JP2002247010A - Optical communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wavelength division multiplexing type optical communication system capable of simultaneously operating a plurality of communication systems based on a plurality of communication protocols by using the same communication medium. SOLUTION: In the wavelength division multiplexing type optical communication system connecting 2 plurality of optical communication nodes by the optical transmission medium and allocating a plurality of kinds of optical signals to respective communication protocols to transmit information data by using an optical signal of a wavelength corresponding to each communication protocol, each optical communication node is provided with an optical transmission means for transmitting information data to the optical transmission medium by an optical signal of an optional wavelength out of the plurality of kinds of wavelengths allocated to the communication protocol used for its own node out of previously determined a plurality of communication protocols and an optical receiving means for selecting and receiving the optical signal of the optional wavelength out of the plurality of kinds of wavelengths allocated to the communication protocol used for its own node from the optical transmission medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical communication system to which a frequency division multiplex system and a wavelength division multiplex system are applied.

[0002]

2. Description of the Related Art (1) In a conventional communication system,
This is realized by converting the information to be communicated into an electric signal and transmitting the electric signal through a communication path. However, in recent years, the amount of information to be transferred has increased sharply as compared with the related art because the CPU power has increased in hardware in addition to the increase in the amount of information itself. until now,
Although such an increase in the amount of information has been dealt with by increasing the information transfer speed, the information transfer speed of an electric signal is limited to about 622 Mbps, which is required for future information communication. It is considered that there is a problem in the information transfer capability to be used. In particular, when performing long-distance communication, transmission errors are likely to occur due to a decrease in the level of the electric signal in the transmission path in information transfer using electric signals, and further problems occur in high-speed information communication. know.

[0003] With respect to such a problem of the electric signal, an optical communication system using an optical fiber is receiving attention.
Optical communication systems have already been introduced in LANs such as Ethernet, and several Gbps of optical signals will be used in the future.
It is expected that a communication capacity of up to several tens of Gbps will be provided. Furthermore, at present, as research on communication services in such optical communication systems on the order of several Gbps, it has been determined that the communication capacity of several Gbps is still insufficient. Studies have been conducted on multiplexing and accommodation in an optical communication system on the order of several Gbps to provide multi-protocol communication services.

As a communication system for further increasing the communication capacity, an optical frequency division multiplexing optical communication system utilizing the frequency characteristics of an optical signal has been actively studied. In this optical frequency division multiplexing method, an optical signal is divided into optical signals of a plurality of frequencies, the optical signals in the divided frequency bands are processed as independent optical signals, and the divided optical signals are processed in the same manner. The transmission and reception are multiplexed in the optical fiber. By using such an optical frequency division multiplexing method, the amount of information that can be transferred in the same optical fiber can be increased to [the number of divisions of the optical frequency] times that when no division multiplexing is performed. It is expected to be applicable to optical communication at the level.

[0005] For multi-protocol communication,
At present, a method of performing communication by multiplexing information according to various communication protocols by using an ATM communication method has been considered. In the ATM communication system, since ATM cells (fixed length packets) are multiplexed asynchronously for communication, flexible multiplexing can be performed even when each communication protocol requires various information transfer rates. Become. Such an ATM
The communication by the system is currently being actively studied as a communication system for forming a backbone network for connecting a plurality of LANs between LANs.

FIG. 19 shows a configuration diagram of a conventional frequency division multiplex communication system. Such an optical communication system includes a system using an optical signal broadcast function by an N × N star coupler shown in (a), and “each optical communication node” in the network as shown in (b) and (c). Optical frequency division multiplexing by assigning one of the frequencies of the divided optical signal to "" or "combination of each optical communication node" and using the communication procedure between optical communication nodes such as single hop or multi hop. There is a thing aiming at realizing the communication of.

However, in such a conventional optical frequency multiplexing system, when dividing and allocating the wavelength and frequency of an optical signal, the wavelength and frequency are allocated to each node or combination of nodes in the network. It is only applicable when the network operates as a single communication system (with a single communication protocol). In such a method in which frequency division is performed in a single communication system, each section in a company has its own network (LA) such as a company network.
N) to build a large-scale network by simultaneously accommodating the multiple types of LANs, and to accommodate a communication system operating with multiple types of communication protocols together in the same network. It was difficult.

As described above, in the conventional optical frequency division multiplexing method, only the efficiency of use of a communication path in a specific communication system has been improved. , Further ingenuity is needed.

[0009] The above points also apply to the conventional wavelength division multiplex communication system. In addition, conventional ATM
FIG. 20 shows a configuration diagram of an optical communication system using a communication method. In such an optical communication system, information from a communication network performing communication according to each communication protocol is converted into an ATM communication protocol by a communication node installed between the ATM network and the ATM, and then the ATM is used. -ATM multiplexing is performed by the function of MUX. In addition, ATM multiplexed information is transferred to an ATM communication system network (AT
M network).

In such a configuration, when a communication node performs protocol conversion to an ATM protocol or multiplexes ATM-converted information in an ATM-MUX, the processing is inevitably performed by an electric signal. Therefore, there is a problem that the information transfer speed that can be assigned to each communication protocol is limited. Because of such a problem, further contrivance is required for a method of multiplexing information of various communication protocols by a conventional ATM communication method.

(2) On the other hand, FIGS. 26 and 27 are diagrams showing the configuration of a conventional loop type network and the configuration of nodes used in the network, respectively.

In an optical communication system using the conventional optical wavelength multiplexing system shown in FIG. 26, six nodes A to F are connected in a loop, and each node has a wavelength ( λ1 to λ6) are assigned in advance.
Also, as shown in FIG.
0, an optical receiver 2001 for receiving a wavelength assigned to another station, transmitting a signal output from a device such as a terminal connected to the own station to the transmission line 2200 at a wavelength assigned to the own station. Transmitting apparatus 2002 for performing the operation, an optical filter 200 for blocking the light of the wavelength allocated to the own station.
3. It has a multiplexing device 2005 for multiplexing signals addressed to its own station. That is, in this optical communication system, the transmitting device transmits information using a predetermined wavelength, and the receiving device receives each transmission wavelength in order to receive the transmission wavelengths of all other stations. To have an optical receiver. Further, the optical filter 2003 is for terminating and erasing the signal transmitted by the own station.

In the above configuration, the information is delivered according to the destination information attached to the information. The transmitting station transmits information including destination information at a transmission wavelength assigned to the transmitting station in advance. Other nodes receive all the wavelengths, analyze the destination information of the received information, and if the information is addressed to the own station, fetch the information to the own station.

In such a conventional communication system, there is a problem that the number of nodes usable in the network is limited by the number of wavelengths used in the network.

[0015]

As described above, in the conventional optical communication system of the optical wavelength (frequency) multiplexing method, when dividing and assigning the wavelength (frequency) of an optical signal, each node or node in the network is divided. , The wavelength (frequency) is assigned to the combination of the communication systems, so that it can be applied only when the network operates as a single communication system (by a single communication protocol). In the method of dividing the wavelength (frequency) within the network, each section in the company constructs its own network (LAN) like an in-house network, and simultaneously accommodates a plurality of types of LANs in a large-scale network. It is difficult to build a network or to accommodate communication systems operating with multiple types of communication protocols together in the same network There was. In addition, as described above, only the efficiency of use of a communication path in a specific communication system has been improved, and it has been difficult to apply the method to an actual network (particularly, a backbone network).

On the other hand, in a conventional optical communication system of an optical wavelength division multiplexing system to which an ATM communication system is applied, when a communication node performs protocol conversion to an ATM protocol, or
When multiplexing ATM-converted information in the TM-MUX, such processing must be performed by an electric signal, which limits the information transfer rate that can be assigned to each communication protocol. There was a problem. Further, because of such a problem, it has been difficult to multiplex information of various communication protocols by the conventional ATM communication system.

The present invention has been made in view of the above-mentioned problems, and even in an environment where communication systems complying with a plurality of types of communication protocols coexist, such as a corporate network, the same communication resources can be used. Communication within different communication systems can be realized, and communication between the plurality of communication systems can be realized by using the same communication resource. The ability to use wavelength or frequency optical signals independently enables multimedia and
An object of the present invention is to provide an optical communication system capable of flexibly constructing a communication system in a multi-protocol and multi-vendor environment and easily realizing functions required for function distribution and load distribution in a communication network.

[0018]

According to the present invention, a plurality of optical communication nodes using any one of a plurality of predetermined communication protocols are connected by an optical transmission medium, and the plurality of optical communication nodes are connected to the plurality of communication protocols. A wavelength division multiplexing type optical communication system, wherein a plurality of types of optical signals are respectively assigned so as not to overlap, and information data is transmitted using an optical signal having a wavelength according to a communication protocol. The node transmits information data by an optical signal of an arbitrary wavelength among a plurality of types of wavelengths assigned to a communication protocol used by the own node among the predetermined plurality of communication protocols for optical transmission. Optical transmission means for transmitting to a medium, and optical transmission of an optical signal of an arbitrary wavelength among a plurality of wavelengths assigned to a communication protocol used by the own node. Characterized in that a light receiving means for receiving selected from the medium.

Preferably, an optical signal having a wavelength assigned to a first communication protocol among the plurality of predetermined communication protocols is received from an optical transmission medium,
The information data obtained by converting the optical signal is subjected to protocol conversion from the first communication protocol to a second communication protocol among the predetermined communication protocols, and the protocol-converted information data Is converted to an optical signal of any wavelength assigned to the second communication protocol and transmitted to the optical transmission medium by the first communication protocol and the second communication protocol. It may be provided for each combination with the communication protocol, or for each combination of the wavelength assigned to the first communication protocol and the wavelength assigned to the second communication protocol.

Further, according to the present invention, a plurality of optical communication nodes using only one of a plurality of predetermined communication protocols are connected by an optical transmission medium, and the plurality of communication protocols are duplicated. A wavelength division multiplexing type optical communication system, wherein the wavelengths of optical signals are assigned one by one so that there is no optical signal, and information data is transmitted using an optical signal having a wavelength according to a communication protocol. An optical transmission means for transmitting information data to the optical transmission medium by an optical signal having a wavelength assigned to a communication protocol used by the own node among the plurality of predetermined communication protocols; Optical receiving means for selecting and receiving an optical signal of a wavelength assigned to a communication protocol used by the own node from the optical transmission medium.

Preferably, an optical signal having a wavelength assigned to a first communication protocol among the plurality of predetermined communication protocols is received from an optical transmission medium,
The information data obtained by converting the optical signal is subjected to protocol conversion from the first communication protocol to a second communication protocol among the predetermined communication protocols, and the protocol-converted information data Is converted into an optical signal of a wavelength assigned to the second communication protocol and transmitted to the optical transmission medium by the first communication protocol and the second communication protocol. May be provided for each combination.

The present invention also relates to a wavelength division multiplexing type optical communication system including two unit optical communication systems, wherein the unit optical communication systems are connected by a predetermined optical communication node. All communication systems
8. The optical communication system according to claim 7, wherein the predetermined optical communication node has a predetermined wavelength from one of the two unit optical communication systems. And transmitting the optical signal to the other unit optical communication system.

Also, the present invention provides a method for optically transmitting a communication node using a specific inter-protocol communication protocol for performing communication between any one of a plurality of predetermined communication protocols and different communication protocols. A plurality of communication media, and assign a wavelength of each optical signal one by one so as not to overlap with the plurality of communication protocols and the specific inter-protocol communication protocol, and use an optical signal having a wavelength corresponding to the communication protocol. An optical communication system of a wavelength division multiplexing system for transmitting information data, wherein the communication node includes:
First optical transmitting means for transmitting information data to the optical transmission medium by an optical signal having a wavelength assigned to a communication protocol used by the own node among the plurality of predetermined communication protocols; A first optical receiving means for selecting an optical signal of a wavelength assigned to a communication protocol used by the own node from the optical transmission medium and receiving the selected signal; Second optical transmission means for transmitting information data to the optical transmission medium by an optical signal having a wavelength assigned by
Second optical receiving means for selecting and receiving an optical signal of a wavelength assigned to the specific inter-protocol communication protocol from the optical transmission medium.

Further, the present invention is an optical communication system including two unit optical communication systems, wherein the unit optical communication systems are connected by a predetermined optical communication node. 12. The optical communication system according to claim 11, wherein the predetermined optical communication node is configured to transmit the specific protocol from one of the two unit optical communication systems to the specific optical communication system. An optical signal having a wavelength assigned to the inter-communication protocol is received and transmitted to the other unit optical communication system.

According to the optical communication system of the present invention, different wavelengths are assigned to each communication protocol of information to be transferred in the same optical transmission medium, so that a plurality of communication systems according to a plurality of communication protocols can simultaneously use the same communication protocol. It can be operated using communication media.

The present invention can be understood as the following inventions.

(A) Further, according to the present invention, a plurality of communication nodes are connected by an optical transmission medium, and information transmission is performed in the optical transmission medium by using optical signals of a plurality of different wavelengths. In a multiplexed optical communication system, each of the communication nodes is an optical transmission unit that transmits information data to the optical transmission medium by an optical signal having a wavelength previously assigned to a communication protocol used by each node, And an optical receiving means for selecting and receiving an optical signal of a wavelength assigned in advance to a communication protocol used by each node. More specifically, the communication node performs wavelength division on a received signal to receive only an optical signal of a required wavelength, and an optical / electrical device for converting the received optical signal into an electric signal. Signaling means;
Packet assembling means for reproducing a packet according to each communication protocol; address identification means for determining whether or not the transmitted packet is information addressed to the own node; and information of the reproduced packet in each communication node. Upper layer processing means for processing, access control means for transmitting information sent from the upper layer processing means to a transmission medium in accordance with a communication protocol followed by the own node, and electric power for converting an electric signal into an optical signal. / Optical signal conversion means, and wavelength multiplexing means for wavelength multiplexing an optical signal having a wavelength deemed unnecessary in the communication node by the optical wavelength demultiplexing means and an optical signal newly transmitted from the communication node. It is good also as a structure which has. In the optical communication system according to the present invention, when there are a plurality of communication systems that perform communication using different communication protocols in a certain network, different wavelengths are assigned to the different communication protocols to provide an optical wavelength division multiplexing system. Communication.

Therefore, the following effects can be obtained. (I) Even if a communication system according to a plurality of communication protocols is accommodated simultaneously using the same communication medium, communication according to a unique protocol is performed between communication nodes according to the plurality of communication protocols. Can be done. (Ii) When a communication system according to a new communication protocol is introduced into a network, it can be easily realized simply by newly adding and assigning a wavelength to be used in the network. (Iii) When accommodating a plurality of communication protocols in the same transmission medium, there is no need to perform multiplexing protocol conversion or multiplexing processing, and the communication system according to each communication protocol can transmit the transmission capacity of the transmission medium. Can be fully used. In addition, the optical communication node is provided with an optical wavelength demultiplexing unit and an optical wavelength multiplexing unit in an interface portion of a normal communication node used in a communication mode in which only one communication protocol exists in the same communication medium. Thus, the effect that the optical communication system can be used as a communication node in the optical communication system is obtained.

(A) In the frequency division multiplexing optical communication system of the present invention, different frequencies are assigned to communication protocol units of information transferred in the same optical transmission medium. That is, in order to achieve the first object, in the present invention, a plurality of communication nodes are connected by an optical transmission medium, and information data is transmitted in the optical transmission medium by using optical signals of a plurality of different frequencies. In a frequency division multiplexing optical communication system performing transmission, each of the communication nodes transmits information data to the optical transmission medium by an optical signal of a frequency previously assigned to a communication protocol used by each node. It is characterized by comprising an optical transmitting means, and an optical receiving means for selecting and receiving an optical signal of a frequency assigned in advance to a communication protocol used by each node. More specifically, the communication node performs frequency division on a received signal to receive only an optical signal of a required frequency, and an optical / electrical device for converting the received optical signal into an electric signal. Signal means, packet assembling means for reproducing packets according to the respective communication protocols, address identification means for determining whether or not the transmitted packet is information addressed to the own node, and information on the reproduced packets. Upper layer processing means for processing in the communication node, access control means for transmitting information sent from the upper layer processing means to a transmission medium in accordance with a communication protocol which the node follows, and conversion of an electric signal into an optical signal Optical / optical signal converting means, and an optical signal of a frequency deemed unnecessary in the communication node by the optical frequency demultiplexing means. It may be configured to have a frequency multiplexing means for frequency multiplexing the optical signals transmitted from the new communication node. In the optical communication system according to the present invention, when there are a plurality of communication systems that perform communication using different communication protocols in a certain network, different frequencies are allocated to the different communication protocols, and an optical frequency division multiplexing method is used. Communication. Therefore, the following effects can be obtained. (I) Even if a communication system according to a plurality of communication protocols is accommodated simultaneously using the same communication medium, communication according to a unique protocol is performed between communication nodes according to the plurality of communication protocols. Can be done. (Ii) When a communication system according to a new communication protocol is introduced into a network, it can be easily realized simply by newly adding and allocating a frequency to be used in the network. (Iii) When accommodating a plurality of communication protocols in the same transmission medium, there is no need to perform multiplexing protocol conversion or multiplexing processing, and the communication system according to each communication protocol can transmit the transmission capacity of the transmission medium. Can be fully used. In addition, the optical communication node is provided with an optical frequency demultiplexing unit and an optical frequency multiplexing unit in an interface portion of a normal communication node used in a communication mode in which only one communication protocol exists in the same communication medium. Thus, the effect that the optical communication system can be used as a communication node in the optical communication system is obtained.

(B) In the optical communication system described in a above, a communication node having a protocol conversion function is connected to the optical fiber, and communication nodes according to different communication protocols connected to the optical transmission medium are connected. Communication protocol conversion means for providing the above communication function.
As a result, in the optical communication system, the following effects can be obtained by providing a protocol conversion node for performing protocol conversion between optical signals of different frequencies in the network. (1) Communication between communication nodes according to different communication protocols existing in a network can be provided. (2) Communication between communication nodes according to different communication protocols can be performed only by each communication node transmitting and receiving an optical signal of a frequency assigned to the communication protocol followed by the own node. (3) Even when a communication system according to a new communication protocol is introduced, it can be easily handled by providing a protocol conversion node corresponding to the new protocol.

(C) Further, in the optical communication system a), an inter-protocol communication protocol for performing communication between different communication protocols is defined, and a divided frequency is assigned to the inter-protocol communication protocol. It may be configured as follows.

In this case, the communication nodes used in the optical communication system include optical signal transmission means for transmitting an optical signal of a frequency assigned to a communication protocol followed by the communication node, and transmission from each communication node. Signal transmission means for multiplexing an optical signal having a plurality of frequencies and transmitting the same in a network, and a frequency assigned to a communication protocol which each communication node follows from the transmitted optical signal. Optical signal receiving means for selecting and receiving only the optical signal of An optical signal transmitting means, and a frequency assigned to the inter-protocol communication protocol among the transmitted optical signals. It may be configured with an optical signal receiving means for selecting and receiving a signal only. As a result, the optical communication system has the following effects by allocating frequencies to communication protocols for performing communication between different communication protocols. (1) Communication between communication nodes complying with different communication protocols can be provided without newly adding a communication node for protocol conversion. (2) Even when a communication system conforming to a new communication protocol is introduced, only a newly introduced node has a function of processing an inter-protocol communication protocol, and communication between communication nodes complying with another communication protocol is possible. Communication can be easily provided.

(D) In the optical communication system b, the optical signals of the respective frequencies assigned to a plurality of communication protocols are selected and received, and a protocol conversion function between the communication protocols is provided. In addition, an optical communication node for protocol conversion for transmitting information by optical signals of respective frequencies may be provided. In this case, the protocol conversion optical communication node performs frequency division of the received optical signal to receive only an optical signal of a required frequency, and electrically converts the received optical signals of a plurality of frequencies into optical signals. Optical / electrical signal converting means for converting the signal into a signal, packet assembling means for reproducing the packet to a packet of a layer capable of protocol conversion according to each received communication protocol, and information transmitted to the own node for the transmitted packet. , An address identifying means for judging whether or not the information is transmitted, a protocol converting means for converting the communication protocol into a desired communication protocol by a protocol convertible layer, and the information follows information sent from the protocol converting means and the address identifying means. An access control means for transmitting to a transmission medium in accordance with a communication protocol; Electrical / optical signal conversion means for converting to an optical signal of the frequency assigned to the protocol, an optical signal of a frequency deemed unnecessary in the protocol conversion function by the optical frequency demultiplexing means, and a new protocol conversion function And an optical frequency multiplexing means for frequency-multiplexing the optical signal transmitted from the multiplexed optical signal. As a result, the optical communication node for protocol conversion can provide an optical communication system such as that shown in the present invention simply by providing an optical frequency demultiplexing means and an optical frequency multiplexing means at the interface part of a normal protocol conversion node. An object of the present invention is to obtain an effect of being usable as a protocol converter in a communication system.

(E) In the optical communication system of c, each communication node used in the optical communication system transmits information by an optical signal of a frequency assigned to a communication protocol followed by the own node, and The node selects and receives the optical signal of the frequency assigned to the communication protocol followed by the node, transmits the optical signal of the frequency assigned to the inter-protocol communication protocol, and transmits the optical signal of the frequency assigned to the inter-protocol communication protocol. May be configured to select and receive the optical signal, and perform protocol conversion between the communication protocol followed by the own node and the inter-protocol communication protocol in the own node. For example, the communication node may perform frequency division on a received optical signal to receive an optical signal of a required frequency, and an optical / wavelength converting unit for converting the received optical signal into an electric signal. An electric signal converter, a normal packet assembler for reproducing a packet of information according to a communication protocol followed by the own node; Inter-protocol communication packet assembling means for reproducing even a packet of a layer which can be converted between protocols, and whether or not the packet sent from each packet assembling means is information addressed to its own node Protocol conversion is performed by the address identification means and the protocol convertible layer, and the packet Protocol conversion means for performing layer conversion to packets of the same layer as the information sent from the multiplexing means, multiplexing means for multiplexing packets sent from the normal packet assembling means and protocol conversion means, and Depending on the upper layer processing means for processing the information in each communication node and the destination of the information sent from the upper layer processing means, whether the information is information addressed to a communication node that follows the same communication protocol or different communication protocol Destination identification means for identifying whether the information is addressed to a communication node complying with the protocol, protocol conversion means for converting information addressed to a communication node complying with a different communication protocol into an inter-protocol communication protocol, and a communication protocol followed by the node. Access control for sending to transmission media according to And means,
Access control means for sending to a transmission medium in accordance with an inter-protocol communication protocol; and electric / optical signal conversion means for converting the transmitted electric signal into an optical signal of a frequency assigned to a desired communication protocol; The optical frequency demultiplexing means may be configured to include an optical signal having a frequency deemed unnecessary in the protocol conversion function and an optical frequency multiplexing means for frequency-multiplexing an optical signal newly transmitted from the protocol conversion function. good. As a result, the optical communication node recognizes the communication between the communication nodes that follow the same communication protocol and the communication between the communication nodes that follow different communication protocols in each communication node. By providing the optical frequency demultiplexing means and the optical frequency multiplexing means, the information can be identified only by identifying the optical frequency, so that the processing amount in the communication node can be reduced. can get.

(F) In the optical communication system a, b or c, a plurality of frequencies may be allocated to one communication protocol when frequencies are allocated in units of a communication protocol. In this case, a communication node used in the optical communication system includes: an optical signal transmitting unit for transmitting an optical signal matching a plurality of frequencies assigned to a communication protocol followed by the communication node;
Optical signal transfer means for multiplexing optical signals having a plurality of frequencies transmitted from each communication node and transferring the signals within a network, and a communication protocol which each communication node follows from the transferred optical signals. And an optical signal receiving means for selecting and receiving optical signals of a plurality of frequencies assigned to the mobile terminal. As a result, the optical communication system has the following effects by assigning a plurality of frequencies to each communication protocol in the network. (1) A communication band required by a communication node according to each communication protocol can be flexibly allocated. (2) It is possible to absorb a difference in transmission method between communication nodes in each communication protocol, a difference in operation clock, and the like.

(G) Further, the optical communication systems b or f may be connected by using the protocol conversion optical communication node shown in f as an interface between optical communication systems. For example, the protocol conversion optical communication node includes an optical frequency demultiplexing unit for frequency-dividing the received optical signal and receiving only an optical signal of a required frequency, and an optical signal demultiplexing the received optical signals of a plurality of frequencies. Optical / electrical signal converting means for converting the packet into a packet, a packet assembling means for reproducing a packet conforming to each communication protocol to a packet of a layer which can be converted, and destination information of the packet. Address identification means for identifying whether the information is addressed to a communication node existing in the network or to a communication node in another network, and for converting to a desired communication protocol by a protocol convertible layer Protocol conversion means and the information sent from the protocol conversion means and the address identification means. And access control means for delivering to the transmission medium in accordance with a communication protocol which, sent the electrical signal has to be converted into optical signals of frequencies allocated to the desired communication system electrical /
Optical signal conversion means, and an optical signal of a frequency deemed unnecessary in the protocol conversion function by the optical frequency demultiplexing means,
An optical frequency multiplexing means for frequency-multiplexing an optical signal to be newly transmitted from the protocol conversion function may be used. As a result, the inter-system connection optical communication node connects a plurality of optical communication systems by adding a network identification unit for the transmitted information to the protocol conversion optical communication node existing in the network. Thus, an effect that communication can be performed can be obtained.

(H) Further, in order to connect the optical communication systems a, c or f with each other, a system which provides a communication interface between the optical communication systems by using a frequency allocated to the inter-protocol communication protocol. An optical communication node for connection may be provided. For example, the inter-system connection optical communication node performs frequency division on a received optical signal to receive only an optical signal of a frequency assigned to a communication protocol for communication between different protocols. Means, optical / electrical signal converting means for converting an optical signal of a received frequency into an electric signal, packet assembling means for reproducing received information into a packet, and destination information of the packet. Identification means for identifying whether the information is addressed to a communication node in a network or to a communication node in another network, and a protocol for converting to a desired communication protocol by a protocol convertible layer The conversion means and the information transmitted from the protocol conversion means and the address identification means correspond to the communication protocol that the information follows. An access control means for transmitting to a transmission medium in accordance with the protocol, an electric / optical signal conversion means for converting the transmitted electric signal into an optical signal of a frequency assigned to the inter-protocol communication protocol, and an optical frequency component. An optical frequency multiplexing unit for frequency-multiplexing an optical signal having a frequency deemed unnecessary in the inter-network connection function by the wave unit and an optical signal newly transmitted from the inter-network connection function may be used. . As a result, the inter-system connection optical communication node uses the frequency assigned to the inter-protocol communication protocol used in the optical communication system also for communication between the optical communication systems,
The effect that the function of the connection apparatus between optical communication systems can be reduced can be obtained.

[0038]

Embodiments of the present invention will be described below with reference to the drawings.

<1> The present invention is applicable to any of an optical communication system based on an optical frequency division multiplexing system and an optical communication system based on an optical wavelength division multiplexing system.
The eighth embodiment will be described using an optical communication system using an optical frequency division multiplexing system. An embodiment of an optical communication system based on an optical wavelength division multiplexing system to which the present invention is applied is self-evident, and therefore, description thereof will be omitted.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
1 is a conceptual diagram of a configuration of an optical communication system according to an embodiment. In FIG. 1, a ring network is used as a network configuration topology. The optical communication system shown in FIG. 1 includes, as a common optical transmission medium used by a plurality of optical communication nodes, one or two bidirectional optical fibers 10 and nine optical communication nodes 21 to 21. 29.

In this optical communication system, optical signals of three frequencies fa, fb, and fc are propagated as optical signals that are optical frequency division multiplexed in the optical fiber 10. Further, the nine optical communication nodes 21 to 29 connected to the optical fiber 10 and performing communication do not communicate with all the optical communication nodes according to the same communication protocol. Is a communication protocol A, the optical communication nodes 22, 25, and 28 are communicating according to a communication protocol B, and the optical communication nodes 23, 26, and 29 are communicating according to a communication protocol C. In this optical communication system, three frequency-divided optical signals are allocated to each of the three communication protocols existing in the system, and each optical communication node is allocated to a communication protocol that is followed by its own node. The communication is performed using the optical signal of the frequency.

That is, the optical communication nodes 21, 24, and 27 complying with the communication protocol A transmit and receive only the optical signal of the frequency fa from the optical fiber 10, and the optical communication nodes 22, 25 and 28 complying with the communication protocol B communicate with the optical fiber 10. Transmit and receive only optical signals of frequency fb from
Optical communication nodes 23, 2 according to communication protocol C
6 and 29 perform communication by transmitting and receiving only the optical signal of the frequency fc from the optical fiber 10.

Here, as a method of allocating a frequency, a method of directly using the frequency of an optical signal defined by a physical layer protocol of an existing communication protocol followed by an existing communication node, or an optical communication Providing frequency conversion means for optical signals in the input / output interface of the node so that the network administrator can assign any frequency to each communication protocol when starting up the network or adding an optical communication node, etc. The method is conceivable.

By allocating such optical frequencies, even when there are a plurality of communication systems performing communication according to different communication protocols, the same transmission medium (optical fiber in FIG. 1) is used for those communication systems. It is possible to construct a network that accommodates a communication system at the same time. In particular, it is possible to easily construct a network that needs to simultaneously accommodate a plurality of networks (LANs) installed in a company, such as a backbone network in a company network.

Further, since a plurality of protocols are simultaneously handled by using the optical frequency division multiplexing system, the optical frequency demultiplexing function and the optical Only by providing a means having a frequency multiplexing function, it can be used as an optical communication node in an optical communication system to which the present invention is applied.

From the above, when constructing the optical communication system of the present invention, it is not necessary to newly create an optical communication node dedicated to the present optical communication system, and the present invention can be easily implemented using an existing optical communication node. An optical communication system can be realized. Further, with such a configuration in which a plurality of communication protocols are accommodated in the same transmission medium, a network that can be easily adapted to a future multi-vendor environment or a multi-protocol environment can be constructed.

(Second Embodiment) FIG. 2 shows a second embodiment of the present invention.
1 is a conceptual diagram of a configuration of an optical communication system according to an embodiment. Here, a ring network is used as the network configuration topology. The optical communication system shown in FIG. 2 has a configuration in which protocol conversion optical communication nodes 31 to 33 for newly providing communication between different communication protocols are added to the optical communication system shown in FIG. I have.

Specifically, there are optical communication nodes 21 to 29 as in the case of FIG. 1, and each optical communication node communicates with each communication protocol and a frequency assigned to the communication protocol. At the same time, the protocol conversion node 31 performs conversion between the communication protocols A and B, the protocol conversion node 32 performs conversion between the communication protocols B and C, and the protocol conversion node 33 performs conversion between the communication protocols A and C. Is going.

By constructing a network having such a configuration, in the case where a plurality of communication systems complying with different communication protocols exist at the same time, an optical communication device having a communication function between optical communication nodes complying with different types of protocols. A communication system can be realized.

Here, in the optical communication system as shown in FIG. 2, the protocol conversion function can be provided even if the optical communication node in the optical communication system shown in FIG. It can respond more flexibly to multi-vendorization. Further, since communication between a plurality of protocols is possible by such a method, a plurality of communication systems according to a plurality of protocols can be treated as if they were one communication system.

(Third Embodiment) FIG. 3 shows a third embodiment of the present invention.
1 is a conceptual diagram of a configuration of an optical communication system according to an embodiment. Here, a ring network is used as the network configuration topology. The optical communication system shown in FIG. 3 defines an inter-protocol communication protocol for providing communication between optical communication nodes that newly follows a different communication protocol from the optical communication system shown in FIG.

More specifically, the optical communication nodes 41 to 49 perform communication according to their own communication protocols, and also perform communication according to the inter-protocol communication protocol. Therefore, in the transmission line 10 of this optical communication system, along with the optical signal assigned to each of the communication protocols of the frequencies fa, fb, and fc, the frequency fI assigned to the inter-protocol communication protocol is used.
Are also propagated.

By using such an optical communication system, an optical communication system having a communication function between optical communication nodes according to different types of protocols is realized when there are a plurality of communication systems according to different communication protocols. You can do it.

By defining the inter-protocol communication protocol as described above, a new protocol conversion node is not introduced as in the case of the second embodiment (FIG. 2).
By connecting optical communication nodes having the same configuration to a transmission medium, it becomes possible to treat a communication system according to a plurality of protocols as if it were one communication system.

(Fourth Embodiment) FIG. 4 shows a fourth embodiment of the present invention.
FIG. 3 is a conceptual diagram of an internal configuration of an optical communication node according to the embodiment. FIG. 4 corresponds to FIG. 1 (first embodiment) or FIG. 2 (second embodiment).
2 shows an internal configuration of an optical communication node according to a communication protocol to which an optical signal of frequency fa is assigned.

FIG. 1 shows a series of information processing procedures in this configuration.
This is shown below with reference to FIG. Here, the IE (Media Access Control) of the communication protocol A is IE.
A procedure for transmitting information from the optical communication node 21 to the optical communication node 27 by using the EE802.5 token ring protocol will be described.

[1] After the transmission source optical communication node 21 receives the token, information transmission to the optical communication node 27 is started. [2] From the access control unit 601 of the optical communication node 21,
The information is E according to the access protocol of the token ring.
Transferred to the I / O conversion unit 211 (the address identification unit 501).
Multiplexing the information transmitted from the optical communication node 21 and performing access control). [3] The E / O converter 211 of the optical communication node 21 converts the packet transmitted by the electric signal into an optical signal packet of the frequency fa and sends it to the transmission medium 10 via the optical frequency multiplexer 102. I do. [4] Optical signals of frequencies fa, fb, fc are multiplexed and transmitted in the transmission medium 10. [5] The optical signals of the frequencies fa, fb, and fc pass through the transmission medium 10 and are input to the optical frequency demultiplexing unit 101 of the optical communication node 27 while being multiplexed. [6] In the optical frequency demultiplexing unit 101 of the optical communication node 27,
Only the optical signal of the frequency fa assigned to the protocol A is taken into the optical communication node 27, and the optical signals of other frequencies are passed through the optical frequency multiplexing unit 102 as it is. [7] The O / E converter 201 of the optical communication node 27 converts the captured optical signal of the frequency fa into an electric signal. [8] The MAC layer packet assembling unit 301 of the optical communication node 27 assembles the transmitted electric signal into a MAC layer packet and sends it to the address identification unit 501. [9] In the address identification unit 501 of the optical communication node 27,
It is determined whether the packet is information addressed to the own node (optical communication node 27) or not based on the MAC address of the transmitted packet. In this case, the information is transferred to the access control unit 601. [10] The upper layer processing unit 901 of the optical communication node 27 performs information processing of the LLC layer or higher, and processing such as providing an interface to a terminal accommodated in the optical communication node.

Here, the case where the token ring protocol is used as the communication protocol has been described. However, the present invention is not limited to the above-described protocol. Communication can be performed.

Although FIG. 4 shows a configuration in which the optical communication node is identified by the MAC layer of the communication protocol A, the node identification method in the optical communication node according to the present invention is not limited to such a method. No higher L
A method of identifying an optical communication node using an LC packet, an IP address, or an address of a physical layer lower than the MAC layer may be considered.

As described above, in the internal configuration of the optical communication node shown in FIG. 4, the other components except the optical frequency demultiplexing unit 101 and the optical frequency multiplexing unit 102 are the same as those of the ordinary token ring system. It can be understood that the configuration is exactly the same as the configuration of the optical communication node that can be used in the communication system. From this fact, the optical communication node used in the optical communication system to which the present invention is applied simply by having the input / output interface portion of the optical communication node performing normal communication to have the demultiplexing function and the multiplexing function of the optical frequency. It becomes possible to build.

(Fifth Embodiment) FIG. 5 shows a fifth embodiment of the present invention.
FIG. 3 is a conceptual diagram of an internal configuration of an optical communication node for protocol conversion according to the embodiment. An optical communication node for protocol conversion according to this embodiment is a communication protocol conversion unit for communication between optical communication nodes performing communication according to different communication protocols in the optical communication system shown in FIG. 2 (second embodiment). It provides functions. The protocol conversion optical communication node shown in FIG. 5 is a protocol conversion optical communication node that provides a protocol conversion function between protocols A and B to which frequencies fa and fb are assigned in the optical communication system shown in FIG. 2 shows an internal configuration of the communication node 31.

FIG. 2 shows a series of information processing procedures in this configuration.
This is shown below with reference to FIG. Here, the optical communication node 21 using the IEEE 802.5 token ring protocol as the MAC of the communication protocol A sends the ANSI X3T9.5 F as the MAC of the protocol B.
The procedure for transmitting information to the optical communication node 25 using the DDI protocol is shown below (because the protocol is converted between token ring and FDDI,
Consider protocol conversion via LLC layer packets).

[1] After the transmission source optical communication node 21 receives the token, the protocol conversion optical communication node 3
Information is transmitted from the optical communication node 21 as an optical signal having a frequency fa toward 1. [2] The optical signals of the frequencies fa, fb, and fc are multiplexed through the transmission medium 10 and input to the optical frequency demultiplexing unit 101 of the protocol conversion optical communication node 31. [3] The optical frequency demultiplexing unit 101 of the protocol conversion optical communication node 31 takes in the optical signal of the frequency fa allocated to the protocol A and the optical signal of the frequency fb allocated to the protocol B, and acquires the other frequencies. Is passed through the optical frequency multiplexing unit 102 as it is. [4] The O / E converter 201 of the protocol conversion optical communication node 31 converts the captured optical signal of the frequency fa into an electric signal. [5] The MAC layer packet assembling section 301 of the protocol conversion optical communication node 31 assembles the transmitted electric signal into a MAC layer packet and sends it to the address identification section 501. [6] The address identification unit 501 of the protocol conversion optical communication node 31 determines whether the packet is information addressed to the own node or not based on the MAC address of the transmitted packet, and when the packet is information addressed to the own node. Is transferred to the protocol conversion unit 702, and if not, the information is transferred to the access control unit 601. [7] After the LLC layer packet is once constructed by the protocol conversion unit 702 of the protocol conversion optical communication node 31, conversion from the communication protocol A to B is performed.
A MAC layer packet according to the protocol B (FDDI) is constructed, and the packet is transferred to the access control unit 602. [8] The access control unit 602 of the protocol conversion optical communication node 31 performs access control of information transmitted from the address identification unit 502 and the protocol conversion unit 702 according to the access protocol of the communication protocol B,
The information is transferred to the E / O conversion unit 212. [9] The electric signal transmitted by the E / O converter 212 of the optical communication node 31 for protocol conversion is converted to the frequency fb
After that, the information is transmitted to the optical frequency multiplexing unit 102. [10] The optical signals of the frequencies fa and fb sent from the E / O converters 211 and 212 by the optical frequency multiplexing unit 102 of the protocol conversion optical communication node 31,
The optical frequency demultiplexing unit 101 multiplexes the optical signal of the frequency fc, which has become unnecessary in the optical communication node for protocol conversion, and sends it to the transmission medium 10. [11] The optical communication node 25 receives the optical signal of the frequency fb from the protocol conversion optical communication node 31,
The information transfer from the optical communication node 21 to the optical communication node 25 ends.

Here, the protocol conversion method from the communication protocol A (token ring) to the communication protocol B (FDDI) has been described, but the protocol conversion from the communication protocol B to the communication protocol A can be realized by exactly the same method.

When the optical communication node for protocol conversion is connected to the optical communication system of the present invention as described above, when viewed from the communication protocol A, the optical communication according to the communication protocol A in the optical communication system shown in FIG. Communication nodes are 21, 2
This is the same as having increased to 5, 27, 31, and 33.

FIG. 5 shows a case in which the Token Ring and FDDI protocols are converted as the communication protocols to be converted. However, the present invention is not necessarily limited to such a combination of protocols. The protocol conversion using the protocol conversion optical communication node of this configuration can be performed on the protocol. In FIG. 5, the identification of the protocol conversion optical communication node is performed using the address of the MAC layer of the communication protocol A, but the node identification method in the protocol conversion optical communication node of the present invention is based on such a method. The method is not limited, and a method of identifying an optical communication node for protocol conversion using an address or an IP address of an upper LLC layer or an address of a physical layer lower than the MAC layer can be considered. . Further, in the method shown in FIG. 5, the protocol conversion between the protocols A and B is performed by the LLC layer packet, but the protocol conversion method in the protocol conversion optical communication node of the present invention is such a method. However, the present invention is not limited to this, and it is of course conceivable that protocol conversion is performed using packets of higher layers.

By using the protocol conversion optical communication node that provides the protocol conversion function according to the above procedure, the optical communication node performs communication according to different communication protocols without changing the optical communication node shown in FIG. Communication between communication nodes can be performed. Further, by constructing a network by combining such an optical communication node and an optical communication node for protocol conversion, a communication system according to a plurality of protocols is connected by the same transmission medium, and it is as if one communication system. It becomes possible to operate as if.

(Sixth Embodiment) FIG. 6 shows a sixth embodiment of the present invention.
FIG. 3 is a conceptual diagram of an internal configuration of an optical communication node according to the embodiment. FIG. 6 shows the frequency f in FIG. 3 (third embodiment).
The internal configuration of the optical communication node 41 according to the communication protocol to which the optical signal a is assigned is shown. For this reason, the optical communication node in FIG. 6 is configured to include both a function for information processing of the communication protocol A and a function for information processing of the inter-protocol communication protocol.

FIG. 3 shows a series of information processing procedures in this configuration.
This is shown below with reference to FIG. Here, a case is considered in which an IEEE 802.5 token ring protocol is used as the MAC layer of the communication protocol A, and an FDDI communication protocol of ANSI X3T9.5 is used as the MAC layer of the inter-protocol communication protocol. For this reason, the information of the token ring protocol and the information of the FDDI protocol in the optical communication node are identified by the LLC layer packet.

First, the information processing procedure for communication in the communication protocol A is almost the same as the information processing procedure in the optical communication node shown in the fourth embodiment (FIG. 4). However, when information is transferred from the address control unit 501 to the upper layer processing unit 901, the LLC layer packet is once constructed and multiplexed with information from the inter-protocol communication protocol. Is transmitted, the transfer destination address of the LLC layer packet is identified, and the MAC layer packet of the communication protocol A is constructed.

Next, an information processing procedure when information is transferred from the optical communication node 41 to the optical communication node 48 in FIG. 3 using the inter-protocol communication protocol will be described.

[1] The source optical communication node 41 is FDD
After receiving the I token, information transmission to the optical communication node 48 is started. [2] The transfer destination address of the LLC layer packet is identified by the destination identification unit 811 from the upper layer processing unit 901 of the optical communication node 41, and if the transfer destination address is not addressed to the optical communication node performing communication according to the communication protocol A, The information is transferred to the MAC layer packet construction unit 722. [3] The MAC layer packet construction unit 722 of the optical communication node 41 segments the LLC layer packet into a MAC layer packet of the inter-protocol communication protocol (FDDI), and then transfers the segment to the access control unit 602. [4] From the access control unit 602 of the optical communication node 41,
In accordance with the access protocol of the inter-protocol communication protocol (FDDI), information is transferred to the E / O conversion unit 212 (after multiplexing the information transmitted from the address identification unit 502 and passing through the optical communication node 41). Perform access control). [5] The E / O converter 212 in the optical communication node 41 converts the packet transmitted by the electric signal into an optical signal packet of the frequency fI, and converts the packet into the transmission medium 10 via the optical frequency multiplexer 102. Send out. [6] Optical signals of frequencies fa, fb, fc and fI are transmitted in the transmission medium 10. [7] Frequency fa, fb, fc, fI through transmission medium 10
While the optical signal of the frequency
8 is input to the optical frequency demultiplexing unit 101. [8] In the optical frequency demultiplexing unit 101 of the optical communication node 48,
An optical signal having a frequency of fI, which is a frequency assigned to the inter-protocol communication protocol, is fetched into the optical communication node, and the O / E converter 202 converts the fetched optical signal of frequency fI into an electric signal. [9] The MAC layer packet assembling section 302 of the optical communication node 48 performs physical layer processing such as establishing frame synchronization of the converted electric signal, and then assembles it into a MAC layer packet and sends it to the address identification section 502. [10] The address identification unit 502 of the optical communication node 48 determines whether the packet is information addressed to the own node or not based on the MAC address of the transmitted packet. The information is transferred to the assembling unit 712, and if not, the information is transferred to the access control unit 602 for the inter-protocol communication protocol. [11] LLC layer packet assembling section 7 of optical communication node 48
After assembling into an LLC packet at 12, the information is sent to the upper layer processing unit 90 by multiplexing with the LLC packet of the information transmitted by the inter-protocol communication protocol by the multiplexing unit 801.
1 to the LLC layer packet.

Here, the case where the FDDI protocol is used as the inter-protocol communication protocol has been described. However, the present invention is not necessarily limited to such a protocol. Communication using the node can be performed. FIG. 6 also shows a configuration in which the optical communication node is identified by the MAC layer of the communication protocol A, but the node identification method in the optical communication node of the present invention is not limited to such a method. A method of identifying an optical communication node using an LLC packet, an IP address, or an address of a physical layer lower than the MAC layer is also conceivable. Further, in FIG. 6, the protocol conversion between the protocol A and the inter-protocol communication protocol is performed by LLC.
Although the protocol conversion is performed by the packet of the layer, the protocol conversion method in the optical communication node for protocol conversion of the present invention is not limited to such a method, and the protocol conversion may be performed by the packet of the higher layer. Of course you can.

By providing a communication function between optical communication nodes performing communication according to different communication protocols in such a procedure, an optical communication node for protocol conversion as shown in FIG. 5 is newly provided. Without any trouble, communication can be performed between optical communication nodes performing communication according to different communication protocols. Further, by constructing such an optical communication node, it becomes possible to connect communication systems according to a plurality of protocols by the same transmission medium and operate as if it were one communication system. .

(Seventh Embodiment) FIG. 7 shows a configuration example of an optical frequency demultiplexing means installed in an input / output interface of an optical communication node used in the optical communication system of the present invention. Here, the optical waveguide 901 and the directional coupler 90
2 shows a configuration in the case of using a ring-type waveguide duplexer 900 composed of only two.

By using such a frequency division system using the frequency characteristics of light, communication of the optical frequency division multiplex system in the optical communication system of the present invention can be realized, and the optical communication node and protocol conversion system of the present invention can be realized. It is possible to easily provide an optical frequency demultiplexing function and an optical frequency multiplexing function in the input / output interface unit of the optical communication node.

When performing such optical frequency demultiplexing and optical frequency multiplexing, it may be better to take into account the influence of light reflection and the like. Therefore, with respect to such reflection of light, it is preferable to dispose a means such as an isolator that allows light to pass only in one direction at a necessary place such as an optical demultiplexer used in the optical communication system of the present invention. It is believed that it may be preferable.

The optical frequency division method that can be used in the optical communication node of the present invention is limited to an optical frequency demultiplexer using a ring-type waveguide type demultiplexer as shown in FIG. Instead, it is obvious that various types such as those using the characteristics of a diffraction grating, those using a prism, and those using a multilayer film can be used. Also,
Based on the optical switch method, which determines whether optical signals of the required frequency are demultiplexed into optical signals using an optical frequency demultiplexer, and then decides whether or not to incorporate them into the optical communication node by an optical switch, or the optical reciprocity theorem A method of providing both the optical frequency demultiplexing function and the optical frequency multiplexing function using a single frequency demultiplexing device is also conceivable.

(Eighth Embodiment) FIG. 8 shows an example of the configuration of an optical frequency multiplexing means for performing frequency multiplexing of an optical signal in the optical communication system of the present invention. FIG. 8 shows an optical frequency multiplexing method using a star coupler 903.

As described with reference to FIG. 7, a method of multiplexing (multiplexing) optical frequencies by using the same optical frequency demultiplexing device as the optical reciprocity theorem is also conceivable. Even when such optical frequency multiplexing is performed, the influence of light reflection may occur as in the case of optical frequency demultiplexing. Again, this is also considered in the optical communication system of the present invention. It is considered that it may be preferable to arrange a function such as an isolator, which allows light to pass only in one direction, at a necessary place such as an optical multiplexer used.

(Ninth Embodiment) FIG. 9 is a conceptual diagram showing the internal configuration of a protocol conversion unit 701 installed inside the protocol conversion optical communication node of FIG. 5 (fifth embodiment). Here, the protocol conversion unit 701 shown in FIG.
2 shows a conceptual diagram of an internal configuration in a case where a MAC layer packet of a communication protocol A is converted into a MAC layer packet of a communication protocol B via a layer 3 (IP) packet.

Hereinafter, the communication protocol A is used to convert the communication protocol B to the communication protocol B using the protocol conversion means having the configuration shown in FIG.
Shows the information processing procedure when performing protocol conversion.

[1] A MAC layer packet of the communication protocol A is input to the protocol conversion unit. [2] The layer 3 packet assembling unit 771 converts the MAC layer packet of the communication protocol A into the upper layer L
Assemble up to layer 3 packets via LC layer packets. [3] After the destination identification unit 772 identifies the IP address of the destination terminal of the layer 3 packet, the packet is transferred to the control information reading unit 773 (read I
The P address is notified to the address mapping unit 774). [4] After reading various control information of the layer 3 packet by the control information reading unit 773, the packet is transferred to the segmentation unit 776 (the read control information is notified to the control information mapping unit 775). [5] Based on the notified IP address, the address mapping unit 774 searches the destination information database 779 for the MAC layer address of the communication protocol B corresponding to the IP address. [6] The control information mapping unit 775 maps the notified control information to the MAC layer control information of the communication protocol B. [7] The segmentation unit 776 performs segmentation of the transmitted layer 3 packet to a MAC layer packet of the communication protocol B via the LLC layer. [8] The control information mapping unit 775 and the address mapping unit 77 by the MAC layer packet construction unit 778
By adding the MAC layer information sent from the communication protocol B.4, a MAC layer packet of the communication protocol B is constructed, and the converted MAC layer packet of the communication protocol B is transmitted.

According to such a method, the communication protocol A
Can be converted into the MAC layer packet of the communication protocol B. However, in this case, the layer 3
Although the method of performing protocol conversion has been described above, other methods of protocol conversion include a method of performing protocol conversion using an LLC layer and a method of performing protocol conversion using a higher layer.

(Tenth Embodiment) FIG. 10 shows an optical signal transmitted / received to / from a transmission medium (optical fiber 10) connected to an optical communication node in each of the optical communication nodes shown in FIGS. 4, 5 and 6. FIG. 1 shows an example of a conceptual diagram of an internal configuration of a frequency conversion means used when communication is performed by actively converting the frequency of the data. In FIG. 10, an optical communication node 21 that communicates with an optical signal having a frequency fx according to a communication protocol A,
An optical communication node 22 that performs communication with an optical signal having a frequency fx according to a communication protocol B, and frequency conversion units 111 and 112 added between each optical communication node and an optical fiber are shown. Here, the frequency fa is assigned to the communication protocol A, and the communication protocol B
Shows a case where the frequency fb is assigned to. In such a case, the frequency conversion unit 1 of the present configuration
An example of the procedure for performing the frequency conversion by 11, 112 will be described below.

(1) Frequency conversion procedure in the optical communication node 21 [1] An optical signal of the frequency fX specified by the physical layer protocol of the optical communication node 21 is received from the optical communication node 21, and the O / E converter 222 After converting to an electric signal and performing retiming processing such as bit synchronization by the retiming control unit 252, E / O conversion is performed by the laser oscillator of the frequency fa assigned to the communication protocol A, and the optical frequency An optical signal is sent to the wave unit 102. [2] The optical signal of the frequency fa assigned to the communication protocol A transmitted from the optical frequency
After being converted into an electric signal by the / E conversion unit 221 and subjected to retiming processing such as bit synchronization by the retiming control unit 251, the laser signal of the frequency fX defined by the physical layer protocol of the optical communication node 21 is used. It performs E / O conversion and sends an optical signal to the optical communication node 21.

(2) Frequency conversion procedure in the optical communication node 22 [1] An optical signal of the frequency fX specified by the physical layer protocol of the optical communication node 22 is received from the optical communication node 22, and the O / E converter 224 After converting into an electric signal and performing retiming processing such as bit synchronization by the retiming control unit 254, E / O conversion is performed by the laser oscillator of the frequency fb assigned to the communication protocol A, and the optical frequency An optical signal is transmitted to the wave unit 104. [2] The optical signal of the frequency fb assigned to the communication protocol A transmitted from the optical frequency
The signal is converted into an electric signal by the / E conversion unit 223, and retiming processing such as bit synchronization is performed by the retiming control unit 253. Then, the signal is transmitted by the laser transmitter of the frequency fX defined by the physical layer protocol of the optical communication node 22. It performs E / O conversion and sends out an optical signal to the optical communication node 22.

However, the frequency conversion method of the optical signal is not limited to the configuration shown in FIG. 9. For example, an optical signal of an arbitrary frequency can be selected and multiplexed by the optical frequency demultiplexing means or the optical frequency multiplexing means. Such a configuration is also conceivable.

Using such an optical signal frequency conversion means,
Communication protocols that existing communication nodes follow.
Optical signals specified by the Tokor physical layer protocol
Not only when the frequency of the
Although they are communicating differently as a col,
If only the protocol specifications are the same,
(For example, the FDDI protocol of ANSI X3T9.5
ATM-For
100Mbps MultimodeFib with um specification
Physical layer defined by rr Interface
Protocol is the same), according to the communication node of the present invention.
Accordingly, the optical communication system of the present invention can be operated.
Further, in the optical signal frequency conversion means shown in FIG.
Conversion frequency can be set arbitrarily by external input
To connect the optical communication node to the optical communication system.
Free frequency allocation by the network administrator when
It can be applied. And such a network
Free optical signal frequency allocation by the network administrator
Accordingly, the optical communication node shown in FIGS.
What communication protocol (physical layer protocol)
Optical communication node that performs communication in
Communication can be performed within the communication system, and the optical communication of the present invention can be performed.
It is possible to operate the communication system more flexibly.

(Eleventh Embodiment) FIG. 11 shows a conceptual diagram of a configuration of an optical communication system according to an eleventh embodiment of the present invention. In the optical communication system of FIG. 11, since a plurality of frequencies are assigned to one communication protocol, the frequency of the optical signal transmitted from the optical communication nodes 51 to 59 connected to the transmission medium 10 is Multiple are defined.

More specifically, frequencies fa1 and fa2 are assigned to communication protocol A, frequencies fb1, fb2 and fb3 are assigned to communication protocol B, and frequencies fc1, fc2 and fc3 are assigned to communication protocol C. Configuration. In addition, since a plurality of frequencies are assigned to the communication protocol, the protocol conversion optical communication nodes 34 to 36 also have a function of transmitting and receiving optical signals of a plurality of types of frequencies. It has a configuration.

By configuring such an optical communication system, an optical communication node according to one communication protocol can transmit information with optical signals of a plurality of frequencies. Despite being connected to one transmission medium, communication can be performed as if connected to a plurality of transmission media at the same time. As a result, the amount of information that can be simultaneously transmitted from the optical communication node can be increased, and communication with a plurality of optical communication nodes can be performed simultaneously.

Further, since a plurality of frequencies are assigned to the same communication protocol, it is possible to simultaneously accommodate different communication systems that use the same communication protocol but operate differently. For example, communication is performed using the communication protocol A, but the frequency in the transmission medium is fa1.
However, if a communication system with the frequency fa2 exists in the transmission medium, these communication systems can exist without interfering with each other. An optical communication system such as "Yes" can be permitted.

Further, the protocol conversion optical communication nodes 34 to 36 in the optical communication system according to the present configuration are not provided with a protocol conversion function for each communication protocol, but are provided with a protocol conversion function for each frequency unit of an optical signal. To provide ".

(Twelfth Embodiment) FIG. 12 shows a conceptual diagram of a connection system of an optical communication system by a protocol conversion optical communication node according to a twelfth embodiment of the present invention. Figure 1
2, one optical communication node 6 for protocol conversion
By connecting 1 to two optical fibers 11 and 12, two optical communication systems (network 1 and network 2) are connected.

According to the present embodiment, even when a plurality of optical communication systems are connected, communication can be performed even if a plurality of optical communication systems are connected to the protocol conversion optical communication node existing in the network by adding network identification means for the transmitted information. The effect of being able to perform is obtained.

Here, as an optical communication node connecting the optical communication systems, a method using the optical communication node shown in FIG. 4 or the optical communication node shown in FIG. 6 may be considered.

(Thirteenth Embodiment) FIG. 13 is a conceptual diagram showing a connection system of an optical communication system using a protocol conversion optical communication node according to a thirteenth embodiment of the present invention. Figure 1
3, the protocol conversion optical communication nodes 71 and 7
There are two optical communication systems (network 1 and network 2) each having an optical communication node 2, and the two existing optical communication nodes for protocol conversion are connected by an optical signal of a specific frequency.

Here, the optical frequency assigned to the optical signal connecting the optical communication systems may be any frequency. Also, as in the case of FIG. 12 (twelfth embodiment), other optical communication nodes for connecting the optical communication systems may be the optical communication node shown in FIG.
The method using the optical communication node shown in FIG.

(Fourteenth Embodiment) FIG.
FIG. 39 is a conceptual diagram of an internal configuration of an optical communication node for protocol conversion in an optical communication system connection system according to a (twelfth embodiment). The protocol conversion optical communication node of FIG. 14 basically has a configuration having two sets of components of the protocol conversion optical communication node shown in FIG. 5 (fifth embodiment).

The difference from the protocol conversion optical communication node shown in FIG. 5 is that the address identification functions 501, 502, 50 inside the protocol conversion optical communication node shown in FIG.
3 and 504, the number of types of addresses to be identified increases, and the access control units 601, 602, and 60
3, 604, the type of information to be controlled is increased. In the protocol conversion optical communication node shown in FIG. 5, it is sufficient to identify whether the communication protocol is for the optical communication node of the communication protocol A or the communication protocol B is for the optical communication node in the optical communication system. In the protocol conversion optical communication node of FIG. 14, it is necessary to identify which of the connected optical communication systems the optical communication node is directed to.

In the optical communication node for protocol conversion shown in FIG. 5, it is sufficient to perform access control on the information obtained by the protocol conversion and the information not requiring the protocol conversion. In, it becomes necessary to control access to information from the connected optical communication system.

(Fifteenth Embodiment) FIG.
FIG. 39 shows a conceptual diagram of an internal configuration of an optical communication node for protocol conversion in an optical communication system connection system according to a thirteenth embodiment. The protocol conversion optical communication node shown in FIG. 15 basically has the function of the protocol conversion optical communication node shown in FIG. 5 (fifth embodiment) and the frequency assigned to the optical communication node shown in FIG. Is replaced by fI and has the function of adding the function of the optical communication node. The difference from these optical communication nodes is that FIG.
As in the case of the protocol conversion optical communication node, the address identification means 50 inside the protocol conversion optical communication node is used.
1, 502, 503 and access control means 601, 60
2 and 603 is that the amount of processing increases.

In the inter-system connection system as shown in FIG. 15, depending on the distance between the systems and the required information transfer quality between the systems, the layer-to-system connection optical communication nodes may be layer 2 packets or MAC layers. A method of directly transferring an electric signal as a packet using a packet is also conceivable.

Here, FIGS. 12 to 15 (first example)
By using the inter-system connection method shown in the second to fifteenth embodiments), a plurality of optical communication systems described in FIG. 1 (first embodiment) and FIG. 2 (second embodiment) exist. In such a case, it is possible to connect the systems without adding so many functions. In particular, as shown in FIG. 15, by connecting a plurality of existing optical communication systems using an optical signal of a unique frequency when connecting the respective optical communication systems, the communication used in each optical communication system is connected. The combination of the protocol and the frequency of the optical signal, the type of frequency to be assigned, and the like can be set independently in each optical communication system, and the connection between the systems can be easily realized.

(Sixteenth Embodiment) FIG. 16 shows an example of a conceptual diagram of a connection system of an optical communication system of the present invention using an optical communication node for connection between systems according to a sixteenth embodiment of the present invention. The inter-system connection method shown in FIG.
This is a connection system for connecting optical communication networks shown in (third embodiment), and is an inter-system connection system that uses an inter-protocol communication protocol for the inter-system connection.

In addition to such a method of performing inter-system connection with one inter-system connection optical communication node between the optical communication systems, two optical communication systems as shown in FIG. Naturally, a method of connecting the optical communication nodes for connection between systems and assigning an optical signal with a unique frequency between the optical communication nodes for connection between systems can also be considered.

(Seventeenth Embodiment) FIG.
FIG. 39 shows a conceptual diagram of an internal configuration of an optical communication node for connection between systems according to a (sixteenth embodiment). The optical communication node for inter-system connection in FIG. 17 basically has a configuration including two sets of components of the optical communication node shown in FIG. 4 (fourth embodiment). The optical communication node shown in FIG. 4 is different from the optical communication node shown in FIG. 14 and FIG. That is, the number of types of addresses to be increased and the number of types of information to be controlled by the access control units 601 and 602 are increased.

By using such an inter-system connection method, even when a plurality of optical communication systems shown in FIG. 3 (third embodiment) exist, the inter-system communication system shown in FIG. By installing a connection optical communication node, it is possible to easily connect a plurality of systems. Also, by using the optical communication node for connection between systems of this configuration, similar to the case of the connection method between systems shown in FIG. In order to connect a plurality of existing optical communication systems using the optical signal of the frequency, the combination of the communication protocol and the frequency of the optical signal used in each optical communication system and the type of frequency to be assigned, The setting can be made independently in each optical communication system, and connection between systems can be easily realized.

(Eighteenth Embodiment) FIG. 18 shows a conceptual diagram of a system configuration other than the ring type topology when configuring the optical communication system of the present invention. As described above, the network topology for constructing the optical communication system of the present invention is not limited to the ring-type topology shown in FIG. An optical communication system configuration based on a bus topology, a star topology based on a star coupler, a normal bus topology, or the like can be considered.

<2> (Nineteenth Embodiment) FIG. 21 shows a nineteenth embodiment of the present invention. In the optical communication system of FIG. 21, three wavelengths λ1, λ2, and λ3 are used for simplicity of description. The optical communication system includes six nodes A to F. Nodes A and D are assigned a wavelength of λ1.
E is assigned a wavelength of λ2, and nodes C and F are assigned wavelengths of λ3.
Is assigned.

FIG. 22 shows a main configuration of each node.
Each node includes a demultiplexer 1000, three optical receivers 1001a to 100c for receiving the wavelengths of λ1 to λ3, respectively, and an optical transmitting device 1 for transmitting the wavelength assigned to the own station.
002, an optical filter 1003 for blocking light of a wavelength assigned to the own station, sorting devices 1004a to 1004c for sorting a signal addressed to the own station and a signal to be relayed by the own station among signals received by the own station. First multiplexing device 10 for multiplexing signals destined for the own station distributed by devices 1004a to 1004c
05, and a second multiplexer 1006 that multiplexes the signal to be relayed by the own station and the signal from the terminal connected to the own station, which is allocated by the allocation device.

Next, the operation of each node of the optical communication system will be described.

Each node is connected to the transmission line 1200 through λ1-
Light having a wavelength of λ3 is wavelength-multiplexed and sent. At each node, the multiplexed optical signal is transmitted to the optical receiver 10 of each node.
01a-c and the optical filter 1003. A device for separating an optical signal (not shown)
For example, an optical coupler, an optical demultiplexer, or the like is used.

In the light sent to the optical filter 1003, only the wavelength assigned to the node is deleted. As a result, the circulating light is erased. As the optical filter 1003 for blocking a specific wavelength, for example, an acousto-optic filter or the like is used.

The signals sent to the optical receivers 1001a to 1001c are separated into respective wavelengths by a demultiplexer 1000 including an optical wavelength demultiplexer. The separated lights are converted into electric signals by the optical receivers 1001a to 1001c corresponding to the respective wavelengths. Optical receiver 1 for converting an optical signal into an electric signal
For 001a to 001c, for example, a combination of a wavelength filter and a photoelectric conversion element or a coherent optical receiver is used.

In this embodiment, in order to receive all the wavelengths used in the network, the number of optical receivers used in the network is set. It is not necessary that only the number of. For example, using a tunable optical receiver,
It is also possible to use time division multiplexing technology.

The information converted into the electric signal is sorted by the sorting devices 1004a to 1004c into information addressed to the own station and information not addressed to the own station based on the destination information written in the information.

Signals addressed to the own station are transmitted from the sorting devices 1004a to 1004c corresponding to the respective wavelengths to the first multiplexer 1010.
At 05, it is multiplexed and sent to a terminal (not shown) connected to its own station.

As described above, the light having the same wavelength as the wavelength assigned to the own station is transmitted to the optical filter 1000 of the own station.
However, signals transmitted from a station using the same wavelength as the own station and not addressed to the own station include information that requires relaying. For example, in FIG. 21, when the node A transmits information to the nodes E to F using the wavelength λ1, the optical signal of the wavelength λ1 is cut off by the node D, so that the node D must reproduce the signal. That is, among the wavelengths allocated to the own station, information that is not transmitted by the own station and is transmitted from the own station to the downstream needs to be retransmitted and relayed. Therefore, the sorting device 1004 corresponding to the wavelength assigned to the own station
The information that needs to be relayed distributed in a to c is transmitted to the optical transmission device 1002 of the own station, and is transmitted to a network transmitted from a terminal connected to the own station. 2 multiplexing apparatus 1006. The information multiplexed by the transmission multiplexing device 1006 is sent to the optical transmitting device 1002, and is converted into light having the wavelength assigned to the own station. The converted optical signal is supplied to an optical filter 10.
The signal is combined with the optical signal that has passed through the third node, and transmitted to the next node.

Next, the flow of information on the network will be described. In FIG. 21, the description will be given focusing on information from the node.

The data is directly transferred from the node A to the nodes B, C and D using the wavelength of λ1.
On the other hand, since information is not directly transmitted to the nodes E and F because of being blocked by the optical filter of the node D, the information is transmitted after being temporarily relayed by the node D. For example, when sending information from node A to node E,
The node A transmits at the wavelength λ1 with destination information indicating that the node A is addressed to the node E. In nodes B to C,
Since the information is not addressed to the own station, it is not processed. Node D
In this case, since the information is not addressed to the own station but information on the wavelength assigned to the own station, it is transmitted again at the wavelength λ1 assigned to the node D. At this time, the light transmitted from the node A has been deleted by the optical filter 1003 of the node D. Therefore, there is no interference with the light transmitted from the node D.

As described above, in this embodiment, the provision of the optical filter and the sorting device makes it possible to allocate the same wavelength to the transmission wavelengths of a plurality of nodes in the network.

(Twentieth Embodiment) Next, a twentieth embodiment will be described.

Since the form of the network in this embodiment is the same as that of the nineteenth embodiment, the description of this embodiment will be given with reference to FIG.

FIG. 23 shows the configuration of a node according to this embodiment. Each node includes a demultiplexer 1000, three optical receivers 1001a to 1001c for receiving the wavelengths of λ1 to λ3, and an optical transmitter 10 for transmitting the wavelength assigned to the own station.
02, an optical filter 1003 for blocking light of a wavelength assigned to the own station, wavelength identifier assigning devices 1007a to 1007c for assigning a wavelength identifier to received information, and converting the wavelength identifier into an electric signal for each wavelength. A first multiplexing device 1008 for multiplexing the assigned information, and a distributing device 100 for distributing the multiplexed information to information addressed to the own station and information relayed by the own station based on the wavelength identifier and the connection identifier.
9. Identifier conversion device 1 for converting identifiers of information to be relayed
010 and a second multiplexer 1011 for multiplexing information to be relayed and information from a terminal connected to the own station.

This embodiment is characterized in that a virtual channel identifier (VCI) and a wavelength identifier (WLI) for identifying a wavelength are used to indicate a destination of information.
The VCI is assigned a unique number for each call within each wavelength link. The wavelength link refers to a section in which the same wavelength is separated by an optical filter. Each node can know how the information is processed by referring to the WLI and VCI.

Next, the operation of each node of the optical communication system will be described.

The optical signal input to the node is input to the optical filter 1003 and the wavelength demultiplexer 1000. Then, the light is separated for each wavelength by the wavelength demultiplexer 1000, subjected to photoelectric conversion for each wavelength by the optical receivers 1001a to 1001c, and sent to the wavelength identifier assigning devices 1007a to 1007c, respectively.

Here, since the VCI is unique only within the optical link, if the wavelength is different, there is a possibility that another call having the same VCI exists. In this case, information is interfered with each other, and a wavelength identifier is assigned to avoid this.

Information to which wavelength identifiers have been assigned by the wavelength identifier assigning devices 1007a to 1007c is input to the first multiplexer 1008 on the receiving side that multiplexes signals received at the respective wavelengths, and is multiplexed. The multiplexed signal is separated by the distribution device 1009 into a signal received by the own station and a signal relayed by the own station based on information of the wavelength identifier and the connection identifier.

The information received by the own station is sent to a terminal (not shown) connected to the own station. On the other hand, a signal to be relayed by the own station is sent to the identifier conversion unit 1010 for conversion into an identifier for the next optical link. In order to multiplex information from the identifier conversion unit 1010 and information from the terminal, the information is sent to the multiplexing device 1011 on the transmission side and multiplexed. The multiplexed signal is converted from an electric signal to an optical signal by the optical transmitter 1002 and transmitted.

(Twenty-First Embodiment) Next, a twenty-first embodiment will be described.

In this embodiment, nodes belonging to a plurality of networks can transfer the information to another network based on the identification information added to the communication information. . Here, as shown in FIG. 24, each node has two networks 1,
2, each network has two optical inputs, and each network has multiplexed light of three wavelengths. These two networks can be applied to, for example, a torus network as shown in FIG. Note that the three types of wavelengths used in each network may be the same set of wavelengths or at least partially differ. Here, both the network 1 and the network 2
Assume that a set of the same wavelengths λ1 to λ3 is used.

As shown in FIG. 24, each node includes a demultiplexer 1000, three optical receivers 1001a to 100c for receiving the wavelengths of λ1 to λ3, and a node for transmitting the wavelength allocated to the own station. An optical transmitting device 1002, an optical filter 1003 for blocking light of a wavelength assigned to its own station, a routing information calculating unit 1012 for calculating routing information from a connection identifier of information, and exchanging information according to the routing information. Exchange device 101
3. It is composed of a routing information deletion unit 1014 for deleting the assigned routing information. Also, the exchange device 1
Other than 013, each corresponds to two networks,
The system is provided one by one.

Next, the operation of each node of the optical communication system will be described.

The optical signal input to the node is input to the optical filter 1003 and the wavelength separation device 1001. Then, the light is separated for each wavelength by the wavelength separation device 1001, and is subjected to photoelectric conversion for each wavelength by the optical receivers 1001a to 1001c.
These are sent to the routing information providing devices 1012a to 1012c, respectively.

The routing information is generated from the connection identifier. In the case of the node shown in FIG. 24, there are three destinations of information input to the node: network 1, network 2, and a terminal 1015 connected to the node. In the routing information adding units 1012a to 1012c,
Information about the output destination is obtained from the content of the connection identifier, and routing information is added. In the case of FIG. 24, for example, the routing information uses 3 bits. Each bit represents the destination for the network 1, the destination for the network 2, and the destination for the terminal. Multicasting is performed by making a plurality of bits significant. The information provided with the routing information is sent to the switching device 1013, and is exchanged according to the routing information. In the switching device 1013, in the case of the above example, the network 1
If the outgoing bit is significant, the information is output to the output corresponding to the network 1; if the outgoing bit is significant, the information is output to the output corresponding to the network 2; If the bit is significant, the information is output to the output corresponding to the terminal. If more than one bit is significant, output information to all outputs corresponding to the significant bits.

The information exchanged according to the routing information is sent to the routing information deleting device 1014 to delete the routing information. The information from which the routing information has been deleted is converted from an electric signal to an optical signal by the optical transmitter 1014 and transmitted to the network.

Although the description of the embodiment of the optical communication system based on the optical wavelength division multiplexing to which the present invention is applied is omitted, the same operation and effects as those of the optical communication system based on the optical frequency division multiplexing can be obtained.

The present invention is not limited to the above-described embodiments, and can be implemented in various modifications without departing from the spirit of the invention.

[0142]

According to the optical communication system of the present invention, different wavelengths are assigned to each communication protocol of information transferred in the same optical transmission medium, so that a plurality of communication systems according to a plurality of communication protocols can be simultaneously established. It can be operated using the same communication medium.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic configuration of an optical communication system according to a first embodiment of the present invention;

FIG. 2 is a diagram illustrating a schematic configuration of an optical communication system according to a second embodiment of the present invention;

FIG. 3 is a diagram showing a schematic configuration of an optical communication system according to a third embodiment of the present invention.

FIG. 4 is a diagram illustrating a schematic configuration of an optical communication node according to a fourth embodiment of the present invention.

FIG. 5 is a diagram showing a schematic configuration of an optical communication node for protocol conversion according to a fifth embodiment of the present invention.

FIG. 6 is a diagram illustrating a schematic configuration of an optical communication node according to a sixth embodiment of the present invention.

FIG. 7 is a diagram showing a schematic configuration of an optical frequency demultiplexing unit according to a seventh embodiment of the present invention.

FIG. 8 is a diagram showing a schematic configuration of an optical frequency multiplexing unit according to an eighth embodiment of the present invention.

FIG. 9 is a diagram showing a schematic configuration of a protocol conversion unit installed inside a protocol conversion optical communication node according to a ninth embodiment of the present invention;

FIG. 10 is a diagram illustrating a schematic configuration of a frequency conversion unit in an optical communication node according to a tenth embodiment of the present invention.

FIG. 11 is a diagram showing a schematic configuration of an optical communication system according to an eleventh embodiment of the present invention.

FIG. 12 is a conceptual diagram showing a connection system of an optical communication system using an optical communication node for protocol conversion according to a twelfth embodiment of the present invention.

FIG. 13 is a conceptual diagram showing another connection method of an optical communication system using an optical communication node for protocol conversion according to a thirteenth embodiment of the present invention.

14 is a diagram showing a schematic configuration of an optical communication node for protocol conversion in the optical communication system connection system of FIG.

15 is a diagram showing a schematic configuration of an optical communication node for protocol conversion in the optical communication system connection system of FIG.

FIG. 16 is a conceptual diagram showing a connection method of an optical communication system using an optical communication node for connection between systems according to a sixteenth embodiment of the present invention.

FIG. 17 is a diagram showing a schematic configuration of an optical communication node for connection between systems according to a seventeenth embodiment of the present invention;

FIG. 18 is a diagram showing a schematic configuration of an optical communication system according to an eighteenth embodiment of the present invention.

FIG. 19 is a conceptual diagram showing an example of a system configuration of a conventional optical frequency division multiplex system.

FIG. 20 is a conceptual diagram showing an example of a system configuration according to a conventional ATM communication system.

FIG. 21 is a diagram showing a schematic configuration of an optical communication system according to a nineteenth embodiment of the present invention.

FIG. 22 is a diagram showing a schematic configuration of a node in FIG. 21;

FIG. 23 is a diagram showing a schematic configuration of a node according to a twentieth embodiment of the present invention;

FIG. 24 is a diagram showing a schematic configuration of a node according to a twenty-first embodiment of the present invention;

FIG. 25 is a diagram showing a configuration of a network to which the nodes in FIG. 24 are applied;

FIG. 26 is a diagram showing an optical communication system using a conventional optical wavelength division multiplexing system.

FIG. 27 is a diagram showing a schematic configuration of a node used in the optical communication system of FIG. 26;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Optical transmission medium 21-29, 41-49 ... Optical communication node 31-33 ... Protocol conversion optical communication node 101 ... Optical frequency demultiplexing unit 102 ... Optical frequency multiplexing unit 201, 202, 211, 212 ... O / E converters (electrical / optical signal converters) 301, 302 ... MAC layer packet assembling units 501, 502 ... address identification units 601, 602 ... access control units 701, 702 ... protocol converters 711, 712 ... LLC layer packet assembling Units 721, 722 MAC layer packet construction unit 801 Multiplexing unit 811 Destination identification unit 901 Upper layer processing unit 1000 Wavelength demultiplexers 1001a-c Optical receiver 1002 Optical transmitter 1003 Optical filter 1004a c: sorting device 1005: first multiplexer 1006: second multiplexer 12 00 ... transmission line

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yoshiaki Takahata 1st, Komukai Toshiba-cho, Saiwai-ku, Kawasaki City, Kanagawa Prefecture Inside the Toshiba R & D Center (72) Inventor Yasuo Masahata Small, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture No. 1, Muko Toshiba, Toshiba R & D Center (72) Inventor Hideaki Nakakita No. 1, Komukai Toshiba, Kochi, Kawasaki, Kanagawa Prefecture, Japan Toshiba R & D Center F-term (reference) 5K002 AA01 AA03 BA04 BA05 BA13 DA02 DA04 DA05 DA11 FA01

Claims (13)

[Claims] An optical communication node using one of a plurality of predetermined communication protocols is connected by an optical transmission medium, and each of the plurality of optical communication nodes is connected so as not to overlap the plurality of communication protocols. An optical communication system of a wavelength division multiplexing system, which allocates a plurality of types of optical signals and transmits information data using an optical signal having a wavelength according to a communication protocol, wherein the optical communication node is the predetermined optical communication node. An optical transmission means for transmitting information data to an optical transmission medium by an optical signal of an arbitrary wavelength among a plurality of types of wavelengths assigned to a communication protocol used by its own node among a plurality of communication protocols; Selecting and receiving, from an optical transmission medium, an optical signal of an arbitrary wavelength among a plurality of types of wavelengths assigned to a communication protocol used by the own node; Optical communication system characterized by comprising a light receiving unit. 2. The optical communication node includes: at least a first communication using an optical signal of a first wavelength among a plurality of wavelengths assigned to a communication protocol used by the own node; A plurality of communications including a second communication using an optical signal of a second wavelength different from the first wavelength among a plurality of types of wavelengths assigned to the communication protocol used by the own node are simultaneously performed. 2. The optical communication system according to claim 1, wherein the optical communication system is capable of being used. 3. The optical communication system according to claim 2, wherein said optical communication node performs said plurality of communications simultaneously using a plurality of wavelengths in order to increase the amount of information that can be transmitted simultaneously. 4. The optical communication node according to claim 2, wherein the optical communication node performs the plurality of communications simultaneously using a plurality of wavelengths in order to simultaneously communicate with the plurality of optical communication nodes. Optical communication system. 5. The optical communication system is operated as a different communication system for each of the wavelengths, and the optical communication node performs communication in the desired communication system using the wavelength of the desired communication system. The optical communication system according to claim 1, wherein: 6. An optical signal obtained by receiving an optical signal of a wavelength assigned to a first communication protocol among the predetermined plurality of communication protocols from an optical transmission medium and converting the optical signal. The information data is subjected to a protocol conversion from the first communication protocol to a second communication protocol among the predetermined plurality of communication protocols, and the protocol-converted information data is transmitted to the second communication protocol. An optical communication node for protocol conversion that converts the optical signal into an optical signal of any wavelength allocated and transmitted to the optical transmission medium, for each combination of the first communication protocol and the second communication protocol, or An arrangement provided for each combination of a wavelength assigned to the first communication protocol and a wavelength assigned to the second communication protocol. Optical communication system according to claim 1. 7. A plurality of optical communication nodes using only one of a plurality of predetermined communication protocols are connected by an optical transmission medium so that the plurality of communication protocols do not overlap. An optical communication system of a wavelength division multiplex system, in which wavelengths of optical signals are assigned one by one, and information data is transmitted using an optical signal having a wavelength according to a communication protocol, wherein the optical communication node has the predetermined An optical transmission unit for transmitting information data to the optical transmission medium by an optical signal having a wavelength assigned to a communication protocol used by the own node among the plurality of communication protocols, And an optical receiving means for selecting an optical signal having a wavelength assigned to the communication protocol from the optical transmission medium and receiving the selected optical signal. 8. The optical communication system according to claim 7, wherein said optical communication node further comprises changing means for changing the assignment of said wavelength to said communication protocol. 9. An optical signal having a wavelength assigned to a first communication protocol among the plurality of predetermined communication protocols is received from an optical transmission medium, and the optical signal is obtained by converting the optical signal. The information data is subjected to a protocol conversion from the first communication protocol to a second communication protocol among the predetermined plurality of communication protocols, and the protocol-converted information data is transmitted to the second communication protocol. An optical communication node for protocol conversion, which converts the optical signal into an optical signal of the assigned wavelength and transmits it to the optical transmission medium,
The optical communication system according to claim 7, wherein the optical communication system is provided for each combination of the first communication protocol and the second communication protocol. 10. A wavelength division multiplexing optical communication system including two unit optical communication systems and connecting said unit optical communication systems by a predetermined optical communication node, wherein said two unit optical communication systems are: In any case, claim 7
Wherein the predetermined optical communication node is an optical signal of a predetermined wavelength from one of the two unit optical communication systems, the unit optical communication system. The optical communication system according to claim 7, wherein the optical communication system receives the signal and transmits the signal to the other unit optical communication system. 11. A wavelength division multiplexing system including first and second unit optical communication systems, wherein the first and second unit optical communication systems are connected by first and second predetermined optical communication nodes. An optical communication system, wherein each of the first and second unit optical communication systems includes:
It has the same configuration as the optical communication system according to claim 7, wherein the first optical communication node receives an optical signal of a predetermined wavelength from the first unit optical communication system, As an optical signal having a specific wavelength for connecting the first and second optical communication nodes to the second optical communication node, and wherein the second optical communication node includes the first optical communication node. 8. The method according to claim 7, further comprising: receiving an optical signal of the specific wavelength from an optical communication node, converting the optical signal into an optical signal of a predetermined wavelength, and transmitting the optical signal to the second unit optical communication system. An optical communication system according to claim 1. 12. An optical transmission medium comprising a plurality of communication nodes that use any one of a plurality of predetermined communication protocols and a specific inter-protocol communication protocol for performing communication between different communication protocols. Connecting, assigning one wavelength of an optical signal to each of the plurality of communication protocols and the specific inter-protocol communication protocol without duplication, and transmitting information data using an optical signal having a wavelength corresponding to the communication protocol. An optical communication system of a wavelength division multiplexing method, wherein the communication node is an optical communication system that has a wavelength assigned to a communication protocol used by the own node among the predetermined plurality of communication protocols. A first optical transmission unit for transmitting information data to the optical transmission medium by a signal, and a communication protocol used by the own node. First optical receiving means for selecting and receiving an optical signal of the allocated wavelength from the optical transmission medium; and transmitting the information data by the optical signal of the wavelength allocated to the specific inter-protocol communication protocol. Second optical transmitting means for transmitting to the transmission medium, second optical receiving means for selecting and receiving from the optical transmission medium an optical signal of a wavelength assigned to the specific inter-protocol communication protocol, An optical communication system comprising: 13. A wavelength division multiplexing type optical communication system including two unit optical communication systems and connecting said unit optical communication systems by a predetermined optical communication node, wherein said two unit optical communication systems are: In any case, claim 1
3. The predetermined optical communication node has the same configuration as that of the optical communication system according to item 2, wherein the predetermined optical communication node transmits the specific inter-protocol communication protocol from one of the two unit optical communication systems to the unit optical communication system. The optical communication system according to claim 12, wherein the optical communication system receives an optical signal having a wavelength allocated to the other unit and transmits the optical signal to the other unit optical communication system.