JPH06104845A - Wavelength multiplexed optical communication network - Google Patents

Abstract

PURPOSE:To obtain a network with the same total node number with a fewer wavelength number by linking ring networks having two nodes or over via a coupling means having wavelength distribution confluence performance so as to use the wavelength again. CONSTITUTION:A wavelength lambda1 is allocated for the communication between nodes 1, 2 in a ring network A and the wavelength lambda1 is allocated again for the communication between nodes 3, 4 in a ring network B and between nodes 5, 6 in a ring network C respectively. Then number of total wavelength to be required is 13. The re-use of the wavelength lambda1 is attained by using wavelength distribution confluence coupling means 21, 22. The wavelength used only for the communication between nodes in a ring network is used in common for the wavelength used only for the communication between nodes in other ring network or the wavelength used only for the communication between nodes in plural ring networks is used for the wavelength used only for the communication between nodes in other plural ring networks and then the re-use of the wavelength is attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wavelength division multiplexing optical communication network using a wavelength division multiplexing optical transmission system for performing communication between nodes by using lights of different wavelengths.

[0002]

2. Description of the Related Art As a configuration of an optical communication network using the wavelength division optical multiplex transmission system, there is a ring network in which a plurality of nodes are connected by an optical fiber in a ring shape. FIG. 3 is a diagram showing the structure of such a ring network, which is described in the literature ("A Wavelen
gth Routing Approach ToOptical Communications Netw
arks ", GRHill, Br Telecom Technol J, Volume 6, Volume 3
No., July 1988, pp24-31) is a simplified representation of the ring network.

In the figure, 1 to 6 are nodes for communicating with each other. The nodes 1 and 2 are optical fibers 31, the nodes 2 and 3 are optical fibers 32, and
The nodes 3 and 4 are connected by an optical fiber 33, the nodes 4 and 5 are connected by an optical fiber 34, the nodes 5 and 6 are connected by an optical fiber 35, and the nodes 6 and 1 are connected by an optical fiber 36. There is.

A bidirectional communication path whose address is light wavelength information is multiplexed in an optical fiber connecting the nodes 1 to 6. That is, for example, wavelengths are assigned as shown in Table 1.

[0005]

[Table 1]

Table 1 shows λ _1-
It indicates that λ ₁₅ is assigned, and bidirectional communication between nodes is possible with a total of 15 waves.

[0007]

Since the conventional ring-shaped wavelength division multiplexing optical communication network is constructed as described above, it is necessary to allocate N (N-1) / 2 wavelengths to the number N of nodes. . Therefore, when the number of nodes increases, the required number of wavelengths becomes several tens or more, but in such a case, an advanced wavelength division technique within the low loss band of the optical fiber is required. Therefore, there is a problem that it is necessary to keep the number of required wavelengths as low as possible.

Therefore, an object of the present invention is to provide a wavelength division multiplexing optical communication network capable of reducing the number of wavelengths required for bidirectional communication with respect to the number of nodes as compared with the conventional case.

[0009]

In a wavelength division multiplexing optical communication network according to the present invention, a plurality of nodes are assigned to any one of a plurality of ring networks which will have two or more nodes, and each ring network is an optical network. Each node is interconnected in a ring shape by a link and is coupled to an adjacent ring network by a coupling means capable of distributing and merging light of an arbitrary wavelength. The coupling means sends the light of the wavelength addressed to the node in one ring network among the multiplexed lights of each ring network to the one ring network, and sends the light of the other wavelengths to the other ring networks.

[0010]

Since each ring network in the present invention is coupled to the adjacent ring network by a coupling means having wavelength distribution and wavelength merging properties, wavelengths used only for communication between nodes in a ring network are The wavelength used only for communication between nodes in the ring network, or the wavelength used only for communication between nodes in one ring network, between the nodes in other ring networks It becomes possible to reuse the wavelength that is shared with the wavelength that is used only for.

[0011]

1 is a block diagram showing the structure of a wavelength division multiplexing optical communication network according to an embodiment of the present invention. According to the present invention, the network has a configuration in which a plurality of ring networks each having an arbitrary number of two or more nodes are coupled via coupling means capable of wavelength distribution and wavelength merging. In this embodiment, the total number of nodes is 6, and there are 3 node groups each having 2 nodes (ring networks A, B, C).
The network in which the are connected is shown.

In FIG. 1, the ring network A and the ring network B are coupled by the coupling means 21, and the ring network B and the ring network C are coupled by the coupling means 22. That is, ring network A
Are nodes 1 and 2, an optical fiber 7 arranged between them, a coupling means 21 having a wavelength distribution / merging property, and a node 1.
And an optical fiber 82 connecting the node 2 and the coupling means 21. The ring network B connects the nodes 3 and 4, the optical fiber 91 connecting the node 3 and the coupling means 21, the optical fiber 92 connecting the coupling means 21 and the node 4, and the coupling means 22 and the node 3. It is composed of an optical fiber 101 and an optical fiber 102 connecting the node 4 and the coupling means 22. The ring network C includes the nodes 5 and 6, the optical fiber 13 arranged between them, the optical fiber 111 that connects the node 5 and the coupling means 22, and the optical fiber that connects the coupling means 22 and the node 6. It is composed of 112.

In such a network, wavelengths are assigned as shown in Table 2, for example.

[0014]

[Table 2]

That is, λ ₁ is assigned to the communication between the node 1 and the node 2 in the ring network A, and further, between the node 3 and the node 4 in the ring network B and the node in the ring network C. Λ ₁ is reassigned between the node 5 and the node 6. Therefore, the total number of wavelengths required is 1.
It becomes 3.

The wavelength λ ₁ can be reused by using the wavelength dividing / merging coupling means 21 and 22. FIG. 2 is a block diagram showing the configuration of such a coupling means. Considering the case where the coupling means shown in FIG. 2 is installed as the coupling means 21 in FIG. 1, the multiplexed lights λ _{1 to} λ ₉ in the ring network A enter the wavelength distributor 14 via the optical fiber 41.

Then, in the wavelength distributor 14, the light having the wavelength λ ₁ required only for communication between the nodes in the ring network A and the wavelength λ required for communication between the ring networks A and B and between the ring networks A and C.
The light of wavelength λ ₁ is divided into the light of wavelength _{2 to} λ _9.
5, light of wavelengths λ _{2 to} λ ₉ is sent to the fiber 48.

On the other hand, the multiplexed light λ in the ring network B₁~ Λ
₁₃Is input to the wavelength distributor 15 via the fiber 43.
Required for communication between ring networks A-B and between ring networks A-C
Wavelength λ ₂~ Λ₉Light and communication between nodes in ring network B
Wavelength λ required only for₁Light and communication between ring networks B-C
Wavelength λ required for communication_Ten~ Λ₁₃Of light. That
For communication between ring networks A-B and ring networks A-C.
The required light is on the fiber 46 and only for communication within the ring network B.
The required light and the light required for communication between ring networks B-C are
Sent to Iba 47.

[0019] Wavelength converging device 16, by sending joins the light of the wavelength lambda ₂ to [lambda] ₉ from the wavelength lambda ₁ of the light and fiber 46 from fiber 45 to fiber 42, multiple light lambda ₁ to [lambda] ₉ is sent to ring network A. In addition, the wavelength multiplexer 17
Are combined with the light of wavelengths λ _{2 to} λ ₉ from the fiber 48 and the light of wavelengths λ ₁ and λ _{10 to} λ ₁₃ from the fiber 47 and are sent to the fiber 44, whereby the multiplexed lights λ _{1 to} λ ₁₃ are transmitted. To the ring network B. As a result, ring network A and ring network B
Can be coupled with while reusing the wavelength λ ₁ .

The ring network B and the ring network C can be connected by the connecting means shown in FIG. Considering the case where the coupling means shown in FIG. 2 is installed as the coupling means 22 in FIG. 1, the multiplexed lights λ _{1 to} λ ₁₃ in the ring network B enter the wavelength distributor 14 via the optical fiber 41.

Then, in the wavelength distributor 14, light having a wavelength λ ₁ required only for communication between nodes in the ring network B and light having wavelengths λ _{2 to} λ ₅ required for communication between the ring networks A and B are used. The light having wavelengths λ _{6 to} λ ₁₃ necessary for communication between the ring networks A and C and between the ring networks B and C is divided into light beams having wavelengths λ _{1 to} λ _{5 in} the fiber 45 and wavelengths λ _{6 to} λ _13. Light is sent to the fiber 48.

On the other hand, the multiplexed lights λ ₁ and λ ₆ in the ring network C
λ ₁₃ is input to the wavelength distributor 15 via the fiber 43. Therefore, it is divided into light of wavelengths λ _{6 to} λ ₁₃ necessary for communication between the ring networks A and C and light of wavelength λ ₁ necessary only for communication between nodes in the ring network C. To be Light required for communication between the ring networks A and C and between the ring networks B and C is sent to the fiber 46, and light required only for communication within the ring network C is sent to the fiber 47.

The wavelength combiner 16 has the wavelengths λ _{1 to} λ ₅ from the fiber 45 and the wavelengths λ _{6 to} λ ₁₃ from the fiber 46.
By merging with the light of and sending out to the fiber 19,
The multiplexed lights λ _{1 to} λ ₁₃ are sent to the ring network B. The wavelength combiner 17 joins the light having the wavelengths λ _{6 to} λ ₁₃ from the fiber 48 and the light having the wavelength λ ₁ from the fiber 47 to combine them.
4 to send the multiplexed lights λ ₁ , λ _{6 to} λ ₁₃ to the ring network C. As a result, ring network B and ring network C
Can also be combined with while reusing the wavelength λ ₁ .

Although the number of nodes in this embodiment is 6, if the total number of nodes is 4 or more, a plurality of node groups having 2 or more nodes can be arbitrarily constructed and the connecting means shown in FIG. 2 is used. As a result, the wavelength can be reused without fail. That is, it is possible to reduce the number of required wavelengths as compared with the conventional network.

[0025]

As described above, the optical communication network according to the present invention has a structure in which the ring network having two or more nodes is connected through the connecting means having wavelength distribution / merging. Since wavelengths can be reused, there is an effect that a network having the same total number of nodes can be realized with a smaller number of wavelengths as compared with the conventional wavelength division multiplexing optical communication network.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of a wavelength division multiplexing optical communication network according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a wavelength distribution / merging coupling means.

FIG. 3 is a configuration diagram showing a configuration of a conventional wavelength division multiplexing optical communication network.

[Explanation of symbols]

 1 to 6 nodes 14,15 wavelength distributor 16,17 wavelength combiner 21,22 coupling means

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Claims (1)

[Claims] 1. An optical link comprising a plurality of nodes, each node transmitting an optical signal of a predetermined wavelength when transmitting to a specific node, and multiplexing and transmitting one or a plurality of optical signals between the nodes. In the WDM optical communication network interconnected with each other, the plurality of nodes are assigned to any one of a plurality of ring networks, each of which interconnects two or more nodes in a ring shape. Between adjacent ring networks, among the multiplexed lights of each ring network, the light of the wavelength addressed to the node in one ring network is transmitted to one ring network, and the light of the other wavelengths is transmitted to the other ring network. A wavelength division multiplexing optical communication network, characterized in that a coupling means for transmitting to the optical fiber is provided.