JPH07264209A - Line allocation method and communication network using it - Google Patents

Abstract

PURPOSE:To allow each mode to dispersively manage a wavelength by allowing a node receiving a flag sent to a control signal line to select a line not used by a multiplex line and to send an idle signal thereby securing a right of use. CONSTITUTION:This communication network has a configuration being a composite of a loop network of the token passing system and a star wavelength multiplex network of the broadcast system, and each of nodes 201-204 acquires a token by the token passing system in the loop line to make acquisition of the token and wavelength allocation in the star line. That is, the token acts as a flag. Then a node acquiring one token existing on the network in the loop transmission line selects a line not used for th star line being a wavelength multiplexed line and sends an idle signal to the selected line to reserve the right of use of the line and makes communication by using a wavelength allocated to the node.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line allocation method for a system in which a plurality of nodes share a plurality of signal lines and, more particularly, to a wavelength allocation method and a network configuration in a WDM optical communication system. Is.

[0002]

2. Description of the Related Art In recent years, a system in which a large amount of information such as a moving image is captured in a computer network has been studied. For example, Masahiro Eda, Takahiro Shiozawa, Masahiko Fujiwara "OQE91"
-126, WDM composite optical LAN and other wavelength multiplexing communication systems described in Technical Report of IEICE [Optical Quantum Electronics] WDM composite optical LAN have been proposed. In this system, a plurality of wavelengths λa and λ1 to λn are used, λa communicates low-speed data and wavelength control information through an existing LAN, and λ1 to λn provide a communication service that does not depend on speed by wavelength multiplexing transmission. To do. The signals of these wavelengths λa and λ1 to λn are accommodated on one loop transmission line.

As a wavelength division multiplex transmission system, a wavelength division multiple access (DA-WDMA) system by demand assignment is adopted, which is used when high speed communication or long holding time communication is requested between certain nodes. , A specific wavelength is assigned to communication between the nodes, and a line channel is secured by the wavelength to perform communication.

The wavelength allocation method will be described in more detail with reference to FIGS. 8 and 9.

FIG. 8 is a block diagram of a node function of the system, 801 is a communication control circuit of an existing LAN, and 802.
Is a DA-WDMA communication control circuit, and 803 connects the signal from a terminal (not shown) to 801 or 802 (for example, a small-capacity signal is 801 and a large-capacity signal is 802). Interface circuit, 804 is a demultiplexer, 805 is a multiplexer, 81
Reference numeral 0 is an optical transmission line.

FIG. 9 is a diagram showing a network configuration of the system. Reference numeral 901 is a control node for managing the wavelength used by each node for communication, and 902 to 905 are nodes for performing communication between terminals.

First, a method of transmitting high speed data from the node 903 to the node 905 will be described. When the node 903 requests to send high-speed data such as video, the interface circuit 803 sends a transmission request and a reception node information signal to the existing L.
The information is sent to the communication control circuit 801 of the AN, which converts the information into an optical signal of wavelength λa, token passing, TD
It is transmitted by the existing communication method such as MA and slotted loop. The optical signal is accommodated in one optical transmission line by the multiplexer 805 and output to the optical transmission line 810, and the nodes 904 and 9
After passing 05, the control node 901 is reached. Since the control node 901 has a wavelength table and manages which node each wavelength is used for, it first checks the state of the receiving node 905, and if it is receiving, waits for the transmission of the node 903. If it is not receiving, the transmission wavelength is assigned by the wavelength table, the node 905 is notified and the reception is prepared, and then the node 903 is notified and the transmission is started. The signal from the control node 901 has a wavelength λa.
Sent over the existing LAN at nodes 905 and 903.
The signal is separated by the demultiplexer 804 from other wavelength signals,
Input to 1. 801 transmits the wavelength allocated to 802, sets the wavelength of the optical transmitter inside 802 to the allocated wavelength at node 903, and sends out the video signal, and node 905 transmits the wavelength of the filter of the optical receiver inside 802. Is set to the assigned wavelength and the video signal from the node 903 is received. When the transmission from the node 903 is completed, 903 notifies the control node 901 of the completion of the transmission, and
01 updates the wavelength table, and 905 cancels the filter setting and terminates the communication.

Similarly, communication is performed between the other nodes by assigning a wavelength by the control node.

In this way, all wavelength allocation is centrally managed by the control node.

[0010]

However, in the above conventional example, since the control node manages all wavelengths,
There is a problem that the control node is required to have high reliability and the cost of the control node becomes high.

Further, there is a drawback that the communication procedure becomes complicated because the communication is performed according to the instruction of the control node.

Therefore, in view of the above problems, an object of the present invention is to disperse wavelength management among the nodes without providing a control node.

As a method of managing wavelengths in a distributed manner, for example, each node can freely select and use a used wavelength and perform retransmission control when a signal collides, or a wavelength used in a network. Although there is a method of detecting and selecting an empty wavelength and transmitting the signal, both methods have a problem that throughput decreases because different nodes may simultaneously transmit signals and signal collision may occur.

[0014]

The present invention provides a multiplex line having a plurality of lines, a control signal line including at least a control signal for controlling the line use right of the multiplex line, and the multiplex line.
A method for allocating a line in a communication network composed of a plurality of nodes connected to respective control signal lines, wherein a node transmitting the flag to the control signal line and incorporating the flag is used in the multiple line. By using the line allocation method, which selects the non-existing line and secures the right to use the line by sending an idle signal to the line, each node disperses wavelengths in a distributed manner without providing a control node. Is managed and the collision of signals does not occur.

[0015]

【Example】

(Embodiment 1) FIGS. 1, 2 and 3 are diagrams showing a first embodiment of the present invention. FIG. 1 shows an optical node configuration, FIG. 2 shows a network configuration, and FIG. 3 shows a time chart.

First, the optical node and network configuration of the present invention will be described.

In FIGS. 1 and 2, 101 is a tunable laser diode (Tu-LD) for transmitting an optical signal of an arbitrary wavelength, and 102 is an optical transmission for driving 101 to convert an input signal into an optical signal. A circuit, 103 is a tunable wavelength filter (Tu-FIL) for extracting an optical signal of an arbitrary wavelength from optical signals of a plurality of wavelengths, 104 is a photodiode (PD) for converting the optical signal into an electric signal, 1
Reference numeral 05 is an optical receiving circuit for equalizing and amplifying and identifying and reproducing the signal from 104, 106 is a wavelength allocation control circuit for managing the communication wavelength of the star line, 107 is an optical or electrical receiver,
Reference numeral 108 denotes a token passing communication control circuit, and 10
9 is an optical or electric transmitter, 201 to 204 are the optical nodes of FIG. 1, 211 is an optical or electric transmission line, 212 is an upstream optical fiber transmission line, 213 is a downstream optical fiber transmission line, and 221 is 4 × 4 star coupler. In FIG. 1, the solid lines represent signal lines and the broken lines represent control lines. The tunable wavelength filter 103 is an element or device that can change the transmission wavelength, and a fiber Fabry-Perot filter or the like can be used. The tunable laser diode 101 is an element or device that can change the oscillation wavelength according to the value of the current flowing through the wavelength control terminal, and for example, a DFB laser or a DBR laser can be used. PIN-PD or APD is used for the photodiode.

In the present embodiment, 109 is an optical transmitter using an LED, 107 is an optical receiver using a PD, and 21
Although 1 is described as an optical fiber transmission line, these may use an electric transmitter, an electric receiver, and an electric transmission line.

The network of this embodiment has a structure in which a token passing loop network and a broadcast star wavelength division multiplexing network are combined, and in the loop transmission line, a node that has acquired one token existing on the network. Perform communication by obtaining the communication right, and in the star type transmission line, the wavelengths assigned to the nodes are used to perform communication without collision of signals with each other. Each optical node connected to the network has both types of communication control circuits, and performs communication by selecting a transmission path suitable for the signal input to the optical node according to the type of the signal. For example, a signal from a computer device connected to an optical node is transmitted by a loop type transmission line suitable for transmitting small data size information at high speed, and a signal from a video device connected to the optical node is transmitted for a long time. It is transmitted by a star type transmission line suitable for transmitting data to many users.

The line allocation method in this network is
The loop line uses the token passing system, and the star line uses the line allocation (wavelength allocation) system of the present invention.
In this embodiment, the loop line is a multiplexed line of star lines, which is a wavelength multiplexing line, that is, a control signal line for transmitting a control signal for controlling the right to use wavelengths.

Next, the wavelength allocation system of the star type communication line of this embodiment will be described with reference to FIGS. Now, a case where a video signal is temporarily transmitted from the node 201 to the node 203 and from the node 202 to the node 204 will be described.

Since the node 201 acquires the transmission right on the star line and allocates the wavelength, the node 201 acquires the token on the loop line by the token passing method. In the token passing method, a signal called a token that gives the right to transmit data is circulated in the network,
The node that received the token sends its own node address, destination node address and data to the transmission line as a packet signal, and each node receives the signal and communicates if the destination address is addressed to itself. It is a method.
That is, the token plays the role of a flag in this embodiment.

The token circulates in one direction in the loop type network at the wavelength λa while being regenerated and relayed at each node. The node 201 receives the token at the receiver 107 (corresponding to FIG. 3-a; hereinafter (b) to (s) show corresponding portions of the time chart of FIG. 3). At the token passing communication control circuit 108. Read. 108 notifies the wavelength allocation control circuit 106 that the token has been received, and 10
Reference numeral 6 controls the tunable filter 103 to detect the optical wavelength used in the star line. In the detection method, first, the filter 103 is scanned over the entire wavelength range used in the star network. In the star network, all signals reach the node, so as the filter is scanned, the signals of the wavelengths used sequentially pass through 103, are converted into electrical signals by the photodiode 104, and are received by the receiving circuit 105. It The received signal is sent to the wavelength allocation control circuit 106, and the node 201 knows the wavelength used in the star line. Reference numeral 106 updates the wavelength management table, selects an unused wavelength, and controls so as to set the oscillation wavelength of the tunable LD 101 to that wavelength. In 101, current is injected into the wavelength control terminal from 106, and the oscillation center wavelength is set to the wavelength λ2, for example. The optical transmission circuit 102 drives the Tu-LD 101 and sends an idle signal of wavelength λ2 to the optical fiber transmission line (b). The pattern of the idle signal at this time may be DC light or a fixed pattern (a mark ratio of 1/2 is good). Further, in order to notify the wavelength information to the node 203, the wavelength allocation control circuit 106 notifies the token passing communication control circuit 108 of the information of the selected wavelength λ2, and transmits it from the transmitter 109 together with the address of the node 201 and the destination address. It is sent to the path 211 (c). The transmitted signal is input to the node 202 and the communication control circuit 10
Read in 8. Since the node 202 has received the token (d), it scans the filter 103 in the same manner as the node 201 and selects an empty wavelength. Node 202 at this time
Receives the idle signal of wavelength λ2 output from the node 201 to the star line, it selects an empty wavelength λ4 other than wavelength λ2. Then, the idle signal of wavelength λ4 is sent to the star line (e), and the information of wavelength λ4 is sent to the loop line (f). The signal sent to the loop line is
It is input to the node 203 through the transmission path 211. Node 2
In 03, the signal is received by the receiver 107 (g) and processed by the token passing communication control circuit 108. The 108 takes in the signal addressed to its own node by looking at the destination address of the signal, reads the wavelength information λ2, and notifies the wavelength allocation control circuit 106 of it. Reference numeral 106 controls the tunable filter 103 to set the reception wavelength to λ2. However, when 103 receives a signal from another node, the filter setting is left as it is and the node 201 is notified that communication is in progress using the token passing communication line. On the other hand, the optical signal of wavelength λ2 sent from the node 201 to the upstream optical fiber transmission line 212 is distributed by the star coupler 221, and is input to all the nodes through the downstream optical fiber transmission line 213. Node 203
When the center wavelength of the tunable filter 103 is set to λ2, the optical signal input to is transmitted through 103, converted into an electric signal by the photodiode 104, and the optical receiving circuit 1
It is received at 05 (h). 105 is a wavelength allocation control circuit 1
06 is notified that the signal is received, and information for instructing the start of communication is sent from the transmitter 109 to the transmission path 211 via the token passing communication control circuit 108 (i). The transmitted signal is input to the node 204 (j), the wavelength allocation control circuit 106 reads the wavelength information λ4, and sets the filter to λ4. When the filter is set and an idle signal of wavelength λ4 is received (k), information for instructing the start of transmission is sent from the transmitter 109 to the transmission line 211 (l). The information signal is the transmission line 211.
Is transmitted to the node 201 (m), and the communication control circuit 108 of the token passing system takes in the data addressed to the own node. Reference numeral 108 instructs the video equipment connected to the node 201 to start transmission. Wavelength allocation control circuit 10
Reference numeral 6 controls the optical transmission circuit 102 to input a video signal to the tunable LD 101, convert the video signal into an optical signal of wavelength λ2, and send it to the upstream optical fiber transmission line 212 (n). The video signal is distributed by the star coupler 221, passes through the downstream optical fiber 213, and is input to all the nodes. The video signal input to the node 203 is incident on the incident surface of the tunable filter 103. Since the center wavelength of 103 is already set to λ2, the video signal passes through 103, is converted into an electric signal by the photodiode 104, and is received by the receiving circuit 105 (o). The video signal input to another node is lost without being received because the wavelength of the tunable filter is not set. On the other hand, the information signal input to the node 201 from the loop line is regenerated and relayed as it is, except for the data addressed to the own node, and sent to the transmission line 211 (p). The signal is node 202
(Q), and a video signal transmission instruction is given to the video equipment connected to the node 202. Node 202
Converts the video signal into an optical signal of wavelength λ4 and converts it into an optical transmission line 21.
2 (r), and the video signal is sent to the star coupler 221.
And is input to the node 204. Since the filter is already set in the node 204, the video signal can be received (s).

In this way, communication is performed without collision of signals from the node 201 to the node 203 and from the node 202 to the node 204. The above communication operation is similarly performed between other nodes.

In the present embodiment, separate transmission lines are used for the star line, which is a wavelength multiplexing line, and the loop line, which is a control signal line, but they can also be multiplexed on the same transmission line by wavelength multiplexing.

(Second Embodiment) A second embodiment will be described.

The network configuration and node configuration are the same as in the first embodiment. In the first embodiment, the tunable filter is scanned to select an empty wavelength after the token is acquired. However, in the present embodiment, the tunable filter is constantly scanned to update the wavelength management table and the wavelength is acquired when the token is acquired. Wavelength allocation is performed by selecting an empty wavelength from the management table. However, since the tunable filter cannot be scanned while the signal is being received, the token is acquired and wavelength is assigned after the tunable filter is scanned at least once after the reception is completed. Other operations are the same as those in the first embodiment.

(Embodiment 3) A third embodiment will be described.

The network configuration is the same as in the first and second embodiments, and the optical node having the configuration shown in FIG. 4 is used. 4, the same parts as those in FIG. 1 are indicated by the same numbers. The only difference is the branch 404 and the tunable filter 4.
01, a photodiode 402, and a light receiving circuit 403 are further provided. Tunable filter 40
1, the photodiode 402 and the optical receiving circuit 403 are provided for wavelength allocation, and the tunable filter 103, the photodiode 104, and the optical receiving circuit 105 are used for receiving video signals, respectively. In this method, as in the second embodiment, the tunable filter 401 is constantly scanned to constantly update the wavelength management table,
When a token is acquired, an empty wavelength is selected from the wavelength management table and wavelength allocation is performed.

In this node configuration, the wavelength management table can be updated even when the video signal is received. Therefore, as in the second embodiment, after the tunable filter is scanned at least once after the reception of the video signal, the token is acquired and the wavelength is allocated. There is no need for the condition to do.

This node configuration is not limited to the wavelength allocation method of the third embodiment, but can be applied to the first and second embodiments.

(Embodiment 4) FIGS. 5, 6 and 7 show a fourth embodiment of the present invention.
FIG. 5 is a block diagram of a third optical node, FIG. 6 is a network configuration, and FIG. 7 is a time chart. In FIGS. 5 and 6, 501 is a laser diode that sends out an optical signal of a specific wavelength, 502 is an optical transmission circuit that current-drives 501, 503 is a photodiode, and 504.
Is an optical receiving circuit for equalizing and amplifying the signal from 503, identifying and reproducing, 505 is a multiplexer for multiplexing optical signals in two wavelength ranges,
506 is a demultiplexer for separating optical signals in two wavelength regions,
7 is a communication control circuit, 601 to 608 are optical nodes of FIG.
Reference numeral 610 denotes an 8-port concentrator for connecting each optical node with an optical fiber for communication, and 611 to 618.
Is a multiplexer having characteristics equivalent to 505, 621 to 628 are demultiplexers having characteristics equivalent to 506, and 631 to 638 are 5
01, an optical transmitter for transmitting an optical signal having the same wavelength as 01,
648 is an optical receiver, 651 is an 8 × 8 star coupler, 6
Reference numeral 52 is a communication control circuit for controlling communication with the communication control circuit 507 of each node, reference numerals 661 to 668 are downlink optical fibers, and reference numerals 671 to 678 are uplink optical fibers. It is indicated by a number.

In this embodiment, the token passing communication control unit in the first embodiment is replaced with a point-to-point communication control unit, and the concentrator and each optical node are point-to-point control signal lines. And a star line, which is a wavelength division multiplexing line. The structure of the star line is the same as that of the first embodiment. First, the operation of the point-to-point control signal line will be described. The communication control circuit 652 of the concentrator 610 constantly sends frame pulses to each optical node at regular time intervals as shown in FIG. 7- (a). The frame pulse F1 is converted into an optical signal having a specific wavelength λa by the optical transmitter 631 and output, and is multiplexed with the signal light of the star line by the multiplexer 611 and sent out to the optical fiber transmission line 661. The frame pulse F2 is converted into an optical signal of wavelength λa by the optical transmitter 632 and output, and is similarly multiplexed with the optical signal of the star line by the multiplexer 612 and sent out to the optical fiber transmission line 662. Similarly, the frame pulses F3 to F8 have a wavelength λ.
a is converted into the optical signal of the optical fiber transmission lines 663 to 66.
8 is sent. The frame pulse F1 is the optical transmission line 661.
It is input to the optical node 601 through the optical path, is separated from the star line signal light by the demultiplexer 506, and is converted into an electric signal by the PD 503. The converted electric signal is received by the optical receiving circuit 504 and processed by the communication control circuit 507. The frame pulses F2 to F8 are similarly received by the optical nodes 602 to 608.

Here, for example, when it is desired to communicate from a computer device connected to the optical node 602 to a computer device connected to the optical node 601, the communication control circuit 507 of the optical node 602 receives data from the computer device. The data signal is sent to the optical transmission circuit 502 to drive the laser diode 501 to convert the data signal into an optical signal and output from the 501. The output optical signal is the multiplexer 505.
Is transmitted to the optical fiber transmission line 672, is transmitted through the optical fiber transmission line 672, and is input to the concentrator 610. The input optical signal is demultiplexed by the demultiplexer 622, converted into an electric signal by the optical receiver 642, and input to the communication control circuit 652.
652 controls the data signal so that it does not overlap with the frame pulse F1 and sends it to the optical transmitter 631. At 631, it is converted into an optical signal and sent out. The converted optical signal is input to the computer device connected to the optical node 601 through the same path as the frame pulse F1.
Data communication is similarly performed between other optical nodes by using a point-to-point control signal line.

Next, a wavelength allocation method in the star line of this embodiment will be described. Now, tentatively, the optical nodes 601 to 607 and the optical nodes 602 to 60
The operation in the case of transmitting the video signal to 8 will be described.
Since the optical node 601 acquires the transmission right and allocates the wavelength on the star line, it first takes in the frame pulse F1 from the point-to-point control signal line (corresponding to FIG. 7-a; the following (b) to (r) are The corresponding part of the time chart of FIG. 7 is shown.). The operation of fetching F1 is as described above. The communication control circuit 507 that has received F1
The wavelength allocation control circuit 106 is notified that the
Reference numeral 06 scans the tunable filter 103 to detect the light wavelength used in the star line. Reference numeral 106 updates the wavelength management table, selects an unused wavelength and sets the oscillation wavelength of the tunable LD 101 to, for example, an empty wavelength λ2. The optical transmission circuit 102 is the Tu-LD 101.
Is driven to send an idle signal of wavelength λ2 to the optical fiber transmission line 671 (b). Further, the wavelength allocation control circuit 10
6 notifies the node 607 of the wavelength information, and notifies the communication control circuit 507 of the information of the selected wavelength λ2.
7 sends the wavelength information signal to the optical transmitter circuit 502. The signal is converted by the LD 501 into an optical signal of wavelength λa, which is sent to the optical fiber transmission line 671 through the multiplexer 505 (c). On the other hand, the frame pulse F2 is input to the optical node 602 and read by the communication control circuit 507. Since the optical node 602 receives F2 (d), the optical node 602 scans the filter 103 in the same manner as the node 601, and selects an empty wavelength. At this time, the idle signal of wavelength λ2 output from the node 601 to the star line first is the concentrator 610.
Since the node 602 has already received it, the vacant wavelength λ4 other than the wavelength λ2 is selected. Then, the idle signal of wavelength λ4 is sent to the star line (e), and the information of wavelength λ4 is sent to the control signal line (f).

On the other hand, the wavelength information signal sent from the node 601 to the control signal line is input to the optical node 607 through the concentrator 610 (g). Communication control circuit 50
The wavelength assignment control circuit 106 reads the wavelength information λ2.
To notify. Reference numeral 106 controls the tunable filter 103 to set the reception wavelength to λ2. On the other hand, node 601
The idle signal of wavelength λ2 sent to the star line is distributed by the star coupler 651 through the demultiplexer 621 of the concentrator 610, and the demultiplexers 611 to 618 are distributed.
And transmitted to each of the downstream optical fiber transmission lines 661 to 668. The idle signal input to the node 607 is
When the center wavelength of the tunable filter 103 is set to λ2, it passes through 103, is converted into an electric signal by the photodiode 104, and is received by the optical receiving circuit 105 (h). 105 notifies the wavelength allocation control circuit 106 that the signal is being received, and sends information for instructing the node 601 to start communication to the control signal line via the communication control circuit 507 (i). Similarly, the node 608 also receives the wavelength information signal from the node 602 and the idle signal of the wavelength λ4 (j, k), and sends a signal for starting communication to the control signal line (l). The communication start information signal transmitted from the nodes 607 and 608 is relayed by the concentrator and input to the nodes 601 and 602 (m, o), and each communication control circuit 507 starts transmission to the video equipment connected to the node. Instruct. Each wavelength allocation control circuit 106 controls the optical transmission circuit 102 to transmit a video signal to the tunable LD 10.
1, the node 601 converts the video signal into an optical signal of wavelength λ2, the node 602 converts it into an optical signal of wavelength λ4, and sends it to the upstream optical fiber transmission lines 671 and 672 (n,
p). Each video signal is a demultiplexer 6 of the concentrator 610.
21 and 622, distributed by the star coupler 651,
It is input to all the nodes through the respective downstream optical fibers 661 to 668. The video signal input to the node 607 is
Since the central wavelength of the tunable filter 103 is already set to λ2, only the video signal of wavelength λ2 passes through the filter 103, is converted into an electric signal by the photodiode 104, and is received by the receiving circuit 105 (q). . Similarly, the node 608 receives the video signal of wavelength λ4 (r). The video signal input to another node is lost without being received because the wavelength of the tunable filter is not set.

In this way, communication is performed from the node 601 to the node 607 and from the node 602 to the node 608 without collision of signals. The above communication operation is similarly performed between other nodes.

In this embodiment, the frame pulse is output in a constant cycle (the time from F1 to the next F1 is constant), and the time interval of each frame pulse is such that the node requesting to acquire the star line receives the frame pulse. After that, selecting the unused line, that is, the time until the idle signal is sent by selecting an empty line by scanning the tunable filter, the time until the idle signal reaches another node, and the frame pulse It is decided in consideration of the time from the output from the concentrator until it reaches each node. This avoids collisions on the acquisition line. This time interval controls the timing of the output of the frame pulse to each node in consideration of the above-mentioned time when each node is different from each other. When the time difference to be considered is small, the longest one among them may be output at equal time intervals. Further, there is a control method in which, instead of strictly controlling the pulse interval to avoid the collision as described above, at least the communication control circuit 652 of the concentrator 610 performs control so that frame pulses do not arrive at each optical node at the same time. At that time, an idle signal is sent to the line acquired by a node, and before the idle signal reaches another node, another node that receives another frame pulse recognizes the line as an unused line. Although there is a possibility that signals will collide on the line, the probability of collision is small and the throughput is large compared to the line allocation method by collision detection that does not rely on the method of the present invention. As still another form, the frame pulse may be output in response to a request from the optical node.

Other Embodiments In the above embodiments, the wavelength allocating method using wavelength multiplexing was described as the line allocating method for the star line, but the present invention is not limited to this. For example, the star line is analog frequency multiplex. The system may be a multiplex line of a system, or a code multiplex system may be used. After the flag is acquired, an unused multiple component (frequency, code, etc.) is selected from the multiple signals and the idle signal of the multiple component is selected. Should be sent to perform line allocation.

The signal transmitted in the present invention is not limited to an optical signal, and an electric signal may be used.

[0041]

As described above, by using the line allocation method of the present invention, each node manages the lines in a distributed manner without providing a line management node, so that no cost is required for the line management node. Moreover, the communication procedure can be simplified. Also, if there is no signal collision,
Alternatively, it can be significantly reduced and throughput can be improved.

[Brief description of drawings]

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

FIG. 2 is a network configuration diagram of the first embodiment of the present invention.

FIG. 3 is a diagram showing a time chart of the first embodiment of the present invention.

FIG. 4 is a configuration diagram of an optical node according to a third embodiment of the present invention.

FIG. 5 is a configuration diagram of an optical node according to a fourth embodiment of the present invention.

FIG. 6 is a network configuration diagram of a fourth embodiment of the present invention.

FIG. 7 is a diagram showing a time chart of the fourth embodiment of the present invention.

FIG. 8 is a diagram showing a node configuration of a conventional example.

FIG. 9 is a diagram showing a network configuration of a conventional example.

[Explanation of symbols]

101 tunable laser diode 102, 502 optical transmission circuit 103, 401 tunable wavelength filter 104, 402, 503 photo diode 105, 403, 504 optical receiving circuit 106 wavelength allocation control circuit 107 optical or electrical receiver 108 token passing system Communication control circuit 109 Optical or electrical receiver 201-204 Optical node 211 of FIG. 1 Optical or electrical transmission line 212, 213, 661-668, 671-678, 8
10 Optical fiber 221, 651 Star coupler 501 Laser diode 505, 611-618, 805 Multiplexer 506, 621-628, 804 Demultiplexer 507, 652 Communication control circuit 601-608 Optical node 610 Concentrator 631-638 of FIG. Optical transmitter 641 to 648 Optical receiver 801 Communication control circuit of existing LAN 802 Communication control circuit of DA-WDMA system 803 Interface circuit 901 Control node 902 to 905 Conventional node

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location H04J 14/02 H04L 12/42 12/44 H04B 9/00 E H04L 11/00 330 340

Claims (13)

[Claims] 1. A multiple line having a plurality of lines, a control signal line including at least a control signal for controlling a line use right of the multiple line, and a plurality of nodes respectively connected to the multiple line and the control signal line. A method for allocating a line in a communication network, wherein a flag is transmitted to the control signal line, a node incorporating the flag selects a line not used in the multiplex line, and sends an idle signal to the line. A line allocation method, characterized in that the right to use the line is secured by doing so. 2. A wavelength division multiplexing line in which a plurality of wavelengths are multiplexed,
A line allocation method in a communication network comprising a control signal line including at least a control signal for controlling a wavelength usage right of the wavelength multiplex line and a plurality of nodes connected to the wavelength multiplex line and the control signal line, respectively. , A flag is transmitted to the control signal line, and the node incorporating the flag selects a wavelength that is not used in the wavelength multiplexing line and sends an idle signal of the wavelength to secure the right to use the wavelength. A line allocation method characterized by the above. 3. The line allocation method according to claim 1, wherein one flag is transmitted on the control signal line. 4. A plurality of flags are controlled and transmitted in the control signal line so that they do not arrive at different nodes at least at the same time.
Line allocation method described. 5. A plurality of flags in the control signal line, and a first node having a line use request fetches one transmitted flag to select an unused wavelength in the wavelength division multiplexing line. However, before the idle signal sent out at the wavelength reaches the second node, another flag arrives at the other node and is controlled and transmitted so as not to start selecting an unused wavelength. 3. The line allocation method according to claim 2, which is characterized in that. 6. A plurality of flags in the control signal line, the first node having a line use request fetches one transmitted flag, and selects an unused line in the multiplex line. , Before the idle signal sent to the line arrives at the second node, another flag arrives at another node and is controlled and transmitted so as not to start selecting an unused line. The line allocation method according to claim 1. 7. The line allocation method according to claim 1, wherein the flag uses a token of a token passing system. 8. The line allocation method according to claim 1, wherein the flag uses a frame pulse transmitted to each node from a concentrator in which a plurality of nodes are connected in a star pattern. 9. The method for selecting an unused wavelength is to scan a tunable filter after capturing a flag and select a wavelength that is not detected. Line allocation method described. 10. The method for selecting an unused wavelength is a method of constantly scanning a tunable filter to store an empty wavelength and selecting an empty wavelength stored when a flag is fetched. 6. The line allocation method according to claim 2, wherein the line allocation method is provided. 11. A communication network using the line allocation method according to claim 1. 12. A WDM line is accommodated in a star type optical transmission line, and a control signal line including at least a control signal for controlling the wavelength usage right of the WDM line is accommodated in a loop type transmission line. A communication network using the line allocation method according to claim 7. 13. A plurality of nodes are connected to a concentrator in a star shape, a signal of a wavelength division multiplexing line is transmitted using a star type optical transmission line, and at least a control signal for controlling a wavelength use right of the wavelength division multiplexing line is transmitted. 9. A signal of a control signal line including the above is transmitted point-to-point between each node via a concentrator.
A communication network using the described line allocation method.