light transmitting means is connected to a second input end of the superimposing means, and an output end of the optical function means is connected to the optical superimposing means. The optical communication network device is connected to a first input terminal, and the optical function circuit means is connected to the information processing means. 3. The main information is transmitted in a network by using an optical signal of a wavelength belonging to the first group, and operation, management, and maintenance information of the network is obtained by using an optical signal of a wavelength belonging to the second group. 3. The optical communication network device according to claim 1, wherein the communication is performed.