JPH06232884A - Exchange - Google Patents

Abstract

PURPOSE:To prevent a cell from being abandoned at an input node in the large capacity exchange and to facilitate and accelerate exchange processing. CONSTITUTION:This exchange is provided with plural input parts and output parts, plural nodes 1-i (i=1, 2...128) provided with exchange processing control parts are connected through a loop-shaped highway 3, and the transmission capacity of this highway 3 is set larger than the total capacity of the input parts of these plural nodes. Since the plural nodes partially take the charge of exchange control, the exchange processing can be facilitated and accelerated, and decentralized control is performed. Further, since hardware scale is almost proportional to the square root of input capacity, the device can be economically constituted. On the other hand, the cell abandonment can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch, and more particularly to a switch in which a plurality of nodes are connected by a highway (broadcast type transmission line) and a cell or the like in an asynchronous transfer mode (ATM) is switched.

[0002]

2. Description of the Related Art The capacity of an exchange, such as an ATM exchange, for exchanging cells having a constant word length as a unit is increasing. As a high-capacity switch, a control-precedence type ATM switch using a broadcasting type transmission line was proposed in the document IEICE Technical Committee Material SSE 90-39 (No. SSE90-39, FIGS. 2 and 4). ing. The exchange proposed above is a cell obtained from an input section having a plurality of input ports, an output section having a plurality of output ports, an input section and an output section with a broadcast type transmission medium (highway), and an input section. First, the header processing unit controls all channels to be switched by the header and opens the gate of the desired output port, and then the signal (cell) at the input unit.
To the selected output port of the output section.

[0003]

In the exchange using the above-mentioned broadcasting type transmission medium, since the exchange processing is collectively performed on the headers of the cells of all the channels obtained at a plurality of input ports (nodes), the exchange processing is performed on the input node. A large-capacity buffer that stores cells is required, and broadcast-type media (highway)
, Does not have sufficient transmission capacity, cell discard occurs at the input node. Furthermore, if the number of exchange channels becomes extremely large, the amount of hardware of the exchange processing control unit becomes extremely large, which makes it impossible to realize. Therefore, a main object of the present invention is to realize a large-capacity exchange using a broadcasting type transmission line with a small capacity of a buffer memory of an input section and a small number of discarded cells. It is another object of the present invention to realize an exchange using a broadcast type transmission line with little cell discard and at the same time easy and fast exchange processing.

[0004]

In order to achieve the above object, an exchange according to the present invention is configured by connecting a plurality of nodes having an input section and an output section and having an exchange processing control section by a loop highway. , The exchange processing control is distributedly controlled by a plurality of nodes. Preferably, the transmission capacity of the highway is set to be equal to or more than the total capacity of the input units of the plurality of nodes. Further, when the exchange processing control unit is provided in each output unit of the plurality of nodes,
It may be provided in the input section. The allocation of the capacity of each input unit of the plurality of nodes may be fixed or movable. The highway preferably uses an optical transmission line such as an optical fiber, but is not limited to this.

[0005]

By controlling exchange processing in a distributed manner by a plurality of nodes, the exchange processing of each output node can be simplified and speeded up, and the device as a whole of a large capacity exchange can be downsized.
Can speed up. That is, if all lines are exchanged together, the scale of hardware constituting the exchange increases in proportion to almost the square of the channel. However, by sharing the exchange control with a plurality of output nodes, the scale of hardware of the exchange as a whole is increased. Since is almost proportional to the number of channels, the processing speed of the node can be increased and the overhead for expanding the scale is small.
If the highway transmission capacity between a plurality of nodes is equal to or larger than the total capacity of the input nodes, cell discard at each node can be prevented and the input buffer memory can be reduced.

[0006]

Embodiment 1 FIG. 1 is a block diagram showing the configuration of a first embodiment of an exchange according to the present invention. In this embodiment, 60,000 channels (10Tbi
It is an exchange that can exchange t / s). A plurality of nodes 1-i (i = 1 ... 128) having an input part and an output part are connected in a loop by a highway 3 having a large transmission capacity and formed of an optical transmission line such as an optical fiber. Each node 1
-I is coupled to a plurality of input channels 5-i and output channels 6-i via an interface 7-i.
In this embodiment, the number of input / output channels of each node 1-i is 51.
2, and the transmission rate of one channel is 150 Mb / s. Therefore, the capacity of the input part of one node is 512 ×
150 Mb / s, and the total capacity of the input parts of multiple nodes is 512 × 128, about 60,000 channels, and the optical transmission line 3
Since the transmission capacity of is more than the total capacity of the input nodes,
The 20 Gb / s optical fiber is composed of (512 + 1) parallel transmission lines.

A master node 2 is provided in the optical highway 3, and a high-speed clock (bit synchronization) signal c is supplied from the master node 2 to each node 1-i via a line 4. Further, a gate signal g for synchronizing the cell signal is supplied from the master node 2 to each node 1-i via the optical highway 3. In this embodiment, STM-1, 5
12 channels are assigned to one node, but 10
The number of nodes may be reduced by assigning a node to each of 24 and 2048 channels. In that case, the control and processing of the node output side buffer is changed only by the increase in the number of channels.

FIG. 2 is a block diagram showing the configuration of an embodiment of the node shown in FIG. Each node 1 has an output unit 11 and an input unit 12. The output unit 11 inputs the cell signal and the gate signal g from the optical transmission line 3 into the output node 11, and the photoelectric conversion unit 11-2 converts the optical signal from the input access unit 11-1 and the access unit 11-1 into an electric signal. , A switching processing control unit 11-3 having a switch for switching cells from the photoelectric conversion unit 11-2 and its logic circuit, and a control unit 11-
It has a buffer 11-4 for temporarily storing the cell signal from the cell 3. The input unit 12 synchronizes the cell signal from the buffer 12-4 and the buffer 12-4 that temporarily stores the cell signal from the external input channel, and inputs the signal to the electric / optical converter 12-2. 3 and an access unit 12-1 for coupling the output of the electrical / optical converter 12-2 to the optical transmission line 3.

Exchange processing control section 11-3 and input control section 1
The 2-3 receives the gate signal g and the clock signal c from the line 4, confirms the cell position, and controls the cell intake from the highway 3 and the cell transmission to the highway 3. In the cell fetching from the highway 3, since the output node number is assigned to the transfer cell, the number is checked at the output node and the one addressed to the own node is fetched. For cell transmission to the highway 3, the cell to be transmitted is inserted after the cell of the immediately preceding switch node. It is conceivable that all signals are received from the highway 3 and reproduced and sent out, or one part is branched, but in the present embodiment, the signal is branched. The switch in the exchange processing control unit 11-3 may be an optical switch.

FIG. 3 is a block diagram showing the structure of the interface unit 7, and FIG. 4 is a diagram showing a process of signal format conversion in each block of FIG. It should be noted that the drawings also show an interface unit of an output unit and an input unit for the sake of simplicity. That is, signals flow from left to right at input nodes and right to left at output nodes. The interface unit 7 of the input unit will be described below. The input channel of 512 is divided into 32 blocks of 16 blocks, and 16 blocks of 150 Mb / s serial signals (channel signals) in one block are respectively serial-parallel conversion circuits 71-1 ... 71.
It is converted to 512 parallel by -16, and is further time-divisionally multiplexed by 16 in the demultiplexing circuit 72. The output of the block 1 is 512 parallel signals having a transmission capacity of 150/32 Mb / s.

In block 2, the outputs of 32 blocks of the same type as block 1 are demultiplexed by the demultiplexing circuit 73 in a time division manner.
2 multiplexed and speed converted, transmission capacity 20 Gb / s 51
Two parallel signals, each 20G optical module 7
It is converted into an optical signal by 4-1 ... 74-32 and sent to the input node 12. The optical module 74 is omitted when the input control unit 12-3 of the input node 12 is composed of an electric circuit.

4 (a), (b), (c) and (d) of FIG.
Are STMs on the left side of the serial-parallel conversion circuit 71 of FIG.
-1,150 Mb / s 1-channel serial signal, right parallel signal of serial-parallel conversion circuit 71, demultiplexing circuit 72
Represents the 16 multiplexed parallel signals on the right side of and the parallel signal on the right side of node 1, and is 64 bytes (512 bits) in (a)
Is a cell signal and includes a header of control information and information bits to be exchanged. The header includes the destination node number. Generally, the transmission speed of one transmission line constituting the highway 3 is B, the number of parallel lines is P, the number of nodes is N,
When the number of wavelength division multiplexing is W, the following relationship is established. However, C is an exchange capacity, that is, a highway transmission capacity. B × P × W = C (1) Therefore, B = C / (P × W) (2)
Becomes

The number T of transmitters and the number R of receivers can be expressed as T = P × N (3) R = P × N × W (4), respectively. Although wavelength multiplexing can reduce the speed of the highway, it increases the number of receivers.

Embodiment 2 FIG. 5 shows the configuration of a node in a second embodiment of the exchange according to the present invention. In this embodiment, the highway 3 is 6
It is configured by four optical transmission lines, and each optical transmission line is configured to be transmitted by 16 wavelength multiplexing. Then, the potential increase in transmission capacity due to wavelength multiplexing is used for reduction of highway speed, reduction of the number of optical transmission lines, and reduction of optical receiving equipment. That is, although 512 optical transmission lines with a transmission capacity of 20 Gbit / s are used in the first embodiment, in the second embodiment, 16 optical transmission lines are used.
Transmission capacity of 10 Gbit / s by wavelength multiplexing
The same exchange capacity as the exchange capacity of 20 Gbit / s × 512 of the exchange of the first embodiment is realized by using 64 optical transmission lines.

In FIG. 5, the output section of the node is provided with a demultiplexer 11-6 for separating 16 wavelengths on each of the 64 highway optical transmission lines 3, and the optical demultiplexer 11-6 is used. The signal is applied to the optical receiver 11-5, converted into an electrical signal, and input to the switching process control unit 11-3 including a switch and a logic circuit. Although the input section is not shown in detail, the 512 channels of the input are divided into 64 blocks, and the 16 channels of each block are respectively provided in the optical transmitter 1.
In 2-5, wavelength multiplexing and phase adjustment are performed and the signal is sent to the optical transmission line 3.

In this embodiment, like the first embodiment, the number of channels of one node is 512 and the number of nodes is 128. However, if the number of channels of one node is 2048, the number of nodes may be 32. Further, since the high-speed signal and the high-speed optical transmission line are used, the phase matching between the respective signals is performed by using the gate signal g from the previous node as a trigger to operate the counter and identifying the cell break. . This phase matching means is required only between the data and the gate signal g at each node, and has an advantage that the phase matching control through the entire exchange is unnecessary.

Third Embodiment FIG. 6 is a block diagram showing the configuration of a third embodiment of the exchange according to the present invention. In this embodiment, the exchange capacity (320
Gbit / s = STM-1 × 2048 ch, number of optical transmission lines (8 × 16), highway transmission speed (2.4 Gbi)
t / s), the number of nodes (16), and the number of wavelength division multiplexing (16). A cell signal input at a specific node is transmitted through a specific optical transmission line group 3-p (p = 1, 2, ... 16). In the figure, 16 nodes 1-i (i = 1, 2,
Each of 3 ... 16) is composed of one transmitting switch 120 having a transmitting function and 15 receiving switches 110 having only a receiving function. Transmission switch 12 of each node
0 is connected to each of the reception switches 110 of all the other nodes in a loop without overlapping. That is, the 16 nodes 1-i are composed of 8 optical transmission line groups 3
-1 ... 3-8 are connected in a loop. Each of the optical transmission line groups 3-1 ... 3-8 is eight lines of 2.4 Gbit / s. The transmitting switch 120 and the 15 receiving switches 110 of each node when connected to it form a unit switch.

Since the configuration operation of each node 1-i is the same, the configuration operation of one node 1-1 will be described below. 150Mb / input from outside to node 1-1
The signal of s, 128 channels is 16 in the optical transmitter 12-5.
The signal is divided into eight blocks of channels, and is transmitted as an optical signal through eight 16-wavelength multiplexed optical transmission lines 3-1.
In the node 1-2, in the reception switch 110-1 which constitutes a part of the output section of the node 1-2, the optical signal from the optical highway 3-1 is branched by the demultiplexer 11-6, and the optical receiver 11- 5
Is converted into an electric signal, the address is confirmed by the output exchange control unit 11-3, and the cell having the number addressed to the own node is read. The remaining signal branched by the demultiplexer 11-6 is the optical amplifier 1
It is amplified at 2-6 and sent to the next node 1-3. The signal that has circulated through the loop optical transmission line 3-1 and finally returned to the node 1-1 has the demultiplexer 11-6, the optical receiver 11-5, the switch, the demultiplexer, and the buffer of the transmission switch 120. It is terminated by the exchange control unit 11-3. The plurality of unit reception switches (for example, 110-2 to 110-16 in the node 1-1) in each node receive only the signals sent from the transmission switch 120-1 of the specific node 1-1. For example, the unit reception switch 110- of the node 1-2
1 receives only the signal sent from the transmission switch 120 of the node 1-1. Further, the unit reception switch 110-1 of the node 1-2 receives only the signal sent from the transmission switch of the node 1-16. The signals read by the plurality of unit reception switches of each node are read out to the interface via a common buffer memory (not shown).

Fourth Embodiment FIG. 7 is a block diagram showing the configuration of a fourth embodiment of the exchange according to the present invention. In this embodiment, wavelength division multiplexing is further applied to the third embodiment (FIG. 6). Eight optical transmission line groups 3-i (i = 1, 2, 3, ... 16) in FIG.
Is substantially the same as that of the second embodiment except that a single optical transmission line group 31 is formed by wavelength multiplexing. Node 1-
In the configuration of i, the demultiplexer 11-6 of FIG. 6 is configured by the demultiplexer 17-1 that demultiplexes the 16-wavelength multiplexed signal, and one transmission switch 120 is provided at the input unit of each node 1-i. And a multiplexer 17-3 for wavelength-multiplexing the outputs of the reception switches 120-2 to 120-16.
The highway 31 is composed of eight transmission lines having a transmission speed of 2.4 Gb / s.

Embodiment 5 FIG. 8 is a block diagram showing the configuration of a fifth embodiment of the exchange according to the present invention. In this embodiment, the same optical transmission line is shared by several nodes, that is, time division multiplexed. Cells from a plurality of nodes 1-i are multiplexed on the same optical transmission line (consisting of 128 lines with a transmission capacity of 2.4 Gb / s). The plurality of lines forming the optical highway 31 are not divided into unit groups, but the entire optical highway is grouped into a high-capacity highway. Therefore, the optical transmitter 12-6 of each node has a capacity for all transmission lines.

Sixth Embodiment FIG. 9 is a block diagram showing the configuration of a sixth embodiment of the exchange according to the present invention. In this embodiment, wavelength multiplexing is further applied to the fifth embodiment to reduce the number of lines. Therefore, at the output of the node, the wavelength demultiplexer 11-6 is provided between the highway 3 and the optical receiver 11-5. Other parts are substantially the same as the parts with the same numbers in FIG. This has the effect of reducing the number of transmission lines of the highway 3 from 128 to 8. In any of the first to sixth embodiments, distribution of cell bit information to a plurality of lines is
Either of (a) one cell is bit-expanded and transmitted by a plurality of transmission lines, and (b) one cell is serially transmitted by one fiber, either of which may be used.

Seventh Embodiment FIG. 10 is a block diagram showing the configuration of a seventh embodiment of the exchange according to the present invention. In the present embodiment, the exchange processing is performed by the input units of the nodes that are substantially distributed, and the bandwidth is limited to the input units.
The access control means is provided to reduce the replacement processing of the output section. In the figure, the input part of each node 1-i is
The plurality of access units 102-1 to 102-16, the destination node number of the cell to be transmitted, and the access unit 102-
Cell distribution unit 10 for distributing cells to 1 to 102-16
3, and the outputs of the access units 102-1 to 102-16 are loop optical transmission line groups 30-1 to 30-, respectively.
16 are sent.

The input unit of each node 1-i demultiplexes an optical signal from a loop (here, an optical loop is applied) 19 for transmitting information of the optical transmission line group 30-1 and the band control table 100. An optical receiver 115 which takes in via 111 and converts into an electric signal, an intra-node exchange control of the separation circuit 116 by using cell control information or the like from the output of the optical receiver 115, and an access unit 102-1 to 102-16 The exchange processing control unit 119 for sending control information to the.

In the bandwidth control table 100, the utilization rate for each node is set in advance. The exchange processing control unit 119 takes in information from the bandwidth control table 100, calculates the number of outputtable cells assigned to each input port, and instructs each of the access units 102-1 to 102-16. When the signal source side of each node corresponds to the bursty signal as much as possible and averages and outputs, only the control for the input of the average value ± several tens% is performed. This average value is managed by the information written in the bandwidth control table 100.

12 and 13 are diagrams showing the construction of an embodiment of the access unit 102. As shown in FIG. Access unit 10
2 has a counter 121 for counting the number of cells of the signal to be sent, and sets the number of cells that can be output from the control circuit 119. Then, cells are sent out until the number of cells to be sent out reaches the above-mentioned outputtable number of cells, and thereafter, the cells are stored in the buffer 122. In the embodiment of FIG. 12, the cell read from the buffer 122 is converted into an optical signal by the photoelectric converter 124, and the optical signal is multiplexed into the optical highway 3 and then the optical amplifier 1 is output.
It is amplified to a predetermined level at 25. In the embodiment of FIG. 13, the cells read from the buffer 122 are the modulator 12
After being converted into an optical signal by the photoelectric converter 124 by 6, the optical signal is amplified to a predetermined level by the optical amplifier 125. When such access control is performed, the cells to be transmitted may have the transmission capacity of the optical highway 3 smaller than the total amount of signals that can potentially be transmitted from each node. In that case, access-restricted light 11 8 is sent to the optical highway 30,
It is instructed whether or not there is a vacancy in the signal frame transmitted by the optical highway 30. That is, the accelerator limited light 118
If there is not (if the signal power is weak), the cell is sent out assuming that there is a space in the frame.

FIG. 11 shows a time chart of access on the transmission side of the access unit 102. The signal power of the transmission line 3 is checked, and if there is no signal, the cell is sent out. The output of the cell branches the gate signal, and a certain delay is given to the gate signal by the delay line 123.
Output to. The optical amplifier 125 sets the required level. Signals can be sent by (a) converting electrical signals into light at each node and multiplexing them into a highway signal, (b) cell sending node sends DC light, and each node modulates the light. There is a way to do it. Further, wavelength division multiplexing may be performed for transmission.
The optical switches for the number of cells designated in the band control table 100 are turned on. The access limiting light 118 determines the number of cells to be sent out. This is the bandwidth control table 1
It is generated in the control unit 119 based on the information from 00.
This signal is wavelength-multiplexed with the cell signal (wavelength λ1) at the wavelength λ2.

Eighth Embodiment In the seventh embodiment, the bandwidth control table 100 is used, but in the present embodiment, means for distributing the control and limiting the cell transmission to the input section of each node is provided.

The means for limiting the cell transmission provided in the input part of each node is a means for notifying all the nodes of the number of transmission requests of the own node, the number of transmission requests transmitted from the own node and all other nodes. And means for calculating the delivery efficiency E given by the equation (6). As a means for notifying all nodes of the number of transmission requests of the own node, a separate line is attached,
Alternatively, the cell is superposed on the cell of the immediately preceding exchange cycle.

Let di be the number of transmission requests from each node. The total number of requests D is D = d1 + d2 + d3 +. ． ． ． ． It is given by dn (5).

Letting the exchange capacity of the exchange be T, the transmission efficiency E
E = T / D (6) Each node transmits the number di ′ cells calculated by the equation (7).

Di ′ = di × E (7) However, when the total number of requests D is smaller than the exchange capacity T of the exchange, the cells of the number of transmission requests di of the own node are transmitted.

In this embodiment, the number of cells to be transmitted does not exceed the exchange capacity T, and efficient allocation is possible for all input nodes. In other words, the more cells that are stored in the input buffer, the larger di 'becomes, and the node load on the buffer can be equalized. In addition, since there is no need for interaction between nodes, control can be performed in a short time.

[0033]

In the exchange of the present invention, the exchange control can be shared by a plurality of nodes, so that the exchange process can be simplified and speeded up. Particularly when configuring a large capacity exchange, when the exchange control is collectively controlled, the hardware scale is generally proportional to the square of the input capacity. However, in the exchange of the present invention, distributed control is performed. Is almost proportional to the square of the input capacitance, so that the device can be economically constructed. Further, by setting the transmission capacity of the highway to be equal to or more than the sum of the input capacity of each node, cell discard can be prevented.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of an exchange according to the present invention.

2 is a block diagram showing a configuration of an embodiment of the node of FIG. 1. FIG.

FIG. 3 is a block diagram showing a configuration of an interface unit 7.

FIG. 4 is a diagram showing a process of signal format conversion in each block of FIG. 3;

FIG. 5 is a diagram showing a configuration of a node in a second embodiment of the exchange according to the present invention.

FIG. 6 is a block diagram showing the configuration of a third embodiment of the exchange according to the present invention.

FIG. 7 is a block diagram showing a configuration of a fourth embodiment of the exchange according to the present invention.

FIG. 8 is a block diagram showing the configuration of a fifth embodiment of the exchange according to the present invention.

FIG. 9 is a block diagram showing the configuration of a sixth embodiment of the exchange according to the present invention.

FIG. 10 is a block diagram showing the configuration of a seventh embodiment of the exchange according to the present invention.

11 is a diagram showing a time chart of transmission side access of the access unit 102. FIG.

FIG. 12 is a diagram showing a configuration of an embodiment of an access unit 102.

FIG. 13 is a diagram showing a configuration of an embodiment of an access unit 102.

[Explanation of symbols]

1: Node 2: Master node 3: Highway (transmission line) 4: Clock signal line 5: Input channel 6: Output channel 7: Interface 11: Output unit 11-1: Access unit 11-2: Photoelectric converter 11-3 : Exchange processing control unit 11-5: Optical receiver 11-6: Demultiplexer 12-1: Access unit 12-2: Electro-optical converter 12-3: Input control unit 12-5: Optical transmitter 12-6: Optical amplifier 12-7: Multiplexing circuit 12-8: Multiplexing circuit 17-1: Demultiplexer 30: Highway (transmission line) 71: Parallel / serial converter 72: Multiplexing / separating circuit 73: Multiplexing / separating circuit 74 : Optical module 100: Band control table 102: Access unit 103: Cell distribution circuit 110: Reception switch 111: Demultiplexer 116: Separation circuit 117: Buffer 119 Exchange processing control 120: transmission switch 121: counter 122: Buffer 123: optical delay line 124: Electrical / optical converter 125: an optical amplifier

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Morihito Miyagi, 1-280 Higashi Koikeku, Kokubunji, Tokyo 1-280, Central Research Laboratory, Hitachi, Ltd. (72) Katsuya Tanaka 1-280, Higashi Koikeku, Kokubunji, Tokyo Hitachi, Ltd. Central Research Center

Claims (13)

[Claims] 1. A plurality of nodes having a plurality of input units, an output unit and a switching control unit are connected by a loop highway, and the transmission capacity of the highway is set to be equal to or more than the total capacity of the input units of the plurality of nodes. An exchange characterized by being configured as follows. 2. The exchange according to claim 1, wherein the exchange processing control unit is configured to perform exchange control at each output unit of the plurality of nodes. 3. A plurality of nodes having a plurality of input units, an output unit and an exchange processing control unit are connected by a loop highway, and the exchange processing control unit performs exchange control at each input unit of the plurality of nodes. An exchange characterized by being configured as described above. 4. The exchange according to claim 3, wherein the control unit sends the number of transmission request cells di of its own node to another node and totals the number of transmission request cells of its own node and other nodes, When the sum total value D is larger than the exchange capacity T, the number of cells equal to the product di · T / D of the transmission request cell number di of the own node and the ratio T / D of the exchange capacity and the total value D. An exchange having a means for transmitting a signal. 5. The exchange according to claim 4, comprising a table in which information on the utilization rate of each node is set, and means for transmitting the utilization rate information from the table to each node, and the exchange processing. An exchange, wherein the control unit has means for controlling the number of transmission cells of the input unit based on the utilization rate information and the number of transmission request cells of the own node. 6. The exchange according to claim 1, 2, 3, 4 or 5, wherein the highway comprises a plurality of transmission lines.
An exchange characterized in that a specific line or a set of lines is connected to a specific node or a set of nodes. 7. An exchange according to claim 1, 2, 3, 4 or 5, wherein the cell signals of the input section are parallelized and transmitted using the plurality of lines. 8. The exchange according to claim 1, 2, 3, 4, or 5, wherein the cell signal of the input section is transmitted by using a single line of the highway. 9. An exchange according to claim 1, 2, 3, 4 or 5, wherein said line is an optical transmission line. 10. The switch according to claim 9, further comprising means for time-division-multiplexing and wavelength-multiplexing transmitting the signal from the input section through the optical transmission line. 11. An exchange according to claim 10, wherein a cell signal of a specific channel of the input section is transmitted using a single wavelength. 12. The switch according to claim 10, wherein the cell signals of the input section are developed in parallel and transmitted using a plurality of wavelengths. 13. The exchange according to claim 1, further comprising means for multiplexing and transmitting a timing signal on the highway line, wherein the node uses the timing signal for input / output timing control. An exchange characterized by having means for performing.