JPH09200217A - Network system and node device to be used for the system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a network working system and a node device capable of simplifying routing control or the like, reducing the size of hardware, preventing the generation of a blocking phenomenon, and easily extending the system by controlling transmitting wavelength to be used when a light transmitter transmits a packet. SOLUTION: The node device 101 connects eight sub-transmission lines to an optical wavelength multiplexed transmission line and terminal equipments 124 to 131 are respectively connected to the sub-transmission lines. A demultilexer 106 separates a wavelength-multiplexed signal in each wavelength, outputs the wavelength-separated signal to an O/E converter 116 and prescribed processing is executed in a signal processing part 107. A clock generation part 102 supplies a clock with a rate equal to the transmission rate of the transmission line, a frame generation part 103 inputs the clock and generates a frame pulse to be used for packet generation, wavelength conversion and buffer control. A wavelength control part 104 controls the transmitting wavelength of the light transmitter 123 in accordance with a prescribed transmitting wavelength control pattern. A buffer control part 105 controls a buffer 121.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network system and a node device, and more particularly, to a node device for connecting a plurality of terminal devices and a plurality of wavelength division multiplexing transmission for connecting a plurality of the node devices. It relates to a network system consisting of roads.

[0002]

2. Description of the Related Art In recent years, ATM (As
The research and development of ynchronous Transfer Mode) has become active. ATM is a method of transmitting information by dividing it into fixed-length packets called cells, and can transmit audio, video, or computer data by multiplexing on the same transmission path, which is an important technology for realizing multimedia. Is being watched as. In particular, B-ISDN (Broadband aspects of Integrated Services
Digital Network: Wideband ISDN) has been adopted as a transfer method, so ATM switches and cell demultiplexing multiplex LSIs required for B-ISDN network switches have been actively announced and released mainly by communication device manufacturers. ing. Also, studies are being conducted in the direction of introducing ATM technology in LAN (Local Area Network).
In addition, since it is expected that ATM transmission technology and wavelength multiplexing technology will be introduced in future optical switching networks, basic experiments such as wavelength conversion in cell units are being conducted.

First, the network configuration of B-ISDN will be described. FIG. 13 shows a part of the B-ISDN network. In the figure, 1301 is an ATM exchange, and 130
2, 1303 are transmission line terminators LT, 1304, 130.
Reference numeral 5 is a broadband network terminating device B-NT. Transmission line terminators LT1302 and 1303 and broadband network terminator B-NT1
A relay device, a synchronous multiplex conversion device, a virtual path cross-connect device, etc. may be inserted between 304 and 1305.

FIG. 14 shows the configuration of the exchange switch section of the ATM exchange 1301. Here, although there are eight input sections, this is one in which eight lines of transmission line terminators LT1302 and 1303 and broadband network terminators B-NT1304 and 1305 are connected to the inputs of the ATM switch 1301 in FIG. This system allows a large number of terminals to communicate with any one of a large number of other terminals. In FIG. 14, 2 × 2
An N × N switch is configured by connecting the switches in multiple stages. Between the transmission line terminating device LT and the broadband network terminating device B-NT, there is a method of transmitting information by mapping ATM cells to a frame of SDH (Synchronous Digital Hierarchy) which is an existing public communication network. Has been.

FIG. 15 shows the SDH frame format and the ATM cell format. An SDH frame consists of 9 rows and 270 columns (270 bytes), 9 rows and 9 columns are section overheads, 9 rows and 1 column are path overheads, and 9 rows and 260 columns are payloads. In the figure, there are section overheads and subsequent path overheads. Expressed differently to make it easier to see the payload. The section overhead is used for managing the transmission line between each device and is standardly defined in the B-ISDN network. The path overhead is used for managing the path between each device. This code is also used in the B-ISDN network. It is defined as a standard, and the payload accommodates ATM cells and immediately follows the path overheads J1, B3, etc. in the figure. A part of this ATM cell shows the remaining data when the payload in the preceding column cannot be accommodated / transmitted. An ATM cell consists of 53 bytes, 48 bytes is an information field, and 5 bytes of the header describe various identifiers. Between the broadband network terminating device B-NT and the transmission line terminating device LT, only the section overhead and the path overhead are processed and the ATM cell of the payload is sent to the exchange 1301.
At 301, the header of the ATM cell is processed and exchanged for communication.

On the other hand, as a LAN, a star-type LAN in which terminals are connected to an ATM hub such as a miniaturized ATM switch 1301 of a B-ISDN network, and a LAN in which ATM nodes are connected in a loop type are being considered. There is. In these LANs, there are various methods such as mapping an ATM cell to a unique frame or transmitting only an ATM cell without using a frame.

Further, although the optical switching network is still in the stage of basic study, it is considered to perform switching on a cell-by-cell basis using a wavelength conversion element, an optical switch or the like.

[0008]

SUMMARY OF THE INVENTION However, ATM
Since the exchange switch requires a decoder, a FIFO, a control unit, and a selector for each 2 × 2 switch, there is a drawback that the overall hardware scale becomes large. Further, even when a certain input signal is connected to an output end different from the signal from the other input end, a blocking phenomenon occurs in which the desired output end cannot be connected depending on the connection status of the other input end. There was a problem.

The transmission speed of B-ISDN and various LANs is currently considered to be 155.52 Mbps.
If it is desired to increase the transmission capacity to 620 Mbps or 2.4 Gbps in the future, the circuit or LSI designed at 155.52 Mbps would have to be recreated, and there was a problem in that the expandability was impaired.

Further, in a network incorporating ATM and wavelength multiplexing technology, when wavelength conversion is performed using, for example, a variable wavelength light source, it takes several tens of ns or more to stabilize the wavelength, so the wavelength is changed. It is conceivable that the ATM cells sent in the meantime are discarded by the receiving unit.

[0011]

In a network system and a node device according to the present invention, an optical wavelength division multiplexing transmission line for transmitting a signal using a plurality (N) of optical wavelengths and a plurality of sub transmission lines are provided for the optical wavelengths. In a network system having a plurality of node devices for connecting to a multiplex transmission line, a demultiplexer for separating wavelength-division-multiplexed light transmitted through an optical wavelength-division multiplex transmission line into respective wavelengths, and an optical output from the demultiplexer An O / E converter for converting a signal into an electric signal, a frame synchronization means for detecting and synchronizing a frame signal from the signals output from the O / E converter, and an output from the O / E converter A cell transmitted from the sub-transmission line while separating the ATM cell to be transmitted to the sub-transmission line from the cell synchronization means for detecting and synchronizing the ATM cell from the signal to be transmitted.
Separation / insertion means for inserting TM cells, buffer means for temporarily storing ATM cells output from the separation / insertion means, frame signal is inserted into the ATM cell stream output from the buffer means, and at least frame signal A packet generating means for assembling a packet composed of a plurality of ATM cells and a wavelength converting part, and a packet output from the packet generating means for converting an optical signal of a desired wavelength among a plurality of transmission wavelengths to perform optical wavelength multiplexing. N sets of optical transmitters to be transmitted to the transmission line are provided, and the transmission wavelengths of the N optical transmitters are changed according to a predetermined transmission wavelength control pattern and at a predetermined position in a packet. Controlling the transmission wavelength of the ATM cell to be transmitted according to the transmission wavelength of the transmission wavelength control means and the transmission wavelength of the optical transmitter for transmitting the packet. A plurality of node devices each including a buffer control means and a multiplexer that multiplexes optical signals of different wavelengths output from the N optical transmitters are provided, and the plurality of node devices are provided in the optical wavelength multiplex transmission line. Configure to connect with.

Further, the packet is composed of a section overhead of 9 rows and 9 columns, a path overhead of 9 rows and 1 column, and a payload section of 9 rows and 260 columns in the SDH frame format.
It is composed of an ATM cell section and a wavelength conversion section of 8 bytes.

Alternatively, the packet has a section overhead of 9 rows and 9 columns, a path overhead of 9 rows and 1 column, and 9 rows 260 in the SDH frame format.
It is composed of the payload part of the column, and the payload part is further 4
It is composed of four ATM cell parts and an empty area of 8 bytes, and the data area of one ATM cell among the 44 ATM cells is used as a wavelength conversion part.

Alternatively, the packet has a section overhead of 9 rows and 9 columns, a path overhead of 9 rows and 1 column, and 9 rows 260 in the SDH frame format.
A payload portion of a column, excluding the payload portion and the frame sync signal portion in the section overhead,
The continuous region is used as the wavelength conversion unit.

Furthermore, the network system and the node device according to the present invention are configured so that the transmission wavelength control pattern is set so that a plurality of optical transmitters do not transmit the same wavelength at the same time.

Furthermore, in the network system and the node device according to the present invention, the transmission wavelength control pattern is common to N optical transmitters, and each optical transmitter sets the common transmission wavelength control pattern to a predetermined time difference. Configure to use.

Furthermore, in the network system and the node device according to the present invention, the wavelength control pattern has the N
Starting from the first wavelength when the transmission wavelengths are arranged in ascending order of wavelength, select the odd-numbered wavelengths in ascending order, and after the wavelength corresponding to the largest odd number, the wavelength corresponding to the largest even number is selected. It is set so that even wavelengths are selected in descending order, the second wavelength is selected, the first wavelength is selected again, and then this is repeated, or the N transmission wavelengths are set to have shorter wavelengths. Starting from the second wavelength when arranged in order, select the even wavelengths in ascending order, the wavelength corresponding to the largest even number, then the wavelength corresponding to the largest odd number, and then the odd wavelengths in descending order. After selecting the first wavelength and selecting the first wavelength, the second wavelength is selected again, and then the setting is repeated.

Furthermore, the network system and the node device according to the present invention are configured such that each buffer means of the plurality of buffer means is divided into a plurality of areas according to the wavelength to be transmitted.

[Operation] In the network system and the node device according to the present invention configured as described above, the routing control of the ATM cell input from the sub transmission line to the separation / insertion unit is performed when the optical transmitter transmits a packet. O / E to receive by controlling the transmission wavelength used
This is performed by changing the converter and controlling the writing and reading in the buffer means individually provided for each separating / inserting means.

Further, the change pattern of the transmission wavelength of each optical transmitter is fixed. Furthermore, arbitration control is performed by setting the transmission wavelength control pattern so that the same wavelength is not transmitted simultaneously by a plurality of optical transmitters.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings together with each embodiment.

<< First Embodiment >> FIG. 1 shows a first embodiment of a node device according to the present invention, showing an example in which eight sub-transmission lines are connected to an optical WDM transmission line. One terminal device is connected to each sub-transmission path.

In FIG. 1, 101 is a node device of the first embodiment. A clock generation unit 102 supplies a clock having a speed equal to the transmission speed of the transmission path. In this embodiment, SDH (Synchronous Digital Hierarch) is used.
155.52 MHz which is the speed of STM-1 (synchronous transfer module 1) of y) is used. In at least one node device 101 in the network, a clock generator 1 that supplies a stable clock by a crystal oscillator or the like.
02 is used, and the clock generation unit 10 of another node device is used.
2 extracts a clock from the output of the O / E converter 116,
Use that clock. In the figure, the clock is input only to the frame generation unit 103, but the other parts are omitted, and the clocks are allocated to the necessary parts of each signal processing unit.
A frame generation unit 103 generates a frame pulse for packet generation, wavelength conversion, and buffer control described later.

Reference numeral 104 denotes a wavelength control unit, which is an optical transmitter 123 according to a predetermined transmission wavelength control pattern described later.
Control the transmission wavelength of. Reference numeral 105 denotes a buffer control unit which, when the sub-transmission line for the destination of the ATM cell stored in the buffer 121 is connected to the adjacent node device, connects the sub-transmission line for the destination of reception at the adjacent node. Control is performed so that reading from the buffer 121 is not performed until the wavelength received by the signal processing unit and the transmission wavelength of the optical transmitter 123 that transmits the cell stored in the buffer 121 match. A demultiplexer 106 demultiplexes the wavelength-multiplexed optical signal transmitted through the optical fiber transmission line for each wavelength and outputs the demultiplexed signal to the O / E converter 116. In this embodiment, a demultiplexer 106 that separates eight wavelengths is used, and
The optical signal of No. 1 is sent to the signal processing unit 107, the optical signal of wavelength λ2 is sent to the signal processing unit 108, and λ3, λ4, λ
5, λ6, λ7, and λ8 are signal processing units 109 and 110,
It is sent to 111, 112, 113, 114.

Further, 107 to 114 are signal processing units, which convert optical signals of respective wavelengths into electric signals, separate ATM cells from SDH frames, and send those addressed to terminals connected to nodes to terminals. The one addressed to the terminal connected to another node is relayed and output, and the ATM from the terminal is also output.
It has a function of inserting a cell into an SDH frame. The signal processing units 107 to 114 have the same internal configuration.
Reference numeral 115 denotes a multiplexer, which multiplexes optical signals of different wavelengths from the respective signal processing units 107 to 114 and outputs them to the optical fiber transmission line.

In each of the signal processing units 107 to 114, 1
Reference numeral 16 is an O / E converter, which converts an optical signal from the demultiplexer into an electric signal. The O / E converter 116 is equipped with a photoelectric conversion element such as a Pin photodiode (Pin-PD), and the waveform is shaped and output by an amplifier, an equalizer, and an identification circuit connected to the subsequent stage of the Pin photodiode. It has a function. Reference numeral 117 denotes a frame synchronization unit, which is SD
Frame synchronization is performed by detecting the A1 and A2 bytes of the H frame. An overhead extraction unit 118 detects various information in the section overhead and the path overhead, displays alarm information, and outputs necessary information to the packet generation unit 1.
Send to 22. A cell synchronization unit 119 performs cell synchronization of ATM cells. A separation / insertion unit 120 separates cells to be transmitted to the sub transmission line from the cell flow output from the cell synchronization unit and sends the cells to the sub transmission line.
It has a function of inserting the cell transmitted from the sub transmission line into the cell stream output from the cell synchronization unit. Its internal configuration will be described later.

Reference numeral 121 denotes a buffer, which has a function of temporarily storing cells output from the separation / insertion unit 120. Its internal configuration will be described later. A packet generation unit 122 adds overhead to the cell flow from the buffer based on the frame signal from the frame generation unit 103 to form a packet, and inserts information from the overhead extraction unit 118 into the overhead. 123 is an optical transmitter using a tunable laser diode (TLD),
Under the control of the wavelength controller 104, the packet output from the packet generator 122 is converted into an optical signal having a predetermined wavelength within the wavelength λ1 to the wavelength λ8 and output. Reference numerals 124 to 131 denote terminals respectively connected to the sub transmission lines, which receive cells output from the separation / insertion unit 120 and create cells to be transmitted to other terminals, and separate / insert the cells through the sub transmission lines. It is transmitted to the unit 120.

FIG. 2 shows an example of the configuration of a network system using the first embodiment of the node device according to the present invention shown in FIG. 1, and shows an example in which four node devices are connected by optical fibers. Reference numerals 201 to 204 denote the node devices shown in FIG. 1, to which eight terminals are connected via eight sub transmission lines. 205 to 208 are optical fibers which are optical wavelength division multiplexing transmission lines. 20
9 to 216 are terminals connected to the node device 201 by a sub transmission line, and 217 to 224 are node devices 202.
225 to 232 are connected to the node device 203 and 233 to 2
Reference numerals 40 are terminals respectively connected to the node devices 204.

FIG. 3 is an internal block diagram of the separation / insertion unit 120 used in the first embodiment of the node device of the present invention. In FIG. 3, reference numeral 301 denotes a decoder, which reads the address part of the header part of the input ATM cell, for example, and instructs the demultiplexer 302 whether or not to output this cell to the sub transmission line. A demultiplexer 302 outputs the input cells to the I / F unit 303 or the FIFO 305 according to an instruction from the decoder 301. Reference numeral 303 denotes an I / F unit, which is a demultiplexer 30.
The cell output from 2 is sent to the sub transmission line,
The cell input from the sub transmission line is output to the FIFO 304. 304 and 305 are FIFO (First In First Out)
), The input cell is temporarily stored, and the insertion control unit 3
By the control from 06, it outputs to the selector in the input order. Reference numeral 306 is an insertion control unit, which is a FIFO 30.
By controlling the reading of 4 and 305 and instructing the selector 307 which FIFO should be selected,
Control is performed to insert the cell transmitted from the sub transmission line into the cell stream output from the cell synchronization unit. A demultiplexer 307 having a selector function selects a FIFO storing a cell to be output according to an instruction from the insertion control unit 306.

FIG. 4 is an internal block diagram of a buffer used in the first embodiment of the present invention. In FIG.
Reference numeral 1 denotes a decoder, which reads an address part of a header part of an input ATM cell, determines whether or not a cell receiving destination is a terminal connected to an adjacent node, and determines a terminal connected to the adjacent node. If not, the demultiplexer 404 is instructed to set the output destination of the demultiplexer 404 to the FIFO 406. On the other hand, when the terminal is connected to the adjacent node, the demultiplexer 404 is instructed to set the output destination of the demultiplexer 404 to the dual port memory 405, and the write start address of the dual port memory 405 to which this cell should be written. The value is instructed to the write address counter 402 in accordance with the wavelength received by the signal processing unit connected to the reception destination terminal in the adjacent node. Reference numeral 402 denotes a write address counter, which sequentially outputs address signals for writing cells to the dual port memory 404 from the write start address value output from the decoder 401.

A read address counter 403 uses the offset value output from the buffer control unit 105 as a read start address and sequentially outputs address signals for reading cells from the dual port memory 405.
Output to A demultiplexer 404 outputs the input cell to the dual port memory 405 or the FIFO 406 according to an instruction from the decoder 401. Four
Reference numeral 05 is a dual port memory for independently writing and reading cell data. 406 is FI
FO (First In First Out), the cells input from the demultiplexer 404 are temporarily stored, and are output to the selector in the input order under the control of the read control unit 509. A demultiplexer selector 407 selects which output of the dual port memory 405 or the FIFO 406 is output to the packet generation unit 122 according to an instruction from the buffer control unit 105.

FIG. 5 is an internal block diagram of the buffer control unit 103 used in the first embodiment of the present invention. In FIG. 5, 501 to 508 are buffer control tables I to VIII, respectively. Each buffer control table I to VIII
Are sequentially read according to the address value output from the wavelength controller 104, and a predetermined offset value is set in each buffer 1.
21 to the read address counter 403. Each of these buffer control tables I to VIII is composed of a read only memory (ROM). The contents of each buffer control table I to VIII will be described later. A read control unit 509 outputs a read control signal for controlling the read of the dual port memory 405 and the FIFO 406 to each buffer 121 by counting the frame signals output from the wavelength control unit 104.

FIG. 6 is an internal block diagram of the wavelength controller 104 used in the first embodiment of the present invention. In FIG. 6, reference numerals 601 to 608 are wavelength control tables I to VIII. Each wavelength control table I to VIII is a 3-bit ROM
The address value output from the counter 609 is sequentially read, and a predetermined wavelength control signal is output to the drive unit of the variable wavelength optical transmission unit 123. These wavelength control tables I to VIII are composed of a read only memory (ROM). The contents of the wavelength control tables I to VIII will be described later.

FIG. 7 is a memory map diagram showing a storage area of the dual port memory 405 used in the first embodiment of the present invention. The storage area of the dual port memory 405 is divided into eight areas according to the wavelength to which the cell is to be transmitted. Storage areas 1 to 8 correspond to transmission wavelengths λ1 to λ8, respectively. The start address of each area is A1, A2, A3, A
4, A5, A6, A7, and A8.

FIG. 8 is a diagram showing the structure of a packet used in the first embodiment of the present invention. The packet structure is the same as the SDH frame format of the conventional example, but 44 ATM cells are accommodated in the payload in order from the beginning position of the payload area, and the remaining 8 bytes are ATM cells as an area of the wavelength conversion unit. Leave it empty. The position of the wavelength conversion unit is not necessarily limited to the position shown in the figure, but in the present embodiment, the description will be made assuming that the last 8 bytes of the payload is the wavelength conversion unit.

In the first embodiment, the contents of the wavelength control table are set as shown in Table 1, for example. Table 1 shows the wavelengths transmitted by the optical transmitter under the control of the wavelength controller.

[0037]

[Table 1]

The offset value of the buffer control table is set as shown in Table 2, for example.

[0039]

[Table 2]

These 16 tables are read by the ROM counter 609 in synchronization. Therefore, the transmission wavelength of each optical transmitter is λ1 to λ3, λ5, λ7, λ
8, λ6, λ4, λ2, λ1 are circulated in this order and transition occurs.
As described above, by cyclically shifting the wavelengths in a discrete manner, the maximum value of the wavelength change amount at the time of changing the wavelength can be reduced. Further, as shown in Table 1, the transmission wavelengths of the respective optical transmitters are out of phase with each other in the cyclic transition of the transmission wavelengths so that the plurality of optical transmitters do not transmit at the same wavelength. In this way, the transmission wavelength control pattern is determined by the wavelength control table.

In Tables 1 and 2, when the transmission wavelength of the optical transmitter is λ1, the offset value for reading the dual port memory 405 of the buffer 121 is assigned the value A1 of the storage area 1, Hereinafter, the transmission wavelengths are λ2, λ3, λ4, λ5, λ6, λ7, and λ8, respectively.
In the case of, values corresponding to the storage area 2, the storage area 3, the storage area 4, the storage area 5, the storage area 6, the storage area 7, and the storage area 8 are respectively assigned. Further, in the buffer of FIG. 4, each storage area is associated with a wavelength received by the signal processing unit to which the terminal of the reception destination is connected in the adjacent node. Therefore, as shown in Table 1,
By setting the wavelength control table and further setting the buffer control table as shown in Table 2, the cell data stored in each buffer is stored in the signal processing unit to which the terminal of the reception destination is connected in the adjacent node. The reading from the buffer is controlled until it matches the wavelength received.

[Setting of Operating Conditions of First Embodiment] First,
Regarding the operation of the first embodiment of the present invention, an ATM whose transmission source is the terminal 209 connected to the node device 201 and whose reception destination is the terminal 229 connected to the node device 203
Cell transmission will be described as an example. In the following description, this ATM cell is called cell A, and it is assumed that there are 10 ATM cells. Further, in the following description, the same reference numerals shown in FIGS. 1 to 7 are used for the same components of different terminal devices for convenience.

The operation of the node device in this embodiment is, as shown in FIG. 9, eight consecutive operation cycles T1, T2, T.
3, T4, T5, T6, T7, and T8. Each operation cycle is 125 μs, and 8 cycles are 1 ms. Within each operation cycle, it is divided into an overhead part (OH) and a payload part (PL) according to the packet configuration of FIG. The overhead section (OH) has an area of 10 bytes × 9 rows at intervals of 270 bytes, and is divided into a section overhead of 9 bytes and a path overhead of 1 byte for each row. Payload part (PL) is
An area for 260 bytes × 9 rows is provided every 270 bytes, and is divided into an ATM cell section and a wavelength conversion section within 260 bytes × 9 rows. The ATM cell section can input 44 ATM cells, for example, the previous 11 cells read from the dual port memory 405 are input and the latter 33 cells read from the FIFO 406. Is entered. The wavelength conversion unit has a size of 8 bytes, and within that time (412 ns = {125 μs / (270 × 9)} ×
In 8), wavelength conversion of the next cycle is performed in the optical transmitter of the signal processing unit.

[Processing Operation in Node Device 201] In the terminal 209 connected to the node device 201 which is the transmission source,
To the data sent to the terminal 229 connected to the node device 203, the address of the terminal 209 connected to the destination node device 201 is added as an address part to assemble the cell A, and the sub-transmission path is used. , Node device 2
01 to the separation / insertion unit 120 of the signal processing unit 107. The I / F unit 303 of the separation / insertion unit 120 sequentially scrapes the cell A transmitted via the sub transmission line into the FIFO 304. After the writing of the cell A into the FIFO 304 is completed, the insertion control unit 306 detects an empty cell in the cell stream being read from the FIFO 305, and outputs the FIFO input to be output by the selector 307 at the position of the empty cell to the FIFO.
By switching to IFO 305 or FIFO 304, 10 cells A from the terminal are inserted one by one in the cell flow of the transmission path. When there is no empty cell, the reading of the FIFO 305 may be stopped and the cell from the FIFO 304 may be inserted. The cell A output from the selector 307 of the demultiplexer is input to the buffer 121.

In the decoder 401 of the buffer 121, the input address portion of the cell A is read. Since the reception destination of the cell A is not the terminal connected to the adjacent node device 202, the decoder 401 sets the output destination of the demultiplexer 404 to the FIFO 406.
Here, when the operation cycle in which the cell A is cut into the FIFO 406 is T8, the FI of the adjacent operation cycle T1 is set.
In the FO read period Tf, the cell A is read under the control of the buffer control unit 105.

In the subsequent operation cycle T1, the wavelength controller 104
0 is simultaneously output to each wavelength control table from the ROM counter 609 as a read address value. The contents of the wavelength control table are read based on the address value. As shown in Table 1 above, the contents read at this time are the control signals corresponding to the wavelength λ1 from the wavelength control table 601, which will be referred to as the wavelength control table 602, the wavelength control table 603, the wavelength control table 604, and the wavelength control. The table 605, the wavelength control table 606, the wavelength control table 607, and the wavelength control table 608 are control signals corresponding to the wavelength λ2, the wavelength λ4, the wavelength λ6, the wavelength λ8, the wavelength λ7, the wavelength λ5, and the wavelength λ3, respectively. These control signals are supplied 8 bytes before the start of the operation cycle T1 and input to each optical transmitter. In the optical transmitter 123, the amount of injected current is set by these wavelength control signals and injected into the wavelength control terminal of the tunable laser diode (TLD) in the optical transmitter 123 to change the transmission wavelength. The last 8 of each cycle
Since no information is sent to the bytes, if the transmission wavelength is completely changed within these 8 bytes, all information other than the 8 bytes of the wavelength conversion unit in the adjacent node device must be received without loss. You can

At the same time, in the read period Td of the dual port memory 405 having the operation cycle T1, the wavelength control unit 10
The read address value 0 output from the ROM counter 609 of No. 4 is input to the buffer control table of the buffer control unit 105. The content of each buffer control table is read by this address value. As shown in Table 2 above, the content read at this time is the offset value A1 corresponding to the storage area 1 from the buffer control table 501. Below, the buffer control table 502, the buffer control table 503, the buffer control table 504,
Buffer control table 505, buffer control table 5
06, the buffer control table 507, and the buffer control table 508 have offset values A2 corresponding to the storage area 2, storage area 4, storage area 6, storage area 8, storage area 7, storage area 5, and storage area 3, respectively. Offset value A4, offset value A6, offset value A8,
The offset value A7, the offset value A5, and the offset value A3. These offset values are output to the read address counter 403 of the buffer 121, respectively. Further, the read control unit 509 of the buffer control unit 105
In the above, based on the frame signal output from the frame generation unit 103, the dual port memory 40 is enabled to read, the FIFO 406 is prohibited to read, and the selector 407 outputs the dual port memory 40 as an input.
A control signal for performing the setting of 5, etc. is output. By inputting these control signals, the buffer 12 of the signal processing unit 107
In No. 1, the read address counter 403 loads the offset value A1 output from the buffer control table 501 and sequentially increments the counter to generate an address for reading the cell scratched in the storage area 1. , To the dual port memory 405. With this read address, 11 cells are sequentially read from the output port of the dual port memory 405 and output to the packet generation unit 122. Since the transmission wavelength of the cell read at this time is λ1, it is addressed to the terminal 217 connected to the adjacent node device 202 or is an empty cell.

At the same time, in the read period Td of the dual port memory 405 having the operation cycle T1, the signal processing unit 1
In the buffer 121 of No. 08, the read address counter 403 is loaded with the offset value A2 output from the buffer control table 502, and similarly to the buffer 121 of the signal processing unit 107, the cells scratched into the storage area 2 are stored. It is read from the dual port memory 405. Similarly, the storage area 4 of the buffer 121 of the signal processing unit 109, the storage area 6 of the buffer 121 of the signal processing unit 110, the storage area 8 of the buffer 121 of the signal processing unit 111, the storage area 7 of the buffer 121 of the signal processing unit 112,
Cells are read from the storage area 5 of the buffer 121 of the signal processing unit 113 and the storage area 3 of the buffer 121 of the signal processing unit 114, and the signal processing units 107 to 11 are read.
4 to the packet generation unit 122. The cell read at this time is one addressed to the terminals 218 to 224 connected to the adjacent node device 202, or an empty cell.

In the FIFO read period Tf following the operation cycle T1, the read control unit 509 of the buffer control unit 105 uses the dual port memory 40 based on the frame signal output from the frame generation unit 103.
5 is prohibited, the FIFO 406 is allowed to be read, and the FIFO 406 is used as an output of the selector 407.
Outputs a control signal for setting the. By inputting these control signals, the buffer 121 of the signal processing unit 107
In, the FIFO 406 is read and the selector 4
It is output to the packet generation unit 122 via 07. 10 cells A that were cut into the FIFO 406 at this time
And 23 other cells, a total of 33 cells are read. Similarly, the buffer 1 of the signal processing units 108 to 114
Also in 21, the cells cut into the FIFO 406 are sequentially read and output to each packet generation unit 122.

The cells read from each buffer 121 are input to each packet generator 122. The packet generator 122 inserts an overhead and a wavelength converter into the cell flow input based on the frame signal from the frame generator 103 to assemble the packet shown in FIG. At this time, the overhead inserted in each packet generation unit 122,
The position and time of the wavelength conversion unit are all the same. further,
A frame signal and various alarm information are inserted into the overhead from the overhead extraction unit 118. The frame signal inserted in the overhead is the same in each packet generation unit 122. The packet assembled by each packet generator 122 is output to each optical transmitter 123.

Each optical transmitter 123 is connected to each packet generator 1
The packet output from 22 is converted into a predetermined wavelength based on the wavelength control signal output from the wavelength control unit 104, and the packet is output to the multiplexer 115. As described above, the wavelength of the optical signal emitted at this time is the wavelength λ1 in the optical transmitter 123 of the signal processing unit 107, the wavelength λ2 in the signal processing unit 108, the wavelength λ4 in the signal processing unit 109, and the wavelength λ4 in the signal processing unit 110. λ6,
The signal processing unit 111 has a wavelength λ8, the signal processing unit 112 has a wavelength λ7, the signal processing unit 113 has a wavelength λ5, and the signal processing unit 114 has a wavelength λ3. Further, the time during which the optical signal is transmitted at the wavelength is 125 μS,
During this period, 44 ATM cells are transmitted. In this way, the wavelengths of the optical signals emitted from the eight optical transmitters 123 are different under the control of the wavelength control unit 104, and therefore, the multiplexer 11 is used.
At 5 the lights of all wavelengths are mixed without being influenced by each other, and the lights of all wavelengths are transmitted to the adjacent node equipment 202 downstream through the optical fiber 205. At this time, the node device 2
The cell A transmitted from the terminal 209 connected to the 01 sub-transmission line to the terminal 229 connected to the sub-transmission line of the node device 203 is transmitted to the node device 202 as an optical signal of the wavelength λ1 as described above. Is transmitted.

[Operation of Node Device 202] Cell A transmitted to the node device 202 as an optical signal of wavelength λ1.
Is subjected to relay transmission processing in the node device 202.
The optical signals of wavelengths λ1 to λ8 transmitted from the node equipment 201 via the optical fiber 205 are transmitted to the node equipment 202.
Demultiplexer 106 demultiplexes each wavelength into each signal processing unit 10
It is incident on the O / E converters 116 of 7 to 114. In the signal processing unit 107, only the optical signal of wavelength λ1 is incident, and the O / E
It is received by the converter 116. Since the cell A was transmitted from the node device 201 as an optical signal of wavelength λ1, it is received by the signal processing unit 107. The cell A received by the O / E converter 116 is output to the frame synchronization unit 117.

In the frame synchronization section 117, the frame synchronization signals (A1, A2) at the beginning of the overhead are detected from the input signal stream, and frame synchronization is performed. The frame synchronization signal is inserted at the head position of each operation cycle T1 to T8, and the frame pattern is detected every cycle 125 μS to maintain synchronization continuously. The frame synchronization signal detected in each operation cycle is sent from different signal processing units of the adjacent node devices, and the frame synchronization signal sent in the operation period T1 is the signal processing unit 107 of the node device 202. The frame synchronization signal transmitted from the node device 202 is transmitted from the node device 202 in the next operation cycle T2.
From the signal processing unit 108 of
At T4, T5, T6, T7 and T8, the node device 202
Signal processing units 109, 110, 111, 112, 11 of
It is sent from 3,114. Each signal processing unit 1
Since the positions of the frame synchronization signals inserted in 07 to 114 are aligned and the transmission path lengths are the same, it is possible to detect the frame synchronization signals sent from different signal processing units and perform frame synchronization.

When the frame synchronization is established, the position of the overhead is known. Therefore, the overhead extraction section 118 detects various information described in the overhead. Similarly to the frame synchronization signal, various kinds of information in the overhead are also detected as information sent from different signal processing units for each operation cycle. For example, in the signal processing unit 107 of the node device 202,
The C2 byte in the path overhead is the node device 201.
From the signal processing unit 107 of No. 108, 10
It is detected in the order of 9, 110, 111, 112, 113, 114. In the signal processing unit 108 of the node device 202, the C2 byte is the signal processing unit 108 of the node device 201.
Starting from 109, 110, 111, 112,
It is detected in the order of 113, 114, 107. The overhead extraction unit 118 detects all of this information from the frame synchronization unit 117 of each of the signal processing units 107 to 114, collects the information for each transmitted signal processing unit, and performs processing. If there is information to be transmitted to the adjacent node device,
The information is output to the packet generator 122.

The signal stream subjected to frame synchronization by the frame synchronization section 117 is output to the cell synchronization section 119. The cell synchronization unit 119 processes only ATM cells in the signal stream and performs cell synchronization. The cell synchronization unit 119 performs error correction and the like in addition to cell synchronization, and also performs processing such as discarding those that cannot be corrected. The cell stream subjected to cell synchronization is output to the separation / insertion unit 120.

In the decoder 301 of the separation / insertion unit 120, the address part of the input cell A is read.
Since the reception destination of the cell A is the terminal connected to the adjacent node device 203, the decoder 301 sets the output destination of the demultiplexer 302 to the FIFO 305.
The cell A cut into the FIFO 305 is the insertion control unit 3
It is read under the control of 06 and output to the buffer 121 via the selector 307.

In the decoder 401 of the buffer 121, the address part of the cell A is read again. Since the reception destination of this cell A is the terminal connected to the adjacent node device 203, the decoder 401 sets the output destination of the demultiplexer 404 to the dual port memory 405, and at the same time, starts writing to the write address counter 402. A5 is output as the address value. The write address counter 402 loads the write start address and sequentially increments the counter to generate the write address of the input cell A, and outputs it to the dual port memory 405. The cell A is input to the input port of the dual port memory 405 via the demultiplexer 404, and the address counter 40
The data is sequentially written in the storage area according to the address output from 2. Here, the cell A is the dual port memory 40.
Assuming that the operation cycle cut into 5 is T1, the read from the dual port memory 405 of the cell A is the wavelength received by the signal processing unit 111 to which the terminal 229 of the reception destination of the adjacent node device 203 is connected. It is controlled so as to wait until the operation cycle T3 in which the transmission wavelength of the optical transmitter 123 of the node device 202 coincides with λ5.

In the node device 202, in the operation cycle T2 subsequent to the operation cycle T1 in which the cell A is cut into the dual port memory 405, 1 is read from the ROM counter 609 of the wavelength control unit 104 as the read address value of the wavelength control tables 601 to 601. It is output to 608 at the same time. The contents of the wavelength control table are read based on the address value. As shown in Table 1 above, the contents read at this time are the control signals corresponding to the wavelength λ3 from the wavelength control table 601, and will be referred to as the wavelength control table 602, the wavelength control table 603, the wavelength control table 604, and the wavelength control. The table 605, the wavelength control table 606, the wavelength control table 607, and the wavelength control table 608 are control signals corresponding to the wavelength λ1, the wavelength λ2, the wavelength λ4, the wavelength λ6, the wavelength λ8, the wavelength λ7, and the wavelength λ5, respectively. Each of these control signals is input to the optical transmitter of each signal processing unit.

Similarly to the above, in the operation cycle T2, the read address value 1 output from the ROM counter 609 of the wavelength controller 104 is input to the buffer control table of the buffer controller 105. Also, the frame generator 1
Various read control signals are generated in the read control unit based on the frame signal output from 03. Based on these control signals, the dual port memory 405 and the FIFO 406 of the buffer of each signal processing unit are read. Dual port memory 40 of each buffer read at this time
As shown in Table 2 above, the storage area of 5 is the signal processing unit 1
The buffer 07 is the storage area 3, and is hereinafter referred to as the buffer of the signal processing unit 108, the buffer of the signal processing unit 109, the buffer of the signal processing unit 110, the buffer of the signal processing unit 111, the buffer of the signal processing unit 112, and the signal processing. Part 1
The buffer of 13 and the buffer of the signal processing unit 114 are a storage area 1, a storage area 2, a storage area 4, a storage area 6, a storage area 8, a storage area 7, and a storage area 5, respectively. The cell read from each buffer 121 in this way is converted into the above-mentioned predetermined optical signal in each optical transmitter 123, and is sent to the optical fiber via the multiplexer 115.

Cell A is the buffer 1 of the signal processing unit 107.
Since the data is stored in the storage area 5 of the dual port memory 405 of No. 21, it is read in the dual port memory read period Td of the subsequent operation cycle T3. The number of cells read out here is 11, and 10 cells A and another one cell are read out. FI of the subsequent operation cycle T3
During the reading period Tf of the FO406, the FIFO4
From 06 to 33 cells are read out. In the operation cycle T3, the ROM counter 609 of the wavelength controller 104 outputs 2 as a read address value to each wavelength control table. The contents of the wavelength control table are read based on the address value. At this time, the transmission wavelength of the optical transmitter of the signal processing unit 107 is set to λ5. Similarly, this address value 2 is also output to the buffer control unit 105, and the buffer control table is read. At this time, the signal processing unit 1
The area read from the dual port memory 405 of the 07 buffer 121 is set to the storage area 5.

Dual port memory 405 and FIFO
The cells read from 106 are switched by the selector 407, output, and input to the packet generation unit 122.
The packet generator 122 assembles the packet, adds various information to the overhead, and outputs the information to the optical transmitter 123.

In the optical transmitter 123, each buffer 121 is read out by the control of each control signal as described above.
The optical transmitter 123 converts the optical signal into a predetermined optical signal, and the multiplexer 1
It is delivered to the optical fiber via 15.

In the dual-port memory read period Td of the operation cycle T3, the cell A is read and sent from the optical transmitter 123 as an optical signal of wavelength λ5 to the optical fiber via the multiplexer 115, and the node device 203. Incident on.

[Operation of Node Device 203] Optical Fiber 2
The wavelength λ transmitted from the node device 202 via 06
The optical signals 1 to λ8 are sent to the demultiplexer 10 of the node device 203.
It is demultiplexed into each wavelength at 6 and is incident on the O / E converter 116 of each of the signal processing units 107 to 114. The signal processing unit 111 receives the packet including the cell A transmitted by the optical signal having the wavelength λ5. Similar to the process in the node device 202, the packet is frame-synchronized by the frame synchronizer 117, cell-synchronized by the cell synchronizer 119, cell A is taken out, and output to the separation / insertion unit 120. To be done.

In the decoder 301 of the separation / insertion unit 120, the address part of the input cell A is read.
Since the reception destination of the cell A is the terminal 229 connected to the self separation / insertion unit 120, the decoder 301 sets the output destination of the demultiplexer 302 to the I / F unit 303.
As a result, the cell A is output to the I / F unit 303 via the demultiplexer 302, transmitted through the sub transmission path, and then received by the terminal 229 that is the reception destination, and the address portion of the cell A is removed. After that, only the data part is taken out and desired processing is performed. In the cell A, 10 ATM cells composed of a header part and 53 bytes of an information part were planned, so the header part is removed and 10 parts of the 48 bytes of the information part are treated as data, 229
Data processing is performed.

In this way, the source node device 201
Cell A from the terminal 209 connected to the sub transmission line of the node device 203 to the terminal 229 connected to the sub transmission line of the node device 203.
Is transmitted.

[Second Embodiment] In the first embodiment,
Although the size of the wavelength converter is 8 bytes, if the time required for wavelength conversion is 8 bytes (412 ns) or more,
As shown in FIG. 10, one of the ATM cells may be used as the wavelength conversion unit. However, header information is inserted into the 5 bytes of the header of the ATM cell, and wavelength conversion is performed within 48 bytes.
Also, the last 8 bytes of the packet shall be a free area.

With this packet structure, the same communication operation as in the first embodiment is performed. From the above example, the overhead part (OH) and the payload part (PL) are 270
Forty-three ATM cell parts are transmitted in nine rows of bytes, and the wavelength conversion part has a size of 48 bytes between them, and within that time (2,469 ns = {125 μs / (270 × 9)} ×
At 48), wavelength conversion of the next cycle is performed in the optical transmitter of the signal processing unit. If there is this period, it is a sufficient time for wavelength conversion to stabilize.

[Third Embodiment] FIG. 11 is a diagram showing the structure of a packet according to the third embodiment. In the first and second embodiments, the position of the wavelength converter is in the payload, but in the third embodiment, it is arranged in the unused 2-byte position in the section overhead. 823 ns in time
The wavelength will be converted during. Further, of the ATM cells in the payload, the ATM cells that straddle the wavelength conversion unit are prohibited from writing data. In the figure,
Writing to the information section of the cell between the 19th and 20th ATM cells is prohibited. The reason will be described.

SDH of ATM cell in B-ISDN
In the frame mapping method, a method is used in which ATM cells are inserted into the payload of the SDH frame format without a gap. That is, ATM
When cells are inserted from the beginning of the payload, the 45th 53-byte ATM cell has 8 bytes in the previous frame and the remaining 45 bytes in the next frame. As described above, some ATM cells are inserted across frames, which is different from the method of leaving 8 bytes so that ATM cells are not inserted across frames as in the first and second embodiments. . BI
SDN ATM cell SDH mapping circuit or LSI
Is already in the stage of development, and when the methods of the first and second embodiments are used, some circuit changes are involved. Therefore, the third embodiment is designed so that the already developed circuit for B-ISDN can be used as it is.

In the third embodiment, the wavelength conversion section is arranged at a position where data is not inserted. If the wavelength is completely changed at this position, the other part where the data is written can be transmitted without data loss.
The position of the wavelength conversion unit may be any position as long as it is a blank part in addition to the position shown in the drawing. Further, if there is information that is not used among various kinds of information other than the frame synchronization signals (A1, A2) in the overhead, that position may be used as the wavelength conversion unit. For example, the pointer portion (H1, H2, H3) is 9
Due to the size of the bite, the time required for wavelength conversion is
Bytes (103ns when one frame is 125μs)
If so, if the wavelength is changed at this position, it becomes technically easy. There is no need to change the circuit by changing the wavelength in the overhead. It is possible to use the existing circuit as it is and change the software for reading judgment.

Writing to the ATM cell that crosses the wavelength conversion unit is prohibited because the packets before and after the wavelength conversion unit are transmitted to different signal processing units, and the ATM cells crossing the wavelength conversion unit are prohibited. This is because the data written in the cell will be lost. Since the prohibition of writing to the cell can be performed by software, it can be performed without changing the circuit.

With this packet structure, the same communication operation as in the first embodiment is performed.

[Other Embodiments] In the first to third embodiments, the packet structure is the same as the SDH frame format. However, the present invention is not limited to this, and as shown in FIG. In addition, another structure may be used as long as it is a fixed-length packet including at least a frame part in which a frame synchronization signal is inserted, a payload part in which a data signal is inserted, and a wavelength conversion part for wavelength conversion.
Further, in the above embodiment, ATM of 156 Mbit / sec is used.
I explained about LAN, but 100BASE-T, 10
The present invention is not limited to 0VG-Any-LAN, mixed use of these, and other high-speed LAN circuit networks. Further, although an example of a ring type is shown in the circuit network to which the present invention is applied, the invention is not limited to this, and for example, an FD that bundles a plurality of LAN
It may be DI (Fiber Distributed Data Interface).

Further, in the above embodiment, the number of wavelengths transmitted through the optical fiber, the wavelengths received and transmitted by each terminal, the number of terminals connected to each node device, and the like are set to eight, and the number of node devices is set to four. However, the number is not limited to these numbers, and may be a large number or a small number. In that case, for example, if the number of wavelengths is N,
The number of sets is set to N in each node device, and the wavelength control table, the buffer control table, the storage area in the dual port memory, and the like are separately provided, so that the software can be changed and the effects of the present invention can be obtained. It can be played.

Further, the synchronization relationship has been described on the assumption that the lengths of the optical fibers between the node devices are the same, but this synchronization problem is indispensable in the transmission by the ATM cell, and the clock generation units provided in the node devices. Even if the lengths of the optical fibers are different by synchronizing with each other, there is no problem.

[0077]

As described above, according to the network system and the node device of the present invention, the optical transmitter transmits a packet for the routing control of the ATM cell input from the sub transmission line to the separation / insertion unit. By controlling the transmission wavelength that is sometimes used, the receiving O / E converter is changed, and the writing and reading are controlled by the buffer means individually provided for each separation / insertion means. Operation, routing control can be simplified,
Since the exchange switch unit in the conventional exchange can be eliminated, the hardware scale of the node device can be reduced.

Further, by setting the transmission wavelength control pattern so that a plurality of optical transmitters do not transmit the same wavelength at the same time, it is possible to prevent the occurrence of the blocking phenomenon and eliminate the need for a control circuit for preventing the blocking. Therefore, there is an effect that the scale of hardware can be reduced. Furthermore, by making the packet structure the same as the SDH frame format, existing circuits can be used. Further, when it is desired to increase the transmission capacity, it is not necessary to make a new circuit or LSI, and a large capacity network can be easily configured only by increasing the number of wavelengths using an existing circuit.

Furthermore, by providing the wavelength conversion section in a portion of the SDH frame format where data is not inserted, communication can be performed without data loss.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a node device according to the present invention.

FIG. 2 is a diagram showing a configuration of a network system according to the present invention.

FIG. 3 is a diagram showing a configuration of a separation / insertion unit according to the present invention.

FIG. 4 is a diagram showing a configuration of a buffer unit according to the present invention.

FIG. 5 is a diagram showing a configuration of a buffer control unit according to the present invention.

FIG. 6 is a diagram showing a configuration of a wavelength control unit according to the present invention.

FIG. 7 is a diagram showing a memory map of a dual port memory according to the present invention.

FIG. 8 is a diagram showing a packet configuration of a first exemplary embodiment according to the present invention.

FIG. 9 is a diagram showing a time chart of the first embodiment according to the present invention.

FIG. 10 is a diagram showing a packet configuration of a second exemplary embodiment according to the present invention.

FIG. 11 is a diagram showing a packet configuration of a third exemplary embodiment of the present invention.

FIG. 12 is a diagram showing a packet structure of another embodiment according to the present invention.

FIG. 13 is a diagram showing a configuration of a conventional network system.

FIG. 14 is a diagram showing a configuration of an exchange switch unit of an ATM exchange.

FIG. 15 is a diagram showing a structure of an SDH frame format.

[Explanation of symbols]

 101, 201-204 Node device 102 Clock generation part 103 Frame generation part 104 Wavelength control part 105 Buffer control part 106 Demultiplexer 107-114 Signal processing part 115 Multiplexer 116 O / E converter 117 Frame synchronization part 118 Overhead extraction Part 119 Cell synchronization part 120 Separation / insertion part 121 Buffer 122 Packet generation part 123 Optical transmitter 124-131, 209-240 Terminal 205-208 Optical fiber 301,401 Decoder 302,307,404,407 Demultiplexer 303 I / F part 304, 305, 406 FIFO 306 Insertion control unit 402 Write address counter 403 Read address counter 405 Dual port memory 501 to 508 Buffer control table 509 Read control unit 60 ～608 wavelength control table 609 ROM counter 1301 ATM switch 1302 and 1303 line termination 1304 and 1305 broadband network termination device

Claims (22)

[Claims] 1. A network having an optical wavelength multiplex transmission line for transmitting a signal using a plurality of (N) optical wavelengths and a plurality of node devices for connecting a plurality of sub transmission lines to the optical wavelength multiplex transmission line. In the system, a demultiplexer that separates the wavelength-multiplexed light transmitted through the optical wavelength-multiplexed transmission line into respective wavelengths, and an O / E converter that converts an optical signal output from the demultiplexer into an electrical signal , The O /
Frame synchronization means for detecting and synchronizing a frame signal in the signal output from the E converter, and cell synchronization for detecting and synchronizing an ATM cell in the signal output from the O / E converter. Means for separating the ATM cell to be transmitted to the sub-transmission line, temporarily inserting and inserting the ATM cell transmitted from the sub-transmission line, and temporarily storing the ATM cell output from the separation-insertion unit. And a packet generating means for inserting a frame signal into the ATM cell stream output from the buffer means to assemble a packet composed of at least the frame signal, a plurality of ATM cells and a wavelength converting section, and the packet generating means. A set of optical transmitters that convert output packets into optical signals of desired wavelengths among multiple transmission wavelengths and send them to the optical wavelength division multiplexing transmission line. Further, there are N sets, and further, transmission wavelength control means for controlling the transmission wavelengths of the N optical transmitters so as to change at a predetermined position within a packet in accordance with a predetermined transmission wavelength control pattern, and a packet is transmitted. A to be transmitted according to the transmission wavelength of the optical transmitter
A plurality of node devices each including a buffer control means for controlling the reading of TM cells from the buffer means and a multiplexer for multiplexing optical signals of different wavelengths output from the N optical transmitters are provided. A network system in which the plurality of node devices are connected by an optical wavelength division multiplexing transmission line. 2. The packet is SDH (Synchronous)
It is composed of a section overhead of 9 rows and 9 columns, a path overhead of 9 rows and 1 column, and a payload section of 9 rows and 260 columns in the frame format of Digital Hierarchy), and the payload section further comprises 44 ATM cell sections and 8 sections.
The network system according to claim 1, wherein the network system comprises a wavelength conversion unit of byte. 3. The packet is SDH (Synchronous)
It is composed of a section overhead of 9 rows and 9 columns, a path overhead of 9 rows and 1 column, and a payload section of 9 rows and 260 columns in the frame format of Digital Hierarchy), and the payload section further comprises 44 ATM cell sections and 8 sections.
2. The network system according to claim 1, wherein the network system comprises a byte free area, and a data area of one ATM cell among the 44 ATM cells is used as a wavelength conversion unit. 4. The SDH (Synchronous) packet
It is composed of a section overhead of 9 rows and 9 columns, a path overhead of 9 rows and 1 column, and a payload section of 9 rows and 260 columns in the frame format of Digital Hierarchy), and the frame synchronization signal section in the payload section and the section overhead is 2. The network system according to claim 1, wherein a continuous area except for the area is used as a wavelength conversion unit, and information is prohibited from being written in an information area of an ATM cell that straddles the wavelength conversion unit. 5. The network system according to claim 1, wherein the transmission wavelength control pattern is set so that a plurality of optical transmitters do not transmit the same wavelength at the same time. 6. The transmission wavelength control pattern is common to N optical transmitters, and each optical transmitter uses the common transmission wavelength control pattern with a predetermined time difference. The network system according to 1 or 5. 7. The transmission wavelength control pattern starts from the first wavelength when the N transmission wavelengths are arranged in ascending order of wavelength, selects odd wavelengths in ascending order, and selects the largest odd number. After the corresponding wavelength, select the wavelength corresponding to the largest even number, then select the even wavelengths in descending order, select the second wavelength, select the first wavelength again, and so on. Or, when the N transmission wavelengths are arranged in ascending order of wavelength, starting from the second wavelength, selecting even-numbered wavelengths in ascending order, and after the wavelength corresponding to the largest even number, It is characterized in that the wavelength corresponding to a large odd number is selected, then the odd wavelengths are selected in descending order, the first wavelength is selected, then the second wavelength is selected again, and then this is repeated. Claim 1 , Network system according to 5 and 6. 8. The network system according to claim 1, wherein the transmission wavelength change position of the wavelength control pattern is a wavelength conversion unit in the packet. 9. The network system according to claim 1, wherein each buffer means of the plurality of buffer means is divided into a plurality of areas according to a wavelength to be transmitted. 10. A packet stream is formed by transmitting packets including frame synchronization signals having different wavelengths and different wavelengths with the same cycle as the frame synchronization signal from a plurality of different optical transmitters, and the packet stream is received. In the network system, the receiving section detects a frame synchronization signal of the same wavelength of each packet and processes the information in the packet by frame synchronization of the packet stream. 11. A plurality of node devices each composed of a plurality of optical transmitting means for transmitting an arbitrary wavelength and a plurality of optical receiving means for receiving an optical signal of a specific wavelength are connected via an optical fiber transmission line. A network system in which a frame synchronization signal and a data signal are exchanged by the plurality of wavelengths between the respective optical fiber transmission lines for communication. 12. A node device for connecting a plurality of (N) optical wavelengths to transmit a signal using optical wavelengths and connecting a plurality of sub transmission lines to the optical wavelengths multiplex transmission line. And an optical demultiplexer for separating the wavelength-division multiplexed light transmitted through the optical wavelength-division-multiplexed transmission line into respective wavelengths, and converting the optical signal output from the demultiplexer into an electrical signal.
A / E converter, a frame synchronizing means for detecting and synchronizing a frame signal from the signals output from the O / E converter, and a signal from the signals output from the O / E converter.
While separating the ATM cell to be transmitted to the sub-transmission line from the cell synchronization means for detecting the TM cell and performing synchronization,
Separation / insertion means for inserting ATM cells transmitted from the sub-transmission line, buffer means for temporarily storing ATM cells output from the separation / insertion means, and frame signal in the ATM cell stream output from the buffer means. Insert
Packet generating means for assembling a packet including at least a frame signal, a plurality of ATM cells, and a wavelength converting section;
N sets of sets each including an optical transmitter for converting a packet output from the packet generation means into an optical signal of a desired wavelength among a plurality of transmission wavelengths and transmitting the optical signal to an optical wavelength multiplexing transmission line, , A transmission wavelength control means for controlling the transmission wavelengths of the N optical transmitters to change at a predetermined position in the packet according to a predetermined transmission wavelength control pattern, and an optical transmitter for transmitting the packet. Buffer control means for controlling reading of ATM cells to be transmitted from the buffer means in accordance with the transmission wavelength, and multiplexer for multiplexing optical signals of different wavelengths output from the N optical transmitters. A node device comprising: 13. The packet is SDH (Synchronou
s Digital Hierarchy) frame format is composed of a section overhead of 9 rows and 9 columns, a path overhead of 9 rows and 1 column, and a payload section of 9 rows and 260 columns, and the payload section further includes 44 ATM cell sections.
The node device according to claim 12, wherein the node device comprises an 8-byte wavelength conversion unit. 14. The packet is SDH (Synchronou
s Digital Hierarchy) frame format is composed of a section overhead of 9 rows and 9 columns, a path overhead of 9 rows and 1 column, and a payload section of 9 rows and 260 columns, and the payload section further includes 44 ATM cell sections.
13. The node device according to claim 12, wherein the node device comprises an empty area of 8 bytes, and a data area of one ATM cell among the 44 ATM cells is used as a wavelength conversion unit. 15. The packet is SDH (Synchronouou).
s Digital Hierarchy) frame format composed of section overhead of 9 rows and 9 columns, path overhead of 9 rows and 1 column, and payload section of 9 rows and 260 columns, and frame synchronization signal section in the payload section and the section overhead. 13. The node device according to claim 12, wherein a continuous area other than the above is used as a wavelength conversion unit, and information is prohibited from being written in an information area of an ATM cell that straddles the wavelength conversion unit. 16. The node device according to claim 12, wherein the transmission wavelength control pattern is set so that a plurality of optical transmitters do not transmit the same wavelength at the same time. 17. The transmission wavelength control pattern is common to N optical transmitters, and each optical transmitter uses the common transmission wavelength control pattern with a predetermined time difference. The node device according to 12 or 16. 18. The transmission wavelength control pattern is the N
Starting from the first wavelength when the transmission wavelengths are arranged in ascending order of wavelength, select the odd-numbered wavelengths in ascending order, and after the wavelength corresponding to the largest odd number, the wavelength corresponding to the largest even number is selected. Select, then select even wavelengths in descending order 2
After selecting the second wavelength, select the first wavelength again, and then repeat the process. Or, start from the second wavelength when the N transmission wavelengths are arranged in ascending order of wavelength. , Select the even wavelengths in ascending order,
After the wavelength that corresponds to the largest even number, select the wavelength that corresponds to the largest odd number, then select the odd wavelengths in descending order, select the first wavelength, and then select the second wavelength again.
18. The node device according to claim 12, 16 or 17, wherein the node device is set to repeat the process thereafter. 19. The node device according to claim 12, 16 or 17, wherein the transmission wavelength change position of the wavelength control pattern is a wavelength conversion unit in the packet. 20. The node device according to claim 12, wherein each of the buffer units of the plurality of buffer units is divided into a plurality of regions according to a wavelength to be transmitted. 21. A plurality of different optical transmitters transmit packets containing frame synchronization signals having different wavelengths and different wavelengths in the same cycle as the frame synchronization signal to form a packet stream and receive the packet stream. A node device characterized in that the receiving section detects a frame synchronization signal of the same wavelength of each packet and acquires the frame synchronization of the packet stream to process the information in the packet. 22. A plurality of optical transmitting means for transmitting an optical signal of an arbitrary wavelength to an optical fiber transmission line, a plurality of optical receiving means for receiving an optical signal of a specific wavelength from the optical fiber transmission line, and the optical signal. A node device, characterized in that a frame synchronizing signal and a data signal are exchanged within a predetermined number of wavelengths by a predetermined wavelength control pattern for communication.