JP3069207B2 - Optical ATM communication path - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication path of an optical switching system and a means used therefor, and more particularly to an optical AT for switching control of fixed-length packets as optical signals in accordance with routing information.
M (Asynchronous Transfer Mo)
de) The present invention relates to an exchange type communication path and means used for the same.

[0002]

2. Description of the Related Art Conventionally, an optical ATM communication path has been proposed as an "ultra-high-speed optical ATM switch using an output buffer" (Research Institute for Switching Systems, SSE90-83, P7-
12, Masato Tsukada, Yoshihiro Shimazu). This optical ATM communication path is composed of a cell coder, a star coupler, a cell selector, a buffer, and a cell coder. First, the information field in the cell coder is speeded up using ultrashort optical pulses.
By converting the header into an optical signal by direct modulation of a laser diode (hereinafter referred to as LD), an ultra-high-speed optical information field cell and a low-speed optical header cell are generated. They are wavelength-multiplexed in time synchronization, and then time-division cell-multiplexed by a star coupler to generate an ultra-high-speed optical highway. Next, in the cell selector, only the cells matching the addresses of the respective outputs are extracted from the highway, subjected to throughput control by the buffer, and converted into electric signals by the cell coder.

[0003]

However, in the above-mentioned conventional optical ATM communication path, signals in a wavelength multiplexed state cannot be input / output to / from a highway of the communication path. Therefore, it is impossible to perform wavelength switching for switching the wavelength of a cell in a communication path. Furthermore, in order to execute wavelength switching, devices such as a variable wavelength selection element and a variable wavelength conversion element have to be used, and complicated control for controlling this element is required. The present invention has been made in view of the above problems, and has a simple structure that enables a wavelength-division multiplexed signal to be input to an ATM communication path and that can perform wavelength switching without requiring a variable wavelength conversion element or a variable wavelength selection element. It is intended to provide an optical ATM communication path.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an optical communication path according to the present invention resolves one cell on the time axis with respect to an input signal in which a plurality of cells are wavelength-multiplexed on the same time. A plurality of partial cells, a multiplexing unit that wavelength-multiplexes the plurality of partial cells constituting the one cell on the same time, and a temporal order of the wavelength-multiplexed cells as the partial cells. On the same highway, an optical switch matrix for spatially switching a plurality of highways connected to respective outputs of the order changing means, and a means for spatially switching the highways. While fixedly assigning wavelengths to the cells on the connected output highway in accordance with their time order, a plurality of cells are split from a state where partial cells are wavelength-multiplexed on the same time. Comprises a separation unit is a means for returning to the state where the wavelength-multiplexed onto one hour.

[0005]

The multiplexing unit converts a state in which a plurality of cells are wavelength-multiplexed on the same time into a state in which a partial cell of one cell is wavelength-multiplexed on the same time. Will be possible. After the cells output by the multiplexing unit are switched in time order by a time switch, the highway is switched by an optical switch matrix, and the wavelength is fixed to the cell according to the output order in which the time switch outputs the cells in the separation unit. Allocate and return to a state where multiple cells are wavelength multiplexed at the same time from a state where wavelength division multiplexing of partial cells is performed at the same time.Wavelength switching within the communication path by controlling the cell output order of the time switch buffer Will be able to do.

[0006]

FIG. 1 is a conceptual diagram showing one embodiment of an optical communication path according to the present invention. The ATM communication path 1 of the present invention is an optical ATM communication path for exchanging communication information in the form of an optical signal in accordance with routing information using fixed-length packets (cells). Each cell of the wavelength-multiplexed input signals 21 and 22 is divided into a plurality of partial cells Cnm, the plurality of cells are time-multiplexed, and the plurality of partial cells of each cell are wavelength-multiplexed on the same time. Multiplexing units 311 and 312 that output first intermediate signals 31 and 32 and cells obtained by wavelength-multiplexing partial cells of the respective cells on the same time are input, and the time between cells that are wavelength-multiplexed as the partial cells Same way highway 39
1, 392 for switching to second intermediate signals 41, 42 to form second intermediate signals 41, 42; and 341 for spatially switching a plurality of highways connected to respective outputs of the sequence switching means. An exchange control unit 38 for controlling the operations of the order changing means and the means for spatially switching.
2 and the cells of the third intermediate signals 51 and 52, which are output on the output highways 351 and 352 connected to the means for spatially switching highways, are fixed in wavelength according to their temporal order. Output signals 61 and 62 in a state in which a plurality of cells are wavelength-multiplexed in the same time from a state in which partial cells are wavelength-multiplexed in the same time while assigning
361.

An input signal 21 composed of cells C1, C2, and C3 and a signal 22 composed of cells C4, C5, and C6, which are wavelength-multiplexed at wavelengths λ1, λ2, and λ3, are input to input terminals 301 and 302, respectively. Each of the cells C1 to C6 is divided into partial cells C11 to C13,
.., C61 to C63. Multiplexing units 311 and 3
Reference numeral 12 denotes an input signal 2 input to each of the input terminals 301 and 302.
1,2,22 wavelength multiplexed cells C1 to C3, C4 to C6
Are wavelength-separated for each of the wavelengths λ1, λ2, λ3, and the partial cells C11 to C11 are serially arranged for each of the wavelength-separated cells.
C13,..., C61 to C63 are serial-parallel-converted into a parallel array, the individual cells are time-multiplexed, and the partial cells of the individual cells are fixedly assigned to the wavelengths ω1, ω2, ω3 and wavelength-multiplexed. It is output to the highways 391 and 392 as 1 intermediate signals 31 and 32. Time switch 321,
322 receives the wavelength-multiplexed partial cells of the first intermediate signals 31 and 32 from the highways 391 and 392, and exchanges the routing information written in the cell header with the exchange control unit 382.
Send to The exchange control unit 382 calculates, from the routing information,
An optical switch matrix 341 composed of a space-division type optical switch, which is a means for spatially switching a plurality of highways, switches a path and sends a destination highway to which cells are to be transmitted, and a wavelength to be output from the separation units 361 and 362 for each cell. The time switches 321 and 322 are controlled so as to output the cells while performing time switching while managing to prevent cell collision between the time switches 321 and 322 and the optical switch matrix 341. Switch.

The time switches 321 and 322 are connected to the first intermediate signals 31 and 321 input from the highways 391 and 392, respectively.
32 functions as an order changing means for rearranging the temporal order between cells based on the header information and outputting the same as second intermediate signals 41 and 42 to the optical switch matrix 341. The optical switch matrix 341 is a highway 39
The cells of the second intermediate signals 41 and 42 input from the first and second cells 392 and 392 exchange the communication paths based on the respective header information, and the third intermediate signals 51 and 42 are output to the output side highways 351 and 352.
52 and functions as a means for spatially switching the highway. The third intermediate signals 51 and 52 are time-multiplexed with the partial cells each time they are separated by the demultiplexers 361 and 362, and are converted into wavelengths corresponding to the respective slits and output as wavelength-multiplexed output signals 61 and 62. End 371,3
72. Here, in the demultiplexing units 361 and 362 in the optical communication path according to the present invention, wavelength multiplexing of cells is configured to allocate wavelengths according to the order in which time switches output cells. In other words, if the time switches 321 and 322 output the cells in an order corresponding to the wavelength assigned when the cells are wavelength-multiplexed by the separation units 361 and 362 based on the routing information in the cell header, the wavelength switching is performed. I can do it.

The exchange control will be described in more detail with reference to an example shown in Table 1. Table 1 shows the relationship between the input state of each cell of the input signals 21 and 22, the contents of the header information of each cell, and the output of the buffer.

[Table 1] Cells C1, C2, and C3 are input to input terminal 301 after being wavelength-multiplexed at wavelengths λ1, λ2, and λ3, respectively.
02, cells C4, C5, and C6 have wavelengths λ1 and λ, respectively.
2, wavelength multiplexed by λ3 and input. The header information of each cell includes information on a destination highway whose path is switched by the optical switch, information on a wavelength to be output, and information on an output priority. As for the output of the buffer of the time switch, the switching control section 382 determines the slot order Sn based on the information on the wavelength to be output in the header information, and determines the output period Fn based on the information on the priority. First, an input buffer type optical AT for changing a time slot that functions as an order changing means.
The order in which cells are output from the time switches 321 and 322 made of M will be described. The number of time slots Sn is provided corresponding to the number of wavelengths λn output from the separation units 361 and 362. If the wavelength to be output from the separation units 361 and 362 is λ1, the time slot is S1, if the wavelength to be output is λ2, the order is S2, and if the wavelength to be output is λ3, the order is S3. I can decide. In the time slot, a plurality of periods Fn are provided based on the number of input highways (in this embodiment, S1, S2, S3
Constitutes one cycle, and the number of cycles is two). Increasing the degree of wavelength multiplexing of the intermediate signals 31, 32,..., 51, 52 as compared with the degree of wavelength multiplexing of the input signals 21 and 22, that is, increasing the degree of division of each cell into partial cells. Thus, the period Fn can be set to a predetermined number of periods.

In the example of Table 1, the time switches 361, 36
The period of the time slot output from the second
The wavelength to be output from λ1,362 is λ2 in cell C
Since there are only three cells, the output of the cell C3 from the time switch 321 is first determined as the order S2 of the cycle F1. Next, the wavelength to be output from the separation units 361 and 362 is λ1
Are cells C4 and C6, and cell C4
4. Since both the cells C6 are output from the time switch 322, the time slots output from the time switch 322 are both S2, and the time slots overlap. It is necessary to delay and output from the time switch 322. In this case, which cell is output first with priority is determined by the priority of the cell in the cell header. That is, if the priority of the cell is high, it is not desirable to delay the cell, so that the cell is output with priority. If the priority of the cell is low, some delay is allowed, and it is possible to wait for the cell. Delay. In Table 1, since the cell C4 has a higher priority, the cell C4 is preferentially output in the order S1 of the cycle F1, and the cell C6 is output in the order S1 of the cycle F2 delayed by one cycle. In addition, the separation unit 361,
The wavelength to be output from 362 is λ3 in cells C1,
Cell C2 and cell C5, and the time slot is determined to be S1, but both cells C1 and C2 are time switches 3
21, the cell C2 having the higher priority is output from the time switch 321 at the period F1.
The time switch 3 in the cycle F2 in which the time for the frame is sent.
21 from the buffer. Since the cells C5 and C2 are output from different time switches, and the switching highways are also different, the cell C5 can be output with the same period F1 as the cell C2. In this embodiment, since only the cells C1 to C6 are described, the period F1 or the period F
2, there are vacancies, but cells following the cells C1 to C6 actually fill these vacancies. The cell whose highway has been switched by the optical switch matrix 341 is input to the separation units 361 and 362, and the separation units 361 and 362
Separates the wavelength-multiplexed partial cells output from the optical switch matrix 341 into individual partial cells, converts the partial cells of individual wavelengths into serial / parallel, then time-multiplexes and wavelength-multiplexes them, and outputs them from output terminals 371 and 372. Output.

FIG. 2 is a diagram showing the configuration of the multiplexing unit 311. Since the configurations of the multiplexing unit 311 and the multiplexing unit 322 are the same, the multiplexing unit 311 will be described here. Input terminal 30
1, a plurality of cells are wavelength-multiplexed (cell C1 has a wavelength λ
1, cell C2 is wavelength-multiplexed at wavelength λ2, and cell C3 is wavelength-multiplexed at wavelength λ3. ) The input signal 21 is input. In this embodiment, the number of wavelengths used is set to three for simplification of the description.
The symbols indicating the wavelengths are also changed from λ1 to λ3 and W1 to W3, but this is to make it easier to understand the operation of the wavelength in the communication path.

The optical splitter 110 splits the wavelength-multiplexed cell input to the input terminal 301 into wavelength selecting elements 120 to 122. Among the wavelength-multiplexed cells output from the optical splitter 110, the wavelength selection element 120 always replaces the cell with the wavelength λ1,
The wavelength selecting element 121 always selects and outputs the cell of the wavelength λ2, and the wavelength selecting element 122 always selects and outputs the cell of the wavelength λ3. Delay elements 131 and 132 are inserted into the outputs of wavelength selection elements 121 and 122. The delay element 131 is a wavelength selection element 1
The cell output from the cell 21 is delayed by the time t with respect to the cell output from the wavelength selection element 120. The delay element 132 delays the cell output from the wavelength selection element 122 by a time 2t with respect to the cell output from the wavelength selection element 120.

Here, the relationship between the time t and the cell will be described.
The cell C1 is composed of partial cells C13, C12, and C11, the cell C2 is composed of partial cells C23, C22, and C21, and the cell C3 is composed of partial cells C33, C32, and C31. T, the time length of the partial cell is t, and in this embodiment, T = 3t is satisfied).
That is, the delay elements 131 and 132 are connected to cells C1, C2,
The position of C3 is shifted by the time length t of one partial cell.

The cell output from the wavelength selection element 120 is input to a serial-parallel converter 71 composed of optical switches 140, 143 and 146 and delay elements 150 and 153 having a delay time t provided between the optical switches. In FIG. 2, at the moment when the leading partial cell C13 of the cell C1 enters the optical switch 146 (the moment when the partial cell C12 enters the optical switch 143 and the moment when the partial cell C11 enters the optical switch 140), the optical switches 140 and 143 are provided. , 146 change from the cross state indicated by the optical switches 141, 144, 147 to the bar indicated by the optical switches 140, 143, 146.
(The state shown in the figure), the state of the bar is maintained for the time t, and then the state is switched to the cross state again. Thus, the serially arranged partial cells C11, C12, and C13 of the cell C1 are respectively arranged in parallel, and the serial conversion of the cell C1 is performed. Delay element 131
Output from the cell C2 are optical switches 141, 144, 14
7 and a serial-to-parallel converter 72 constituted by delay elements 151 and 154 having a delay time t provided between the optical switches.
The cell C3 output from the delay element 132 is the optical switch 1
42, 145, 148 and the serial / parallel converter 73 constituted by the delay elements 152, 155 having a delay time t provided between the optical switches, are developed into partial cells, respectively. The cell C2 is expanded after the time t when the cell C1 is developed in parallel, the cell C3 is expanded after the time t, and the wavelength selection element 120 is expanded after the time t.
Performs a serial-to-parallel conversion of the cell output next to the cell C1.

The partial cells output from the optical switches 140 to 148 are time-division multiplexed and input to the wavelength conversion elements 160 to 162. The wavelength conversion element 160 always converts the input partial cell wavelength to W1 and outputs it, and the wavelength conversion element 161 always converts the input partial cell wavelength to W2 and outputs it.
The wavelength conversion element 162 always sets the input partial cell wavelength to W
3 and output. The output lights of the wavelength selection elements 160 to 162 are multiplexed by the optical multiplexer 170 and output from the output end to the highway 391 as the second intermediate signal 31 which is wavelength-multiplexed. As a result, after the input signal 21 is output to the D highway for each partial cell on a cell-by-cell basis, each partial cell is uniquely wavelength-converted corresponding to the D highway, that is, corresponding to the input order. Then, light of each wavelength is synthesized and wavelength-multiplexed.

FIG. 3 is a diagram showing the configuration of the separation unit 361. Since the configurations of the separation unit 361 and the separation unit 362 are the same, only the separation unit 361 will be described here. The cell of the third intermediate signal 51 output from the optical switch matrix 341 is input to the input terminal 200 connected to the highway 351 (the partial cells Cp1, Cq1, and Cr1 have the wavelength W1, and the partial cells Cp2, Cq2, and Cr2 have the wavelength. W2, partial cell C
p3, Cq3, and Cr3 are wavelength-multiplexed at the wavelength W3). Here, Cp is the time slot S1 in the cycle F1.
In addition, Cq exists in the time slot S2 in the cycle F1, and Cr exists in the time slot S3 in the cycle F1. The optical splitter 210 is connected to the input terminal 20 connected to the highway 351.
The wavelength-multiplexed Cp, Cq, and Cr partial cells input to 0 are branched to wavelength selection elements 220 to 222. Of the wavelength-multiplexed Cp, Cq, and Cr partial cells output from the optical branching device 210, the wavelength selection element 220 is always the partial cell of the wavelength W1, the wavelength selection element 221 is always the partial cell of the wavelength W2, Reference numeral 222 always selects and outputs the partial cell of the wavelength W3. Delay elements 230 and 231 are connected to outputs of the wavelength selection elements 220 and 221, respectively.
The delay element 230 converts the partial cells Cp1, Cq1, and Cr1 output from the wavelength selection element 220 to the partial cells Cp3, Cq3, and Cr3 output from the wavelength selection element 222 for a time 2t.
Just delay. The delay element 231 delays the partial cells Cp2, Cq2, and Cr2 output from the wavelength selection element 221 with respect to the partial cells Cp3, Cq3, and Cr3 output from the wavelength selection element 222 by a time t.

The partial cell C output from the wavelength selection element 222
p3, Cq3, Cr3 are optical switches 242, 245, 2
48 and a serial-parallel converter 81 constituted by delay elements 252 and 255 having a delay time t provided between the optical switches.
To enter. Partial cell C output from the wavelength selection element 222
At the moment when the partial cell Cp3 corresponding to the first cell of one cycle among p3, Cq3 and Cr3 is input to the optical switch 248 (this is also the moment when the partial cell Cq3 is input to the optical switch 245 and the partial cell Cr3 is input to the optical switch 242). The optical switches 242, 245, and 248 are switched from the cross state to the bar state. After the bar state is maintained for the time t, the optical switches are switched again to the cross state. Thus, serial / parallel conversion of the partial cells Cp3, Cq3, and Cr3 is performed. The partial cells Cp2, Cq2, Cr2 output from the delay element 231
Is a serial-parallel converter 82 composed of optical switches 241, 244, 247 and delay elements 251, 254 with a delay time t provided between the optical switches. The partial cells Cp1, Cq1, Cr1 output from the delay element 230 are The parallel expansion is performed by the serial-parallel converter 83 composed of the optical switches 240, 243, 246 and the delay elements 250, 253 having a delay time t provided between the optical switches. After the time t when the partial cells Cp3, Cq3, and Cr3 are developed in parallel, the partial cells Cp2, Cq2, and Cr2 are obtained after the time t, and the partial cells Cp1, Cq1, and Cr1 are provided after the time t. , Cr3, and the partial cells existing in the next frame are cyclically serial-parallel-converted. The partial cells output from the optical switches 240 to 248 are time-multiplexed, and
To 262. The wavelength conversion element 262 always converts the input partial cell wavelength to λ1 and outputs it, the wavelength conversion element 261 always converts the input partial cell wavelength to λ2 and outputs it, and the wavelength conversion element 260 outputs the input partial cell wavelength. The wavelength of the cell is always converted to λ3 and output. Wavelength selection element 260
The output lights 262 are multiplexed by the optical multiplexer 270 and output to the output terminal 371 as the wavelength-multiplexed output signal 61. In the embodiment of FIG. 3, the time slot S in the cycle F1
1, λ1 is assigned to the cell Cp existing in the time slot S2 within the period F1, and λ2 is assigned to the cell Cq existing in the time slot S2 within the period F1.
Λ3 is fixedly assigned to each of the cells Cr existing in the time slot S3 and output. That is, for example, the cell Cp is output from the buffer to the time slot S2, and the cell Cq is output to the time slot S1, S
3, Cp is output from the multiplexing unit at λ2, Cq is output at λ1, λ3 (broadcast), and wavelength switching is performed. The configuration of the multiplexing unit 311 shown in FIG. 2 and the configuration of the demultiplexing unit 361 shown in FIG.
The wavelength of the input signal can be uniquely converted according to the input order.

[0018]

According to the present invention, a wavelength multiplexed signal can be input to the input highway, so that the switching capacity can be increased as compared with the conventional optical communication path. In addition, since wavelength switching is uniquely performed by controlling the time switch, an optical ATM communication path having a simple structure can be obtained without requiring a device such as a variable wavelength selection element or a variable wavelength conversion element.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing the concept of the configuration of an optical ATM communication channel according to the present invention.

FIG. 2 is a conceptual diagram showing a configuration of a multiplexing unit of an optical ATM communication channel according to the present invention.

FIG. 3 is a conceptual diagram showing a configuration of a separation unit of an optical ATM communication path according to the present invention.

[Explanation of symbols]

1: optical ATM communication path 21, 22: input signal 31, 32, 41, 42, 51, 52: intermediate signal 61, 62: output signal 71, 72, 73, 81, 82, 83: serial-parallel converter 110, 210: optical splitter 120-122, 220-222: wavelength selection element 130-132, 150-155, 230-232, 2
50 to 255: delay element 140 to 148, 240 to 248: optical switch 160 to 162, 260 to 262: wavelength conversion element 170, 270: optical coupler 301, 302, 351: input end 311, 312: multiplexing part 321, 322: time switch, order changing means 341: optical switch matrix 351, 352, 391, 392: highway 361, 362: separation unit 371, 372, 392: output terminal 382: exchange control unit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04L 12/28 H04B 10/02 H04Q 3/52

Claims (6)

(57) [Claims] 1. A method for transmitting a plurality of fixed-length packets (cells) to multiple wavelengths.
Weight was entered Le - in optical ATM communication path for exchanging while communicating information computing information in accordance with an optical signal, an optical switch matrix to switch the plurality of highway to the respective spatial, and time switch installed in the optical switch matrix front , wavelength multiplexing a plurality of cells placed in front of the switch said time
The cells that make up the input
Multiplexes the partial cells constituting the same cell on the same time
Means for controlling the optical switch matrix and the time switch based on header information of each cell . 2. A method for transmitting a plurality of fixed-length packets (cells) to a plurality of wavelengths.
A plurality of cells are exchanged in an optical ATM communication path for exchanging communication information with an overlapped input as an optical signal in accordance with routing information.
Means for decomposing one cell constituting an input wavelength-multiplexed into a plurality of partial cells and wavelength-multiplexing the plurality of partial cells on the same time; and a temporal order of the wavelength-multiplexed cells as the partial cells. 1. An optical ATM communication path, comprising: means for changing the order on the same highway; and means for spatially switching a plurality of highways connected to respective outputs of the order changing means. 3. When a plurality of cells collide on the same highway when spatially exchanging the output of a cell permutation means for reordering cells among a plurality of highways, one of the collided cells 3. The optical ATM communication path according to claim 2, further comprising buffer means for outputting from only the order changing means for changing the order of the cells and waiting for the remaining cells in the order changing means for changing the order of the cells. 4. A method in which a plurality of fixed-length packets (cells) are
In an optical ATM communication channel in which communication information is exchanged as an optical signal in accordance with routing information in accordance with routing information, one cell is decomposed into a plurality of cells for an input signal in which a plurality of cells are wavelength-multiplexed on the same time. Means for making a partial cell of the above, means for wavelength-multiplexing a plurality of partial cells constituting the one cell on the same time, and order for exchanging the temporal order of the wavelength-multiplexed cells as the partial cells on the same highway Switching means; means for spatially switching a plurality of highways connected to each output of the order changing means; and cells on the output highway connected to the means for spatially switching highways according to their temporal order. Means for returning a state in which a plurality of cells are wavelength-multiplexed on the same time from a state in which partial cells are wavelength-multiplexed on the same time, while allocating wavelengths fixedly. Optical AT characterized by comprising
M call path. 5. An optical ATM communication path for exchanging communication information in the form of an optical signal in accordance with routing information using cells, wherein a cell in which a plurality of cells are wavelength-multiplexed on the same time is separated for each wavelength. A first serial-parallel conversion unit that converts the separated cells for each wavelength into a plurality of partial cells by performing serial-parallel conversion collectively for each of a plurality of bits; First time multiplexing means for sequentially allocating partial cells of the same order of each cell on each highway in accordance with the order within each cell, and outputting from the first time multiplexing means A plurality of first wavelength converting means for fixedly assigning a wavelength to a partial cell in correspondence with the highway, and a plurality of partial cells constituting one cell multiplexing outputs of the time multiplexing means on the same time. First wavelength multiplexing means for performing wavelength multiplexing such that the time order of the wavelength multiplexed cells as the partial cells is changed on the same highway, and connected to each output of the order changing means. Means for spatially switching a plurality of highways, respectively; second wavelength separating means for separating, for each wavelength, wavelength multiplexing of wavelength-multiplexed cells on an output highway connected to the means for spatially switching highways; A second serial-parallel converter for serial-to-parallel conversion of the plurality of time-multiplexed partial cells separated by the second wavelength demultiplexer, and a plurality of cells output from the second serial-parallel converter; A second time multiplexing means for time-multiplexing the partial cells on different highways with the partial cells of each cell; and an order changing means for changing the order of the cells comprises a highway. Second time-multiplexed hand a wavelength in the order in which output cells
An optical ATM telephone comprising: a plurality of wavelength converting means fixedly assigned to each stage highway; and a second wavelength multiplexing means for wavelength-multiplexing the outputs of the plurality of wavelength converting means and outputting the output from an output end. Road. 6. A method in which a plurality of fixed length packets (cells) are
Exchanging communication information with the overlapped input as optical signals according to routing information.
Optical switch matrix for switching to
The time switch installed at the previous stage of the tricks and the time switch
Input wavelength-multiplexed multiple cells installed before
Decompose cells to be formed into multiple partial cells to form one cell
Multiplexing means for wavelength multiplexing partial cells to be synchronized on the same time
Time for time multiplexing of the cells of the optical ATM communication path provided with the
In the multiplexing means, a splitter for splitting the input wavelength multiplexed signal, a wavelength selecting element for selecting a specific wavelength from the output of the splitter, a delay element for giving a specific different delay for each output of the wavelength selecting element , An optical switch and a delay element arranged in a lattice for serial / parallel conversion and time multiplexing of the output of the delay element, a wavelength conversion element for converting a plurality of outputs to different wavelengths, and a multiplexing for multiplexing the output of the wavelength conversion element Time multiplexing means for an optical ATM communication path, comprising a transmitter.