JPH01109991A - Wavelength split exchange system - Google Patents

Abstract

PURPOSE:To contrive to attain the connection function of 1:m and m:1 by connecting 3 stages of switch nodes comprising a wavelength conversion switch, an optical switch, a multiplexer and a demultiplexer by a link. CONSTITUTION:In giving information A (wavelength lambda1) and information B (wavelength lambda2) from an incoming highway #1 and outputting them to the A (wavelength lambda1) and B (wavelength lambda2) of the outgoing highway #1 and the A (wavelength lambda1) and the B (wavelength lambda2) of the highway #2 respectively, at first they are demultiplexed by a demultiplexer B of a switch node SN1 and the result is given to a wavelength conversion switch W. Then prescribed wavelength conversion is applied by the control of a control memory M and the signal subject to wavelength multiplex is outputted to the SN2 from the multiplexer G via the optical switch S. Thus, the memory M seeks an idle route to provide the signal and it is outputted at a prescribed wavelength to a prescribed outgoing highway. Thus, the internal link of the switch circuit network of each stage is used through wavelength multiplex to attain 1:many or many:1 connection.

Description

[Detailed Description of the Invention] [Summary 1] Regarding a wavelength division switching system that wavelength-division-exchanges signals that are wavelength-multiplexed and input from an incoming highway and outputs them to an outgoing highway, it is possible to perform one-to-many connection. The purpose of the wavelength division switching system is to realize a wavelength division switching system in which a signal with wavelength multiplicity m is received from an input highway, wavelength division exchanged, and outputted to an output highway. Each switch node of the tertiary node is provided in three stages, and these switch nodes are connected by a link. Each switch node is composed of a wavelength conversion switch, an optical switch, a multiplexer, and a demultiplexer, and switching is performed using control memory. The primary switch node and the secondary switch node are controlled one-to-one and one-to-one.
The connection function is configured such that each of the tertiary switch nodes is provided with a one-to-l connection function, and internal links are used by wavelength multiplexing.

[Industrial Field of Application] The present invention relates to a wavelength division switching system that performs wavelength division switching on intersecting signals that are wavelength-multiplexed and input from an incoming highway and outputs them to an outgoing highway.

In switching networks that handle information at various speeds, such as telephone, data, and image, the information for each speed is wavelength-multiplexed into signals of different wavelengths and sent. Conventionally, such wavelength-multiplexed signals could only be exchanged on a one-to-one basis. For this reason, there is a demand for an exchange system with a high degree of freedom that allows one-to-many exchange.

[Prior Art] FIG. 4 is a diagram showing the configuration principle of a conventional system. Each of the primary, secondary, and tertiary nodes has a 3×3 blockage3. 3 of switch node SN that performs switch exchange of output 3
It has a tiered structure.

Then, there is a primary link between the primary node and the secondary node, and the 2nd
The next node and the tertiary node are each connected by a secondary link. On the incoming highway, a plurality of pieces of information are modulated with different wavelengths for each type of information, and these plurality of wavelengths are wavelength-multiplexed. The entrance highway (hw) side is λ1 to λ from highways #1 to #3, respectively.
3 wavelength-multiplexed information enters, and wavelength-multiplexed information λ1 to λ3 exits from highways #1 to #3 from the exit highway side. On the outbound highway, it is separated by wavelength and only contains specific information.

Each switch node SN is composed of a wavelength conversion switch that converts the wavelength, a multiplexer and a demultiplexer that switch the spatial position of the highway, and transfers information coming from a plurality of incoming highways from the control memory M. Data is exchanged by switching according to applied signals. Now, if we assume that information A coming in at λ1 on the first incoming highway #1 is switched to wavelength λ3 on the third outgoing highway #3 and sent out, the route that information A passes is, for example, the thick line in the diagram. It will look like the line shown.

FIG. 5 is a configuration block diagram showing an embodiment of a conventional system, and is a concrete example of the principle diagram shown in FIG. 4. Each switch node SN in FIG.
From the wavelength conversion switch WO and the demultiplexer B, the tertiary nodes are each composed of a multiplexer G and a wavelength conversion switch Wo.

The wavelength conversion switch circuit W o is composed of a demultiplexer 8, three wavelength conversion switches W, and a multiplexer G, as shown in FIG. As shown in FIG. 7, the wavelength conversion switch converts the signal train A of wavelength λ1, for example.

By receiving control light of wavelength λ2 in response to signals B, C, ..., the signal trains A, B of wavelength λ2 are generated from the output.
, C, . . . and is an existing technology. Control of wavelength conversion by these wavelength conversion switches W is performed by a control memory M.

[Problems to be Solved by the Invention] In the conventional system shown in Figures 4 and 5, each link is determined for each wavelength, so one piece of information that comes in from the incoming highway is transmitted from the outgoing highway. You could only exit from one exit. In other words, conventionally, one-to-one conversion was possible, but one-to-many broadcast distribution like CATV was not possible.

The present invention has been made in view of these points, and
The purpose is to provide a wavelength division switching system that enables one-to-many connections.

Means for Solving Problem E 1 FIG. 1 is a block diagram of the principle of the present invention. System G,
It has a three-stage configuration of t1, next node, secondary node, and tertiary node, and the switch nodes SN1. Three stages of SN2 and SN3 are provided. These switch nodes constitute an optical switch matrix of 3 inputs x 3 outputs. 1
The next node and the secondary node are connected by a primary link, and the secondary node and the tertiary node are connected by a secondary link.

Switch node SN1 constituting the primary node is branching filter B
, a wavelength conversion switch W, an optical switch S, and a multiplexer G, and constitutes a secondary node.
is composed of a multiplexer G1 demultiplexer BB, a wavelength conversion switch W, an optical switch S, and a multiplexer G, and a switch node SN3 that constitutes the tertiary node is a multiplexer G9 demultiplexer B, and an optical switch S1 multiplexer. It consists of a wavelength conversion switch W, a wavelength conversion switch W, and a multiplexer G. With this configuration, the primary switch node SNI and the secondary switch node SN2 have wavelength multiplicity m
In the case of (3 in the example of the figure, λ1 to λ3), 1
Tertiary switch node SN3 performs pair-to-one and m-to-one connection functions.
has a one-pair connection function. Each switch node is controlled by a control memory M.

[Function] As shown in Fig. 1, information A comes in from the incoming highway #1 at a wavelength λ1, and information B comes in at a wavelength λ2. B to λ1 of highway #2, A to λ3, λ of highway #3
Consider outputting A to λ1 and A to λ3.

The control memory M controls the switching of each switch node according to predetermined conditions. In the conventional system shown in Figure 4, the internal links between the switch nodes at each stage are allocated for each wavelength, so multiple pieces of information that enter one input highway are sent to two separate channels.
I could only exit to the next node. Therefore, in the present invention, the primary and secondary nodes are configured such that 1:n11 and m:1.3 tertiary nodes can be connected 1:m. As a result, each internal link is connected as shown by the thick solid line.
Point-to-many communication is realized.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a block diagram showing an embodiment of the present invention. This embodiment is a concrete representation of the principle diagram in FIG. 1, and the same parts as in FIG. 1 are designated by the same reference numerals. In this example, as in the case of Figure 1, the incoming highway #
1. Information A that comes in at wavelength λl is exit highway #1
λ1. Information B coming in at λl of #2, λ1 of #3, and the wavelength λ2 of the incoming highway #1 is transmitted to the outgoing highway #1.
It shows how they are distributed to λz of #1 and λ3 of #2, respectively. In the following explanation, the route through which the signal flows is shown with a thick line.

Information A of wavelength λ1 and information B of wavelength λ2 coming from the first incoming highway #1 enter the first stage switch node SN1. First, λ! at branching filter B! , λ2° and λ3, and enter the respective wavelength conversion switches W. Here λ1 is λ
1, λ2 is directly wavelength-converted to λ2. The output of each wavelength conversion switch W is branched into three, and enters an optical switch S provided in each branch path. As shown in FIG. 3, the optical switch S receives the control light, switches the branching destination of the light into two directions, and turns on only a specific direction.

All three optical switches S that receive wavelength λ1 are turned on,
Of the optical switches S receiving the wavelength λ2, only the lower switch is turned on (hereinafter, the optical switches S that are turned on are indicated by diagonal lines). Three multiplexers G placed after the optical switch S
The outputs of the optical switches S at each stage are input to all of them.

And the upper row.

Information A of λ1 (hereinafter referred to as λ1/A) is input to the middle multiplexer G, and λr/A and λ2/B are input to the lower multiplexer G. Such wavelength conversion control and switch control of the optical switch S are controlled by the control memory M (the same applies hereinafter). Then, λs/A from the upper multiplexer G, 21/A from the middle multiplexer G, λI/A, λ2/B from the lower multiplexer G,
are output respectively.

Among these outputs, the output λ1/A of the upper stage multiplexer G enters the upper stage secondary switch node SN2.

Upper, middle, and lower stage signals from the primary node enter the multiplexing WG of the switch node SN2, but no signals are output from the middle and lower stage switch nodes SN1. Therefore,
In this case, only one signal, λl/A, enters the multiplexer G. This signal is separated by the subsequent demultiplexer B and enters only the wavelength conversion switch W in the upper stage. The wavelength conversion switch W is λ
1 input is output as is as a λ1 signal. The output λ+/A of this wavelength conversion switch W is the upper optical switch S.
The signal passes through only the multiplexer G in the upper stage and is output only from the multiplexer G in the upper stage.

Signal λ1/A entering middle stage secondary switch node SN2
passes through multiplexer 09 and demultiplexer B to the upper wavelength conversion switch W.
It is entered only in This wavelength conversion switch W also outputs this λl/A as it is without performing wavelength conversion. This λl/
A passes only through the middle optical switch S, and passes through the middle optical multiplexer G.
Output from only.

The lower secondary switch node SN2 has λ1/A and λ2.
A superimposed signal of the two signals of /B is input.

This input signal passes through a multiplexer G and enters a demultiplexer B, where the demultiplexer B separates λl and λ2. λl/A enters the wavelength conversion switch W in the upper stage and is output as a signal as it is. On the other hand, λ2/B enters the wavelength conversion switch W in the middle stage and is output as a signal as is. The output λ+/A of the wavelength conversion switch W in the upper stage passes through the optical switch S in the lower stage and enters the multiplexer G in the lower stage. The output λ2/B of the wavelength conversion switch W in the middle stage passes through the optical switches S in the upper and middle stages, and enters the multiplexer G in the upper and middle stages, respectively. As a result, from the lower secondary switch node SN2,
Signals are output from the multiplexers G in the upper, middle, and lower stages, with λ2/B from the upper stage, λ2/B from the middle stage, and λi/A from the upper stage.
becomes.

Next, the tertiary node will be explained. 2t/A and λ2/B enter the upper tertiary switch node SN3. After these signals are multiplexed by a multiplexer BG, they enter a demultiplexer B where they are separated into λ1 and λ2. Of these, λ1/A
passes only through the upper optical switch S and enters the upper multiplexer G. λ2/B passes only through the middle optical switch S and enters the middle multiplexer G. The output λ1/A of the upper stage multiplexer G enters the wavelength conversion switch W and is output as is and then enters the multiplexer G. The output λ2/B of the middle stage multiplexer G enters the wavelength conversion switch W and is output as is. It is output and enters multiplexer G.

The multiplexer G is λ! /A and λ2/B, multiplexes these signals, and outputs a wavelength-multiplexed signal of λ1 and λ2.

Next, λ1/A and λ2/B enter the middle stage tertiary switch node SN3. After these signals are multiplexed by a multiplexer G, they enter a multiplexer B and are separated into λl and λ2 by the multiplexer B. Of these, λ1/A passes only through the upper optical switch S and enters the upper multiplexer 21iG. λ2/B passes only through the lower optical switch S and enters the lower multiplexer G. The output λ1/A of the upper multiplexer G enters the wavelength conversion switch W, is output as it is, and enters the multiplexer G. On the other hand, the output λz/B of the multiplexer G in the lower stage enters the wavelength conversion switch W and undergoes wavelength conversion. That is, the wavelength λ2 is converted to the wavelength λ3. Then, the output λ of this wavelength conversion switch W
s/B enters multiplexer G.

The multiplexer G receives λ1/A and λ3/B, combines them, and outputs a wavelength-multiplexed signal of λ1 and λ3.

Next, only λ1/A enters the lower tertiary switch node SN3. This signal passes through a multiplexer G, enters a demultiplexer B, and is separated by the demultiplexer B. The output λ1/△ passes through the upper and lower optical switches to the upper and lower multiplexer G.
to go into. The output λ1/A of the upper multiplexer G enters the wavelength conversion switch W, is output as it is, and enters the multiplexer G. On the other hand, the output λs/A of the lower stage multiplexer G enters the wavelength conversion switch W and undergoes wavelength conversion. In other words, the wavelength λ1 is converted to the wavelength λ3. Then, the output λ3/A of this wavelength conversion switch W enters the multiplexer G.

The multiplexer G receives λs/A and λs/A, combines them, and outputs a wavelength-multiplexed signal of λ1 and λ3.

Above, the signal λ coming in from the first incoming highway #1
1/A, λ2/B to the first exit highway #1
A, λz/B to the second exit highway #2, λl/
A, λs/B to the third exit highway #3
The case where 1/A and λ3/A are respectively switched and wavelength converted and outputted has been described in detail. Here, the route through which the signal passes is not limited to the solid line in the figure, and various routes can be taken. That is, when an input signal is received, the control memory M searches for an empty route and inputs the signal to that route. In other words, according to the present invention, if there is an empty link, it is possible to enter it without fail.

[Effects of the Invention] As explained in detail above, according to the present invention, one-to-many connections can be achieved by wavelength multiplexing the internal links of the switch network at each stage, which were previously assigned to each wavelength. A wavelength division switching system can be provided that can enable.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the principle of the present invention, Fig. 2 is a block diagram of a configuration showing an embodiment of the present invention, Fig. 3 is a conceptual diagram of optical switch operation, Fig. 4 is a diagram of the principle of construction of a conventional system, and Fig. 5 FIG. 6 is a block diagram showing the configuration of an embodiment of a conventional system, FIG. 6 is a diagram showing the configuration of a wavelength conversion switch circuit, and FIG. 7 is a conceptual diagram of the operation of the wavelength conversion switch. In Figure 1, SN1 is the primary switch node, SN2 is the secondary switch node, SN3 is the tertiary switch node, G is the multiplexer, B is the demultiplexer, W is the wavelength conversion switch, S is the optical switch, and M is the optical switch. Control memory.

Claims (1)

[Claims] In a wavelength division switching system that receives a signal with wavelength multiplicity m from an incoming highway, performs wavelength division switching and outputs the signal to an outgoing highway, switch nodes include a primary node, a secondary node, and a tertiary node. (SN1), (SN2), and (SN3) are provided in three stages each, and these switch nodes are connected by links, and each switch node includes a wavelength conversion switch (W), an optical switch (S), and a multiplexer ( G) and a duplexer (B), the switching is controlled by the control memory (M), and the primary switch node (SN1) and the secondary switch node (SN1) are connected.
SN2) is equipped with a 1-to-m and m-to-1 connection function, and the tertiary switch node (SN3) is equipped with a 1-to-m connection function, and the internal links are configured to be wavelength-multiplexed. wavelength division switching system.