JPH0851401A - Optical ring network communication system - Google Patents

Abstract

PURPOSE:To simplify access control and to efficiently transfer a cell by connecting plural nodes without determining the number of nodes to be stored in a system by the wavelength multiplicity of a ring and restricting it by the number of multiplexed wavelengths and reducing the constitutional size of an access node. CONSTITUTION:This communication system consists of one exchange node 11 connected to all waves having wavelength multiplexed on a ring and plural access nodes 12 connected two wavelengths. i.e., a control wavelength lambda0 and a specific wavelength lambdai. The access control information of each access node 12 is assembled as a frame in each slot for transferring a data cell based upon one control wavelength lambda0. A transmission node 12 transmits a cell by its own wavelength lambdai and writes control information by the control wavelength lambda0. The exchange/transfer of a cell is executed by converting the wavelength of a transmitting cell into the wavelength of a receiving node 12 by the exchange node 11 based upon the control information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching system for exchanging unit data in a ring type network in which a plurality of rings are multiplexed on a ring transmission line (for example, a wavelength multiplexing ring).

[0002]

2. Description of the Related Art FIG. 7 is a block diagram of a configuration example and an access node showing a conventional optical ring network communication system. Incidentally, the conventional example is based on Japanese Patent Laid-Open No. 4-369130 and SB-6-6 of the 1991 Spring National Convention of the Institute of Electronics, Information and Communication Engineers.

In FIG. 7, when a plurality of access nodes are connected to an optical ring transmission line in which a plurality of wavelengths λ1 to λn are wavelength-multiplexed, and when data cells are transmitted and received by slot exchange between the nodes, each access node Is assigned a unique wavelength as a node address, and when a node transmits data, it transmits in the wavelength slot of the wavelength that becomes the address of the receiving node on the other side, and the receiving node transmits data on the wavelength that becomes its own node address. The receiving operation was performed by taking all the cells as their own. Furthermore,
Before transmitting a data cell, the transmitting node detects whether or not there is an empty wavelength slot in the receiving node of the other party by capturing all the wavelength slots of the transmitting node and performing an access control operation.

[0004]

As described above, in the conventional optical ring network communication system, one of the wavelengths multiplexed in the transmission line is assigned as a fixed node address to each access node. There is a problem that the number of nodes that can be accommodated is determined by the number of wavelength division multiplexing of the ring. In addition, it is necessary to capture and monitor all wavelength slots in order to determine whether or not transmission to the node is possible, and optical reception circuits and optical transmission circuits are required for the number of wavelengths so that transmission at any wavelength is possible. There is a problem that the device configuration of the node becomes complicated and large, and access control at each node also becomes complicated.

The present invention has been made in order to solve the above problems, and it is possible to loosen the constraint on the number of nodes that can be accommodated in the system, reduce the configuration scale of the access node, and perform access control. The purpose is to simplify.

[0006]

An optical ring network communication system according to the present invention is characterized by having the following elements. (A) A ring-shaped transmission line in which optical signals are wavelength-multiplexed,
(B) a plurality of access nodes that are connected to the transmission path and that transmit and receive data using optical signals of specific wavelengths,
(C) A switching node which is connected to the transmission line and converts an optical signal of a specific wavelength used by a certain access node into an optical signal of another specific wavelength used by another access node.

In the optical ring network communication system according to the present invention, the transmission line further transmits a control signal of a specific wavelength for transmitting control information. The access node transmits / receives data by reading / writing control information of the control signal using an optical signal of a specific wavelength. Also, the switching node executes wavelength conversion based on the control information set in the control signal.

The optical ring network communication system according to the present invention further transmits data in slot units for each wavelength. The control information includes synchronization information for synchronizing transmission / reception data, acquisition display information indicating a use state of slots of respective wavelengths, and transmission / reception access node information for identifying transmission / reception access nodes. The access node transmitting data checks whether or not both the wavelength used by the transmitting access node and the wavelength used by the receiving access node for receiving data are empty slots according to the acquisition display information, and if the slots are empty, transmit access is performed. Data is inserted into the empty slot of the wavelength used by the node. The switching node converts the optical signal from the transmitting access node into an optical signal of a wavelength used by the receiving access node based on the setting of the transmitting / receiving access node information, and inserts it into an empty slot of the wavelength used by the receiving access node. . The reception access node receives the data addressed to itself by monitoring the transmission / reception access node information.

In the optical ring network communication system according to the present invention, the control information further comprises reservation display information for reserving a slot.

In the optical ring network communication system according to the present invention, when the wavelengths of the transmitting access node and the receiving access node receiving the data from the corresponding transmitting access node are the same, the receiving access node does not pass through the switching node. The data is received when the data arrives at the corresponding receiving access node.

In the optical ring network communication system according to the present invention, the switching node separates a plurality of wavelengths.
Demultiplexer / multiplexer for multiplexing, wavelength conversion switch for wavelength conversion, control unit for controlling wavelength conversion switch based on control information, optical transmission circuit for converting control signal between electric signal and optical signal And a light receiving circuit.

In the optical ring network communication system according to the present invention, the access node comprises the following circuits. A demultiplexer that takes in the wavelength assigned to the control signal and the wavelength assigned to the own node by branching from the transmission line, and a multiplexer for multiplexing on the transmission line. A synchronization circuit that detects a signal for synchronizing from each control signal with each optical transmission circuit and optical reception circuit and synchronizes the received signal. A reception control circuit that reads control information, determines whether or not there is data addressed to its own node in each slot, and controls data reception. A data separation circuit that separates data from the slot of the wavelength assigned to the own node according to an instruction from the reception control circuit, and a reception processing circuit that performs reception processing of the separated data. An access control circuit that monitors control information to detect / acquire a slot empty at the wavelengths of the own node and an access node to be transmitted, and reserve a slot if no slot is detected. A control information insertion circuit that performs the process of inserting the control information. A transmission processing circuit that processes the data to be transmitted, and a data insertion circuit that inserts the data to be transmitted into the slot in which the wavelength of the own node has been acquired according to an instruction from the access control circuit.

[0013]

The optical ring network communication system according to the present invention comprises a ring-shaped transmission line in which optical signals are wavelength-multiplexed, and a plurality of access nodes and one switching node are connected to the transmission line. An optical signal of a specific wavelength is assigned to the access node. The switching node uses the wavelength used in the access node on the transmitting side, for example, the wavelength used for the access node on the receiving side, for example, λi, for the optical signal of λi.
Wavelength conversion to the optical signal of. Therefore, each access node can transmit and receive data by the optical signal of the wavelength assigned to the own node.

The optical ring network communication system according to the present invention further allocates a dedicated wavelength for transmitting control information. The access node is connected to two wavelengths, a wavelength assigned to the control signal and a wavelength assigned to the own node for transmitting / receiving data.
The switching node is connected to all wavelengths including the wavelength assigned to the control signal. When transmitting the data, the access node transmits the data using the wavelength assigned to itself and writes the control information in the control signal. The switching node performs wavelength conversion based on the control information. Further, the access node detects that there is communication addressed to its own node by monitoring the control signal, and receives data at the wavelength assigned to the own node.

The optical ring network communication system according to the present invention transmits data in slot units for each wavelength. The control information includes synchronization information, acquisition display information indicating the usage status of slots of each wavelength, and transmission / reception access node information (for example, transmission node address and reception node address). Here, as the node address, for example, a wavelength assigned to each access node and an identification number can be used in combination. Thereby, a plurality of access nodes can be assigned to one wavelength, and a plurality of access nodes can be connected without being limited by the number of wavelengths multiplexed on the transmission path. Also,
The transmitting access node checks the acquisition display information of the control information, detects a slot in which both wavelength slots used by the transmitting / receiving access node are empty, and inserts data into the empty slot of the wavelength used by the transmitting access node. At the same time, acquisition display information of the corresponding slot and transmission / reception access node information are set in the control signal. The switching node converts the corresponding slot from the transmission access node into a wavelength used by the reception access node set in the control information. The receiving access node monitors the control information and fetches data from the corresponding slot addressed to itself.

In the optical ring network communication system according to the present invention, when both slots of the transmission / reception access node are not empty, the transmission node sets the reservation display information of the control information so as to reserve both slots of the transmission / reception wavelength. As a result, the slot emptied due to the end of data transfer and the end of slot wavelength conversion can be reliably used as the next transfer slot.

In the optical ring network communication system according to the present invention, when the wavelength of the access node transmitting the data is the same as the wavelength of the access node receiving the data, the slot containing the data passes through the switching node. The data can be received when it arrives at the receiving access node.

The optical ring network communication system according to the present invention is accommodated because the wavelength conversion is performed by the wavelength conversion switch based on the control information in one switching node connected on the ring-shaped transmission line. This facilitates communication and access control between access nodes having different wavelengths.

In the optical ring network communication system according to the present invention, the optical transmission circuit and the optical reception circuit required by each access node are composed of only two wavelengths, that is, the wavelength for the control signal and the wavelength assigned to each access node. Therefore, it is not necessary to mount circuits other than the corresponding two wavelengths,
The configuration scale of the access node is simplified.

[0020]

【Example】

Example 1. FIG. 1 shows a configuration of an optical ring network in this embodiment, and FIG. 2 is a diagram showing a data cell transfer mode in the present invention. In FIG. 1, 11 is an exchange node (denoted by EN in the figure), 12 is an access node (denoted by AN in the figure), and 13 is a ring-shaped transmission line in which a plurality of wavelengths are wavelength-multiplexed.

Next, the operation will be described. A plurality of wavelengths λ0 to λn are wavelength-multiplexed in the ring-shaped transmission line 13, the wavelength λ0 is a control wavelength for transmitting control information for data cell transfer, and the wavelengths λ1 to λn are data wavelength transfer. Wavelength. One switching node 11 exists in the ring and is connected to all wavelengths λ0 to λn. Further, each of the plurality of access nodes is connected to two of the control wavelength λ0 and the specific data cell transfer wavelength λi, and the wavelength accommodated by the own node as a node address, for example, λi and the node NO within the wavelength, for example, with #k. As a result, the number of nodes that can be accommodated in the system is (number of wavelength division multiplexing of the ring) × (node
(Number of NOs), which is multiplied by (number of node NOs) compared to the conventional one.

Data cells are transferred in units of wavelength slots shown in FIG. 2, and the wavelength slot is synchronized with an access control frame formed in the control wavelength λ0, and n slots for λ1 to λn are one frame. Therefore, each access node 12 operates in synchronization with the frame fetched at λ0. For example, node address (λ
2, # i) access node 12 has node address (λi, #
k) when transmitting a cell to the access node 12,
From the access control frame of the
Insert a cell into the own wavelength slot of the slot where the wavelength λi accommodated by the partner node is empty, and display the acquired display information of the own wavelength slot and the acquired display information of the partner wavelength slot in the control frame of the corresponding slot. The transmission operation is performed by setting. Receiving this, switching node 11 performs wavelength conversion from λ2 to λi for cells in the same frame according to the information in the control frame, and inserts the data cell into the designated λi slot. The counterpart receiving access node 12 constantly monitors the information of the control frame, detects a cell addressed to the own receiving node number in the accommodated slot of the wavelength λi, and takes in the cell to receive the data. The access node 12 that has completed reception of the cell releases the wavelength slot in which the reception cell has been inserted.

FIG. 3 shows the structure of an access control frame of a control wavelength λ0 for transmitting control information for data cell transfer in the optical ring network in this embodiment. In FIG. 3, the access control frame includes a frame synchronization information F and a wavelength slot (λ) for data cell transfer.
1 to λn) The control information is multiplexed.

Further, each wavelength slot control information indicates reservation display information for reserving the corresponding slot, acquisition display information indicating that it is in use for data cell transfer, and address of the access node that has reserved the slot. It is composed of a reserved node address, a transmission node address related to the data cell transfer in the slot, and a reception node address.

For example, in FIG. 2, the node address (λ
2, # i) access node 12 has node address (λi, #
When a cell is transmitted to the access node 12 of k), the cell is inserted into the slot λ2 of the slots in which both the transmission side wavelength λ2 and the reception side wavelength λi are empty, and the λ2 in the control frame of the corresponding slot is And the acquisition display information is set at the positions of λi and (λ2,
#i), and set the receiving node address to (λi, # k). Receiving this, the switching node 11 performs wavelength conversion from λ2 to λi for cells in the same frame according to the information of the control frame and inserts the data cell into the designated slot of λi. At the same time, the λ2 wavelength slot is opened by clearing the acquired display information in the control information of the λ2 wavelength slot. The receiving access node 12 monitors the information of the control frame, and when it detects a cell addressed to its own receiving node number in the accommodated slot of wavelength λi, the receiving access node 12 takes in this and receives the data cell. The access node 12 that has completed the reception of the data cell clears the acquisition display in the control information of the .lambda.i wavelength slot to open the wavelength slot in which the received data cell has been inserted.

As described above, in the optical ring network communication system of this embodiment, the connection configuration of each node on the ring-shaped transmission line in which optical signals are wavelength-multiplexed is connected to all wavelength-multiplexed wavelengths. It is assumed that there is one switching node and a plurality of access nodes connected to two wavelengths of a wavelength λ0 for transmitting control information and a specific wavelength λi. Also, a control signal is assigned to one wavelength λ 0, and control information used when each node transmits and receives is assembled into a frame for each slot for transferring a data cell. In this embodiment, how to transfer a data cell using this control information has been described. Further, as a result, a plurality of nodes can be accommodated in arbitrary wavelength-multiplexed wavelengths, and a plurality of nodes can be connected without being limited by the number of wavelengths multiplexed in the transmission path.

Example 2. In the present embodiment, a case will be described in which when there is no empty wavelength slot, the corresponding wavelength slot is reserved by the wavelength slot control information.

FIG. 2 shows a transfer mode of data cells in the optical ring network in this embodiment. Figure 2
In FIG. 3, a cell is normally inserted in a slot in which both the transmitting side wavelength and the receiving side wavelength are empty, but when there is no empty in either one or both wavelength slots,
The wavelength slot control information is used to reserve the corresponding wavelength slot.

For example, when the access node 12 with the node address (λ2, # i) transmits a cell to the access node 12 with the node address (λi, # k), the transmission side access node 12 uses the wavelength slots λ2 and λi. The slot reservation display is set in the wavelength slot control information of (1) and (λ2, #i) is set as the reserved node address. Other access nodes 12 cannot use the reserved wavelength slot for data cell transfer. The access node 12 having the node address (λ2, #i) then monitors the reserved wavelength slot, performs the data cell transfer process when the acquisition display of λ2, λi becomes empty, and transmits the both wavelength slot control information. Clear the reservation display and reserved node address. When an empty wavelength slot is detected before the reserved wavelength slot becomes empty, the data cell transfer processing is performed by the detected empty wavelength slot, and the reserved wavelength slot reservation display and the reserved node address are released.

As described above, in this embodiment, an example in which the wavelength slot of the transmission side node and the wavelength slot of the reception side node are reserved by the control wavelength in the transmission side access node when there is no empty wavelength slot has been described. . This enables reliable data cell transfer with little cell discard.

Example 3. In the present embodiment, how to transmit and receive a data cell when the wavelength accommodated in the transmission side access node 12 and the wavelength accommodated in the reception side access node 12 are the same will be described.

FIG. 4 shows a transfer mode of data cells in the optical ring network in this embodiment. Normally, for the transfer of a data cell between access nodes 12 having different wavelengths, the cell is inserted into the slot of the transmission side wavelength where both the slots of the transmission side wavelength and the reception side wavelength are empty,
Although the wavelength is converted by the switching node 11 and then received by the receiving access node 12, the wavelength accommodated by the access node 12 transmitting the data cell and the wavelength accommodated by the access node 12 receiving the data cell. , The data cell can be received when the wavelength slot including the data cell arrives at the receiving node before passing through the switching node.

For example, in FIG. 3 and FIG. 4, when the access node 12 with the node address (λn, # j) transmits a cell to the access node 12 with the node address (λn, # k), the wavelengths on the transmitting side and the receiving side are The cell is inserted in the empty wavelength slot of λn, and the acquisition display is performed only at the position of λn in the control frame of the corresponding wavelength slot, and (λn, # j) is set as the transmitting node address and the receiving node address is set as the receiving node address. Set (λn, # k). When the receiving access node 12 is located closer to the transmitting access node 12 than the switching node 11, the receiving access node 12 takes in the data at the time when the transmitting access node 12 detects the transmitting data cell before passing through the switching node 11 and stores the data. Reception is performed.

In the figure, the node address (λ2,
#i) access node 12 has node address (λ2, # k)
If the switching node 11 that transmits a cell to the access node 12 is located closer to the transmitting access node 12 than the receiving access node 12, the transmitting side operation is the same as the above, but the switching node 11 receiving this Performs no processing and allows the wavelength slot to pass through. When the transmission data cell is detected by the reception access node 12, this is taken in and data reception is performed.

As described above, in this embodiment, when the wavelength accommodated by the access node transmitting the data cell and the wavelength accommodated by the access node receiving the data cell are the same, the slot containing the data cell is included. Described above is an example in which the data cell can be received when the data arrives at the receiving node before passing through the switching node. As a result, cells can be efficiently transferred.

Example 4. In this embodiment, the configuration of the exchange node will be described. FIG. 5 shows the configuration of the exchange node 11 in this embodiment. In FIG. 5, 11 is an exchange node, and 13 is a ring-shaped transmission line in which a plurality of wavelengths are wavelength-multiplexed. Reference numeral 601 denotes a demultiplexer for separating the wavelengths of λ0 to λn, 602 denotes a multiplexer for multiplexing the wavelengths of λ0 to λn, 60
Reference numeral 3 designates an optical transmission circuit for converting an access control frame of λ0 into electricity, and 604 designates an access control frame of λ0 for optical →
It is a light receiving circuit for electrical conversion. Reference numeral 51 denotes a wavelength conversion switch that converts the wavelength signal input thereto in wavelength slot units in accordance with an instruction from the control circuit and outputs the wavelength signal to a designated port. Reference numeral 52 denotes a control circuit which processes the electrically converted access control frame of λ 0 in frame units, analyzes each wavelength slot control information, and gives an instruction to the wavelength conversion switch.

Next, the operation will be described. The wavelengths λ0 to λn received from the ring-shaped transmission line 13 are demultiplexers 601.
Are separated by. Of these, the control wavelength λ 0 is converted from light to electric in the optical receiving circuit 604 and is input to the control circuit 52. The control circuit 52 is all performed by electric signal processing,
The frame synchronization information is detected from the control wavelength to establish frame synchronization, and the wavelength conversion instruction for each wavelength slot control information is transmitted to the wavelength conversion switch 51 from each wavelength slot control information to which wavelength slot the data cell is converted to which wavelength slot. I do. Further, the control circuit 52 clears the acquisition display in the corresponding wavelength slot control information for the transmission wavelength slot after the wavelength slot conversion to open the slot.

The access control frame of the electric signal outputted from the control circuit 52 is converted from electricity to light by the optical transmission circuit 603 and inputted to the multiplexer 602 at the wavelength of λ 0. The wavelengths λ1 to λn individually separated by the demultiplexer 601 are
The optical signal is input to the wavelength conversion switch 51 as it is, and the wavelength conversion switch 51 converts the data cell of the wavelength slot input according to the wavelength conversion instruction signal from the control circuit 52 into the data cell of the designated wavelength slot, and each λ1 ~ Λn
Output to the port. The optical signal output to each port is
Ring-shaped transmission line 1 wavelength-multiplexed by the multiplexer 602
Will be issued in 3.

As described above, this embodiment has described the example in which the wavelength conversion is performed by the wavelength conversion switch based on the information of the control wavelength λ0 in one switching node connected on the ring. As a result, communication between access nodes having different wavelengths can be easily realized, and access control can be simplified.

Example 5. In this embodiment, the configuration of the access node will be described. FIG. 6 shows the configuration of the access node 12 having the node address (λi, # j) in this embodiment. In FIG. 6, 12 is an access node, 6
01 is a demultiplexer for separating the wavelengths of λ 0 and λ i, and 602 is λ 0
This is a multiplexer that multiplexes the wavelengths of and λ i. 603 electrically connects the access control frame of λ0 and the wavelength slot of λi →
It is an optical transmission circuit that performs optical conversion. Reference numeral 604 denotes an optical receiving circuit for converting the access control frame of λ0 and the wavelength slot of λi from light to electricity. A frame synchronization circuit 605 detects frame synchronization information from the access control frame of .lambda.0 and establishes frame synchronization. A reception control circuit 606 separates and analyzes each wavelength slot control information from the access control frame, outputs the wavelength slot control information, and controls the reception wavelength cell slot. Reference numeral 607 is a data cell separation circuit for separating the data cell from the data cell reception wavelength slot, and 608 is a reception processing circuit for processing the reception data cell and outputting the data to the device accommodated in the node. Reference numeral 609 denotes an access control circuit for performing access control of the wavelength slot to be transmitted,
A control information insertion circuit 610 sets control information in the wavelength slot control information of the access control frame according to the processing result of the access control circuit 609. Reference numeral 611 is a transmission processing circuit that assembles the transmission data received from the device accommodated in the node into a data cell, and 612 is a data cell insertion circuit that inserts the transmission data cell into the wavelength slot according to the instruction of the access control circuit 609.

Next, the operation will be described. Of the wavelengths of λ0 to λn multiplexed on the ring-shaped transmission line 13, the demultiplexer 6
After the wavelengths λ0 and λi are individually separated by 01, the optical receiving circuit 604 performs optical-to-electrical conversion, and the access control frame of λ0 is the frame synchronizing circuit 605 and the receiving control circuit 60.
6, and the reception wavelength slot of λ i is input to the data cell separation circuit 607.

The frame synchronization circuit 605 detects frame synchronization information from the access control frame of λ0 to establish frame synchronization, and supplies slot timing to each part other than the optical transmission circuit 603 and the optical reception circuit 604. The reception control circuit 606 separates and analyzes each wavelength slot control information from the access control frame, outputs it to the access control circuit 609, and controls the reception of the wavelength slot. The data cell separation circuit 607 separates the data cell from the reception wavelength slot based on the instruction from the reception control circuit 606, and the reception processing circuit 608 performs the reception processing on the separated data cell, and the device accommodated in the node. Output the data to.

The access control circuit 609 receives a data transmission request from a control device or the like connected to the node, and performs access control such as detection of empty wavelength slots and reservation from the wavelength slot control information analyzed by the reception control circuit 606. Then, the control information insertion circuit 610 is notified of the processing result. In accordance with this, the control information insertion circuit 610 inserts control information into the wavelength slot control information of the access control frame. In parallel with this, the transmission data from the device accommodated in the node is assembled into data cells by the transmission processing circuit 611 and inserted into the wavelength slot designated by the data cell insertion circuit 612.

As described above, the access node described in this embodiment does not need to be equipped with an optical transmission circuit and an optical reception circuit for all wavelength-multiplexed wavelengths, and has two wavelengths of the control wavelength λ 0 and the accommodation wavelength λ i. The example of mounting the optical receiving circuit and the optical transmitting circuit required only for the above processing has been described. This can solve the problem that the configuration scale of the access node becomes complicated.

[0045]

According to the present invention, since the access node can transmit and receive at the wavelength assigned to its own node, the device configuration of the access node can be simplified and downsized, and the access control can be simplified. Can be achieved.

Further, according to the present invention, since control information can be sent by a specific wavelength, finer access control can be performed more easily.

Further, according to the present invention, since a plurality of access nodes can be accommodated in arbitrary wavelengths that are wavelength-multiplexed, it is possible to connect a plurality of access nodes without being limited by the number of wavelengths multiplexed in the transmission line. In addition, each access node can use the control information to transfer data in slot units for each wavelength.

Further, according to the present invention, since the control information for reserving the slot is provided, it is possible to transfer data reliably with less cell discard.

Further, according to the present invention, when the wavelengths of the access node transmitting data and the access node receiving the data are the same, cell transfer can be efficiently performed.

Further, according to the present invention, in the switching node, wavelength conversion is performed by the wavelength conversion switch based on the control information, so that communication between access nodes having different allocated wavelengths can be easily realized. Access control can be simplified.

Further, according to the present invention, since it is not necessary for each access node to be equipped with an optical transmission circuit and an optical reception circuit for all wavelength-multiplexed wavelengths, there is a problem that the configuration scale of the access node becomes complicated. Can be resolved.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an optical ring network of the present invention.

FIG. 2 is a diagram showing a transfer mode of data cells in the optical ring network of the present invention.

FIG. 3 is a diagram showing a configuration of an access control frame having a control wavelength λ0 in the optical ring network of the present invention.

FIG. 4 is a diagram showing a data cell transfer mode in the optical ring network of the present invention.

FIG. 5 is a diagram showing a configuration of a switching node in the optical ring network of the present invention.

FIG. 6 is a diagram showing a configuration of an access node having a node address (λi, # j) in the optical ring network of the present invention.

FIG. 7 is a diagram showing a conventional optical ring network communication system.

[Explanation of symbols]

11 switching nodes, 12 access nodes, 13 ring-shaped transmission lines, 51 wavelength conversion switches, 52 control circuits, 601 demultiplexers, 602 multiplexers, 603 optical transmission circuits, 604 optical reception circuits, 605 frame synchronization circuits,
606 reception control circuit, 607 data cell separation circuit,
608 reception processing circuit, 609 access control circuit, 6
10 control information insertion circuit, 611 transmission processing circuit, 61
2 Data cell insertion circuit.

Claims (7)

[Claims] 1. An optical ring network communication system having the following elements: (a) a ring-shaped transmission line in which optical signals are wavelength-multiplexed, (b) an optical signal connected to the transmission line, each using an optical signal of a specific wavelength. A plurality of access nodes for transmitting and receiving data, (c) an exchange node connected to the transmission line for converting an optical signal of a specific wavelength used by one access node into an optical signal of another specific wavelength used by another access node. 2. The transmission path further transmits a control signal of a specific wavelength for transmitting control information, and the access node transmits / receives data by reading / writing control information of the control signal, and transmits / receives an optical signal of a specific wavelength. The optical ring network communication system according to claim 1, wherein the switching node executes wavelength conversion based on control information set in the control signal. 3. The optical ring network communication system further transmits data in slot units for each wavelength, and the control information indicates synchronization information for synchronizing transmission / reception data and a slot usage state for each wavelength. The access node that has the acquisition display information and the transmission / reception access node information for identifying the transmission and reception access nodes, and that transmits the data is the wavelength used by the transmission access node according to the acquisition display information and the reception access node that receives the data. Checks whether both slots of the wavelength used by are empty slots and, if they are empty, inserts data into the empty slot of the wavelength used by the transmitting access node, and the switching node sets the transmission / reception access node information based on the setting. , The optical signal from the transmitting access node to the optical signal of the wavelength used by the receiving access node In other words, the optical fiber is inserted into an empty slot of a wavelength used by the receiving access node, and the receiving access node monitors the transmission / reception access node information and receives data addressed to the own node. Ring network communication system. 4. The optical ring network communication system according to claim 3, wherein the control information further comprises reservation display information for reserving a slot. 5. When the transmitting access node and the receiving access node that receives data from the transmitting access node have the same wavelength, the receiving access node receives the data before passing through the switching node. The optical ring network communication system according to claim 4, wherein the data is received at the point of time. 6. The switching node comprises a demultiplexer / multiplexer for demultiplexing / multiplexing a plurality of wavelengths, a wavelength conversion switch for wavelength conversion, a controller for controlling the wavelength conversion switch based on control information, and a control signal. 6. The optical ring network communication system according to claim 5, wherein the optical ring network communication system comprises an optical transmitting circuit and an optical receiving circuit for converting between an electric signal and an optical signal. 7. A demultiplexer in which the access node branches and takes in a wavelength assigned to a control signal and a wavelength assigned to its own node from the transmission line, and a multiplexer for multiplexing on the transmission line. Each optical transmission circuit and optical reception circuit detects the signal for synchronizing from the control signal and synchronizes the received signal with the synchronization circuit and reads the control information and whether there is data destined for its own node in each slot. Determines and controls the reception of data, a data separation circuit that separates data from the slot of the wavelength assigned to its own node according to an instruction from the reception control circuit, and performs reception processing of the separated data The receiving processing circuit and the control information are monitored to detect / acquire the slot empty at the wavelength of the own node and the access node to be transmitted, and when the sky is not detected, An access control circuit that reserves slots, a control information insertion circuit that inserts these control information, a transmission processing circuit that processes data to be transmitted,
6. The optical ring network communication system according to claim 5, wherein the optical ring network communication system is configured by a data insertion circuit that inserts data to be transmitted into a slot in which a wavelength of its own node is acquired in accordance with an instruction from the access control circuit.