JP2000004460A - Optical communication node and optical communication network - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for a control network with high reliability by changing setting of a wavelength path for each node on a transfer path of the wavelength path through distributed processing and to process switching of many wavelength paths at the same time by distributing loads for the wavelength path setting processing. SOLUTION: The node is provided with a control signal receiver 21 that receives a control light received from an input path and provides an output of transfer path setting information included in the control light and with a control signal transmitter 22 that provides an output of the control light including the transfer path setting information to be transferred to a succeeding optical communication node to an output path in addition to optical demultiplexers 13(a-c), optical multiplexers 14(a-c), a spatial optical switch 17 and a control section 19 that references a routing table to control the spatial switch 17. Then the control section 19 references the routing table based on the transfer path setting information to switch a connecting state of the spatial switch 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to wavelength division multiplexing (W
The present invention relates to an optical communication node and an optical communication network for setting a wavelength path by wavelength routing using DM (DM) technology. In particular, the present invention relates to an optical communication node and an optical communication network for setting and releasing a connection as needed when a communication request occurs.

[0002]

2. Description of the Related Art In an optical communication network, the introduction of a WDM technique utilizing the broadband characteristics of an optical fiber has begun.
In particular, in a wavelength path network such as an optical add / drop network or an optical cross-connect network, it is possible to switch wavelength paths, such as recovery from a failure or changing the capacity of a wavelength path, using a wavelength routing technique of a WDM signal.

A wavelength path network is a network in which a wavelength path connecting a source node and a destination node is set, a predetermined wavelength is set for each wavelength path, and a node routes a WDM signal as it is. .

FIG. 9 shows a configuration example of a conventional wavelength path network. This network includes optical communication nodes 5a, 5b, 5c, 5d, 5e, 5 having optical cross-connect switches.
f, wavelength multiplexing optical links 2a, 2b, 2c, 2d, 2e, 2f, 2g connecting these optical communication nodes, and a control network 6 for controlling the optical communication nodes via a control network communication line.

FIG. 10 shows a configuration example of a conventional optical communication node. The present optical communication node includes input-side optical fibers 11a, 1
Optical demultiplexers 13a, 13b, 1 connected to 1b, 11c
3c, optical multiplexers 14a, 14b, 14c connected to the output side optical fibers 12a, 12b, 12c, output ports of optical demultiplexers, input ports of optical multiplexers, and drop ports 15
Space optical switch 17 for connecting between
The control unit 18 controls the spatial light switch 17 according to a routing table in which information input via a control network communication line is set. As the optical demultiplexer 13 and the optical multiplexer 14, an arrayed waveguide grating type multiplexer / demultiplexer or the like is used. As the spatial light switch 17, an optical waveguide switch utilizing the thermo-optic effect which usually requires a switching time of about several milliseconds is used.

[0006] Input side optical fibers 11a, 11b, 11c
The wavelength-division multiplexed optical signals input to the optical communication node from the optical demultiplexers are demultiplexed by the corresponding optical demultiplexers 13a, 13b, and 13c, and routed to predetermined output ports via the spatial optical switch 17. For example, the main signal light having this node as the destination node is separated into the drop port 15,
The main signal light originating from this node is input from the add port 16 and merges. The optical signals transferred to the other nodes are multiplexed by the corresponding optical multiplexers 14a, 14b, 14c and transmitted to predetermined output side optical fibers 12a, 12b, 12c.

In this network, the wavelength paths are centrally set by the control network 6. The wavelength path is semi-fixed, and the wavelength path is changed only at the time of failure recovery or capacity change. When such a setting change of the wavelength path is instructed to the control network 6, the control network 6 issues a rewriting signal of the routing table to the corresponding optical communication node. The corresponding optical communication node changes the wavelength path by switching the connection of the spatial optical switch 17 according to the rewritten routing table. The switching time of the optical cross-connect switch is about 1 ms, and is sufficiently applicable to network failure recovery and wavelength path capacity change.

[0008]

The wavelength path network has a feature that a wavelength path can be flexibly reconfigured by wavelength routing.

However, the conventional centralized control wavelength path network requires a highly reliable control network 6 in addition to the main signal network, and has the following problems. (1) The control network 6 for instructing the optical cross-connect switch of each optical communication node to change the setting of the wavelength path is necessary for a large amount of equipment such as a central control device and an optical fiber transmission line serving as a control network communication line. (2) In the central control unit, 1
Since the wavelength path setting change processing that requires a relatively long time of about 00 ms or more is performed in a unified manner, it is not suitable for applications in which a large number of switchings are simultaneously processed, such as switching of wavelength paths for each session.

According to the present invention, the setting of the wavelength path is changed for each node corresponding to the transfer path of the wavelength path by the dispersion processing, thereby eliminating the need for a highly reliable control network and dispersing the load of the wavelength path setting processing. It is an object of the present invention to provide an optical communication node and an optical communication network that can simultaneously switch a large number of wavelength paths.

[0011]

An optical communication node according to the present invention includes an optical demultiplexer, an optical multiplexer, a spatial optical switch, and a control unit for controlling a spatial optical switch by referring to a routing table. A control signal receiver that receives control light input from the path and outputs transfer path setting information included in the control light, and a control light that includes transfer path setting information to be transferred to the next optical communication node is output to the output path. A control signal transmitter for outputting, and the control unit includes means for switching the connection state of the spatial light switch with reference to the routing table based on the transfer path setting information.

Further, the optical communication node of the present invention includes a wavelength converter for switching the wavelength of each wavelength path before or after the spatial optical switch, and the control unit sets a transfer path output from the control signal receiver. Means for setting a wavelength to be switched by the wavelength converter based on the information may be included.

The optical communication node according to the present invention has a configuration in which the control light and the main signal light have different wavelengths, and the control light demultiplexed by the optical demultiplexer is received by the control signal receiver. The control light transmitted from the signal transmitter is multiplexed by an optical multiplexer.

Further, the control light may include routing table information, and the control unit may include means for rewriting the routing table according to the routing table information. Further, the control light may include synchronization information, and the control unit may include means for establishing synchronization between the optical communication nodes according to the synchronization information.

Further, the control unit of the optical communication node according to the present invention comprises:
When setting a wavelength path by referring to the routing table, if there is no space in the wavelength of the output path of the transfer destination due to the existing wavelength path, the spatial optical switch selects another output path having a space. May be included.

An optical communication network according to the present invention connects an output route and an input route of an optical communication node according to the present invention via a wavelength division multiplexing optical link, and sets a transfer path for control light to which each optical communication node is transferred. The wavelength path is set based on the information.

[0017]

FIG. 1 shows an embodiment of an optical communication network according to the present invention. The optical communication network according to the present invention includes optical communication nodes 1a, 1b, 1c, 1d, 1e, 1
f, wavelength multiplexing optical links 2a, 2b, 2c, 2d, 2e, 2f, 2g connecting these optical communication nodes. The wavelength multiplexing optical link wavelength multiplexes the main signal light and the control light including the transfer path setting information and transmits the multiplexed light. Each optical communication node is configured to have a control unit 19 that performs setting control of a wavelength path according to the transfer path setting information of the control light.

(First Embodiment of Optical Communication Node: Claims 1 and 3) FIG. 2 shows a first embodiment of the optical communication node of the present invention. The optical communication node has an input side optical fiber 11
Optical demultiplexers 13a, 13 connected to a, 11b, 11c
b, 13c, output side optical fibers 12a, 12b, 12c
The optical multiplexers 14a, 14b, 14c connected to the optical multiplexer, the main signal light output port of the optical demultiplexer, the main signal light input port of the optical multiplexer, and the spatial optical switch 17 for connecting the drop port 15 and the add port 16; A control signal receiver 21 for receiving control light including transfer path setting information demultiplexed by the optical demultiplexer;
Spatial optical switch 1 based on the received transfer path setting information
And a control signal transmitter 22 for transmitting control light including transfer path setting information to be transmitted to the next optical communication node on the transfer path to the optical multiplexer.

In the present embodiment, the wavelengths of the control light including the transfer path setting information and the main signal light are different from each other.
Is input to the control signal receiver 21,
The control light output from the control signal transmitter 22 is the optical multiplexer 1
4 are combined.

As the optical demultiplexer 13, a multilayer filter, a bulk type using a diffraction grating, a fiber type using an optical fiber grating, or an arrayed waveguide diffraction grating made of a silica-based optical waveguide on a substrate is integrated. A waveguide type optical component can be used. As the optical multiplexer 14, besides the same optical components as the optical demultiplexer 13, a fiber-type or waveguide-type optical coupler can be used.

The spatial light switch 17 utilizes mechanical, thermo-optic, electro-optic, acousto-optic, optical holography, etc., and is made of a material such as an optical semiconductor, dielectric crystal, glass, polymer, or liquid crystal. Various spatial light switches such as bulk type, fiber type, and waveguide type manufactured by the above method can be used.

Referring now to FIGS. 1, 2 and 3,
A wavelength path setting operation in an optical communication network using the optical communication nodes according to the first embodiment will be described. To set a wavelength path from the optical communication node 1a to the optical communication node 1f via the optical communication nodes 1b and 1c, the optical communication node 1a generates a packet including transfer path setting information, and controls this to control the wavelength λ0. Optical communication node 1 after converting to light
b to the wavelength-division multiplexing optical link 2a connected to b. The optical demultiplexer 13 of the optical communication node 1b demultiplexes the control light having the wavelength λ0, the control signal receiver 21 converts the control light into an electric signal, extracts the transfer path setting information, and the control unit 19 performs the transfer. The spatial light switch 17 is switched according to the path setting information, and the output path of the main signal light is set. The transfer path setting information to be transferred to the next optical communication node 1c is transmitted to the control signal transmitter 2
2 is transmitted to the wavelength multiplexing optical link 2b connected to the optical communication node 1c via the optical multiplexer 14 as control light having the wavelength λ0. Similarly, in the optical communication node 1c, the corresponding path is switched by the spatial optical switch 17, and the control light is transferred to the optical communication node 1f which is the destination node.

According to the above procedure, the transfer path setting information is sequentially transferred by the control light of the wavelength λ 0, and each optical communication node 1
In b and 1c, each spatial light switch 17 is switched based on the transfer path setting information. The optical communication node 1f, which is the destination node, sets the wavelength path from the optical communication nodes 1a to 1f by transferring the ACK information in the order of the optical communication nodes 1c, 1b, and 1a by using the control light having the wavelength λ0.

When the wavelength path is set, the optical communication node 1
The main signal transmitted from the optical communication node 1a to the optical communication node 1f via the optical communication nodes 1b and 1c is converted by the optical communication node 1a into a main signal light having a predetermined wavelength .lambda.1.
The data is forwarded to the optical communication node 1f via a, 2b, and 2e. The setting of the wavelength path is released by transferring the release signal along the wavelength path by using the control light having the wavelength λ0 as in the case of setting the wavelength path.

Next, an operation example of the optical communication node of the present invention will be described with reference to FIG. Main signal light of a maximum of n wavelengths is wavelength-multiplexed on each of the input optical fibers 11a to 11c except for control light including one or more transfer path setting information. In this case, each wavelength multiplexing optical link 2
In a to 2g, a maximum of n wavelength paths can exist simultaneously in the same link. The wavelength multiplexed signal light input from each input side optical fiber is split by the optical splitter 13 for each wavelength, the control light including the transfer path setting information is input to the control signal receiver 21 and the main signal light is input. Is input to the spatial light switch 17.

The control signal receiver 21 converts the control light into an electric signal and extracts transfer path setting information. Control unit 19
Selects a wavelength multiplexed optical link and a wavelength of a transfer destination according to information such as a destination optical communication node, a source optical communication node, and the use state of an optical link based on the transfer path setting information by referring to a routing table. I do. If the wavelength of the wavelength multiplexing optical link of the best transfer destination is full,
A detour routing for selecting another wavelength multiplexed optical link as a transfer destination is performed (claim 6).

The spatial optical switch 17 switches the connection state according to the selected wavelength-division multiplexed optical link and wavelength, and sets a wavelength path to the next optical communication node. The spatial optical switch 17 separates the wavelength path destined for this optical communication node and connects it to the drop port 15, while connecting to the add port 16 and connects the wavelength path destined for this optical communication node as the source. Join. The control signal transmitter 22 includes:
The transfer path setting information is converted into control light of wavelength λ0 again, sent to the optical multiplexer 14 corresponding to the selected wavelength multiplexed optical link, and transferred to the next optical communication node via the wavelength multiplexed optical link.

After setting the wavelength path, when the main signal light of the set wavelength reaches the optical communication node from the input side optical fibers 11a to 11c, it is split by the optical splitters 13a to 13c for each wavelength, and the spatial optical switch is used. The signals are output to predetermined output routes at 17, respectively, and are wavelength-multiplexed by the optical multiplexers 14a to 14c.
Output side optical fiber 12a of selected wavelength multiplexed optical link
To 12c.

In the above, an example has been described in which the control unit 19 does not change the routing table and the control light of the wavelength λ0 is transferred to each optical communication node. This applies only when the routing table is unchanged from the initially set one, or only when the optical communication node replaces or changes the new routing table when it needs to be changed.

However, it is usually desirable to be able to transfer routing table information from one location and change the routing table of the entire network. To this end, a routing table rewriting means is provided in the control unit 19 of each optical communication node (claim 4). Then, by utilizing the fact that the control light having the wavelength λ0 is terminated at each optical communication node as described above, new routing table information or routing table change information and transfer path setting information are multiplexed and transferred to the control light. Thus, the routing table can be changed.

The switching of the connection state of the space optical switch 17 by the control light is a connection setting method by the control light (claim 1). On the other hand, the rewriting of the routing table information by the control light is a method of updating a routing table used for setting a wavelength path (connection) (claim 4). For example, ATM SVC (Swit
In the case of setting a connection as needed, as in the case of (ched Virtual channel), updating the routing table and setting a wavelength path are different functions. Note that AT
In the case of a conventional fixed wavelength path setting such as a PVC (Permanent Virtual Channel) in M, it is necessary to switch the wavelength path at the same time as rewriting the routing table when a failure occurs.

Similarly, a means for performing synchronization control may be provided in the control unit 19 of each optical communication node so that the synchronization signal and the transfer path setting information are multiplexed with the control light of the wavelength λ 0 and transferred. 5). With this, it is possible to uniquely secure bit synchronization between optical communication nodes regardless of the presence or absence or the number of main signal lights to be transmitted and received. Often, an optical communication node can be operated without a synchronization network for synchronizing the optical communication nodes.

As described above, according to the present embodiment, the control signal receiver 21 and the control signal transmitter 2 for transmitting and receiving the control light including the transmission path setting information to each optical communication node.
By providing 2, the wavelength path can be set by dispersion control. Also, by transmitting the control light at a different wavelength from the main signal light, the control light and the main signal light can be separated as they are at the optical communication node, and the main signal light can be converted to an electric signal. Without forwarding to the next node. In addition, call loss due to wavelength path setting failure can be reduced by the detour routing.

(Second Embodiment and Third Embodiment of Optical Communication Node: Claims 2 and 3) FIG. 4 shows a second embodiment of the optical communication node of the present invention. FIG. 5 shows a third embodiment of the optical communication node of the present invention. A feature of the second and third embodiments is that each optical communication node includes a wavelength converter,
This is to enable wavelength conversion for each link for each wavelength path.

That is, in the second embodiment, the wavelength converter 31 is connected to the optical demultiplexers 13a to 13c and the spatial light switch 17
, And each main signal light demultiplexed by the optical demultiplexer is converted into a predetermined wavelength and input to the spatial optical switch 17. In the third embodiment, the wavelength converter 31 is disposed between the spatial optical switch 17 and the optical multiplexers 14a to 14c, and the main signal light output from the spatial optical switch 17 is converted to a predetermined wavelength. Features. Other configurations are the same as those of the first embodiment shown in FIG.

The wavelength converter 31 has a configuration that performs light-to-light wavelength conversion using four-wave mixing of an organic material or an inorganic material, or light-electricity-light conversion using a light receiver and a semiconductor laser. Can be used.

The wavelength path setting operation of the optical communication network using the optical communication nodes according to the present embodiment is basically the same as the wavelength path setting operation according to the first embodiment. That is,
As shown in FIG. 6, each of the optical communication nodes 1a, 1b, 1c,
The wavelength path is set in accordance with the transfer path setting information of the control light of wavelength λ0 to which 1f is transferred. The wavelength converter 31 of each optical communication node further sets the wavelength of the main signal light in the order of λ1, λ2, λ3. The place to switch is different.

Here, an example of setting a wavelength path with wavelength switching will be specifically described with reference to FIG. In the example shown here, the optical communication nodes 1b and 1
f, wavelength-multiplexed optical links 2b and 2e, and a wavelength path (thin solid line) of wavelength .lambda.1 are set.
It is assumed that a wavelength path (broken line) of wavelength multiplexed optical links 2c and 2a and wavelength .lambda. In such a situation, a case where a new wavelength path is set between the optical communication nodes 1a and 1f will be described. However, the wavelength that can be accommodated in the same optical link is up to two wavelengths λ1 and λ2.

Due to the existence of the existing wavelength path and the limitation of the wavelength to be accommodated in the wavelength division multiplexing optical link, the wavelength path between the optical communication nodes 1a and 1f (the wavelength division multiplexing optical links 2a, 2b, 2e).
Cannot be set using the same wavelength. Therefore, the wavelength path sets the wavelength multiplexing optical link 2a to the wavelength λ1.
(Thick solid line), the wavelength division multiplexed optical links 2b and 2e
(Dashed line). That is, in the optical communication node 1b, it is necessary to perform wavelength conversion from the wavelength λ1 to λ2, and the routing table of the control unit 19 is set as shown in FIG.

As described above, when there is an existing wavelength path and a new wavelength path is added, and when the wavelength of the wavelength multiplexed optical link is occupied by the existing wavelength path, the wavelength path of the same wavelength is used. May not be set. However, by appropriately performing wavelength conversion in the optical communication node as in the present embodiment, it is possible to set a new wavelength path while suppressing the influence of the existing wavelength path.

The detour routing in the optical communication node will be specifically described with reference to FIG. In the example shown here, the optical communication nodes 1a and 1
c, wavelength multiplexed optical links 2a and 2b and a wavelength path (thin solid line) of wavelength .lambda.1 are set.
It is assumed that a wavelength path (broken line) of wavelength multiplexing optical links 2b and 2e and wavelength .lambda. In such a situation, a case where a new wavelength path is set between the optical communication nodes 1a and 1f will be described. However, the wavelength that can be accommodated in the same optical link is up to two wavelengths λ1 and λ2.

The wavelength path between the optical communication nodes 1a and 1f (wavelength multiplexed optical links 2a, 2b, 2e) due to the existence of the existing wavelength path and the limitation of the accommodated wavelength of the wavelength multiplexed optical link.
Cannot be set even if the wavelength is converted. Therefore, the wavelength path sets the wavelength multiplexed optical links 2a, 2d, and 2g and the wavelength λ2 (dot-dash line) as detour paths. Here, the routing table of the control unit 19 of the optical communication node 1b is as shown in FIG. That is, from the output setting of the existing part, it can be seen that the wavelength multiplexing optical link 2b has already used the wavelengths λ1 and λ2 and cannot be newly established. In addition, it can be seen that the wavelength multiplexing optical link 2d can be newly used because it is not used.

As described above, when there is an existing wavelength path and a new wavelength path is added, if the wavelength of the wavelength multiplexed optical link is occupied by the existing wavelength path, the wavelength path of the same route is used. May not be set. However, by using another wavelength multiplexed optical link with reference to the routing table as in the present embodiment, a new wavelength path can be set without releasing the existing wavelength path.

[0044]

As described above, the optical communication node and the optical communication network according to the present invention are provided with the control signal receiver and the control signal transmitter, and transfer the transfer path setting information between the nodes so that the exclusive use is possible. A wavelength path can be set and released by distributed control on the same optical communication network without requiring a control network.

Further, the optical communication node and the optical communication network according to the present invention can simultaneously switch a large number of wavelength paths with a small control delay by setting a wavelength path by dispersion control for each node corresponding to a transfer path of the wavelength path. It is possible to

Further, the wavelength division multiplex transmission of the control light including the transfer path setting information and the main signal light at different wavelengths,
The control light can be separated and combined at the same time using the optical demultiplexer and the optical multiplexer that separate and combine the main signal light, and the node configuration can be simplified.

Further, a means for rewriting the routing table and a means for establishing synchronization are provided in the control unit, and the routing table information and the synchronization information are transferred simultaneously with the transfer path setting information. Control can be performed.

Further, by performing wavelength conversion in the optical communication node and setting a wavelength path by changing the wavelength for each optical link, a large number of wavelength paths can be accommodated with a small number of wavelengths. A network can be built. In addition, when a wavelength path is added, an unused wavelength can be easily selected regardless of the wavelength of the existing wavelength path, so that the wavelength path setting process is simplified, and the wavelength path setting delay at the node is reduced. Can be reduced.

Further, by using wavelength conversion and detour routing, an economical optical communication network with small call loss and high wavelength use efficiency can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an optical communication network according to the present invention.

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

FIG. 3 is a diagram illustrating a wavelength path setting operation according to the first embodiment.

FIG. 4 is a block diagram showing a second embodiment of the optical communication node according to the present invention.

FIG. 5 is a block diagram showing a third embodiment of the optical communication node according to the present invention.

FIG. 6 is a diagram illustrating a wavelength path setting operation involving wavelength switching according to the second and third embodiments.

FIG. 7 is a diagram showing an example of setting a wavelength path with wavelength switching.

FIG. 8 is a diagram showing a setting example of detour routing.

FIG. 9 is a block diagram showing a configuration example of a conventional wavelength path network.

FIG. 10 is a block diagram showing a configuration example of a conventional optical communication node.

[Explanation of symbols]

1a, 1b, 1c, 1d, 1e, 1f Optical communication node 2a, 2b, 2c, 2d, 2e, 2f, 2g Wavelength multiplexing optical link 5a, 5b, 5c, 5d, 5e, 5f Optical communication node 6 Control network 11a, 11b, 11c Input side optical fiber 12a, 12b, 12c Output side optical fiber 13a, 13b, 13c Optical demultiplexer 14a, 14b, 14c Optical multiplexer 15 Drop port 16 Add port 17 Space optical switch 18, 19 Controller 21 Control signal Receiver 22 Control signal transmitter 31 Wavelength converter

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seiji Norimatsu 3-19-2 Nishi Shinjuku, Shinjuku-ku, Tokyo Japan Telegraph and Telephone Corporation (72) Inventor Kiyoshi Tanaka 3- 192-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo No. Nippon Telegraph and Telephone Corporation (72) Inventor Shigeki Aizawa 3-19-2 Nishi Shinjuku, Shinjuku-ku, Tokyo Japan Nippon Telegraph and Telephone Corporation (72) Kimio Oguchi 3-9-1, Nishishinjuku, Shinjuku-ku, Tokyo No. Nippon Telegraph and Telephone Corporation F term (reference) 5K002 AA05 BA05 BA06 BA31 DA02 DA09 DA11 EA03 5K069 BA09 CB10 DA03 DA05 DB33 EA22 EA24 EA26

Claims (7)

[Claims] 1. An optical demultiplexer provided corresponding to one or more input routes, an optical multiplexer provided corresponding to one or more output routes, and demultiplexing by the optical demultiplexer. A spatial optical switch connecting the main signal light to the optical multiplexer or the drop port, and connecting the main signal light input from the add port to the optical multiplexer; and connecting the spatial optical switch with reference to a routing table. An optical communication node comprising: a control unit that controls a state; a control signal receiver that receives control light input from the input path and outputs transfer path setting information included in the control light; A control signal transmitter that outputs control light including transfer path setting information to be transferred to the communication node to the output path, wherein the control unit refers to the routing table based on the transfer path setting information. Previous An optical communication node comprising means for switching a connection state of the space optical switch. 2. The optical communication node according to claim 1, further comprising: a wavelength converter for switching a wavelength of each wavelength path at a stage before or after the spatial optical switch, wherein the control unit is output from a control signal receiver. An optical communication node comprising: means for setting a wavelength to be switched by the wavelength converter based on transfer path setting information. 3. The optical communication node according to claim 1, wherein the control light and the main signal light have different wavelengths, and the control light demultiplexed by the optical demultiplexer is received by the control signal receiver. Configuration
An optical communication node having a configuration in which control light transmitted from a control signal transmitter is multiplexed by an optical multiplexer. 4. The optical communication node according to claim 1, wherein the control light includes routing table information, and the control unit includes means for rewriting the routing table according to the routing table information. An optical communication node. 5. The optical communication node according to claim 1, wherein the control light includes synchronization information, and the control unit includes means for establishing synchronization between the optical communication nodes in accordance with the synchronization information. An optical communication node, characterized in that: 6. The optical communication node according to claim 1, wherein the control unit sets a wavelength path by referring to a routing table, and sets an output route of a transfer destination by an existing wavelength path. An optical communication node including means for switching a connection state of a spatial optical switch so as to select another output path having a vacancy when there is no vacancy at the wavelength. 7. An optical communication node according to claim 1, wherein an output path and an input path are connected via a wavelength division multiplexed optical link, and control light is transferred to each optical communication node. An optical communication network having a configuration for setting a wavelength path based on route setting information.