JP3467036B2 - Network system, node device, and transmission control method - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a network system, a node device, and a transmission control method.

[0002]

2. Description of the Related Art In recent years, with the speeding up of terminal devices, a network consisting of a plurality of channels, for example, a wavelength multiplexing transmission line using a plurality of optical wavelengths, has been used in order to speed up a network connecting terminal devices. Network systems are being considered. This type of network system, node device and method are roughly classified into two.

First, as shown in FIG. 22, a node device 117 for connecting a plurality of terminal devices 124 and a wavelength multiplexing using a plurality of optical wavelengths for connecting a plurality of the node devices. This is a configuration including the transmission path 125.

In the network system of the first classification shown in FIG. 22, the packet transmitted from the terminal device 123 and input to the input I / F unit 121 is identified according to the destination terminal or node device. The switching unit 119 exchanges the packet so that the packet is transmitted at the predetermined fixed wavelength transmitting unit 120 that transmits the packet at the wavelength, and the packet is output to the predetermined fixed wavelength transmitting unit 120 and transmitted at the predetermined wavelength. afterwards,
Even in the node device existing on the way to the node device to which the receiving destination terminal device is connected, packets to the same destination terminal or the same node device are relayed at the same wavelength, and finally the purpose is set. The switching device controls the output destination so that the fixed wavelength receiving unit 118 of the node device outputs the output I / F 122 to which the terminal device of the receiving destination is connected, and the predetermined output I / F unit And is received by the terminal device. The switching unit of the node device transmits the input packet to a plurality of fixed wavelength transmitting units,
By controlling the switching operation to which of the I / F units the packet is output, it functions to route the packet to the desired terminal device of the desired node device.

The second type of network system is a so-called transmission media sharing type system which is connected by wavelength multiplexing transmission lines having a topology such as a bus and a star. When transmitting packets from these terminals, these systems issue a request for the use of the wavelength multiplexing transmission line to the server that manages the wavelength used by each terminal, and then allocate the wavelength to be used from the server. The so-called demand assign method is used to perform arbitration control so that multiple terminals do not conflict with each other using the same wavelength. In the network system of the second classification, packet transmission is performed using this assigned wavelength.

[0006]

FIG. 23 shows a first configuration example of the exchange section used in the conventional example of the first classification described above. The exchange part is shown. In FIG. 23, reference numeral 126 is a decoder section, which reads the address section of the packet and instructs the control section which output destination the packet should be output to.
Reference numeral 127 is a FIFO (FirstInFirstOu).
In step t), the input packets are temporarily stored and output to the output line in the order of input under the control of the control unit. Reference numeral 128 is an input line for supplying the packet signal output from the FIFO to the input of the switch. Code 1
Reference numeral 29 denotes a switch, which has a function of switching whether or not the packet signal input to the input line is used as the output line. Reference numeral 130 is a control unit, which controls the reading of the FIFO and the opening / closing of each switch according to the output from the decoder. Reference numeral 131 denotes an output line that supplies the packet signal output from the switch to the output light.

FIG. 26 shows the structure of packets exchanged in these packet exchanges.
In the above, reference numeral 140 is the address portion of the destination terminal of this packet, and reference numeral 141 is the data portion carried by this packet.

In the first configuration example of the exchange section,
For each output destination, it is necessary to detect the occurrence of output competition for the inputs from all the inputs and perform arbitration control. Therefore, it takes time for this control, and the throughput decreases.

Further, in the network system of the first classification, packets to the same destination are always exchanged to the same output destination and transmitted at the same wavelength, so that the traffic of a specific wavelength increases, and There was a case where the communication in the wavelength of became a bottleneck.

FIG. 24 shows a second configuration example of the exchange section,
An exchange unit is configured by connecting 2 × 2 switches each having two inputs and two outputs, which will be described later, in multiple stages. Figure 24
Reference numeral 132 denotes a 2 × 2 switch having two inputs and two outputs, and has two functions of a straight line that connects the input and the output straight and a cross that connects and crosses.
By connecting these 2 × 2 switches in a shuffle net shape, an omega type exchange section with 8 inputs and 8 outputs is realized.

FIG. 25 shows 2 × the number of inputs and the number of outputs 2 described above.
It is a switch internal block diagram of 2. In FIG. 25, reference numeral 1
Denoted at 33 and 134 are a decoder I and a decoder II, which read the address part of an input packet and instruct the control part which output end should output this packet. Reference numeral 135
And 136 are FIFOI (FirstInFirstOu)
t) FIFO II, which temporarily stores the input packets and outputs them to the selector in the input order under the control of the control unit. Reference numerals 137 and 138 denote selectors I and II, which are controlled by the control unit to select the FIFO storing the packet signal to be output to the output destination. Selector I137 selects FIFOI135,
The state in which the selector II 138 is selecting the FIFO II 136 is the above-mentioned straight traveling, and the selector I 137 is the FIF.
Select OII 136, Selector II 138 is FIFO
The state where II135 is selected is the above-mentioned intersection.

In the second configuration example of the exchange section, there is a problem that a so-called blocking phenomenon occurs in which a desired output destination cannot be connected depending on the already connected input / output relationship. This means that, for example, when the input 5 and the output destination 3 in FIG. 24 are connected, the upper left 2 × 2 switch is set to the crossing state, but in order to connect the input 1 to the output destination 1, , It is necessary to set the upper left 2 × 2 switch to the straight-ahead state, so blocking will occur.

Also in this second configuration example, it is necessary to detect the occurrence of output competition for all inputs, and to perform arbitration control. Therefore, it takes time until a packet is output, and throughput is lowered. Resulting in.

Further, the problem that the traffic of a specific wavelength increases has not been solved.

On the other hand, the conventional network system of the second classification is constructed as shown in FIG. 27 and has the following problems.

FIG. 27 shows a conventional example of the second classification, which is a network system in which a server having a function of allocating wavelengths used by each terminal and a plurality of terminals are connected in a bus type. Shows an example of.

In FIG. 27, reference numeral 142 is an optical fiber which is a bus type wavelength division multiplexing transmission line. Code 1
43 is a server having a wavelength allocation function. Reference numeral 14
4 is a terminal device. Reference numeral 145 is a multiplexer / demultiplexer, which has the functions of emitting the optical signal emitted from the variable wavelength transmission unit to the optical fiber, and dividing the optical signal transmitted on the optical fiber to the fixed wavelength reception unit. is doing. Reference numeral 146 is a variable wavelength transmission unit equipped with a tunable laser diode (TLD), which converts the packet signal output from the packet processing unit into an optical signal of a predetermined wavelength under the control of the wavelength control unit, Emit it to the junction switch. Reference numeral 147 denotes a filter having a function of transmitting only an optical signal of a predetermined wavelength and blocking an optical signal of another wavelength, and an optical signal of a predetermined wavelength transmitted through the filter, converted into an electric signal, and output Consisting of a photodiode with the function of
It is a fixed wavelength receiver. The transmission wavelength of the filter of the fixed wavelength receiving unit is assigned differently for each terminal. Reference numeral 149 is a wavelength control unit that controls the transmission wavelength of the variable wavelength transmission unit to a desired wavelength. Reference numeral 150 is an allocation control unit that allocates the use of a plurality of wavelengths used in this network system and performs arbitration control regarding use competition of each wavelength.

In this conventional example, since the optical fiber, which is a bus type wavelength multiplexing transmission path, is shared by each terminal, control is performed so that the transmission wavelengths from the variable wavelength transmission units of a plurality of terminals do not overlap. Arbitration function is required. Therefore, the demand assign method is used. When transmitting a packet, each terminal first sets the transmission wavelength of the variable wavelength transmission unit to a wavelength that can be received by the server,
A transmission request packet specifying the receiving destination terminal is transmitted to the server. Upon receiving this transmission request packet, the server searches the wavelength allocation control unit for the usage status of the optical signal of the wavelength that can be received by the terminal designated as the reception destination. If it is in use, the communication permission / non-permission packet indicating non-permission is transmitted by setting the transmission wavelength of the variable wavelength transmission unit to a wavelength that can be received by the terminal that has transmitted the transmission request packet. The terminal that has transmitted the transmission request packet sets the transmission wavelength of the variable wavelength transmission unit to a wavelength that can be received by the destination terminal when the communication is permitted after receiving the communication permission / non-permission packet, and the desired wavelength is set. Send a packet. If the communication is not permitted, after waiting for a predetermined time, the transmission request packet is sent again to the server, and the process is repeated until the communication permission is obtained. In this way, the arbitration function for controlling the transmission wavelengths from the variable wavelength transmission units of a plurality of terminals so as not to overlap with each other is realized.

In the second conventional example of the classification, the filters of the respective terminals are set so that the wavelengths of the optical signals to be transmitted are different. Therefore, the wavelengths of the optical signals incident on the respective photodiodes are different and unique. It is a thing. Therefore, by changing the transmission wavelength of the tunable laser diode (TLD) of the terminal from which the packet is transmitted, it is possible to realize a routing function for transmitting the packet to a desired reception destination.

However, in the example of the conventional network system of the second classification, the transmission of the transmission request packet and the communication with the server for the arbitration such as the reception of the communication permission / non-permission packet are required, and the network. Since the arbitration control of all wavelengths used above must be performed by the server, the load on the arbitration control unit in the server becomes large, and the arbitration itself takes time, which reduces the throughput of the network system. was there. Furthermore, in the wavelength control unit of each terminal device, it is necessary to control the transmission wavelength to a predetermined wavelength for each communication with the server and communication with the destination terminal, so high-speed wavelength control is required. .

Further, since all packets addressed to the same destination are communicated at the wavelength assigned by the server, even in the conventional network system example of the second classification, the traffic of a specific wavelength increases. And
It sometimes became a bottleneck in communication at a specific wavelength.

[0022]

In order to solve the above-mentioned problems, the present invention is a node device, in which a plurality of storage means for storing signals to be transmitted and signals from the respective storage means are transmitted. Channel changing means for sequentially changing the channels to be used, and in the case of transmitting a signal in which a transmission channel for transmitting from the node device is not specified, regardless of the channel changed by the channel changing by the channel changing means. And a control means for controlling the signal to be transmitted.

Further, in a network system for connecting a plurality of node devices with a plurality of channels, at least one node device has a plurality of storage means for storing a signal to be transmitted and a signal from each of the storage means. And a channel changing means for switching the channels to be transmitted one after another, and a channel changed by the channel changing means by the channel changing means when transmitting a signal in which a transmission channel for transmitting from the node device is not designated. Irrespective of the above, there is provided a network system comprising: a control unit that controls to transmit the signal.

A method of controlling signal transmission in a node device having a plurality of storage means for storing a signal to be transmitted, wherein the channels from which the signals from the respective storage means are transmitted are switched one after the other. In the case of transmitting a signal whose transmission channel is not specified when transmitting from the device, the transmission control method is controlled so that the signal is transmitted regardless of the channel changed by the channel switching. I will provide a.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION (Embodiment 1) In this embodiment, an optical signal of a plurality of wavelengths is used as a plurality of channels and a wavelength multiplexing transmission line is used as a multi-channel transmission line to form a ring type network configuration.

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 wavelength division multiplexing transmission line. For each sub transmission line,
One terminal device is connected to each.

In FIG. 1, reference numeral 1 is a control unit of the node device, which has a buffer control unit 2 and a wavelength control unit 3 therein. Reference numeral 2 is a buffer control unit,
The terminal which is the destination of the packet stored in the buffer
When connected to the adjacent node device, the fixed wavelength that outputs the packet to the separation / insertion unit to which the destination terminal is connected in the adjacent node, the wavelength that the receiving unit receives, and the variable that transmits the packet stored in the buffer Control is performed so that reading from the buffer is not performed until the transmission wavelengths of the wavelength transmission unit match. The wavelength controller 3 controls the transmission wavelength of the variable wavelength transmission means according to a predetermined transmission wavelength control pattern described later. Reference numeral 4 denotes an optical fiber which is an optical wavelength division multiplexing transmission line, and functions as a transmission line between the multiplexer of the node device adjacent to the upstream side and the branching device of the own node device. Reference numeral 5 is a branching device, which branches the optical signal transmitted through the optical fiber 4 and outputs the branched optical signal to the eight fixed wavelength receiving units. Reference numerals 6 to 13 denote fixed wavelength receiving section I to fixed wavelength receiving section VIII, which are fixed wavelength receiving means using photodiodes, and the internal configuration thereof will be described later. Each fixed wavelength receiver I6 to fixed wavelength receiver VIII
13 receives only the packets transmitted by the optical signals of one wavelength corresponding to the wavelengths λ1 to λ8, respectively. Reference numerals 14 to 21 denote the separating / inserting unit I to the separating / inserting unit VIII which are the separating / inserting means, and separate the packet to be transmitted to the sub transmission line from the packet stream output from the fixed wavelength receiving unit. , And has a function of sending the packet to the sub-transmission line and inserting a packet transmitted from the sub-transmission line into the packet stream output from the fixed wavelength receiving unit. The internal structure will be described later. 22 to 29
Are buffers I to VIII, which are buffer means, and have a function of temporarily storing the packets output from the separating / inserting means. The internal structure will be described later. Reference numerals 30 to 37 denote variable wavelength transmitters I to VIII, which are variable wavelength transmitters using a tunable laser diode (TLD), and transmit packets output from the buffer to the wavelength controller. By control, the wavelength λ1 is converted into an optical signal of a predetermined wavelength within the wavelength λ8, and the optical signal is transmitted through the multiplexer 38 to the optical fiber 39 which is an optical wavelength multiplex transmission line. The internal structure will be described later. Here, the fixed wavelength receiving unit I6, the separating / inserting unit I14, the buffer I22, and the variable wavelength transmitting unit I30.
Form a set, and the packet received by the fixed wavelength receiving unit I6 is processed inside this set and is not processed by another set. Similarly, the fixed wavelength receiving unit II7, the demultiplexing inserting unit II15, the buffer II23, and the variable wavelength transmitting unit II3.
1 is a set, and the same applies to other fixed wavelength receiving units, separation / insertion units, buffers, and variable wavelength transmitting units. Code 3
Reference numeral 8 denotes a multiplexer, which multiplexes the optical signals of wavelengths λ1 to λ8 sent from the eight variable wavelength transmitters, and outputs the multiplexed signals to the optical fiber 39. Reference numeral 39 is an optical fiber which is an optical wavelength division multiplexing transmission line, and functions as a transmission line between the multiplexer of the own node device and the branching device of the node device adjacent to the downstream side. Reference numerals 40 to 47 denote sub transmission paths I to VIII, which serve as a transmission path for packets between the separation / insertion unit and the terminal. Reference numerals 48 to 55
Are sub transmission lines I40 to VIII, respectively.
The terminals I to VIII connected to the terminal 47 receive the packet output from the separation / insertion unit, create a packet to be transmitted to another terminal, and transmit the packet to the separation / insertion unit via the sub transmission path. .

FIG. 2 is a structural example 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 56 to 59 denote the elements in FIG.
In the node device shown in FIG. 3, eight terminals are connected via eight sub transmission lines. Reference numerals 60 to 63 are optical fibers which are optical wavelength division multiplexing transmission lines.

The optical fibers 60 to 63 correspond to the optical fibers 4 and 39 of FIG. 1 as follows. That is, in the node device I56, the optical fiber 4 of FIG. 1 is the optical fiber 63 of FIG. 2, and the optical fiber 39 of FIG. 1 is the optical fiber 60 of FIG. Further, in the node equipment II57, the optical fiber 4 of FIG.
The optical fiber 60 of FIG. 2 and the optical fiber 39 of FIG.
Is the optical fiber 61 of FIG. Below node device II
The same applies to I58 and node device IV59.

FIG. 3 is an internal configuration diagram of the fixed wavelength receiving unit I6 to fixed wavelength receiving unit VIII13 used in the first embodiment of the node device of the present invention. In FIG. 3, reference numeral 64 is a filter, which has a function of transmitting only optical signals of fixed wavelengths assigned to the fixed wavelength receiving units and blocking optical signals of other wavelengths. The transmission wavelengths of the filters of the fixed wavelength receiving units are λ1 for the fixed wavelength receiving unit I6, λ2 for the fixed wavelength receiving unit II7, and λ for the fixed wavelength receiving unit III8.
3, fixed wavelength receiver IV9 is λ4, fixed wavelength receiver V1
0 is λ5, the fixed wavelength receiving unit VI11 is λ6, the fixed wavelength receiving unit VII12 is λ7, and the fixed wavelength receiving unit VIII3 is λ5.
It is set to 8. Here, each wavelength is numbered in ascending order of wavelength. That is, λ1 <λ2 <λ3 <
λ4 <λ5 <λ6 <λ7 <λ8.

Reference numeral 65 is a receiving section using a photodiode, which converts an optical signal of a predetermined wavelength transmitted through the filter into an electric signal and outputs the electric signal to the separating / inserting section. The receiving unit is equipped with a Pin photodiode (Pin-PD), and has a function of performing waveform shaping by an amplifier, an equalizer, and an identification circuit connected to the subsequent stage of the Pin photodiode and outputting the waveform.

FIG. 4 shows the separation / insertion section I14 to the separation / insertion section VII used in the first embodiment of the node device of the present invention.
It is an internal block diagram of I21. The internal configurations of the separation insertion section I14 to the separation insertion section VIII21 are all the same. In FIG. 4, reference numeral 66 is a decoder I, which reads the address part of an input packet and determines whether or not this packet should be output to the sub transmission line I67.
Instruct. Reference numeral 67 is a demultiplexer, which receives the input packet according to the instruction of the decoder I66, and
The data is output to the F unit 68 or the FIFO II 70. Code 68
Is an I / F unit, which sends the packet output from the demultiplexer to the sub transmission line and outputs the packet input from the sub transmission line to the FIFO I 69. Reference numerals 69 and 70 denote a FIFO (FirstInFir).
stOut), the input packets are temporarily stored, and are output to the selector in the input order under the control of the insertion control unit 71. Reference numeral 71 is an insertion control unit that controls the reading of the FIFOI 69 and the FIFOII 70, and the FI to be selected by the selector I72.
By instructing FO, control is performed to insert the packet transmitted from the sub transmission line into the packet stream output from the fixed wavelength receiving unit. Reference numeral 72 is a selector I, which selects the FIFO storing the packet signal to be output, in accordance with an instruction from the read control unit.

In this embodiment, the packet structure is the same as that of the conventional example shown in FIG.

FIG. 5 is an internal block diagram of the buffers I22 to VIII29 used in the first embodiment of the present invention. The buffers I22 to VIII29 all have the same internal configuration. In FIG. 5, reference numeral 7
Reference numeral 3 denotes a decoder II, which reads an address part of an input packet, determines whether or not the destination of packet reception is a terminal connected to an adjacent node, and when it is not a terminal connected to an adjacent node, The demultiplexer is instructed to set the output destination of the demultiplexer to the FIFO III 78. On the other hand, when the terminal is connected to the adjacent node, the demultiplexer is instructed to set the output destination of the demultiplexer to the dual port memory 77, and the write start address value of the dual port memory 77 to write this packet is set. In the adjacent node, according to the wavelength received by the fixed wavelength receiving means for outputting the packet to the separating / inserting means to which the destination terminal is connected,
The write address counter 74 is instructed.

Reference numeral 74 is a write address counter, which outputs to the dual port memory 77 address signals for sequentially writing packets from the write start address value output from the decoder II 73. Reference numeral 75 is an address counter, which sequentially outputs an address signal for reading a packet to the dual port memory 77, using the offset value output from the buffer control unit as a read start address. Reference numeral 76 is a demultiplexer II
The input packet is converted to the dual port memory 77 or the FIFO III7 according to the instruction of the decoder.
Output to 8. Reference numeral 77 is a dual port memory for independently writing and reading packet data. As shown in the memory map of FIG. 6, the storage area of the dual port memory 77 is divided into eight areas according to the wavelength at which the packet should be transmitted. The storage areas I to VIII correspond to respective channels, that is, transmission wavelengths λ1 to λ8, respectively. The start address of each area is A1, A2, A3, A4,
A5, A6, A7, and A8. Reference numeral 78 is FI
FOIII (FirstInFirstOut), which temporarily stores the input packets and outputs them to the selector in the input order under the control of the read control unit. Reference numeral 79 is a selector II, which is a dual port memory 77 or FIF according to an instruction from the buffer control unit.
It is selected whether any output of OIII78 is output to the variable wavelength transmission unit.

FIG. 7 is an internal block diagram of the buffer controller 2 used in the first embodiment of the present invention. In FIG. 7, reference numerals 80 to 87 are buffer control table I to buffer control table VIII, respectively. From each buffer control table I80 to buffer control table VI
The II 87 is sequentially read by the address value output from the wavelength control unit, and a predetermined offset value is stored in the buffer I.
22 to the read address counter 75 of the buffer VIII29. These tables are composed of a read only memory (ROM). Buffer control table I80 to buffer control table VII
The contents of I87 will be described later. Reference numeral 88 denotes a read control unit, which counts the clock signals output from the wavelength control unit, thereby allowing the dual port memory 77 and the FI
A read control signal for controlling the reading of the FOIII 78 is output from the buffer I22 to the buffer VIII29.

FIG. 8 is an internal block diagram of the wavelength controller 3 used in the first embodiment of the present invention. In FIG.
Reference numerals 89 to 96 are wavelength control table I to wavelength control table VIII, respectively. The wavelength control table I89 to the wavelength control table VIII96 are sequentially read according to the address value output from the 3-bit ROM counter 97, and a predetermined wavelength control signal is output to the drive unit of the variable wavelength transmission unit. These tables are composed of a read only memory (ROM). From wavelength control table I89 to wavelength control table VIII96
The contents of will be described later. Reference numeral 98 is a clock generator, which generates a predetermined clock signal and sends it to the buffer controller, and also divides this clock signal and outputs it to the ROM counter.

FIG. 9 shows a variable wavelength transmitter I30 to a variable wavelength transmitter VIII used in the first embodiment of the present invention.
It is an internal block diagram of 37. The variable wavelength transmission unit I30 to the variable wavelength transmission unit VIII37 have the same internal configuration. In FIG. 9, reference numeral 99 is a drive unit, and the inside thereof is composed of a signal superposition unit 101 and a current injection unit 100. Reference numeral 100 denotes a current injection unit, which injects current into three regions of a DBR type tunable laser diode (TLD) including a light emitting region, a phase control region, and a DBR region according to a wavelength control signal from the wavelength control unit. The transmission wavelength is controlled from λ1 to λ
Control up to 8. Reference numeral 101 denotes a signal superimposing unit that superimposes the electric signal from the buffer on the bias current from the current injecting unit to cause the DBR tunable laser to emit an optical signal whose intensity is modulated at a predetermined wavelength.
Reference numeral 102 is a DBR tunable laser diode (TLD). Reference numeral 103 is a DBR region, which is a region for changing the transmission wavelength by changing the refractive index according to the injection carrier amount. Reference numeral 104 is a phase control region, which is a region for matching the phase in the DBR region of the transmission wavelength and the phase in the light emitting region. Reference numeral 105
Is a light emitting region and is an active portion for laser oscillation.
Reference numeral 106 is a diffraction grating for unifying the transmission wavelengths.

In the first embodiment, the contents of the wavelength control table I89 to the wavelength control table VIII96 are set as shown in Table 1. Table 1 shows the wavelengths transmitted by the variable wavelength transmission unit under the control of the wavelength control unit. The offset values of the buffer control table I80 to the buffer control table VIII87 are shown in Table 2.
It is set as shown in.

[0040]

[Table 1]

[0041]

[Table 2]

These 16 tables are read by the ROM counter 97 in synchronization. Therefore, the transmission wavelength of each tunable laser diode (TLD) is λ
1 to λ3, λ5, λ7, λ8, λ6, λ4, λ2, λ
It makes a transition in the order of 1. 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. For example, changing from λ1 to λ2, λ3, λ4, λ5, λ6, λ7, and λ8 in order increases the amount of wavelength change when changing the wavelength to λ1 next to λ8, resulting in a heavy load on the device.
Although the life of the device and the reliability of control are reduced, such a large wavelength change can be prevented by setting as described above. Further, as shown in Table 1,
The transmission wavelength of each tunable laser diode (TLD) is
The phases of the cyclic transitions of the transmission wavelengths are shifted so that the transmission at the same wavelength is not performed. In this way, the wavelength control table I
From 89, the transmission wavelength control pattern is determined by the wavelength control table VIII96.

In Tables 1 and 2, when the transmission wavelength of the variable wavelength transmission unit is λ1, the offset value for reading the dual port memory of the buffer is assigned the value A1 of the storage area I. When the transmission wavelengths are λ2, λ3, λ4, λ5, λ6, λ7, and λ8, respectively, storage area II, storage area III, storage area IV, storage area V, storage area VI, storage area VII, and storage area A value corresponding to the area VIII is assigned. In the buffer of FIG. 5, storage areas I to V
III is associated with the wavelength received by the fixed wavelength receiving unit that outputs the packet to the demultiplexing / inserting unit to which the reception destination terminal is connected in the adjacent node. Therefore, by setting the wavelength control table as shown in Table 1 and further by setting the buffer control table as shown in Table 2, the packet data stored in each buffer is received by the adjacent node at the destination terminal. The reading from the buffer is controlled in synchronization with the wavelength received by the fixed wavelength receiving unit that outputs a packet to the demultiplexing / inserting unit connected to.

With reference to the time charts of FIGS. 1 to 9 and FIG. 10, the operation of the first embodiment of the present invention will be described below. Yes, the reception destination is the terminal V52 connected to the sub transmission line V44 of the node device III58.
The packet transmission will be described as an example. In the following description, this packet is called packet A. In the following description, the same reference numerals shown in FIGS. 1 to 9 are used for the same components of different node devices for convenience.

The operation of the node device in this embodiment is, as shown in FIG. 10, eight consecutive operation cycles T1, T2,
It is composed of T3, T4, T5, T6, T7, and T8. Further, these eight operation cycles are divided into Td which is a read period of the dual port memory 77 and Tf which is a read period of the FIFO III 78 by the operation in the buffer. In this embodiment, T1
Each T8 is a fixed period.

In the terminal I48 connected to the sub transmission line I40 of the node device I56 which is the transmission source, the node device II
The data sent to the terminal V52 connected to the sub-transmission line V44 of I58 is added with the address of the terminal V52 connected to the sub-transmission line V44 of the node device III58, which is the receiving destination, as an address part, and is shown in FIG. With the configuration, the packet A is assembled and transmitted to the separation / insertion unit I14 of the node device I56 via the sub transmission line I40. The I / F unit 68 of the separation / insertion unit I14 of the node device I56 FIFs the packet A transmitted via the sub transmission line I40.
Scratch into OI69. After the writing of the packet A into the FIFO I69 is completed, the insertion control unit finds a break in the packet stream read from the FIFO II 70, and inputs the FIFO input to be output by the selector to the FIFO I 69.
Then, the reading of the FIFO II 70 is stopped and the reading of the FIFO I 69 is started. After the reading of the packet A cut into the FIFOI 69 is completed, the insertion control unit switches the input of the FIFO to be output by the selector to the input from the FIFOII 70 again, stops the reading of the FIFOI 69, and reads the FIFOII 70. To resume. The packet A output from the selector is input to the buffer I22.

In the decoder II73 of the buffer I22, the address part of the input packet A is read. Since the destination of reception of this packet A is not the terminal connected to the adjacent node device II 57, the node device I 5
In 6, the channel for transmitting this packet, that is, the packet in which the wavelength is not specified, is set, and the decoder II 73 sets the output destination of the demultiplexer II 76 to the FIFO III 78.
Set to. Here, packet A is FIFOIII78
Assuming that the operation cycle is set to T8, the read period T of the FIFO III 78 of the adjacent operation cycle T1
In f, the packet A is read by the control of the buffer control unit 2.

In the subsequent operation cycle T1, R of the wavelength controller 3
The OM counter 97 simultaneously outputs 0 as a read address value from the wavelength control table I89 to VIII96. The content of the wavelength control table is read by this 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 I89. The wavelength control table II90, the wavelength control table III91, the wavelength control table IV92, and the wavelength control will be described below. The table V93, the wavelength control table VI94, the wavelength control table VII95, and the wavelength control table VIII96 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 input from the variable wavelength transmission unit I30 to the drive unit 99 of the variable wavelength transmission unit VIII37. In the drive unit 99, the injection current of the current injection unit is set by these wavelength control signals, and the transmission wavelength of each tunable laser diode (TLD) is set to a predetermined wavelength.

At the same time, in the read period Td of the dual port memory of the operation cycle T1, the ROM of the wavelength controller 3
The read address value 0 output from the counter 97 is
It is input to the buffer control tables 80 to 87 of the buffer control unit 2. The contents of VIII87 are read from the buffer control table I80 by this address value. As shown in Table 2 above, the contents read at this time are the offset value A1 corresponding to the storage area I from the buffer control table I80, and the buffer control table II81, buffer control table III82, buffer control table IV83, Buffer control table V84,
Buffer control table VI85, buffer control table VII86, and buffer control table VIII87
Are storage area II, storage area IV, and storage area V, respectively.
I, storage area VIII, storage area VII, storage area V,
And an offset value A2, an offset value A4, an offset value A6, an offset value A8 corresponding to the storage area III,
The offset value A7, the offset value A5, and the offset value A3. These offset values are output from the buffer I22 to the respective read address counters 75 of the buffer VIII29. Further, in the read control unit 88 of the buffer control unit 2, the wavelength control unit 3
Based on the clock signal output from the dual port memory 77, it outputs a control signal for permitting reading of the dual port memory 77, inhibiting reading of the FIFO III 78, and setting the dual port memory 77 as an input output from the selector 79. By inputting these control signals, the buffer I22
, The read address counter 75 outputs the offset value A1 output from the buffer control table I80.
Is loaded and the counter is sequentially incremented to generate an address for reading the packet that has been scratched in the storage area I, and outputs it to the dual port memory 77. Packets are sequentially read from the output port of the dual port memory 77 by this read address and output to the variable wavelength transmission unit I30. Since the transmission wavelength is λ1, the packet read at this time is addressed to the terminal I48 of the sub transmission line I40 of the adjacent node device II57.

At the same time, in the read period Td of the dual port memory of the operation cycle T1, in the buffer II23, the read address counter 75 is loaded with the offset value A2 output from the buffer control table II81, and is stored as in the buffer I22. Region I
II57 of the adjacent node device that has been scratched into I
Packet addressed to the terminal II49 adjacent to the sub transmission line II41 of the dual port memory 77.
And is output to the variable wavelength transmission unit II31. Similarly, the storage area IV of the buffer III24, the storage area VI of the buffer IV25, the storage area VIII of the buffer V26, the storage area VII of the buffer VI27, the storage area V of the buffer VII28, and the buffer VIII29.
From the variable wavelength transmission unit III32 to the variable wavelength transmission unit VI.
It is output to each II 37. At this time, namely Td
The packet read in is the adjacent node device I
I57 to sub transmission lines V to I57 sub transmission lines, respectively.
It is addressed to the terminal connected to III47.

In the read period Tf of the FIFO 78 following the operation cycle T1, the read control unit of the buffer control unit 2 prohibits the read of the dual port memory 77 based on the clock signal output from the wavelength control unit 3, and the FIFO III 78. And a control signal for setting the FIFO III 78 as an input output from the selector 78 and outputting the control signal. By inputting these control signals, in the buffer I22, the FIFO III
78 is read and output to the variable wavelength transmission unit I30 via the selector 79. FIFO III 78 at this time
Packet A, which is the packet that has been cut into the packet, in which the wavelength to be transmitted is not specified, that is, the packet in which the destination terminal is not connected to the downstream adjacent node device, is read. Similarly, buffer II23 to buffer VIII2
Also in 9, the packets that have been cut into the FIFO III 78 are sequentially read and output from the variable wavelength transmitter I30 to the variable wavelength transmitter VIII37.

Each of the variable wavelength transmitters I30 to VIII37 includes a buffer I22 to a buffer VIII.
The packet output from 29 is converted into a predetermined wavelength based on the wavelength control signal output from the wavelength control unit, and the multiplexer 38
Emit to. The wavelengths of the optical signals emitted at this time are, as described above, the wavelength λ1 of the variable wavelength transmitter I30, the wavelength λ2 of the variable wavelength transmitter II31, the wavelength λ4 of the variable wavelength transmitter III32, and the wavelength λ4 of the variable wavelength transmitter IV33. λ6, the variable wavelength transmitter V34 has a wavelength λ8, the variable wavelength transmitter VI35 has a wavelength λ7, the variable wavelength transmitter VII36 has a wavelength λ5, and the variable wavelength transmitter VIII37 has a wavelength λ3. Like this 8
Since the wavelengths of the optical signals emitted from the individual variable wavelength transmission units are different under the control of the wavelength control unit 3, they are mixed in the multiplexer 38 without being influenced by each other, and the lights of all wavelengths are The light enters the optical fiber 39 and is transmitted to the adjacent node device II 57 downstream. At this time, the node device I5
The packet A transmitted from the terminal I48 connected to the sub transmission line I40 of No. 6 to the terminal V52 connected to the sub of the node device III58 to the terminal V52 is an optical signal of the wavelength λ1 as described above. Device II 57.

As an optical signal of wavelength λ1, node device II
The packet A transmitted to the node 57 is the node device II5.
In step 7, relay transmission processing is performed as follows.

Node device I56 via the optical fiber 60
The optical signals of wavelengths λ1 to λ8 transmitted from the optical fiber are branched by the branching device 5 of the node equipment II57 and fixed wavelength reception unit I6.
Is incident on the fixed wavelength receiving unit VIII13. In the fixed wavelength receiving unit 6, only the optical signal having the wavelength λ1 passes through the filter 64 and is received by the photodiode (PD). Since the packet A is transmitted from the node device I56 as an optical signal of wavelength λ1, it is received by the fixed wavelength reception unit I6. The packet A received by the fixed wavelength receiving unit 16 is output to the demultiplexing / inserting unit I14.

In the decoder I66 of the separation / insertion unit I14, the address part of the input packet A is read. Since the destination of the reception of the packet A is the terminal connected to the adjacent node device III58 and not the terminal connected to the self-separation / insertion unit, the decoder 66 sets the output destination of the demultiplexer 67 to the FIFOII70. In this way, the packet A that has been cut into the FIFO II 70
Is read under the control of the insertion control unit 71, and is output to the buffer I22 via the selector 72.

In the decoder 73 of the buffer I22,
The address part of packet A is read again. Since the destination of reception of this packet A is the terminal V52 connected to the adjacent node device III58, the decoder 73 directs the output destination of the demultiplexer 76 to the dual port memory 77.
And at the same time, A5 is output to the write address counter 74 as the write start address value. The write address counter 74 loads the write start address and sequentially increments the counter to generate the write address of the input packet A,
Output to the dual port memory 77. The packet A is input to the input port of the dual port memory 77 via the demultiplexer 76, and is sequentially written in the storage area V according to the address output from the address counter 74.

Here, assuming that the operation cycle in which the packet A is written in the dual port memory 77 is T1,
When the packet A is read from the dual port memory 77, the fixed wavelength receiver V10 that outputs the packet to the demultiplexing / inserting unit V18 to which the terminal of the receiving destination of the adjacent node device III58 is connected receives the wavelength λ5 received by the node device II.
It is controlled so as to wait until the operation cycle T3 when the transmission wavelengths of the variable wavelength transmission unit I30 of 57 coincide.

In the node equipment II 57, the packet A
Of the operation cycle T written in the dual port memory 77
In the operation cycle T2 following 1, the ROM counter 97 of the wavelength controller 3 outputs 1 as the read address value from the wavelength control table I89 to VIII96 at the same time. The content of the wavelength control table is read by this 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 I89.
0, wavelength control table III91, wavelength control table I
V92, wavelength control table V93, wavelength control table V
The I94, the wavelength control table VII95, and the wavelength control table VIII96 have wavelengths λ1, λ2, and λ2, respectively.
Wavelength λ4, wavelength λ6, wavelength λ8, wavelength λ7, and wavelength λ
5 is a control signal corresponding to 5. These control signals are transmitted from the variable wavelength transmitter I30 to the variable wavelength transmitter VIII, respectively.
It is input to the drive unit 99 of 37. By this control, the channels transmitted by the variable wavelength transmitters 30 to 37, that is, the wavelengths are changed in synchronization with each other so that the same wavelength is not transmitted by a plurality of variable wavelength transmitters. Similarly to the above, in the operation cycle T2, the ROM counter 9 of the wavelength control unit 3
The read address value 1 output from 7 is input to the buffer control table of the buffer control unit 3. Also, various read control signals are generated in the read control unit 88 based on the clock signal output from the wavelength control unit 3. Based on these control signals, the buffer I22 to the buffer VI
II29 dual port memory 77 and FIFO II
I78 is read. The storage area of the dual port memory 77 of each of the buffers 22 to 29 read at this time is
As shown in Table 2 above, the buffer I22 is the storage area III, and is the buffer II23, the buffer III24, the buffer IV25, the buffer V26, the buffer VI27, the buffer VII28, and the buffer VI.
II29 is a storage area I, a storage area II, a storage area IV, a storage area VI, a storage area VIII, a storage area VII, and a storage area V, respectively. The packet read from each buffer in this way is converted into the above-mentioned predetermined optical signal in the variable wavelength transmission unit I30 to the variable wavelength transmission unit VIII37, and is transmitted to the optical fiber via the multiplexer 38. It

Since the packet A is written in the storage area V of the dual port memory 77 of the buffer I22,
It is read in the dual port memory read period Td of the subsequent operation cycle T3.

In the operation cycle T3, 2 is output from the wavelength counter table I89 to VIII96 as the read address value from the ROM counter 97 of the wavelength controller 3. The content of the wavelength control table is read by this address value. At this time, the transmission wavelength of the variable wavelength transmission unit I30 is set to λ5. Similarly, this address value 2 is also output to the buffer control unit 2 and the buffer control table is read. At this time, the area of the buffer I22 read from the dual port memory 77 is set to the storage area V. As described above, each buffer is read out by the control of each control signal, converted into a predetermined optical signal by the variable wavelength transmission unit, and transmitted to the optical fiber via the multiplexer 38. The packet A is read in the dual port memory read period Td of the operation cycle T3, is sent from the variable wavelength transmission unit I30 as an optical signal of wavelength λ5 to the optical fiber via the multiplexer 38, and is incident on the node device III58. .

Node device II5 via the optical fiber 61
The optical signals of wavelengths λ1 to λ8 transmitted from the optical fiber 7 are branched by the branching device 5 of the node device III58 and are incident on the fixed wavelength receiving unit VIII13 from the fixed wavelength receiving unit I6. In the fixed wavelength receiving unit V10, only the optical signal of wavelength λ5 passes through the filter 64 and is received by the photodiode (PD). The packet A is a node device I as an optical signal of wavelength λ5.
Since it was transmitted from I57, it is received by the fixed wavelength reception unit V10. Packet A received by fixed wavelength receiver V10
Is output to the separation / insertion unit V18.

In the decoder I66 of the separation / insertion section V18, the address section of the input packet A is read. The receiving destination of this packet A is the self-separation insertion unit V18.
Since it is a terminal connected to, the decoder 66 sets the output destination of the demultiplexer I67 to the I / F unit 68. As a result, the packet A is output to the I / F unit 68 via the demultiplexer I67, transmitted through the sub-transmission line V44, and then received by the terminal V52 which is the receiving destination, and the address portion of the packet is removed. After that, only the data part is taken out and desired processing is performed.

In this way, the source node device I56
The packet A transmitted from the terminal I48 connected to the sub transmission line I40 of the node device I58 to the terminal V52 connected to the sub transmission line V44 of the node device III58 is the node device I
After the packet A is transmitted from the variable wavelength transmission unit I30 of 56 at any wavelength (λ1 in the above description) according to the timing of input to the node device I56, the node device I56 is transmitted.
In the node device II57 adjacent to the upstream side of the II58, it is converted into the optical signal of the wavelength λ5 received by the fixed wavelength receiving unit V10 which outputs the packet to the demultiplexing / inserting unit V18 to which the terminal of the receiving destination of the node device III58 is connected. After that, the node device III58 receives the fixed wavelength reception V10, separates it at the separation / insertion unit V18, transmits it through the sub transmission line V44, and then receives it at the terminal V52.

(Second Embodiment) FIG. 11 shows a second embodiment of the internal structure of the buffers I22 to VIII29 of the first embodiment of the present invention.

In FIG. 11, reference numeral 106 is a decoder II.
FIFO 108 to 11 that read the address part of the input packet and write this packet
5, and instructs the demultiplexer III 107. Reference numeral 107 denotes a demultiplexer III which decodes the packet signal input from the separation / insertion unit into a decoder III10.
According to the instruction from 6, the data is output to a predetermined FIFO. Reference numerals 108 to 115 are FIFs provided for each transmission wavelength.
The packet signal output from the demultiplexer III 107 is O and is temporarily stored, and the packet signal is read according to an instruction from the buffer control unit. In the present embodiment, the FIFO IV 10 can be applied to packets for which the destination terminals are not connected to each other and the transmission wavelength does not need to be designated.
No. 8 to FIFOXI 115 are appropriately stored. At this time, a packet for which a transmission wavelength is not designated may be stored in a FIFO having a sufficient storage area. Reference numeral 116 is a selector III, which selects a predetermined FIFO from the FIFOIV 108 to the FIFOXI 115 according to a control signal from the buffer control unit and outputs the output signal to the variable wavelength transmission unit.

Table 3 shows an embodiment of the buffer control table which is preferably used in the buffer configuration example of FIG.
The number of the FIFO to be read is shown. The structure of the buffer control unit is the same as in FIG.

[0067]

[Table 3]

In this embodiment, in each operation period,
The FIFO shown in the buffer control table of Table 3 is selected, the packet signal that has been cut in is read out, and is output to the variable wavelength transmission unit. For example, in the operation period T1, in the buffer I22, the packet signal in which the FIFOIV is selected and written is read out and output to the variable wavelength transmission unit I30 and output at the wavelength λ1.

In this embodiment, by using a plurality of FIFOs, it is not necessary to give an offset to the read counter as in the structure of the first embodiment, so that the structure of the buffer section can be simplified.

(Third Embodiment) FIG. 12 is a diagram showing the configuration of a part of node devices in the network system according to the present embodiment. The structure of this node device is the same as the node device shown in FIG.
37 from fixed wavelength transmitter I 151 to fixed wavelength transmitter VI
It was changed to II158. Fixed wavelength transmitter I15
1 to fixed wavelength transmitter VIII158 has wavelength λ
Only the optical signals of 1 to λ8 can be transmitted.

The network system of this embodiment has the same configuration as that of FIG. 2, but the node device II57 in FIG.
12 is used as the node device IV59, and the node device I56 shown in FIG. 1 is used as in the first embodiment.

In this network configuration, from the terminal I48 connected to the node device II57 to the node device III.
Consider transmitting packet C to terminal V52 connected to 58.

As in the first embodiment, the packet C from the terminal I48 connected to the node equipment II 57 is the node equipment II.
It is input to the separation / insertion unit I14 of 57. Separation insertion part I1
The packet C inserted into the packet stream from the fixed wavelength reception unit I6 in 4 is transmitted from the fixed wavelength transmission unit I151 through the channel of wavelength λ1 and input to the node device III58. Although the node device III58 is a node device to which the destination terminal of the packet C is connected, the packet C has the wavelength λ1.
Since the data is transmitted through the channel No., the data is not input to the separation / insertion unit V18 to which the destination terminal is connected, but is relayed to the node device IV59. Similarly, the node device I
The packet C is also relayed by V59, and the packet C is the node device I5.
6 is input.

In the buffer I22 of the node device I56, the packet C is stored in the storage area V of the dual port memory 77 according to its address, and the variable wavelength transmission unit I
When the transmission wavelength of 30 reaches λ5, it is read out and sent to the node device II57. Node device II57
After the packet C is relayed and transmitted by the node device III58
Is received by the fixed wavelength receiving unit V10, separated by the demultiplexing and inserting unit V18 according to the address, and input to the terminal V52 which is the destination terminal.

In the present embodiment, a variable wavelength transmitter,
Since the node device which does not have the buffer and the means for controlling them is used, it is possible to construct the network system at a lower cost.

Further, the node device having the configuration as shown in FIG. 13 can be used as a part of the node device of the network system. The node device having the configuration shown in FIG. 13 has a configuration in which the fixed wavelength receiving unit corresponding to wavelengths λ7 and λ8, the demultiplexing / inserting unit, and the fixed wavelength transmitting unit are removed from the node device shown in FIG. The filter 159 is a filter for transmitting only channels not supported by this node device, that is, only signals of wavelengths λ7 and λ8 to the node device on the downstream side,
The wavelengths λ1 to λ6 are cut off. Even when the node device having such a configuration is present in the network system, at least one variable wavelength transmission unit capable of synchronously changing the transmission channel is provided in the network as in the node having the configuration shown in FIG. If there is a node device, the packet can be transmitted to a desired destination terminal by changing the channel for transmitting the packet, that is, the wavelength, in the node device.

In the above embodiments, the channels in the variable wavelength transmission section, that is, the transmission wavelengths are set to λ1 to λ8, but the number of channels is not limited to eight. However, when the number of channels is N, the pattern to be changed is to start from the first wavelength when the N wavelengths are arranged in the shortest order, select the odd numbered wavelengths in ascending order, and select the largest one. After the odd numbered wavelength, the largest even numbered wavelength is selected, the even numbered wavelengths are selected in descending order, the second shortest wavelength is selected, and then the shortest wavelength is selected again, or Starting from the second wavelength when the N wavelengths are arranged in the shortest order, the even-numbered wavelengths are sequentially selected in ascending order, the largest even-numbered wavelengths are selected, and the largest odd-numbered wavelengths are sequentially selected. By selecting the odd numbered wavelengths in descending order, selecting the shortest wavelength, and then selecting the second shortest wavelength again, the channel,
That is, the amount of change when changing the wavelength can be reduced, and even if all the variable wavelength transmitters of this pattern are used, it is possible to prevent a plurality of variable wavelength transmitters from transmitting at the same wavelength at the same time. However, other than such a pattern, it does not matter if the channels transmitted by the respective transmission units are changed synchronously and are not simultaneously transmitted on the same channel.

(Embodiment 4) The node device shown in FIG.
The node device of FIG. 1 has a configuration in which a fixed wavelength receiving unit corresponding to wavelengths λ7 and λ8, a demultiplexing / inserting unit, a buffer, and a variable wavelength transmitting unit are removed. A filter 159 similar to the configuration of FIG. 13 is also provided here. In the node device having such a configuration, the transmission wavelengths of the variable wavelength transmission unit are λ1 to λ, which are wavelengths received by the node device.
6 is set to be sequentially selected. For example, λ1 → λ
A pattern such as 3 → λ5 → λ6 → λ4 → λ2 → λ1 can be used. The present invention can be implemented by using the node device having such a configuration. However, when the node device having such a configuration is used, since the wavelengths λ7 and λ8 cannot be output from this node device, at least one other node device has a wavelength λ that can be output by this node.
At least one wavelength from 1 to λ6 and λ7, λ8
It is necessary to have a fixed wavelength receiving unit and a variable wavelength transmitting unit corresponding to. As a result, even if the signal is transmitted at any wavelength, it is transmitted at a desired wavelength by being relayed by the node device of FIG. 14 and the other node device. For example, the node device of FIG. 14 and the wavelengths λ1 and λ
7, there are node devices corresponding to λ8, and the other node devices are those shown in FIG. 12, in order to transmit the packet transmitted at λ2 at λ8, first transmit at λ2. 14 is output by the node device of FIG. 14, and the packet transmitted by λ1 by the node device corresponding to λ1, λ7, and λ8 is λ8.
It should output with. Further, node devices corresponding to λ1 and λ7 and node devices corresponding to λ7 and λ8 may be provided, and packets may be appropriately relayed in these node devices. The wavelength corresponding to each node device can be set appropriately, but in this embodiment also, in each node device, the wavelength output by the variable wavelength transmission unit is changed in a predetermined pattern, and the packet is read from the buffer in accordance with this. As a result, it is not necessary to determine the wavelength to be transmitted for each packet and control the transmission wavelength, so that efficient transmission can be performed.

(Embodiment 5) In this embodiment, FIG.
A node device as described is used. In FIG. 15, FIG.
The same reference numerals are given to the common parts with. The difference from the node device of FIG. 1 is that the wavelength output from the transmitter “I” 163 to the transmitter “VIII” 170 is not variable.
And a connection change unit 162 that changes the connection relationship between the buffer and the transmission unit, and a connection change control unit 161 that controls the connection change unit 162. In this embodiment, the wavelength of each transmitter is not changed,
A predetermined wavelength is assigned to each transmission unit, and the transmission unit that can be output from the buffer is changed in a predetermined pattern. The network configuration in this embodiment is similar to that shown in FIG.

Reference numeral 162 is a connection changing section which is a connection changing means, the input ends I to VIII are connected to the buffers I to VIII, respectively, and the output ends I to VIII are respectively transmitted. It is connected from the part I to the transmission part VIII. The input end I corresponds to the channel of λ1, and the input end I corresponds to the output end I. Further, λ2 corresponds to the input end II, and the output end II corresponds to the input end II. Similarly, each input end corresponds to each channel, and each input end corresponds to each output end. The internal configuration of the connection changing unit will be described later.

Reference numerals 163 to 170 denote transmitting units I to VI which are transmitting means using a semiconductor laser.
II, the packet output from the connection changing unit is converted into an optical signal of a predetermined wavelength and is sent to the optical fiber, which is the physical medium of the optical wavelength multiplex transmission line, via the multiplexer. As a semiconductor laser, a DFB having a multi-electrode structure
A (Distributed FeedBack) type laser is used. Λ1 to λ8 are assigned as the transmission wavelengths to the transmission units I to VIII by controlling the injection current amount of each electrode of the present DFB type laser.

FIG. 16 shows an example of the structure of a packet used in the first embodiment.
Reference numeral 1 is a field in which channel identification information of a packet is written, and specifically, a channel for identifying a channel processing group to which a separation / insertion unit connected via a sub-transmission path is connected to a destination terminal of the packet. The address is described. Reference numeral 172 is a field for describing the node device identification information of the packet, and specifically, a node address for identifying the node device to which the terminal of the destination of packet reception is connected is described. Reference numeral 173 is a data section carried by this packet. Tables 4 and 5 show the node address of each node device and the channel address for identifying each channel processing group in this embodiment.

FIG. 17 shows the separation / insertion section I to the separation / insertion section VII used in the fifth embodiment of the node device of the present invention.
It is an internal block diagram of I. Separation insertion part I to separation insertion part V
The internal configurations of III are all the same. In this embodiment, a comparator I174 and a latch I175 are used instead of the decoder in FIG. In FIG. 17, reference numeral 174 is a comparator I, which compares the node address portion, which is the node device identification information of the packet output from the latch I, with the comparison input value #I,
When they match, the demultiplexer I outputs the separation instruction signal, and when they do not match, the relay instruction signal is output. As the value of the comparison input value #I, the value shown in Table 4 is used corresponding to the node address of each node device. Code 17
A latch 5 latches the node address portion of the packet and outputs it to the comparator. Reference numeral 67 is a demultiplexer, which compares the input packet with the comparator I
I / F unit or FI
Output to FOII.

FIG. 18 is an internal configuration diagram of the buffers I to VIII used in the first embodiment of the present invention. The buffers I to VIII have the same internal structure. Also in the buffer, a comparator II176 and a latch II177 are used instead of the decoder of FIG.
Is used. In this configuration, the input packet is divided into a packet in which the output end to be output by the connection changing unit is designated and a packet in which the output end to be output is not designated, and is temporarily stored. Furthermore, the packet in which the output end to be output by the connection changing unit is designated is temporarily stored separately for each output end to be output. The output terminals I to VIII of the connection changing section are respectively from the transmission section I to the transmission section VI.
Since the transmission units I to VIII correspond to the channel processing group I to the channel processing group VIII, respectively, they are connected to the output terminal I to the output terminal V.
III corresponds to the channel processing groups I to VIII. In the present embodiment, the packet in which the output end to be output by the connection changing unit is designated is a packet whose reception destination is a terminal connected to the adjacent node via the sub transmission line, and the designated The output end corresponds to the channel processing group to which the separation / insertion unit to which the destination terminal is connected via the sub transmission line.

In FIG. 18, reference numeral 176 is a comparator II, which compares the node address part of the packet output from the latch II with the comparison input value #II. Is output, and if they do not match, an unspecified signal is output. As the value of the comparison input value #II, the value corresponding to the node address of the node device adjacent in the transmission direction downstream of each node device is used. Reference numeral 177 is a latch II, which latches the node address portion of the packet and
Output to I.

FIG. 19 is an internal block diagram of the connection changing unit used in the first embodiment of the present invention. The connection change section
It has eight input ends and eight output ends. In FIG. 19, reference numerals 178 to 185 denote selectors I to VIII. Selector I to selector VIII
Eight signals from the input end I to the input end VIII are input,
A packet input from a predetermined input end is output to the output end based on a selection signal described later output from the connection change control unit. As a result, the connection relationship between the input end and the output end is set, and the channel processing group that processes the transmitted packet is changed.

FIG. 20 is an internal block diagram of the connection change control unit used in the first embodiment of the present invention. In FIG. 20, reference numerals 186 to 193 denote connection control table I to connection control table VIII, respectively. The connection control table I to the wavelength control table VIII are sequentially read according to the address value output from the 3-bit ROM counter, and a predetermined selection signal is output to each selector of the connection changing unit. These tables are composed of a read only memory (ROM). The contents of the connection control tables I to VIII will be described later. It is a ROM counter and the clock generator is the same as that in FIG.

In the fifth embodiment, the contents of the connection control tables I to VIII are shown in Table 6.
It is set as shown in.

Table 6 shows the input terminals selected by the selectors VIII from the selectors I of the connection changing section under the control of the connection control section. The selectors I to VII are shown.
Since I is connected to the output end VIII from the output end I, the connection relationship between the input end and the output end is determined by this Table 6. Further, Table 6 is set so that no two or more input terminals are connected to the same output terminal at the same time. Table 7 shows the relationship between the input end and the output end set by the connection control table 1 to the connection control table VIII for each output address value of the ROM counter.

On the other hand, the structure of the buffer control unit in this embodiment is the same as that of FIG. 7, but the offset values of the buffer control table I to the buffer control table VIII are shown in Table 8.
It is set as shown in. These 16 tables are synchronously circulated and read by the ROM counter. Therefore, the connection relationship between the input terminal and the output terminal is a circulation pattern in which the output terminals to which the respective input terminals are connected are circulated.

In Table 6, Table 7 and Table 8, when the connection destination of each input terminal is the output terminal I, the offset value for reading the dual port memory of the buffer is the storage area I.
Value A1 is assigned to each of the input terminals, and the connection destinations of the respective input terminals are respectively output terminal II, output terminal III, output terminal IV, output terminal V, output terminal VI, output terminal VII, and output terminal VII.
In the case of I, storage area II, storage area III,
Storage area IV, storage area V, storage area VI, storage area V
Values corresponding to II and storage area VIII are assigned. Further, in the buffer of FIG. 18, the storage areas I to VIII are associated with the channel processing group to which the separation / insertion unit to which the reception destination terminal is connected in the adjacent node belongs. Therefore, by setting the connection control table as shown in Table 6 and further setting the buffer control table as shown in Table 8, the packets stored in the respective buffers are received by the terminal destined for reception at the adjacent node. When the connection with the output end corresponding to the channel processing group to which the connected separation / insertion unit belongs is performed, the reading from the buffer is controlled.

As shown in FIG. 21, the operation of the node device according to the present embodiment is such that eight consecutive operation cycles T are obtained by cyclically reading out eight values from each of the 16 tables.
1, T2, T3, T4, T5, T6, T7, and T8. Further, these eight operation cycles are Td which is a read period of the dual port memory and T which is a read period of the FIFO depending on the operation in the buffer.
It is divided into f.

Hereinafter, FIG. 2, FIG. 3, FIG. 6, FIG. 7, FIG.
16 ,. ． ． With reference to the time charts of FIGS. 20 and 11, the operation of the fifth embodiment of the present invention will be described.
The transmission source is the terminal I48 connected to the sub transmission line I40 of the node device I56, and the reception destination is the node device III.
A description will be given of an example of packet transmission of the terminal V52 connected to the sub transmission line V44 of 58. In the following description, this packet is called packet A. Further, in the following description, the same reference numerals will be used for the same components of different node devices for convenience.

In the terminal I48 connected to the sub-transmission line I40 of I56 of the node device which is the transmission source, the node device I
The data sent to the terminal V52 connected to the sub transmission line V44 of II58 includes the channel address value of the terminal V52 connected to the sub transmission line V44 of the node device III58 which is the reception destination shown in Tables 4 and 5. As “5”,
With the configuration shown in FIG. 16 added with “3” as the node address value, the packet A is assembled and transmitted to the separation / insertion unit I14 of the node device I56 via the sub transmission line I40. The I / F unit of the separation / insertion unit I14 of the node device I56 sequentially scrapes the packet A transmitted via the sub transmission line I40 into the FIFO I. Packet A FIFO
After the scraping into I is completed, the insertion control unit
Find a break in the packet flow being read from the FIFO, and input the FIFO to be output by the selector 72 to the FIFO I
The reading of the FIFO II is stopped and the reading of the FIFO I is started so as to set the input from the. After the reading of the packet A that has been written into the FIFOI is completed, the insertion control unit determines the FIFO to be output by the selector 72.
The input of O is switched again to the input from FIFOII, the reading of FIFOI is stopped, and the FIFOI
The reading of I is resumed. The packet A output from the selector 72 is input to the buffer I.

In the buffer I, the node address part of the input packet A is latched by the latch II 177 and compared with the node address value of the node device II adjacent in the downstream in the transmission direction by the comparator II 176. The node address part of packet A is set to "3",
Since it does not match the node address value “2” of the node device II adjacent in the downstream in the transmission direction, the comparator II outputs a non-designated signal to the demultiplexer II. With this undesignated signal, the demultiplexer II sets the output destination of the packet A to the FIFO III.

Here, assuming that the operation cycle in which the packet A is squeezed into the FIFO III is T8, the packet A is read by the control of the buffer controller in the FIFO read period Tf of the adjacent operation cycle T1.

In the subsequent operation cycle T1, the connection change control unit 1
The ROM counter 97 of 61 simultaneously outputs 0 as a read address value to the connection control tables I to VIII. The content of the connection control table is read by this address value.

The content read at this time is, as shown in Table 6 above, a selection signal for connecting the output end I to the input end I from the connection control table 1. Table III, connection control table IV, connection control table V, connection control table VI,
Connection control table VII and connection control table VII
I has an output terminal II to an input terminal II and an output terminal II.
I to input terminal III, output terminal IV to input terminal IV, output terminal V to input terminal V, output terminal VI to input terminal VI, output terminal 7 to input terminal 7, and output terminal VIII to input terminal VII
It is a selection signal for connecting to I. These selection signals are input from the selector I178 of the connection changing unit 162 to the selector VIII185, a predetermined input terminal is selected, and connected to the output terminal.

At the same time, in the read period Td of the dual port memory of the operation cycle T1, the connection change control unit 161
The read address value 0 output from the ROM counter 97 is input to the buffer control table of the buffer control unit 2. The contents of the buffer control table VIII are read from the buffer control table I by this address value. As shown in Table 8 above, the content read at this time is the offset value A1 corresponding to the storage area I from the buffer control table I, and the buffer control table II, buffer control table III, buffer control table IV, The buffer control table V, the buffer control table VI, the buffer control table VII, and the buffer control table VIII are respectively stored in the storage area I.
I, storage area III, storage area IV, storage area V, storage area VI, storage area 7, and offset value A2, offset value A3, offset value A4, offset value A5, offset value A6, offset corresponding to storage area VIII The value A7 and the offset value A8. These offset values are respectively transferred from the buffer 122 to the buffer VII.
It is output to the read address counter 75 of I29.
In the read control unit of the buffer control unit, based on the clock signal output from the connection change control unit, the read enable FIFO III of the dual port memory is prohibited from being read, and the output of the multiplexer I is output from the dual port memory. Outputs a control signal for setting. By inputting these control signals, the buffer I22
, The read address counter 75 outputs the offset value A1 output from the buffer control table I80.
Is loaded and the counter is sequentially incremented to generate an address for reading the packet that has been scratched in the storage area I, and outputs it to the dual port memory 77. Packets are sequentially read from the output port of the dual port memory 77 by this read address and output to the input terminal I of the connection changing unit.

At this time, the packet read from the buffer I is addressed to the terminal I on the sub transmission line I of the adjacent node device II57 because the input end I is connected to the output end I.

At the same time, in the read period Td of the dual port memory of the operation synchronization T1, in the buffer II23, the read address counter 75 is loaded with the offset value A2 output from the buffer control table II81 and stored in the same manner as in the buffer I22. Region I
The packet cut into I is read from the dual port memory 77 and output to the input terminal II. Similarly, storage area III of buffer III24 and buffer IV2
5, storage area IV of buffer V26, storage area VI of buffer VI27, storage area VI of buffer VII28, storage area VII of buffer VII28, and storage area VI of buffer VII29.
The packets are read from II and II respectively, and output end II
From the output terminal VIII. The packets read at this time are addressed to the terminals connected from the separating / inserting unit II of the adjacent node device II57 to the separating / inserting unit VIII via the sub transmission path.

In the FIFO read period following the operation cycle T1, the read control unit of the buffer control unit uses the clock signal output from the connection change control unit to prohibit reading of the dual port memory and FIFOI.
It outputs a control signal for permitting the reading of II and setting the FIFO III as an input source output from the multiplexer II. By inputting these control signals, FIFOIII is read in the buffer 122,
It is output to the input terminal I via the multiplexer II.
At this time, the packet A that has been cut into the FIFO III is read out. Similarly, in the buffers II23 to VIII29, the packets scratched into the FIFOIII are sequentially read and output from the input end II to the input end VIII.

In the connection change unit, the packet output from the buffer I22 to the buffer VIII29 is output to the predetermined output terminal as described above based on the selection signal output from the connection change control unit. The packet output from each output terminal of the connection changing unit is converted from the transmitting unit I into an optical signal of a predetermined wavelength in the transmitting unit VIII, and is output to the multiplexer 38.

As described above, the wavelengths of the optical signals emitted at this time are as follows: the transmitter I163 has the wavelength λ1, the transmitter II164 has the wavelength λ2, the transmitter III165 has the wavelength λ3, and the transmitter IV.
166 is the wavelength λ4, the transmitter V167 is the wavelength λ5, the transmitter VI168 is the wavelength λ6, and the transmitter VII169 is the wavelength λ4.
7, and the transmitter VIII170 has a wavelength λ8. In this way, since the wavelengths of the optical signals emitted from the eight transmitters are different, they are mixed in the multiplexer 38 without being influenced by each other, and the lights of all wavelengths are incident on the optical fiber 39. And the node device II57 adjacent to the downstream side.
Be transmitted to. At this time, the sub transmission line I of the node device I56
From the terminal I48 connected to the node 40 to the node device III5
The packet A transmitted to the terminal V52 connected to the sub transmission line V44 of No. 8 is transmitted to the node device II57 as the optical signal of the wavelength λ1 as described above.

As an optical signal of wavelength λ1, node device II
The packet A transmitted to the node 57 is the node device II5.
7 the channel processing group is changed and the wavelength λ5
Is relayed and transmitted to the downstream node device through the channel.

The node device I56 is transmitted via the optical fiber 60.
The optical signals of the wavelengths λ1 to λ8 transmitted from the receiver are branched by the branching device of the node device II57 and are incident from the receiver 16 to the receiver VIII13. In the receiver I, only the optical signal of wavelength λ1 passes through the filter I, and the photodiode (P
D) Received at I. Since the packet A is transmitted from the node device I56 as an optical signal of wavelength λ1, it is received by the receiving unit I. The packet A received by the receiving unit I6 is output to the separating / inserting unit I14.

In the separation / insertion unit I14, the node address portion of the input packet A is latched by the latch I175 and compared with the node address value of the own node device II by the comparator I174. Since the node address portion of the packet A is set to "3" and does not match the node address value "2" of the own node device II, the comparator I outputs a relay instruction signal to the demultiplexer I. By the relay instruction signal, the demultiplexer I sets the output destination of the packet A to the FIFO II. The packet A cut into the FIFO II in this manner is read out under the control of the insertion control unit and output to the buffer I22 via the selector 72.

In the buffer I, the node address portion of the input packet A is latched by the latch II 177 and compared with the node address value of the node device III adjacent downstream in the transmission direction by the comparator II 176. Since the node address part of the packet A is set to "3" and coincides with the node address value "3" of the node device III adjacent in the transmission direction, the comparator II outputs a designated signal to the demultiplexer II. . By this designated signal, the demultiplexer II sets the output destination of the packet A in the dual port memory table, and at the same time, the channel address of the packet A is "5".
Therefore, A5 is output to the write address counter 74 as the write start address value. The write address counter 74 loads the write start address and sequentially generates the write address of the packet A input by incrementing the counter.
Output to the dual port memory 77. The packet A is input to the input port of the dual port memory 77 via the demultiplexer II, and the packet A is sequentially written in the storage area V according to the address output from the address counter 74.

When the packet A is read from the dual port memory, the output end V and the packet A corresponding to the channel processing group V to which the separation / insertion unit V to which the terminal of the reception destination of the adjacent node device III58 is connected are written. Input terminal I of the connection changing unit to which the existing buffer is connected
This is performed in an operation cycle T5 in which and are connected.

Here, if the operation cycle in which the packet A is written in the dual port memory is T1, the connection change control unit 16 is operated in the operation cycle T2 following the operation cycle T1.
The ROM counter 97 of 1 outputs 1 as a read address value to the connection control tables I to VIII at the same time. The content of the connection control table is read by this address value. The contents read at this time are shown in Table 6 above.
As shown in FIG. 5, the connection control table I is a selection signal for connecting the output end I and the input end VIII. The connection control table II, the connection control table III, the connection control table IV, the connection control table V, and the connection Control table V
I, connection control table VII, and connection control table V
III has an output end II as an input end I and an output end I as
II to input terminal II, output terminal IV to input terminal III, output terminal V to input terminal IV, output terminal VI to input terminal V, output terminal VII to input terminal VI, and output terminal VIII to input terminal. 7 is a selection signal for connection. These selection signals are sent from the selector I178 to the selector V, respectively.
Input to III 185, a predetermined input end is selected and connected to the output end.

Similarly to the above, in the operation cycle T2, the read address value 1 output from the ROM counter 97 of the connection change control unit 161 is input to the buffer control table of the buffer control unit 161. Further, various read control signals are generated in the read control unit based on the clock signal output from the connection change control unit. Based on these control signals, the dual port memory and the FIFO III of the buffer VIII 29 are read from the buffer I 22. The storage area of the dual port memory of each buffer read at this time is the buffer 1 as shown in Table 8 above.
Is the storage area II, and the following is buffer II,
The buffer III, the buffer IV, the buffer V, the buffer VI, the buffer VII, and the buffer VIII are respectively the storage area III, the storage area IV, the storage area V, the storage area VI, the storage area VII, the storage area VIII, and the storage area. Region I. The packet thus read from each buffer is input from the input end I of the connection changing unit to the input end VIII, and is output from the transmission unit I163 to the transmission unit VIII170 from the predetermined output end connected as described above. The signal is converted into a predetermined optical signal from the transmission unit I to the transmission unit VIII, and is transmitted to the optical fiber via the leather incinerator 38.

In the subsequent operation cycle 3 and operation cycle 4 as well, the ROM counter 97 of the connection change control unit 161 outputs 2, 3 as read address values, the connection control table and the buffer control table are read, respectively, and the predetermined values are set. Dual port memory and FIFO
The packet is read from, the connection changing unit transfers to a predetermined channel processing group, and is output as an optical signal from the transmitting unit.

Since the packet A is scratched into the storage area V of the dual port memory of the buffer I22, the dual port memory read period Td of the subsequent operation cycle T5.
Read at.

In the operation cycle T5, 4 is output from the ROM counter 97 of the connection change control unit 161 as a read address value to the connection control tables I to VIII. The content of the connection control table is read by this address value. At this time, the input end I is connected to the output end 5.

Similarly, this address value 4 is also output to the buffer control unit 2 and the buffer control table is read out. At this time, the area read from the dual port memory of the buffer I22 is set to the storage area V. The packet A is read in the dual port memory reading period Td of the operation cycle T5, and the input end I of the connection changing unit is read.
From the transmitter V167 to the wavelength λ5.
Is transmitted to the optical fiber through the multiplexer 38 and is incident on the node equipment III58.

Thus, the packet A received by the receiving section I3 of the node equipment II57 as the optical signal of the wavelength λ1 is
The channel changing group is changed from 1 to V by the connection changing unit, and is transmitted from the transmitting unit V24 as an optical signal of wavelength λ5.

The optical signals of the wavelengths λ1 to λ8 transmitted from the node equipment II57 via the optical fiber are branched by the branching device of the node equipment III58 and enter the receiving portion I6 to the receiving portion VIII13. In the receiver V, only the optical signal of wavelength λ5 passes through the filter V and the photodiode (P
D) Received at V. Since the packet A is sent from the node equipment II 57 as an optical signal of wavelength λ5, it is received by the receiving unit V. The packet A received by the receiver V10 is
It is output to the separation / insertion unit V18.

In the separation / insertion section V18, the node address section of the input packet A is latched by the latch I175 and compared with the node address value of the self node apparatus III by the comparator I174.

Since the node address portion of the packet A is set to "3" and coincides with the node address value "3" of the own node device III, the comparator I outputs the demultiplexing instruction signal to the demultiplexer I.

In response to this separation instruction signal, the demultiplexer I outputs the input packet A to the I / F section. I
The packet A output to the / F section is transmitted through the sub-transmission line V, and then received by the terminal V that is the destination of the reception. After the address section of the packet is removed, only the data section is extracted and the desired packet is obtained. Processing is performed.

In this way, the source node device I56
The packet A transmitted from the terminal I48 connected to the sub transmission line I40 of the node device I58 to the terminal V52 connected to the sub transmission line V44 of the node device III58 is the node device I
After being transmitted at the wavelength of λ1 from the transmission unit I of the node device II57, in the node device II57, the separation / insertion unit V1 to which the terminal of the reception destination of the node device III48 is connected via the sub transmission line.
The channel of the channel processing group to which 6 belongs, that is, after the channel processing group is changed to the channel processing means corresponding to the optical signal of the wavelength λ5 which is the transmission wavelength, the channel processing group is transferred, and then received by the node device III58 reception V10 and separated / inserted by the V18. After being separated by the sub-transmission line V, the sub-transmission line V is transmitted and then received by the terminal V.

In this embodiment, the connection changing unit is
Since the selectors are used in combination and the input terminals of these selectors are selected by the ROM table, the control of the connection changing unit is simplified.

The number of input terminals and output terminals of the connection changing unit may be the same as the number of channels.

In the present embodiment, since the transmission wavelength of one transmitting section is not variable, a cheaper light source can be used, and wavelength control is unnecessary.

[0125]

[Table 4]

[0126]

[Table 5]

[0127]

[Table 6]

[0128]

[Table 7]

[0129]

[Table 8]

(Other Embodiments) In the present invention, the wavelength at which the packet is output from the node is selected (the packet is output from the buffer in synchronization with the transmission wavelength of the transmitting unit becoming a desired wavelength, Or, the output from the buffer is read from the buffer in synchronization with the connection to the transmitter that outputs the desired wavelength), and the wavelength (channel) for transmitting packets is changed to the desired wavelength, and the desired wavelength is changed. By separating the transmitted packet by the separating means, the packet is transmitted to the desired destination terminal. In this configuration, as shown in FIG. 16, a packet is separated by the separating means (node device) address indicating the separating means for separating the packet into the packet, or the node device storing the separating means. By giving a wavelength address indicating a wavelength (channel) to be used as a destination address, the node device that relays the packet determines the timing of reading the packet from the buffer by referring to the wavelength address, and the separating means By determining whether or not to separate the packet by referring to the separation means address, it is possible to reduce the addition required to determine the address of the packet. However, as in the third and fourth embodiments, when not all the node devices are configured to change the wavelength for transmitting the packet, the packet input to the separating means is already transmitted at the predetermined wavelength. Since it is necessary to determine whether or not, the separating means cannot judge whether or not to separate only by referring to the separating means address.
In such a case, the node device that outputs the packet at the wavelength corresponding to the wavelength address of the packet, when outputting the packet, adds information indicating that the packet has already been transmitted at the predetermined wavelength. By doing so, in the separating means, it is possible to determine whether or not to separate by referring only to the added information and the separating means address.

Although the ring type network configuration is shown in the above embodiment, the present invention is not limited to this.
Other network configurations such as bus type are also possible.

Further, in the above embodiment, one terminal is connected to the separating / inserting means, but this is not limited to one, and it is possible to connect a plurality of terminals. It is also possible to connect another network to which a plurality of terminals are connected to the separating / inserting means.

Further, in the above embodiment, the separating / inserting unit is used as a means for separating the packet to the connected terminal and inserting the packet from the terminal into the packet stream on the multi-channel transmission line. It may be provided separately from the means. However, even in that case, it is preferable that the separating means is located upstream of the inserting means.

Further, in the above embodiment, each wavelength is separated and received by each node device by using a branching device and a filter, but a demultiplexer capable of separating wavelength-multiplexed light for each wavelength may be used. Moreover, the configuration of the node device can be further simplified.

The storage capacity of the memory such as the FIFO of the separation / insertion unit and the buffer used in each node device and the dual port memory is the size of the packet to be transmitted, the transmission capacity required for the network, and the operation of changing the transmission channel. It can be determined in consideration of the length of the cycle.

In the above embodiment, an optical signal is used as the signal,
We realized multiple channels with multiple lights of different wavelengths,
A plurality of channels can be realized with an electric signal by a frequency multiplexing technique or the like.

As described above, according to each of the above-described embodiments, even if the signals are destined to the same destination, the signals for which the transmission channel is not specified are transmitted to various channels. Can be averaged.

Further, since the channels are switched at the same time so that the respective signals are not transmitted to the same channel at the same time, the arbitration control for each channel becomes unnecessary.

Further, since the above-mentioned switching is performed every predetermined time, the signal transmission intervals to the channels can be equalized.

By storing the signal for which the transmission channel is designated and the signal for which the transmission channel is not designated separately, it is possible to perform transmission on the designated channel and transmission without designation by simple control.

By storing the designated transmission channels separately, it is possible to perform transmission to a desired channel with simple control.

Further, by changing the transmission channels of the plurality of transmitters corresponding to the plurality of storage means for storing the transmission signals, the configuration and control of the exchange unit can be simplified.

Further, by switching the connection relationship between the plurality of storage means for storing the transmission signal and the transmission section for transmitting the signal on the fixed channel, the configuration and control of the exchange section can be simplified. .

Further, by switching the transmission channel according to a predetermined pattern so that each signal is not transmitted to the same channel at the same time, arbitration control for each channel becomes unnecessary.

[0145]

As described above, according to the present invention, even if signals of the same destination are not designated as transmission channels, they are transmitted to various channels.
The throughput of each channel can be averaged.

[Brief description of drawings]

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

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

FIG. 3 is a diagram showing a configuration of a fixed wavelength receiving unit according to the first embodiment of the present invention.

FIG. 4 is a diagram showing the configuration of the separation / insertion unit according to the first embodiment of the present invention.

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

FIG. 6 is a diagram showing a memory map of the dual port memory according to the first embodiment of the present invention.

FIG. 7 is a diagram showing a configuration of a buffer control unit according to the first embodiment of the present invention.

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

FIG. 9 is a diagram showing a configuration of a variable wavelength transmission unit according to a first embodiment of the present invention.

FIG. 10 is a diagram showing a time chart of the first embodiment according to the present invention.

FIG. 11 is a diagram showing a configuration of a buffer according to a second exemplary embodiment of the present invention.

FIG. 12 is a diagram showing the configuration of a node device according to a third embodiment of the present invention.

FIG. 13 is a diagram showing another configuration of the node device according to the third embodiment of the present invention.

FIG. 14 is a diagram showing the configuration of a node device according to a fourth embodiment of the present invention.

FIG. 15 is a diagram showing the configuration of a node device according to a fifth embodiment of the present invention.

FIG. 16 is a diagram showing the structure of a packet used in the fifth embodiment of the present invention.

FIG. 17 is a diagram showing the configuration of a separation insertion part used in the fifth embodiment according to the present invention.

FIG. 18 is a diagram showing a configuration of a buffer unit used in a fifth embodiment according to the present invention.

FIG. 19 is a diagram showing the configuration of a connection changing unit used in the fifth embodiment of the present invention.

FIG. 20 is a diagram showing the configuration of a connection control unit used in a fifth embodiment of the present invention.

FIG. 21 is a diagram showing a time chart used in the fifth embodiment of the present invention.

FIG. 22 is a diagram showing a configuration of a first conventional example.

FIG. 23 is a diagram showing an 8 × 8 electric switch of a first conventional example.

FIG. 24 is a diagram showing another 8 × 8 electric switch of the first conventional example.

FIG. 25 is a diagram showing a 2 × 2 electric switch of a first conventional example.

FIG. 26 is a diagram showing the structure of a packet.

FIG. 27 is a diagram showing a configuration of a second conventional example.

[Explanation of symbols]

1 control unit 2 buffer control section 3 Wavelength control unit 4 optical fiber 5 turnout 6 to 13 fixed wavelength receiver 14-21 Separation insertion part 22 to 29 buffers 30-37 variable wavelength transmission 38 Multiplexer Optical fiber 40-47 Sub transmission line 48-55 terminals 56-59 node equipment 60-63 optical fiber

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04L 12/42 H04B 10/20 H04J 14/00 H04J 14/02

Claims (11)

(57) [Claims] 1. A node device comprising a plurality of storage means for storing a signal to be transmitted, a channel changing means for sequentially switching a channel to which a signal from each of the storage means is transmitted, and a transmission from the node device. And a control means for controlling the signal to be transmitted regardless of the channel changed by the channel switching by the channel changing means when transmitting a signal whose transmission channel is not specified. A node device characterized by: 2. The channel changing means according to claim 1, wherein the channels from which the signals from the storage means are transmitted are switched simultaneously so that the signals from the storage means are not transmitted to the same channel at the same time. A node device characterized by the above. 3. The channel changing means according to claim 1, wherein the channels from which the signals from the storage means are transmitted are switched simultaneously so that the signals from the storage means are not transmitted to the same channel at the same time. Further, the node device is characterized in that the switching is performed every predetermined time. 4. The storage device according to claim 1, wherein the storage unit distinguishes between a signal for which a channel is designated when transmitting from the node device and a signal for which a channel is not designated, and stores the signals. Node device. 5. The channel switching unit according to claim 4, wherein the control unit switches the channel by the channel changing unit when the signal stored in the storage unit specifies a channel for transmission from the node device. A node device, wherein the signal is read from the storage means in synchronization with switching to the designated channel by the. 6. The storage device according to claim 4, wherein the storage unit stores a signal for which a channel is designated when transmitting from the node device, separately for each designated transmission channel. Node device. 7. The transmitter according to claim 1, further comprising a plurality of transmitting means for transmitting a signal from the storage means, the plurality of transmitting means corresponding to each of the plurality of storage means, and the channel changing means transmitting the respective transmitting means. A node device characterized by changing a channel. 8. The transmitter according to claim 1, further comprising a plurality of transmitting means for transmitting the signal from the storage means through a specific channel, wherein the respective transmitting means can transmit different channels, and the channel changing means includes the A node device characterized by switching the connection relationship between a storage means and each of the transmission means. 9. The signal from each of the storage means according to claim 1, wherein the channel changing means follows a predetermined pattern so that the respective signals from the respective storage means are not simultaneously transmitted to the same channel. A node device, characterized in that it switches a channel on which is transmitted. 10. A network system for connecting a plurality of node devices with a plurality of channels, wherein at least one node device has a plurality of storage means for storing a signal to be transmitted, and a signal from each of the storage means. And a channel changing means for sequentially switching channels to be transmitted, and a channel changed by the channel changing means by the channel changing means when transmitting a signal in which a transmission channel for transmitting from the node device is not designated. And a control means for controlling the signal to be transmitted regardless of the above. 11. A signal transmission control method in a node device having a plurality of storage means for storing a signal to be transmitted, wherein the channel to which the signal from each storage means is transmitted is switched one after another, In the case of transmitting a signal whose transmission channel is not specified when transmitting from the device, control is performed such that the signal is transmitted regardless of the channel changed by the channel switching. .