JP2002271357A - Ethernet (r) optical communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical communication system that can effectively utilize an existing optical fiber net. SOLUTION: A control block 211 transmits an electric signal regarding an Ethernet frame for converting to a light signal by a second Ethernet light transformer 42. The light signal is supplied to a first Ethernet light transformer 41 via a second optical coupler 52, optical fiber 35 with one core, and a first optical coupler 51. The light signal supplied to the first Ethernet light transformer 41 is converted to the electric signal regarding the Ethernet frame for transmitting to a first terminator hub 31. The terminator hub 31 transmits the Ethernet frame to a first server 11. Downlink transmission from the first server 11 to each terminal 21 is also achieved by the transmission of the Ethernet frame of the first server 11 and terminator hub 31, and the directional coupling of the optical coupler.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical communication system using one or more servers and a plurality of terminal devices. More specifically, the present invention relates to an optical communication system using wavelength multiplexing and directional coupling functions. The present invention relates to an Ethernet optical communication system that performs two-way communication using optical fibers.

[0002]

2. Description of the Related Art Conventionally, a system disclosed in Japanese Patent Application Laid-Open No. 07-183870 is known as a system for distributing data by two-way communication. FIG.
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram illustrating a configuration of a content distribution system disclosed in JP-183870A. In this system,
The CATV center converts analog video, which is content to be distributed, into FDM (Frequency Division).
The signal is multiplexed into a plurality of channels by a Multiplex (frequency multiplex) method and distributed to each subscriber's house using optical communication. On the other hand, each subscriber can request desired content using another line, and the CATV center distributes desired content in response to each subscriber's request. Therefore, in the content distribution system described in Japanese Patent Application Laid-Open No. 07-183870, it is necessary that the up line and the down line are separate systems.

[0003] On the other hand, when a method of converting an Ethernet interface into an optical signal and transmitting the signal is described in Japanese Patent Application Laid-Open No. H10-79745, the upstream line and the downstream line are connected to the same path by a two-core optical fiber cable. It can be accommodated. FIG. 8 shows the configuration of Japanese Patent Application Laid-Open No. 10-79745.
FIG. 1 is a diagram showing a configuration of an Ethernet optical communication system described in Japanese Unexamined Patent Publication. In the conventional Ethernet optical communication system described in JP-A-10-79745, a server 1
11 is converted into an optical signal by an E / O (electric / optical) converter 150 connected to the first terminal hub 31, and is converted to an O / E (optical / optical) signal through an optical fiber 113.
(Electrical) conversion 160. The optical signal supplied to the O / E converter 160 is converted into an electric signal and sent to the terminal 112. On the other hand, the electric signal transmitted from the terminal 112 is
The optical signal is converted into an optical signal by the E / O converter 150 and supplied to the O / E converter 160 via the optical fiber 113. O /
The optical signal supplied to the E-converter 160 is converted into an electric signal and sent to the server 111 through the termination hub 131. Here, the optical fiber 113 is a two-core optical fiber cable. Further, the bidirectionality of the communication depends on the functions of the terminal 112, the terminal hub 131, and the server 111. In this manner, in the Ethernet optical communication system described in Japanese Patent Laid-Open No. Hei 10-79745, it is possible to accommodate the uplink and the downlink on the same path.

As described above, when considering a system that distributes data from a server to a plurality of terminals and performs two-way communication,
In the system disclosed in Japanese Patent Application Laid-Open No. 07-183870, it is necessary to provide an uplink line and a downlink line on different paths. on the other hand,
If the Ethernet optical communication system described in JP-A-10-79745 is used, the upstream line and the downstream line can be accommodated in the same path, but it is necessary to use a two-core optical fiber.

[0005]

However, the existing optical fiber network is generally composed of a single-core optical fiber cable. Therefore, when an existing optical fiber network is used to construct an optical communication system using the above-described two-core optical fiber, the server and the terminal are connected to each other using a pair of one-core optical fibers. There is a need. Therefore, in the above-described optical communication system, only half of the number of existing optical fiber cables can be installed. As described above, the above-described optical communication system has a problem that the existing optical fiber cable cannot be effectively used.

Accordingly, an object of the present invention is to provide an optical communication system capable of effectively utilizing an existing optical fiber network.

[0007]

Means for Solving the Problems and Effects of the Invention In order to achieve the above object, the present invention has the following features.

A first aspect of the present invention is an optical communication system for performing bidirectional optical communication between first and second devices connected via a single-core optical fiber, which is disposed at one end of the optical fiber. A first interface device interposed between one end of the optical fiber and the server for performing an interface between an electric signal and an optical signal; and the other end of the optical fiber. And a second interface means interposed between the other end of the optical fiber and the terminal for performing an interface between an electric signal and an optical signal. The server transmits an electric signal including data addressed to the terminal to the first interface means only when data is not being received, and the terminal transmits data addressed to the server only when data is not being received. Including the electrical signal in the second interface The first interface means converts the electric signal from the server into an optical signal and supplies it to the optical fiber, and converts the optical signal sent from the terminal via the optical fiber into an electric signal. The second interface means converts the electric signal from the terminal into an optical signal, supplies the optical signal to the optical fiber, and converts the optical signal sent from the server via the optical fiber into an electric signal. The signal is converted into a signal and supplied to the terminal.

As described above, according to the first aspect, bidirectional optical communication between one terminal and one first server can be realized by a single-core optical fiber. Therefore, one terminal can be installed for one optical fiber, and an optical communication system that can effectively use the existing optical fiber network can be constructed.

In a second aspect of the present invention, the first invention is provided through N (N is an integer of 2 or more) optical fibers, each of which has a single core.
An optical communication system for performing bidirectional optical communication between a device and N second devices, comprising: a first server as a first device disposed at one end of each optical fiber; N first interface means interposed between one end of the optical fiber and the first server for performing an interface between an electric signal and an optical signal; and each of the first interface means and the first 1
Between the first server and each first server.
Terminating hub for exchanging data with the interface means, N terminals as second devices disposed at the other end of each optical fiber, and the other end of each optical fiber and each terminal And N second interface means for interfacing between the electric signal and the optical signal,
When transmitting data addressed to the terminal from the first server, the first server
Server transmits an electric signal including data addressed to the terminal to the terminal hub, and the terminal hub transmits the electric signal sent from the first server to the first interface means corresponding to the destination terminal. Then, the first interface means converts the electric signal sent from the terminal hub into an optical signal and supplies the optical signal to the optical fiber, and the second interface means converts the electric signal to the first interface via the optical fiber. When the optical signal transmitted from the face means is converted into an electric signal and transmitted to the terminal, and the terminal transmits data addressed to the first server, the terminal converts the electric signal including the data addressed to the server into a second signal. To the interface means, the second interface means converts the electric signal sent from the terminal into an optical signal and supplies it to the optical fiber, and the first interface means transmits the signal through the optical fiber. Second Inn The optical signal transmitted from the interface means is converted into an electric signal and transmitted to the terminal hub. The terminal hub transmits the electric signal transmitted from the first interface means to the first server, and transmits the electric signal to the first server. Server sends an electrical signal containing data destined for the terminal to the terminating hub only when data is not being received, and the terminal sends an electrical signal containing data destined for the first server only when data is not being received. Sending the signal to the second interface means, wherein the terminating hub
Is stored temporarily, and only when the data from the corresponding destination is not being received, the temporarily stored data is transmitted to the corresponding destination.

As described above, according to the second aspect, the terminal hub prevents collision of upstream signals from a plurality of terminals, while the operation of the terminal, the terminal hub, and the first server causes a single-core optical fiber. It is possible to realize bidirectional optical communication between a plurality of terminals connected by the first server and the first server. Therefore, one-to-many bidirectional optical communication can be constructed with single-core optical fibers as many as the number of terminals, and an optical communication system capable of effectively utilizing an existing optical fiber network can be constructed. .

A third invention is an invention according to the second invention, wherein a second server for unilaterally distributing data to each terminal and an electric signal output from the second server are transmitted to the first server. An optical / optical conversion / distribution unit for converting the optical signal into a light signal having a wavelength different from the wavelength of the optical signal output by the interface means, and distributing the optical signal in the N direction; one end of each optical fiber;
And N wavelength multiplexing devices interposed between the first and second interface means. The optical signal supplied is multiplexed with the supplied optical signal, and the optical signal sent from the corresponding second interface means via the optical fiber is supplied to the corresponding first interface means. The interface unit demultiplexes the optical signal supplied from the corresponding wavelength multiplexing device via the optical fiber into an optical signal from the corresponding first interface unit and an optical signal from the second server. ,
Each is converted into an electric signal and supplied to the terminal.

As described above, according to the third aspect, the terminal hub prevents collision of upstream signals from a plurality of terminals, while the wavelength multiplexing technique and the operations of the terminal, the terminal hub, and the first server use the terminal hub. It is possible to combine unidirectional distribution from the second server and bidirectional optical communication between the first server and a plurality of terminals connected by a single optical fiber. Therefore, an optical communication system combining one-way distribution and one-to-many two-way optical communication can be constructed with single-core optical fibers as many as the number of terminals, and the existing optical fiber network can be effectively utilized. It is possible to construct an optical communication system capable of performing the above.

According to a fourth aspect of the present invention, there is provided an optical communication system for performing bidirectional optical communication between a first device and N (N is an integer of 2 or more) second devices via a single-core optical fiber. A system as a first device disposed on one end side of an optical fiber, and a first device that is interposed between the one end of the optical fiber and the server and performs multiplexing and demultiplexing of an optical signal. N is interposed between the wavelength multiplexing device, the first wavelength multiplexing device, and the server, performs an interface between the electric signal and the optical signal, and is set to output optical signals of different wavelengths. Pieces of the first interface means, and each of the first interface means and the server are interposed between the first interface means and the server.
Terminating hub for exchanging data with the interface means, N terminals as second devices disposed on the other end of the optical fiber, and between the other end of the optical fiber and the terminal A second wavelength multiplexing device that is interposed and performs multiplexing and demultiplexing of an optical signal, and an interface between the electric signal and the optical signal that is interposed between the second wavelength multiplexing device and each terminal Do
And N second interface means each set to output an optical signal having a different wavelength, and when transmitting data addressed to the terminal from the server, the server transmits an electric signal including the data addressed to the terminal. The terminal hub transmits the electric signal sent from the server to the first interface means corresponding to the destination terminal, and the first interface means sends the electric signal sent from the server to the terminal hub. Converting the electrical signal into an optical signal and supplying it to a first wavelength multiplexing device,
The first wavelength multiplexing device multiplexes the optical signals sent from one or more first interface means and supplies the multiplexed optical signal to the optical fiber, and the second wavelength multiplexing device outputs the multiplexed optical signal via the optical fiber. The optical signal sent from the first wavelength multiplexing device is demultiplexed into an optical signal output by the first interface means and supplied to the corresponding second interface means, and the second interface means comprises: When the optical signal transmitted from the second wavelength multiplexing device is converted to an electric signal and transmitted to the terminal, and the terminal transmits data addressed to the server, the terminal converts the electric signal including the data addressed to the server into the second signal. To the interface means of
The second interface means converts an electric signal transmitted from the terminal into an optical signal and supplies the optical signal to a second wavelength multiplexing device, and the second wavelength multiplexing device converts one or more second interfaces. The first wavelength division multiplexer multiplexes the optical signal sent from the means and supplies the combined signal to the optical fiber, and the first wavelength division multiplexer converts the optical signal transmitted from the second wavelength division device through the optical fiber to the second fiber.
Demultiplexes the optical signal output by the first interface means and supplies it to the corresponding first interface means. The first interface means converts the optical signal sent from the first wavelength multiplexing device into an electric signal. To the terminal hub, and the terminal hub transmits the electric signal sent from the first interface means to the server, and the server transmits the data addressed to the terminal only when the data is not being received. The terminal transmits the electrical signal including the data destined for the server to the second interface means only when data is not being received, and the terminal hub transmits the electrical signal including the data destined for the server from the server or the terminal. The received data is temporarily stored, and the temporarily stored data is transmitted to the corresponding destination only when data from the corresponding destination is not being received.

[0015] As described above, according to the fourth aspect of the present invention, collision prevention of uplink signals from a plurality of terminals is realized by the wavelength multiplexing technique and the termination hub, while the operation of the terminals, termination hubs, and the server achieves one core. Bidirectional optical communication can be realized between the N terminals connected to the optical fiber and the first server. Therefore, one-to-many bidirectional optical communication can be constructed with a single-core optical fiber, and an optical communication system that can effectively utilize an existing optical fiber network can be constructed.

According to a fifth aspect of the present invention, bidirectional optical communication is performed between a first device and N (N is an integer of 2 or more) second devices via a single-core optical fiber. An optical communication system for distributing data unilaterally from a third device to each second device, comprising: a first server as a first device disposed at one end of an optical fiber; A second server as a third device coexisting with the first server at one end of the fiber, and an optical signal interposed between one end of the optical fiber and the first and second servers; A wavelength multiplexing device for performing multiplexing and demultiplexing, and an interface between the wavelength multiplexing device and the first server for performing an interface between an electric signal and an optical signal, and each of the optical signals having a different wavelength. And N first interface means configured to output A terminating hub interposed between the first means and the first server for exchanging data between the first server and each of the first interface means; An electrical / optical converter interposed between the optical interfaces for converting an electrical signal into an optical signal having a wavelength different from the wavelength of the optical signal output from each first interface means, and disposed at the other end of the optical fiber; N terminals as a second device, a branch coupler that is interposed between the other end of the optical fiber and the terminal and performs multiplexing and branching of an optical signal, and between the branch coupler and each terminal. A first server that performs an interface between an electric signal and an optical signal and that is configured to output optical signals of different wavelengths. From the second server to each terminal When distributing data, the first server transmits an electric signal including data destined for the terminal to the terminal hub, and the terminal hub transmits the electric signal sent from the server to the first terminal corresponding to the destination terminal. The first interface means converts the electric signal sent from the terminating hub into an optical signal and supplies the optical signal to the wavelength multiplexing apparatus. An electric signal including data to be distributed is transmitted to the electric / optical converter, and the electric / optical converter converts the electric signal transmitted from the second server into an optical signal and supplies the optical signal to the wavelength multiplexing apparatus, The multiplexer multiplexes the optical signals sent from the one or more first interface means and the electric / optical converter and supplies the multiplexed optical signal to the optical fiber. The optical signal sent from the multiplexer is divided into N And supplies it to each of the second interface means. The second interface means converts the optical signal sent from the branching coupler into the corresponding optical signal from the first interface means and the second optical signal. When the data is converted to an electric signal from the server and converted into an electric signal and supplied to the terminal, and the terminal transmits data addressed to the first server, the terminal transmits the data addressed to the first server. The second interface means converts the electric signal sent from the terminal into an optical signal and supplies the optical signal to the branch coupler, and the branch coupler outputs the signal. The optical signals transmitted from the plurality of second interface means are multiplexed and supplied to the optical fiber, and the wavelength multiplexing device converts the optical signal transmitted from the branching coupler via the optical fiber to the optical fiber. Into the optical signal output by the second interface means. The first interface means converts the optical signal sent from the wavelength multiplexing device into an electric signal and transmits the electric signal to the terminal hub. The first server transmits the electric signal sent from the first interface means to the first server, and the first server transmits the electric signal including the data addressed to the terminal to the terminal hub only when the data is not being received. , The terminal transmits an electric signal including data addressed to the first server to the second interface means only when data is not being received, and the terminal hub is transmitted from the first server or the terminal. Data is temporarily stored, and the temporarily stored data is transmitted to the corresponding destination only when data from the corresponding destination is not being received.

According to the fifth aspect of the present invention, the wavelength multiplexing scheme and the termination hub prevent collision of uplink signals from a plurality of terminals, while the wavelength multiplexing technique and the operation of the terminal, termination hub, and server. By this means, it is possible to realize optical communication combining unidirectional distribution from the second server and bidirectional communication between the plurality of terminals connected to the single optical fiber and the first server. It becomes possible. Therefore,
An optical communication system that combines one-way data distribution and one-to-many two-way communication can be constructed with a single-core optical fiber, and an existing optical fiber network can be used effectively. It is possible to build.

According to a sixth aspect of the present invention, bidirectional optical communication is performed between a first device and N (N is an integer of 2 or more) second devices via a single-core optical fiber. An optical communication system for distributing data unilaterally from a third device to each second device, comprising: a first server as a first device disposed at one end of an optical fiber; A second server as a third device disposed coexisting with the first server at one end of the fiber, and inserted between one end of the optical fiber and the first server and the second server; A wavelength multiplexing device that multiplexes and demultiplexes optical signals, and is interposed between the wavelength multiplexing device and the first server, performs an interface between the electric signal and the optical signal, and each has a different wavelength. N first interface means configured to output an optical signal; A terminating hub interposed between the interface means and the first server for exchanging data between the first server and each first interface means; a wavelength multiplexing device and a second server; And an electric / optical converter for converting an electric signal into an optical signal having a wavelength different from the wavelength of the optical signal output from each first interface means, and disposed at the other end of the optical fiber. N terminals as a second device, and inserted between the other end of the optical fiber and the terminal,
A branching coupler for multiplexing and branching optical signals, and an optical signal and an optical signal interposed between the branching coupler and each terminal. N first interface means configured to output an optical signal having a different wavelength from each of the first interface means and the electrical / optical converter, and When transmitting data destined for a terminal from a server and unilaterally distributing data from a second server to each terminal, the first server transmits an electric signal including data destined for the terminal to a termination hub, and Transmits the electric signal sent from the server to the first interface means corresponding to the destination terminal, and the first interface means converts the electric signal sent from the terminal hub into an optical signal And many wavelengths Supplied to the device, the second server, an electric signal containing the data to be unilaterally distributed to each terminal electric /
The optical / optical converter converts the electric signal transmitted from the second server into an optical signal and supplies the optical signal to the wavelength multiplexing device. The optical signals sent from the interface means and the electric / optical converter are combined and supplied to the optical fiber.
The optical signal transmitted from the wavelength multiplexing device via the optical fiber is distributed to N and supplied to each second interface means, and the second interface means transmits the optical signal transmitted from the branching coupler. Demultiplexing the signal into a corresponding optical signal from the first interface means and an optical signal from the second server;
When each of them is converted into an electric signal and supplied to the terminal, and the terminal transmits data addressed to the first server, the terminal transmits the data to the first server.
The second interface means, the second interface means converts the electric signal sent from the terminal into an optical signal, and supplies the optical signal to the branching coupler; The branch coupler multiplexes the optical signals transmitted from the one or more second interface means and supplies the multiplexed optical signal to the optical fiber. The wavelength multiplexing device transmits the optical signal from the branch coupler via the optical fiber. The incoming optical signal is demultiplexed into an optical signal output by the second interface means and supplied to the corresponding first interface means, and the first interface means transmits the optical signal sent from the wavelength multiplexing device. The signal is converted into an electric signal and transmitted to the terminal hub, and the terminal hub transmits the electric signal sent from the first interface means to the first server.

According to the sixth aspect of the present invention, the wavelength multiplexing system and the termination hub prevent collision of upstream signals from a plurality of terminals, while realizing the wavelength of upstream optical signals and the downstream optical signal. By making the wavelength different from the wavelength and the wavelength multiplexing technology, both the unidirectional distribution from the second server and the communication between the plurality of terminals connected to the single optical fiber and the first server. It is possible to realize optical communication in which the two-way communication is combined. Therefore, an optical communication system that combines one-way data distribution and one-to-many bidirectional communication can be constructed with a single-core optical fiber, and an optical communication system that can effectively utilize an existing optical fiber network. A system can be constructed.

A seventh invention is an invention according to any one of the first to sixth inventions, wherein an Ethernet system is used as a communication system.

According to the seventh aspect, an Ethernet system generally used as a communication system can be used, and an optical communication system that effectively utilizes existing communication equipment can be constructed.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a block diagram showing an Ethernet optical communication system according to a first embodiment of the present invention. First, the configuration of the Ethernet optical communication system according to the first embodiment will be described.

In the Ethernet optical communication system according to the first embodiment, a first server 11 is connected to a first termination hub 31. A first Ethernet optical converter 41 is connected to the n port side of the first termination hub 31. A first optical coupler 51 is connected to each of the first Ethernet optical converters 41. The first optical coupler 51 is connected to the terminal 21 by an optical fiber 35.

The terminal 21 includes a second optical coupler 52 and a second
, And a control block 211. The second optical coupler 52 is connected to the first optical coupler 51 via the optical fiber 35. The second optical coupler 52 is connected to the second Ethernet optical converter 42. The second Ethernet optical converter 42 exchanges an electric signal with the control block 211. The number of terminals 21 may be any number. In FIG. 1, it is assumed that n terminals 21 exist. The user may install the first Ethernet optical converter 41 and the first optical coupler 51 in accordance with the number of the terminals 21.

Next, the function of each component of the Ethernet optical communication system according to the first embodiment will be described.

The first server 11 has a first terminal hub 31
The transmission / reception of the Ethernet frame with each terminal 21 is performed through the terminal.

The first terminal hub 31 is an aggregating device having a switching function of transmitting and receiving Ethernet frames and aggregating Ethernet interfaces at the physical layer. The first terminating hub 31 is composed of one to n ports, and a first Ethernet optical converter 41 for mutually converting an electric signal and an optical signal is connected to the n port side. The first server 11 is connected to the side. The first terminal hub 31 includes a memory (not shown). The first terminal hub 31 is connected to the terminal 21.
And the Ethernet frame output from the first server 11 and stores the Ethernet frame in a temporary memory. The first terminal hub 31 refers to the destination MAC address of the Ethernet frame stored in the memory and sequentially outputs the Ethernet frame to a port corresponding to the MAC address. That is, it can be said that the first terminal hub 31 is a so-called switching hub having a switching function.

The first Ethernet optical converter 41 has a first
Is converted into an optical signal having a wavelength of λ1 and supplied to the first optical coupler 51. On the other hand, the optical signal from the first optical coupler 51 is converted into an electric signal, and the electric signal is sent to the first terminal hub 31. Here, for example, when the optical fiber 35 is in a single mode, the wavelength λ1 is the wavelength in the 1300 [nm] band or the 1550 [nm] band.
Is multimode, a wavelength in the 850 [nm] band is assigned. In addition, for the conversion from an electric signal to an optical signal and the conversion from an optical signal to an electric signal, an intensity modulation method or the like can be used.

The first optical coupler 51 is a so-called directional coupler. The first optical coupler 51 outputs the optical signal output from the light emitting element of the first Ethernet optical converter 41 only to the optical fiber 35 in the terminal direction. Also, the first
Optical coupler 51 converts the optical signal supplied from the terminal side to the first
Is supplied only to the light receiving element in the Ethernet optical converter 41 of FIG. It can be said that the combination of the first Ethernet optical converter 41 and the first optical coupler 51 performs an interface between an electric signal and an optical signal.

The optical fiber 35 is a single-core optical fiber.

The second optical coupler 52 includes a first optical coupler 5
The function is the same as that of the first embodiment, and the optical signal supplied via the optical fiber 35 is supplied to the second Ethernet optical converter 42. On the other hand, the second optical coupler 52 propagates the optical signal supplied from the second Ethernet optical converter 42 to the first optical coupler 52 via the optical fiber 35.

The second Ethernet optical converter 42 has a first
Has the same function as the Ethernet optical converter 41 of FIG.
The optical signal supplied from the optical coupler 52 is converted into an electric signal and sent to the control block 211. On the other hand, the second Ethernet optical converter 42 converts the electrical signal related to the Ethernet frame from the control block 211 into an optical signal having the wavelength λ1 and supplies the optical signal to the second optical coupler 52. It can be said that the combination of the second Ethernet optical converter 42 and the second optical coupler 52 performs an interface between an electric signal and an optical signal.

The control block 211 controls the first terminal hub 3
1 transmits / receives an Ethernet frame to / from the first server 11. Therefore, an electric signal related to the Ethernet frame transmitted to the first server 11 is transmitted to the second Ethernet optical converter 42. Further, the control block 211 controls the terminal 21 based on the electric signal related to the Ethernet frame received from the second Ethernet optical converter 42.

Next, an operation when an Ethernet frame is transmitted from the terminal 21 to the first server 11 (hereinafter, this transmission is referred to as “uplink transmission”) will be described. First, the control block 211 determines whether or not an Ethernet frame from the first server 11 is being received. If the first
If the Ethernet frame from the server 11 is being received, the control block 211 suspends the transmission of the Ethernet frame addressed to the first server 11 in order to avoid the collision of the Ethernet frame. On the other hand, if the Ethernet frame from the first server 11 is not being received, the control block 211 transmits an electric signal related to the Ethernet frame addressed to the first server 11 to the second Ethernet optical converter 42. The bidirectional communication between the terminal 21 and the first server 11 is realized by the transmission operation of the Ethernet frame as described above. Next, the terminal 21
Detects whether the transmitted Ethernet frame has reached the first terminal hub 31 without colliding with another frame, based on a response signal from the first terminal hub 31.
If a collision has occurred, no response signal comes from the first end hub 31. In such a case, the terminal 21 retransmits the Ethernet frame.

The second Ethernet optical converter 42 converts the electric signal output from the control block 211 into an optical signal having the wavelength λ1 and supplies the optical signal to the second optical coupler 52. The conversion into the optical signal may be performed by an intensity modulation method or the like.

The optical signal supplied to the second optical coupler 52 propagates to the first optical coupler 51 via the optical fiber 35. The optical signal is transmitted to the first optical coupler 51 by the first optical coupler 51.
Is supplied to the light receiving element of the Ethernet optical converter 41.
The optical signal supplied to the light receiving element of the first Ethernet optical converter 41 is converted into an electric signal and transmitted to the first termination hub 31.

When the electric signal related to the Ethernet frame from the first Ethernet optical converter 41 reaches the first terminal hub 31, the first terminal hub 31 sends a response signal indicating that the Ethernet frame has arrived safely. Transmit to terminal 21. This response signal is used for the collision detection performed by the terminal 21 described above. Next, the first terminal hub 31
Stores data related to the electric signal in a temporary memory. The first terminating hub 31 sequentially transmits the electrical signals related to the Ethernet frame temporarily stored in the memory to the first server 11. At this time, the first terminal hub 31
Determines whether an Ethernet frame output from the first server 11 is being received. If an Ethernet frame from the first server 11 is being received, the first termination hub 31 suspends transmission of the Ethernet frame. On the other hand, if the Ethernet frame is not being received from the first server 11, the first terminal hub 31 transmits the Ethernet frame to the first server 11. The first terminal hub 31 determines whether or not the Ethernet frame has successfully arrived at the first server 11 based on a response signal from the first server 11. In this way, the first termination hub 31 prevents electrical collision of Ethernet frames between the terminals 21 and
In this case, bidirectional communication between the first server 11 and the terminal 21 is realized by preventing collision between the transmission frame from the first server and the transmission frame from the first server.

The first server 11 has a first terminal hub 31
When the electrical signal related to the Ethernet frame output from the first terminal hub is received, a response signal indicating that the Ethernet frame has arrived safely is transmitted to the first terminal hub 31. This response signal is used for the collision detection performed by the first terminal hub 31 described above. The first server 11 is a first terminal hub 3
A response process to the terminal 21 is performed based on the Ethernet frame output from the terminal 1.

Next, an operation when an Ethernet frame is transmitted from the first server 11 to the terminal 21 (hereinafter, this transmission is referred to as “downlink transmission”) will be described. The first server 11 transmits the electric signal related to the Ethernet frame with the MAC address corresponding to the terminal 21 to the first terminal hub 3.
Send to 1. At this time, the first server 11 determines whether the Ethernet frame output from the first terminal hub 31 is being received. If the first termination hub 31
If the first server 11 is receiving an Ethernet frame from the terminal 21, the transmission of the Ethernet frame addressed to the terminal 21 is temporarily stopped. On the other hand, if the Ethernet frame from the first terminal hub 31 is not being received, the first server 11 transmits the Ethernet frame addressed to the terminal 21 to the first terminal hub 31. First server 11
Determines whether the Ethernet frame has successfully reached the first terminal hub 31 based on a response signal from the first terminal hub 31. Thus, the first server 11
Performs the collision prevention of the electric signal related to the Ethernet frame with the first terminal hub 31 and performs the first server 11
And the terminal 21 are realized.

When the electric signal related to the Ethernet frame from the first server 11 reaches the first terminal hub 31,
The first termination hub 31 transmits a response signal to the effect that the Ethernet frame has arrived successfully to the first server 1. This response signal is used for collision detection in the first server 11 described above. Next, the first terminal hub 31 stores the Ethernet frame in the temporary memory. The first terminating hub 31 sequentially transmits the electrical signals related to the Ethernet frame temporarily stored in the memory to the first Ethernet optical converter 41 corresponding to the terminal 21 that is the destination of the Ethernet frame. At this time, the first termination hub 31 determines whether an Ethernet frame is being received at the port corresponding to the terminal 21 that is the destination of the Ethernet frame. If an Ethernet frame is being received at the port, the first termination hub 31 suspends transmission of the Ethernet frame addressed to the terminal 21. On the other hand, if the Ethernet frame is not being received at the port, the first terminating hub 31 transmits an electrical signal related to the Ethernet frame addressed to the terminal 21 to the first Ethernet optical converter 41. Next, the first terminal hub 31 determines whether or not the Ethernet frame has successfully reached the terminal 21 based on a response signal from the terminal 21. In this way,
The first terminating hub 31 prevents bi-directional communication between the transmission frame from the first server 11 and the transmission frame from the terminal 21 and realizes bidirectional communication between the first server 11 and the terminal 21.

The first Ethernet optical converter 41 has a first
The electrical signal output from the termination hub 31 is converted into an optical signal having the wavelength λ1 and supplied to the first optical coupler 51. First
Optical coupler 51 converts the optical signal supplied from first Ethernet optical converter 41 into first Ethernet optical converter 4.
The light propagates to the second optical coupler 52 via the optical fiber 35 without being reflected by one light receiving element.

The second optical coupler 52 propagates the supplied optical signal to the light receiving element of the second Ethernet optical converter 42. The optical signal supplied to the light receiving element of the second Ethernet optical converter 42 is converted into an electric signal,
11 is transmitted. Upon receiving the electric signal related to the Ethernet frame, the control block 211 transmits a response signal indicating that the Ethernet frame has arrived safely to the first terminal hub 31. The response signal is used for the collision detection at the first terminal hub 31 described above. The control block 211 controls itself based on the received Ethernet frame.

As described above, with the configuration of the first embodiment, an Ethernet optical communication system for performing bidirectional communication between the terminal 21 and the first server 11 using a single-core optical fiber cable is constructed. It is possible to do. The bidirectional communication between the terminal 21 and the first server 11 is guaranteed by the operation of transmitting the Ethernet frame in the terminal 21, the first termination hub 31, and the first server 11. Also, the prevention of collision of the Ethernet frames output from the terminals 21 is guaranteed by the temporary memory function of the Ethernet frame and the function of transmitting the Ethernet frame in the first terminal hub 31.

FIG. 2 shows a state in which the number of terminals of an existing Ethernet optical communication system constructed of two-core optical fibers using the Ethernet optical communication system according to the first embodiment can be doubled. It is a schematic diagram. FIG. 2 (a)
Although the number of terminals is three, the first optical coupler 51 is connected to the optical fiber 35 side of the first Ethernet optical converter 41.
Is provided, the first terminal hub 31 is installed, and the Ethernet optical communication system according to the first embodiment is constructed. In FIG. 2B, the number of terminals becomes six. As described above, by using the Ethernet optical communication system according to the first embodiment, it is possible to increase the number of terminals up to twice using existing optical fiber cables.

In the first embodiment, the first terminal hub 31 is provided for performing bidirectional communication between the n terminals 21 and the first server 11. However, without providing the first terminating hub 31, one terminal 21 and the first server 11 are connected by a single-core optical fiber, and the first optical coupler 51 is connected to one end of the single-core optical fiber. The terminal 21 and the first server 1 are inserted through the first Ethernet optical converter 41.
By operating 1 in the same manner as described above, it is possible to realize bidirectional optical communication between one-to-one devices connected by a single optical fiber. At this time, the first server 1
1 and the terminal 21 may be operated to transmit the Ethernet frame only when the Ethernet frame is not being received.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention.
It is a block diagram showing the Ethernet optical communication system concerning an embodiment. First, the configuration of the Ethernet optical communication system according to the second embodiment will be described.

In the Ethernet optical communication system according to the second embodiment, the first server 11 is connected to the first terminal hub 31. A third Ethernet optical converter 43 is connected to the n port side of the first termination hub 31. A first optical coupler 51 is connected to each of the third Ethernet optical converters 43. The first optical coupler 51 is connected to the first WDM 61. First W
The DM 61 is connected to the second WDM 62 by the optical fiber 35.
Is connected to The n terminals 22 are connected to the second WDM 62.

The terminal 22 comprises a control block 211 and a fourth
, And a second optical coupler 52. The second optical coupler 52 is connected to the second WDM 62. The second optical coupler 52 is connected to the fourth Ethernet optical converter 44. The fourth Ethernet optical converter 44 exchanges an electric signal with the control block 211. As in the first embodiment, the number of terminals 22 may be any number. In FIG. 3, it is assumed that n terminals 22 exist. The user may install the third Ethernet optical converter 43 and the first optical coupler 51 according to the number of the terminals 22.

In the Ethernet optical communication system according to the second embodiment, a user assigns a wavelength of an optical signal emitted by each terminal 22 to each terminal 22. In addition, the user assigns the wavelength assigned to each terminal 22 to the wavelength of the optical signal emitted by the fourth Ethernet optical converter 44 and the third Ethernet optical converter 43 corresponding to each terminal 22. . Here, the wavelengths assigned to each terminal 22, the fourth Ethernet optical converter 44, and the third Ethernet optical converter 43 are λ1, λ2,.
λn. For example, λ1 = 1300 [nm], λ2 =
1310 [nm],..., Λn = 1300 + 10 ×
(N-1) [nm].

Next, the function of each component of the Ethernet optical communication system according to the second embodiment will be described.

The first server 11, the first end hub 31,
Regarding the control block 211 and the optical fiber 35, the first
Since the function is the same as that of the embodiment, the description is omitted.

The first optical coupler 51 and the second optical coupler 52 are the same as those in the first embodiment. In the second embodiment, the wavelengths of the optical signals supplied to them differ from each other. However, since the first optical coupler 51 and the second optical coupler 52 split the optical power regardless of the wavelength of the supplied optical signal, they function in the same manner as in the first embodiment.

The third Ethernet optical converter 43 has functions in addition to the functions of the first Ethernet optical converter 41.
A function of individually setting the wavelength of the output optical signal is added. For example, the third Ethernet optical converter 43 can have the function of the light emitting element by utilizing the characteristic that the wavelength of the emitted light changes according to the temperature change. The user sets the wavelength of the optical signal output from the third Ethernet optical converter 43 to the same wavelength as the wavelength assigned to the corresponding terminal 22. In the second embodiment, the wavelengths of the optical signals output from the third Ethernet optical converter 43 are λ1,
λ2,..., λn.

The first WDM 61 is a WDM (Wavel).
angle Division Multiplexin
g: wavelength division multiplexing) method, the first optical coupler 51
, And λn supplied from the optical fiber 35 and multiplexed, and supplies the multiplexed optical signal to the second WDM 62 via the optical fiber 35. Further, the first WDM 61 demultiplexes the optical signal supplied from the second WDM 62 via the optical fiber 35 into optical signals of wavelengths λ1, λ2,. To the first optical coupler 51.

The second WDM 62 uses the WDM method to transmit the wavelengths λ 1, λ 2 supplied from the second optical coupler 52.
2,... Λn are multiplexed and supplied to the first WDM 61 via the optical fiber 35. Also, the second WD
M62 converts the optical signal supplied from the first WDM 61 via the optical fiber 35 by the WDM method into a wavelength λ.
, Λn, and is supplied to each second optical coupler 52.

The fourth Ethernet optical converter 44 has a third
Has the same function as the Ethernet optical converter 43 of FIG. Therefore, the user needs the fourth Ethernet optical converter 44
Set the wavelength of the optical signal to be output to the same wavelength as the wavelength assigned to the corresponding terminal 22. In the second embodiment, the wavelengths of the optical signals output from the fourth Ethernet optical converter 44 are set to λ1, λ2,..., Λn, respectively.

In the second embodiment, the reason why the upstream signals from the terminals 22 are converted into optical signals of different wavelengths is that each terminal 22
This is for the purpose of concentrating the optical signal on the single optical fiber by the second WDM 62.

Next, the operation when data is transmitted (upward transmission) from the terminal 22 to the first server 11 will be described. The control block 211 operates in the same manner as in the first embodiment, and transmits an electric signal related to an Ethernet frame to the first server 11 to the fourth Ethernet optical converter 44. The operation of the control block 211 in the second embodiment is the same as in the first embodiment, and a description thereof will be omitted.

The fourth Ethernet optical converter 44 converts the electric signal related to the Ethernet frame output from the control block 211 into an optical signal of a wavelength assigned to itself, and supplies the optical signal to the second optical coupler 52. .

The optical signal supplied to the second optical coupler 52 propagates only to the second WDM 62. Second WDM6
2, optical signals from a plurality of terminals 22 are supplied.

The second WDM 62 includes a plurality of second terminals 2
The optical signals of different wavelengths supplied from 2 are multiplexed by the WDM method. The optical signal multiplexed by the second WDM 62 is supplied to the first WDM 61 via the optical fiber 35.

The first WDM 61 splits the multiplexed optical signal supplied from the second WDM 62 via the optical fiber 35 into optical signals of respective wavelengths from λ1 to λn, corresponding to each wavelength. To the first optical coupler 51. The optical signal supplied to the first optical coupler 51 is propagated to the third Ethernet optical converter 43 as it is. The third Ethernet optical converter 43 converts an optical signal relating to the received Ethernet frame into an electric signal and transmits the electric signal to the first termination hub 31.

The first termination hub 31 operates in the same manner as in the first embodiment, temporarily stores the received Ethernet frame in the memory, and sequentially transmits the Ethernet frame to the first server 11. . The detailed operation of the first terminating hub 31 is the same as that of the first embodiment, and a description thereof will be omitted.

The first server 11 performs a response process to the terminal 22 based on the electric signal related to the Ethernet frame output from the first terminal hub 31. The operation of receiving the Ethernet frame in the first server 11 is the same as that in the first embodiment, and a description thereof will be omitted.

Next, an operation in the case of transmitting data (downward transmission) from the first server 11 to the terminal 22 will be described. The first server 11 operates in the same manner as in the first embodiment, and transmits an Ethernet frame to the first termination hub 31. The operation of transmitting the Ethernet frame in the first server 11 is the same as the operation in the first embodiment, and a description thereof will be omitted.

The first termination hub 31 operates in the same manner as in the first embodiment, and transmits an electric signal relating to the Ethernet frame to the third Ethernet optical converter 43.
The operation of the first terminal hub 31 is the same as that of the first embodiment, and the description is omitted.

The third Ethernet optical converter 43 has the first
The optical signal received from the terminal hub 31 is converted into an optical signal having a wavelength assigned to the optical signal, and the optical signal is supplied to the first optical coupler 51. The optical signal supplied to the first optical coupler 51 is propagated only to the first WDM 61.

The first WDM 61 includes a first optical coupler 51
Are multiplexed and supplied to the second WDM 62 via the optical fiber 35. Here, it is confirmed that there is a possibility that optical signals of different wavelengths are propagated from the plurality of first optical couplers 51 by the switching function of the first termination hub 31.

The second WDM 62 splits the multiplexed optical signal supplied from the first WDM 61 into optical signals having wavelengths from λ1 to λn, and the second WDM of the terminal 22 corresponding to each wavelength. The split optical signal is supplied to the optical coupler 52. However, actually, since there is a terminal 22 at which distribution from the first server is not performed at that moment, the demultiplexed optical signal is not supplied to all the n terminals 22.

The optical signal supplied to the second optical coupler 52 is supplied to a light receiving element of the fourth Ethernet optical converter 44. The subsequent operation of the fourth Ethernet optical converter 44 is the same as the operation of the second Ethernet optical converter 42 in the first embodiment, and a description thereof will be omitted. Further, the operation of the control block 211 is the same as that of the first embodiment, and the description is omitted.

As described above, according to the configuration of the second embodiment, one-core optical fiber cable
It is possible to construct an Ethernet optical communication system that performs two-way communication with n. Terminal 22 and first server 1
1 is guaranteed by the operation of transmitting the Ethernet frame in the terminal 22, the first terminal hub 31, and the first server 11. The prevention of collision of Ethernet frames output from each terminal 22 is the first.
This is guaranteed by the temporary memory function of the Ethernet frame, the transmission function of the Ethernet frame, and the wavelength multiplexing method in the termination hub 31 of FIG.

(Third Embodiment) FIG. 4 shows a third embodiment of the present invention.
It is a block diagram showing the Ethernet optical communication system concerning an embodiment. In the Ethernet optical communication system according to the third embodiment, a second server 12 that stores contents such as moving images and unilaterally distributes the contents is used.

In the Ethernet optical communication system according to the third embodiment, a first terminal hub 31 is connected to the first server 11. A first Ethernet optical converter 41 is connected to the n port side of the first termination hub 31. A first optical coupler 51 is connected to each of the first Ethernet optical converters 41. On the other hand, the second
The electrical / optical converter 71 is connected to the server 12. The third optical coupler 53 is connected to the electric / optical converter 71. First optical coupler 51 and third optical coupler 5
3 is connected to the third WDM 63. Third W
The DM 63 is connected to the terminal 23 via the optical fiber 35.

The terminal 23 includes a fourth WDM 64, a second optical coupler 52, an optical / electrical converter 72, a second Ethernet optical converter 42, a receiving block 212, and a control block 213. . The fourth WDM 64 is connected to the third WDM 63 via the optical fiber 35.
The fourth WDM 64 is connected to the optical / electrical converter 72 and the second optical coupler 52. The optical / electrical converter 72
The electric signal is sent to the receiving block 212. The second optical coupler 52 is connected to the second Ethernet optical converter 42. The second Ethernet optical converter 42 sends an electric signal to the control block 213. The control block 213 controls the reception block 212. As in the first embodiment, the number of terminals 23 may be any number. In FIG. 4, it is assumed that n terminals 23 exist. The user only needs to install the first Ethernet optical converter 41, the first optical coupler 51, and the third WDM 63 in accordance with the number of terminals 23.

In the Ethernet optical communication system according to the third embodiment, it is assumed that an optical signal having a wavelength λ1 (for example, λ1 = 1300 [nm]) is assigned to a downstream signal from the first server 11. . Also, the downstream signal from the second server 12 includes a wavelength λ0 (for example, λ0 = 1
It is assumed that an optical signal of 550 [nm]) is assigned. It is also assumed that an optical signal of wavelength λ1 is assigned to the upstream signal from terminal 23.

Next, the function of each component of the Ethernet optical communication system according to the third embodiment will be described.

In the Ethernet optical communication system according to the third embodiment, the first server 11, the first termination hub 31, the first Ethernet optical converter 41, the first optical coupler 51, The second optical coupler 52, the second Ethernet optical converter 42, and the optical fiber 35 have the same functions as those in the first embodiment, and a description thereof will be omitted.

The second server 12 stores data such as moving images, and unilaterally transmits the information to each terminal 23. For example, the second server 12 transmits the multiplexed MPEG2 (Moving Picture Expe
rts Group 2) Deliver the stream to each terminal 23.

The electric / optical converter 71 is connected to the second server 12
Is converted into an optical signal having the wavelength λ0, and the optical signal is supplied to the third optical coupler 53. As a method of converting an electric signal into an optical signal, an intensity modulation method or the like is used.

The third optical coupler 53 is a so-called branch coupler. The third optical coupler 53 includes an electric / optical converter 71
The power of the optical signal from is divided by n. The n-divided optical signal is propagated to the third WDM 63.

The third WDM 63 is a third optical coupler 53
The optical signal of the wavelength λ0 output from the multiplexing device and the optical signal of the wavelength λ1 supplied from the first Ethernet optical converter 41 via the first optical coupler 51 are multiplexed by the WDM method, and are multiplexed via the optical fiber 35. To supply the optical signal to the fourth WDM 64. The third WDM 63 is the fourth WDM 6
4 receives the optical signal and demultiplexes it into an optical signal of wavelength λ1 and an optical signal of wavelength λ0. However, in the third embodiment, since the upstream signal from the terminal 23 is limited to the optical signal of the wavelength λ1, the third WDM 63 is actually
Only the optical signal of the wavelength λ1 output from the WDM 64 is supplied to the first coupler 51.

The fourth WDM 64 converts the optical signal supplied from the third WDM 63 by the WDM method into wavelengths λ0 and λ.
The optical signal is demultiplexed into an optical signal of 1. The fourth WDM 64 has a wavelength λ
The optical signal of 0 is supplied to the optical / electrical converter 72, and the optical signal of the wavelength λ1 is supplied to the second optical coupler 52. Further, the fourth WDM 64 supplies the optical signal of the wavelength λ1 supplied from the second Ethernet optical converter 42 via the second optical coupler 52 to the third WDM 63 via the optical fiber 35 as it is.

The optical / electrical converter 72 is a fourth WDM 64
Is received, converted into an electric signal, and sent to the receiving block 212. As a method of converting an optical signal into an electric signal, an intensity modulation method or the like is used.

The receiving block 212 has a function of receiving an electric signal sent from the optical / electrical converter 72 and a function of selecting, demodulating, demodulating and displaying / reproducing the received content according to an instruction from the control block 213. included.

The control block 213 receives the electric signal related to the Ethernet frame output from the second Ethernet optical converter 42. As with the control block 211 in the first embodiment, when the control block 213 receives the Ethernet frame, it transmits a response signal indicating that the Ethernet frame has been successfully received to the first terminal hub 31. The control block 213 instructs the receiving block 212 based on the received electric signal related to the Ethernet frame. Further, the control block 213 controls the first server 11
When data is transmitted to the second Ethernet optical converter 42, the operation is performed in the same manner as in the control block 211 in the first embodiment, and the Ethernet signal related to the data is transmitted.

Reception block 212 and control block 213
Specifically, the relationship is as follows. First, an MPE in which a plurality of programs are multiplexed from the second server 12.
Assume that a G2 stream is transmitted. It is assumed that the first server 11 transmits information necessary for demodulating the multiplexed stream distributed from the second server 12 to the terminal 23 in response to a request from the terminal 23. In such an assumption, the control block 213 determines whether the reception block 2
12, the reception block 212 is provided with the channel of the program to be displayed and reproduced and information necessary for demodulating the channel. The receiving block 212 selects a channel from the received multiplexed stream based on such information from the control block 213, demodulates and displays and reproduces the channel.

Next, the operation when data is transmitted (upward transmission) from the terminal 23 to the first server 11 will be described. The control block 213 operates similarly to the control block 211 according to the first embodiment, and transmits an electric signal related to an Ethernet frame addressed to the first server 11 to the second Ethernet optical converter 42.

The second Ethernet optical converter 42 converts the electric signal sent from the control block 213 into an optical signal having the wavelength λ 1 and supplies it to the second optical coupler 52. Second
The optical signal of the wavelength λ1 supplied to the optical coupler 52 of the fourth
Is supplied to the WDM 64, and the third
Is supplied to the WDM 63.

The third WDM 63 converts the optical signal of wavelength λ1 supplied from the fourth WDM 64 into the first optical coupler 51.
To supply. Hereinafter, the operation is performed in the same manner as in the first embodiment, and the optical signal related to the Ethernet frame is converted into an electric signal and transmitted to the first terminal hub 31.

The first terminal hub 31 operates in the same manner as in the first embodiment, and transmits an Ethernet frame to the first server 11. After that, the first server 11 also
It operates in the same way as in the first embodiment. For the operation at the first terminal hub 31 and the first server 11, the first
The description is omitted because it is the same as that of the embodiment.

Next, the operation when data is transmitted (downward transmission) from the first server 11 and the second server 12 to the terminal 23 will be described. The first server 11, the first termination hub 31, the first Ethernet optical converter 41, and the first optical coupler 51 operate in the same manner as in the first embodiment, and provide the third WDM 63 with the wavelength λ1. The optical signal is supplied. Therefore, description of the operations of the first server 11, the first termination hub 31, the first Ethernet optical converter 41, and the first optical coupler 51 will be omitted.

Here, since the first terminal hub 31 has a switching function, the Ethernet frame output from the first server 11 is supplied only to the third WDM 63 corresponding to the terminal 23 of the transmission destination. Make sure it is not.

On the other hand, the second server 12 transmits an electric signal of data to be distributed to each terminal 23 to the electric / optical converter 71. The electrical / optical converter 71 converts the electrical signal sent from the second server 12 into an optical signal of wavelength λ0 and supplies the optical signal to the third optical coupler 53. The third optical coupler 53 is
The power of the optical signal supplied from the electrical / optical converter 71 is distributed to n and supplied to each third WDM 63.

The third WDM 63 transmits the optical signal of wavelength λ 1 transmitted from the first Ethernet optical converter 41 via the first optical coupler 51 and the third optical coupler 53 from the electrical / optical converter 71. And the optical signal of wavelength λ0 transmitted through the WDM system. The optical signal multiplexed by the third WDM 63 is transmitted to the fourth optical
To the WDM 64.

The fourth WDM 64 splits the supplied optical signal into optical signals of wavelengths λ0 and λ1. The optical signal having the wavelength λ0 is supplied to the optical / electrical converter 72, converted into an electric signal, and transmitted to the receiving block 212 by the optical / electrical converter 72. On the other hand, the optical signal of the wavelength λ1 is supplied to the second optical coupler 52. The optical signal supplied to the second optical coupler 52 is supplied to a light receiving element of the second Ethernet optical converter 42. As in the first embodiment, the optical signal supplied to the second Ethernet optical converter 42 is converted into an electric signal and transmitted to the control block 213. The control block 213 operates in the same manner as the control block 211 in the first embodiment, and transmits a response signal indicating that the electric signal related to the Ethernet frame has been successfully received to the first terminal hub 31. This response signal is used for collision detection at the first terminal hub 31. The control block 213 controls the reception block 212 based on the received electric signal related to the Ethernet frame.

As described above, according to the configuration of the third embodiment, the two-way communication between the terminal 23 and the first server 11 and the one-way communication between the It is possible to construct an Ethernet optical communication system that performs a combination of various types of distribution.
The two-way communication between the terminal 23 and the first server 11
3. Guaranteed by the transmission operation of the Ethernet frame in the first terminal hub 31 and the first server 11. In addition, prevention of collision of Ethernet frames output from each terminal 23 is guaranteed by the function of the first terminal hub 31.

(Fourth Embodiment) FIG. 5 shows a fourth embodiment of the present invention.
It is a block diagram showing the Ethernet optical communication system concerning an embodiment. First, the configuration of the Ethernet optical communication system according to the fourth embodiment will be described.

In the Ethernet optical communication system according to the fourth embodiment, a first terminal hub 31 is connected to the first server 11. On the n port side of the first termination hub 31, n third Ethernet optical converters 43 are connected. A first optical coupler 51 is connected to each of the third Ethernet optical converters 43.
On the other hand, an electrical / optical converter 71 is connected to the second server. A fifth WDM 65 is connected to the first optical coupler 51 and the electrical / optical converter 71. Fifth WDM
Reference numeral 65 is connected to the fourth optical coupler 54 via the optical fiber 35. The fourth optical coupler 54 includes n terminals 2
4 is connected.

The terminal 24 includes a sixth WDM 66, a second optical coupler 52, a fourth Ethernet optical converter 44,
An optical / electrical converter 72, a receiving block 212, and a control block 213 are provided. The sixth WDM 66 is connected to the fourth optical coupler 54. In addition, the sixth WDM6
6 is connected to the optical / electrical converter 72 and the second optical coupler 52. The second optical coupler 52 is connected to the fourth Ethernet optical converter 44. Optical / electrical converter 72
Sends an electrical signal to the receiving block 212. The fourth Ethernet optical converter 44 sends an electric signal to the control block 213. The control block 213 includes the reception block 212
Control. As in the first embodiment, the number of terminals 24 may be any number. In FIG. 5, n terminals 24
Suppose that exists. The user may install the third Ethernet optical converter 43 and the first optical coupler 51 in accordance with the number of the terminals 24.

In the Ethernet optical communication system according to the fourth embodiment, as in the second embodiment, each terminal 24 is individually assigned a wavelength of an optical signal to be emitted. Therefore, the fourth Ethernet optical converter 44 and the third Ethernet optical converter 4 corresponding to each terminal 24
The wavelength assigned to each terminal 24 is also assigned to the wavelength of the optical signal emitted by 3. here,
Each terminal 24, the fourth Ethernet optical converter 44 and the third
Wavelength assigned to the Ethernet optical converter 43 of λ
1, λ2,..., Λn. For example, λ1 = 130
0 [nm], λ2 = 1310 [nm],..., Λn =
It is assumed that 1300 + 10 × (n−1) [nm]. It is also assumed that an optical wavelength λ0 (for example, λ0 = 1550 [nm]) is assigned to a downstream signal from the second server.

Next, the function of each component of the Ethernet optical communication system according to the fourth embodiment will be described.

In the Ethernet optical communication system according to the fourth embodiment, the first server 11, the first termination hub 31, the first optical coupler 51, the optical fiber 35, and the second optical coupler 52 Since the function is the same as that of the first embodiment, the description is omitted. Further, a third Ethernet optical converter 43 and a fourth Ethernet optical converter 44
This function is the same as that of the second embodiment, and the description is omitted. Furthermore, in the Ethernet optical communication system according to the fourth embodiment, the second server 1
2. Regarding the electrical / optical converter 71, the optical / electrical converter 72, the receiving block 212 and the control block 213, the third
Since the function is the same as that of the embodiment, description thereof will be omitted.

The fifth WDM 65 has basically the same function as the first WDM 61 according to the second embodiment. However, the fifth WDM 65 is different from the first WDM 61 in that an optical signal of wavelength λ0 from the second server 12 and optical signals of wavelengths λ1, λ2,. The signals are multiplexed or demultiplexed by the WDM method.

The fourth optical coupler 54 is a so-called branch coupler. The fourth optical coupler 54 distributes the power of the optical signal from the fifth WDM 65 to n, and outputs the n sixth WDMs.
The optical signal is supplied to 66. Also, the fourth optical coupler 5
4 multiplexes optical signals of different wavelengths from each terminal 24 and supplies them to the fifth WDM 65 via the optical fiber 35. The fourth optical coupler 54 multiplexes the optical signals but does not perform the demultiplexing.

The sixth WDM 66 has basically the same function as the fourth WDM 64 according to the third embodiment.
However, the sixth WDM 66 is preset so as to split an optical signal having a wavelength corresponding to each terminal 24. The sixth WDM 66 demultiplexes the optical signal of the wavelength assigned to each terminal 24 and the optical signal of the wavelength λ0. Also, the sixth WD
M66 supplies the optical signal from the second optical coupler 52 to the fourth optical coupler 54.

Next, the operation when data is transmitted from terminal 24 to first server 11 (uplink transmission) will be described. The control block 213 of each terminal 24 operates in the same manner as the control block 211 in the first embodiment, and outputs the electric signal related to the Ethernet frame addressed to the first server 11 to the fourth server.
To the Ethernet optical converter 44. The fourth Ethernet optical converter 44 converts the electric signal into an optical signal having a wavelength assigned to the terminal 24 and supplies the optical signal to the second optical coupler 52. The optical signal supplied to the second optical coupler 52 is supplied to a sixth WDM 66. 6th WDM6
6 supplies the optical signal to the fourth optical coupler 54.

The fourth optical coupler 54 multiplexes optical signals of different wavelengths collected from each terminal 24 and supplies them to the fifth WDM 65 via the optical fiber 35. Fifth WDM65
Separates the optical signal into optical signals of wavelengths λ1 to λn,
This is supplied to the first optical coupler 51. Hereinafter, the optical signal supplied to the first optical coupler 51 is converted into an electric signal by the third Ethernet optical converter 43 in the same manner as in the second embodiment, and transmitted to the first termination hub 31. Is done. Upon receiving the electrical signal related to the Ethernet frame, the first termination hub 31 sends a response signal indicating that the reception was successful to the terminal 2.
Send to 4. The electric signal transmitted to the first terminal hub 31 is transmitted to the first server 11 in the same manner as in the second embodiment. When the first server 11 receives the electrical signal related to the Ethernet frame output from the first terminal hub 31, the first server 11 transmits a response signal indicating the successful reception to the first terminal hub 31. The first server 11 performs a response process to the terminal 24 based on the electric signal.

Next, the operation when data is transmitted from the first server 11 to the terminal 24 (downlink transmission) will be described. The first server 11, the first terminating hub 31, the third Ethernet optical converter 43, and the optical coupler 51 operate in the same manner as in the second embodiment, and transmit the fifth WDM 65 to an Ethernet frame. An optical signal having wavelengths λ1 to λn is supplied. In addition, the second server 12 and the electric / optical converter 71
The same operation as in the third embodiment is performed, and the fifth WDM
An optical signal having a wavelength λ0 is supplied to 65.

The fifth WDM 65 is the first optical coupler 51
And the optical signal supplied from the electrical / optical converter 71 is WDM
The optical signals are multiplexed according to the method, and the optical signal is supplied to the fourth optical coupler 54 via the optical fiber 35. The fourth optical coupler 54 distributes the optical signal supplied from the fifth WDM 65 to n and supplies the optical signal to the sixth WDM 66 existing in each terminal 24.

The sixth WDM 66 is connected to the fourth optical coupler 54.
The optical signal supplied from the terminal 24 and the optical signal of the wavelength λ0
And is demultiplexed into an optical signal having a wavelength and supplied to the optical / electrical converter 72 and the second optical coupler 52. The optical / electrical converter 72 converts the optical signal of the wavelength λ0 related to the Ethernet frame output from the sixth WDM 66 into an electric signal, and transmits the electric signal to the receiving block 212. The second optical coupler 52 is similar to the second optical coupler 52 in the sixth WDM
The optical signal supplied from 66 is transmitted to the light receiving element of the fourth Ethernet optical converter 44. The fourth Ethernet optical converter 44 operates similarly to the second embodiment, converts the optical signal into an electric signal, and transmits the electric signal to the control block 213. The control block 213 transmits a response signal to the effect that the Ethernet frame has been successfully received to the first terminal hub 31. The control block 213 controls the reception block 212 based on the electric signal related to the Ethernet frame output from the fourth Ethernet optical converter 44.

As described above, according to the configuration of the fourth embodiment, one-core optical fiber cable can be used.
It is possible to construct an Ethernet optical communication system that combines two-way communication with n and unidirectional distribution. The bidirectional communication between the terminal 24 and the first server 11 is guaranteed by the operation of transmitting the Ethernet frame in the terminal 24, the first server 11, and the first terminal hub 31. Further, the prevention of collision of the Ethernet frame output from each terminal 24 is guaranteed by the function of the first terminal hub 31 and the wavelength multiplexing method.

(Fifth Embodiment) FIG. 6 shows a fifth embodiment of the present invention.
It is a block diagram showing the Ethernet optical communication system concerning an embodiment. In the Ethernet optical communication system according to the fifth embodiment, the third server 13 is connected to the second termination hub 32 with two cores. Second termination hub 3
The second Ethernet optical converter 45
Are connected with two cores. An electric / optical converter 71 is connected to the second server 12. The fifth Ethernet optical converter 45 and the electrical / optical converter 71 have a seventh WD.
M67 is connected. The seventh WDM 67 is connected to the fourth optical coupler 54 via the optical fiber 35. The fourth optical coupler 54 is connected to n terminals 25.

The terminal 25 includes an eighth WDM 68, a sixth Ethernet optical converter 46, a control block 214,
An optical / electrical converter 72 and a receiving block 212 are provided. The eighth WDM 68 is connected to the fourth optical coupler 54. In addition, a sixth Ethernet optical converter 46 and an optical / electrical converter 72 are connected to the eighth WDM 68. The sixth Ethernet optical converter 46 and the control block 214 are connected by two cores. The sixth Ethernet optical converter 46 transmits an electric signal to the control block 214. On the other hand, the optical / electrical converter 72 transmits an electric signal to the receiving block 212. The control block 214
The control of the reception block 212 is performed. As in the first embodiment, the number of terminals 25 may be any number. In FIG. 6, it is assumed that n terminals 25 exist. The user may install the fifth Ethernet optical converter 45 according to the number of the terminals 25.

In the fifth embodiment, each terminal 25 has λ2, λ4, λ6,.
n is an input wavelength λ1, λ3, λ5,..., λ
2n-1 are assigned. Λ0 is assigned to the second server as an output wavelength. For example, λ1
= 1300 [nm], λ2 = 1310 [nm], λ3 =
1320 [nm],..., Λ2n = 1300 + 10 ×
(2n-1) [nm], and λ0 = 1550 [nm].

Next, the function of each component of the Ethernet optical communication system according to the fifth embodiment will be described.

In the Ethernet optical communication system according to the fifth embodiment, the second server 12, the electric / optical converter 71, the optical fiber 35, the fourth optical coupler 54, the optical / electric converter 72, and the receiving block 212 Has the same function as that according to the fourth embodiment, and a description thereof will be omitted.

The third server 13 is connected to the second terminal hub 32
To transmit / receive an Ethernet frame to / from each terminal 25 via the terminal.

The second terminating hub 32 is an aggregating device having a switching function of transmitting and receiving an Ethernet frame and aggregating an Ethernet interface at a physical layer. The second terminating hub 32 is composed of 1 to 2n ports, and a 5th Ethernet optical converter 45 for mutually converting an electric signal and an optical signal is connected to the 2n port side. On the side, a third server 13 is connected. The second termination hub 32 includes a memory (not shown). The second termination hub 32 receives the Ethernet frame output from the terminal 25 and the third server 13, and stores the Ethernet frame in a temporary memory. The second termination hub 32 refers to the destination MAC address of the Ethernet frame stored in the memory, and sequentially outputs the Ethernet frame to a port corresponding to the MAC address. That is, it can be said that the second terminal hub 32 is a so-called switching hub having a switching function.

The fifth Ethernet optical converter 45 has the second
It has the same function as the third Ethernet optical converter 43 in the embodiment. Therefore, the user can individually set the wavelength of the optical signal emitted by the fifth Ethernet optical converter 45. Further, the light receiving element of the fifth Ethernet optical converter 45 can receive light signals of different wavelengths. This takes advantage of the feature that the light receiving element can receive optical signals of a wide range of wavelengths. In the fifth embodiment, the wavelength of the optical signal emitted from the fifth Ethernet optical converter 45 is different from the wavelength of the optical signal received. However, as described above, the light receiving element of the fifth Ethernet optical converter 45 can receive an optical signal without depending on the wavelength of the received optical signal. Therefore, the user must set the wavelength of the optical signal emitted by the light emitting element of the fifth Ethernet optical converter 45, but does not need to individually set the light receiving function of the light receiving element.

The seventh WDM 67 receives the optical signal of wavelength λ 0 from the second server 12 and the wavelength λ from the third server 13.
, Λ3, λ5,..., Λ2n-1
The signals are multiplexed by the M method. On the other hand, the seventh WDM 67
The wavelengths λ2, λ4, λ6 combined from the terminal 25 side,.
.., The optical signal of λ2n is demultiplexed by the WDM method.

The eighth WDM 68 has basically the same function as the sixth WDM 66 in the fourth embodiment. Therefore, the eighth WDM 68 demultiplexes the optical signal output from the fourth optical coupler 54 into an optical signal of the wavelength λ0 and an optical signal of the wavelength assigned to each terminal 25. However, unlike the sixth WDM 66, the eighth WDM 68 is supplied with an optical signal having a wavelength different from the wavelength of the optical signal output from the sixth Ethernet optical converter 46.
Therefore, the eighth WDM 68 has a function of directly supplying the optical signal from the sixth Ethernet optical converter 46 to the fourth optical coupler 54 in addition to the function of the sixth WDM 66.

The sixth Ethernet optical converter 46 converts the electric signal related to the Ethernet frame from the control block 214 into an optical signal of the wavelength assigned to the terminal 25 and emits light. Also, the sixth Ethernet optical converter 46
Receives the optical signal output from the eighth WDM 68,
Convert to electrical signals.

The control block 214 controls the second terminal hub 3
The transmission / reception of the Ethernet frame with the third server 13 is performed via the communication server 2. Therefore, the electrical signal related to the Ethernet frame transmitted to the third server 13 is transmitted to the sixth Ethernet optical converter 46. Further, the control block 214 controls the reception block 212 based on the electric signal related to the Ethernet frame received from the sixth Ethernet optical converter 46.

Next, the operation when data is transmitted from terminal 25 to third server 13 (uplink transmission) will be described. The control block 214 transmits an electric signal related to the Ethernet frame to the sixth Ethernet optical converter 46. The sixth Ethernet optical converter 46 converts the electric signal to the wavelengths (λ2, λ4, λ
6,..., 2n) and supplies the optical signal to the eighth WDM 68. Eighth WDM 68
Supplies the optical signal output from the sixth Ethernet optical converter 46 to the fourth optical coupler 54.

The fourth optical coupler 54 is connected to an eighth WDM 68
And multiplexes the optical signals having different wavelengths supplied from the optical fiber 35 and supplies the multiplexed optical signal to the seventh WDM 67 via the optical fiber 35.

The seventh WDM 67 is connected to the fourth optical coupler 54.
From the wavelengths λ2, λ4, λ6,.
, And demultiplexes the optical signal into λ2n optical signals and supplies them to the fifth Ethernet optical converter 45 corresponding to each wavelength. The fifth Ethernet optical converter 45 converts an optical signal related to the Ethernet frame output from the seventh WDM 67 into an electric signal and transmits the electric signal to the second termination hub 32.

The second termination hub 32 stores the Ethernet frame output from the fifth Ethernet optical converter 45 in a temporary memory. The second termination hub 32 sequentially transmits the electrical signals related to the Ethernet frame temporarily stored in the memory to the third server 13. In this manner, the second termination hub 32 prevents the Ethernet frames output from the plurality of terminals 25 from electrical collision.

The third server 13 is connected to the second terminal hub 32
A response process to the terminal 25 is performed based on the Ethernet frame output from.

Next, the operation when data is transmitted (downward transmission) from the third server 13 and the second server 12 to the terminal 25 will be described. The second server 12 transmits an electric signal of data to be distributed to each terminal 25 to the electric / optical converter 71, as in the third embodiment. Electric / optical converter 7
1 converts the electric signal output from the second server 12 into an optical signal having the wavelength λ0, and supplies the optical signal to the seventh WDM 67.

On the other hand, the third server 13 transmits an electric signal related to the Ethernet frame to the second terminal hub 32. The second termination hub 32 switches the Ethernet frame transmitted from the first server 11 based on the destination MAC address, and transmits the Ethernet frame to the fifth Ethernet optical converter 45.

The fifth Ethernet optical converter 45 has the second
Of the electric signals output by the termination hub 32 of each of the terminals 25 (λ1, λ3, λ5,.
.., Λ2n-3 or λ2n-1) and supplies the optical signal to the seventh WDM 67.

The seventh WDM 67 includes an electric / optical converter 71
The optical signal supplied from the fifth Ethernet optical converter 45 is multiplexed by the WDM method and supplied to the fourth optical coupler 54 via the optical fiber 35. Fourth optical coupler 5
4 divides the optical signal supplied from the seventh WDM 67 into n and supplies the optical signal to the eighth WDM 68 of each terminal 25.

The eighth WDM 68 includes a fourth optical coupler 54.
Is split into an optical signal having a wavelength λ0 and an optical signal having a wavelength assigned for input in the terminal 25, and is split into an optical / electrical converter 72 and a sixth Ethernet optical converter 46. Supply.

The optical / electrical converter 72 is an eighth WDM 68
Is converted into an electric signal and transmitted to the receiving block 212. On the other hand, the sixth Ethernet optical converter 46 converts an optical signal related to the Ethernet frame output from the eighth WDM 68 into an electric signal, and transmits the electric signal to the control block 214. The control block 214 controls the reception block 212 based on the electric signal output from the sixth Ethernet optical converter 46.

As described above, according to the configuration of the fifth embodiment, one-core optical fiber cable can be used.
It is possible to construct an Ethernet optical communication system that combines two-way communication with n and unidirectional distribution. The two-way communication between the terminal 25 and the third server 13 is realized when the wavelength of the upstream signal output from the terminal 25 is different from the wavelength of the downstream signal output from the third server 13. . That is, even if the upstream signal and the downstream signal are transmitted at the same time, the collision of the optical signal in the optical fiber 35 does not occur. Further, between the second terminal hub 32 and the third server 13, the second terminal hub 32 and the fifth Ethernet optical converter 45, and between the control block 214 and the sixth Ethernet optical converter 46, two cores are provided. Therefore, no electrical collision occurs between them. Further, the prevention of the collision of the Ethernet frame output from each terminal 25 is guaranteed by the function of the second terminal hub 32 and the wavelength multiplexing method.

In the embodiments of the present invention, Ethernet is used as a communication method. However, the communication method is not limited to Ethernet, and the frame multiplexing control technology and the bidirectional communication between a 1-to-N server and each terminal can be used. By using a communication system having the characteristic of managing the network by polling control technology, it is possible to construct an optical communication system that performs two-way communication with a single optical fiber by using the same configuration as the present invention. Becomes

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an Ethernet optical communication system according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating a state in which the number of terminals of an Ethernet optical communication system constructed with existing two-core optical fibers can be doubled using the Ethernet optical communication system according to the first embodiment; is there.

FIG. 3 is a block diagram illustrating an Ethernet optical communication system according to a second embodiment of the present invention.

FIG. 4 is a block diagram illustrating an Ethernet optical communication system according to a third embodiment of the present invention.

FIG. 5 is a block diagram showing an Ethernet optical communication system according to a fourth embodiment of the present invention.

FIG. 6 is a block diagram illustrating an Ethernet optical communication system according to a fifth embodiment of the present invention.

FIG. 7 is a diagram showing a configuration of a content distribution system disclosed in Japanese Patent Application Laid-Open No. 07-183870.

FIG. 8 is a diagram showing a configuration of an Ethernet optical communication system described in Japanese Patent Application Laid-Open No. H10-79745.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 1st server 12 2nd server 13 3rd server 21,22,23,24,25 Terminal 31 1st termination hub 32 2nd termination hub 35 Optical fiber 41 1st Ethernet optical converter 42 1st 2 Ethernet optical converter 43 3rd Ethernet optical converter 44 4th Ethernet optical converter 45 5th Ethernet optical converter 46 6th Ethernet optical converter 51 1st optical coupler 52 2nd optical coupler 53 third optical coupler 54 fourth optical coupler 61 first WDM 62 second WDM 63 third WDM 64 fourth WDM 65 fifth WDM 66 sixth WDM 67 seventh WDM 68 eighth WDM 71 Electric / optical converter 72 Optical / electric converter 211, 213, 214 Control block 212 Receiving block 111 Server 112 Terminal 13 Termination hub 150 Electrical / optical converter 160 optical / electrical converter 113 two-core optical fiber cable

Claims (7)

[Claims] 1. An optical communication system for performing bidirectional optical communication between first and second devices connected via a single-core optical fiber, wherein the first and second devices are arranged at one end of the optical fiber. A server as one device, inserted between one end of the optical fiber and the server,
First interface means for performing an interface between an electric signal and an optical signal; a terminal as the second device disposed on the other end of the optical fiber; Second interface means interposed between the terminal and an electric signal and an optical signal, wherein the server only transmits data addressed to the terminal when data is not being received. Transmitting an electric signal including data addressed to the server to the second interface means only when data is not being received, The first interface means converts an electric signal from the server into an optical signal and supplies the optical signal to the optical fiber, and converts the optical signal sent from the terminal via the optical fiber into an electric signal. The second interface means converts an electric signal from the terminal into an optical signal, supplies the optical signal to the optical fiber, and transmits the optical signal from the server via the optical fiber. An optical communication system, wherein an incoming optical signal is converted into an electric signal and supplied to the terminal. 2. A single core N (where N is 2
An optical communication system for performing bidirectional optical communication between a first device and N second devices via the above (integer) optical fibers, and is disposed at one end of each of the optical fibers. A first server as the first device, and N number of first servers which are interposed between one end of each of the optical fibers and the first server and perform an interface between an electric signal and an optical signal. First interface means, interposed between each of the first interface means and the first server, and exchange of data between the first server and each of the first interface means; Terminating hub, N terminals as the second device disposed on the other end side of each of the optical fibers, interposed between the other end of each of the optical fibers and each of the terminals, N to interface between electrical and optical signals
The first server transmits an electric signal including the data addressed to the terminal to the terminal hub when transmitting data addressed to the terminal from the first server. The termination hub transmits the electric signal sent from the first server to first interface means corresponding to the destination terminal, and the first interface means transmits the electric signal from the termination hub to the first interface means. The transmitted electric signal is converted into an optical signal and supplied to the optical fiber. The second interface means transmits the optical signal transmitted from the first interface means via the optical fiber. Is converted to an electric signal and transmitted to the terminal. When the terminal transmits data addressed to the first server, the terminal transmits an electric signal including data addressed to the server to the second interface. The second interface means converts the electric signal sent from the terminal into an optical signal and supplies the optical signal to the optical fiber, and the first interface means transmits the optical fiber And converts the optical signal sent from the second interface means to an electric signal and transmits the electric signal to the terminal hub. The terminal hub outputs the electric signal sent from the first interface means. A signal is transmitted to the first server, the first server transmits an electric signal including data addressed to the terminal to the terminal hub only when data is not being received, and the terminal transmits the data to the terminal hub. An electric signal including data addressed to the first server is transmitted to the second interface means only when data is not being received, and the terminating hub transmits the data transmitted from the first server or the terminal. Temporarily storing data, only when not receiving the data from the appropriate destination, and transmits the data stored at the one towards the appropriate destination, an optical communication system. 3. A second server that unidirectionally distributes data to each of the terminals, and a wavelength of an optical signal output by the first interface unit from an electric signal output from the second server. Electric / optical conversion / distribution means for converting the optical signal into optical signals of different wavelengths and distributing the optical signal in the N direction; and N optical signals interposed between one end of each optical fiber and each of the first interface means Wherein each of the wavelength multiplexing devices multiplexes an optical signal supplied from the electric / optical conversion / distribution unit with a corresponding optical signal supplied from the first interface unit. Supplying an optical signal transmitted from the corresponding second interface means via the optical fiber to the corresponding first interface means, wherein each of the second interface means comprises a corresponding wavelength multiplexing device. Light from The optical signal supplied via the fiber is demultiplexed into a corresponding optical signal from the first interface means and an optical signal from the second server, and each is converted into an electric signal to convert the signal into an electric signal. The optical communication system according to claim 2, wherein the optical communication system is supplied to the optical communication system. 4. An optical communication system for performing bidirectional optical communication between a first device and N (N is an integer of 2 or more) second devices via a single-core optical fiber. A server as the first device disposed on one end side of the optical fiber, and inserted between one end of the optical fiber and the server;
A first wavelength multiplexing device that performs multiplexing and demultiplexing of optical signals, and is interposed between the first wavelength multiplexing device and the server, and performs an interface between an electric signal and an optical signal;
N number of first interface means each set to output an optical signal of a different wavelength, interposed between each said first interface means and said server, said server and each first A terminating hub for exchanging data with the interface means, N terminals as the second device disposed on the other end of the optical fiber, and the other end of the optical fiber and the terminal A second wavelength multiplexing device interposed between the second wavelength multiplexing device and each of the terminals, for multiplexing and demultiplexing an optical signal, and an electric signal and an optical signal Interface with
And N second interface means each set to output an optical signal having a different wavelength, and when transmitting data addressed to the terminal from the server, the server transmits data addressed to the terminal. The terminal hub transmits an electric signal including the electric signal to the terminal hub, and the terminal hub transmits the electric signal sent from the server to first interface means corresponding to the terminal of the destination, and the first interface means Converts the electric signal sent from the terminal hub into an optical signal and supplies the optical signal to the first wavelength multiplexing device, wherein the first wavelength multiplexing device is provided with one or more first interface means. Multiplexes the optical signal sent from the first wavelength multiplexing device and supplies the multiplexed optical signal to the optical fiber. The second wavelength multiplexing device transmits the optical signal transmitted from the first wavelength multiplexing device via the optical fiber. The first The optical signal output from the interface unit is demultiplexed and supplied to the corresponding second interface unit, and the second interface unit converts the optical signal sent from the second wavelength multiplexing device into an electric signal. When the data is converted to a signal and transmitted to the terminal, and the terminal transmits data addressed to the server, the terminal transmits an electric signal including the data addressed to the server to the second interface means, A second interface unit that converts an electric signal transmitted from the terminal into an optical signal and supplies the optical signal to the second wavelength multiplexing device; Optical signals sent from the second interface means are multiplexed and supplied to the optical fiber, and the first wavelength multiplexing device is sent from the second wavelength multiplexing device via the optical fiber. Koshin coming Is demultiplexed into an optical signal output from the second interface means and supplied to the corresponding first interface means. The first interface means is sent from the first wavelength multiplexing device. Converting the received optical signal into an electrical signal and transmitting the electrical signal to the termination hub. The termination hub transmits the electrical signal transmitted from the first interface unit to the server, and the server receives the data. Only when it is not in the middle, the terminal transmits an electric signal including data addressed to the terminal to the terminating hub, and the terminal transmits the electric signal including data addressed to the server to the second hub only when data is not being received. The terminating hub temporarily stores the data sent from the server or the terminal, and temporarily stores the data only when data from the corresponding destination is not being received. Characterized in that it transmits the data to the appropriate destination, an optical communication system. 5. A two-way optical communication between a first device and N (N is an integer of 2 or more) second devices via a single-core optical fiber, and a third device. An optical communication system for performing unilateral data distribution to each second device from a first server as the first device disposed at one end of the optical fiber, and the optical fiber A second server as the third device, which is disposed at one end of the optical fiber together with the first server, and is inserted between one end of the optical fiber and the first and second servers. A wavelength multiplexing device that performs multiplexing and demultiplexing of an optical signal, interposed between the wavelength multiplexing device and the first server, and performs an interface between an electric signal and an optical signal;
N first interface means, each set to output an optical signal of a different wavelength, interposed between each of the first interface means and the first server; A terminating hub for exchanging data between the first server and each of the first interface means; and an intervening hub interposed between the wavelength multiplexing device and the second server for transmitting an electric signal to each of the first interfaces. An electrical / optical converter that converts an optical signal having a wavelength different from the wavelength of the optical signal output by the face unit; and N terminals as the second device disposed on the other end of the optical fiber; A branch coupler that is interposed between the other end of the optical fiber and the terminal, and that performs multiplexing and branching of an optical signal; and an electric signal that is interposed between the branch coupler and each of the terminals. Interface with optical signals, each with a different And N second interface means set to output an optical signal of a wavelength, wherein the first server transmits data addressed to the terminal and the second server transmits data to each terminal. When the data is to be distributed, the first server transmits an electric signal including data addressed to the terminal to the terminal hub, and the terminal hub transmits the electric signal transmitted from the server to the destination hub. Transmitting to the first interface means corresponding to the terminal, the first interface means converts the electric signal sent from the terminal hub into an optical signal, and supplies the optical signal to the wavelength multiplexing device; The second server transmits an electric signal including data to be unilaterally distributed to each of the terminals to the electric / optical converter, and the electric / optical converter transmits the electric signal transmitted from the second server. To optical signal The wavelength multiplexing device converts the optical signal from one or more of the first interface means and the optical signal sent from the electric / optical converter into the optical fiber. The branch coupler distributes the optical signal sent from the wavelength multiplexing device through the optical fiber to N, and supplies the optical signal to each of the second interface means. The interface means demultiplexes the optical signal sent from the branch coupler into a corresponding optical signal from the first interface means and a corresponding optical signal from the second server, and each of them is electrically separated. When the data is converted to a signal and supplied to a terminal, and the terminal transmits data addressed to the first server, the terminal transmits an electric signal including data addressed to the first server to the second interface means. Sent to the The interface means converts an electric signal transmitted from the terminal into an optical signal and supplies the optical signal to the branch coupler, and the branch coupler is transmitted from one or more of the second interface means. Multiplexed optical signals are supplied to the optical fiber, and the wavelength multiplexing device outputs the optical signal sent from the branching coupler via the optical fiber to the second interface means. Demultiplexed optical signal and supplies it to the corresponding first interface means, wherein the first interface means converts the optical signal sent from the wavelength multiplexing device into an electric signal and converts the optical signal into an electric signal. The termination hub transmits an electric signal transmitted from the first interface means to the first server, and the first server transmits the electric signal only when data is not being received. Device address The terminal transmits an electric signal including data addressed to the first server to the second interface means only when data is not being received. The terminating hub temporarily stores data sent from the first server or the terminal, and directs the temporarily stored data to the corresponding destination only when data from the corresponding destination is not being received. An optical communication system characterized in that the optical communication system transmits the data. 6. A bidirectional optical communication between a first device and N (N is an integer of 2 or more) second devices via a single-core optical fiber, and a third device. An optical communication system for performing unilateral data distribution to each second device from a first server as the first device disposed at one end of the optical fiber, and the optical fiber A second server as the third device disposed coexisting with the first server on one end of the optical fiber; and between one end of the optical fiber and the first server and the second server. A wavelength multiplexing device that is interposed and performs multiplexing and demultiplexing of an optical signal; and is interposed between the wavelength multiplexing device and the first server to perform an interface between an electric signal and an optical signal. ,
N first interface means, each set to output an optical signal of a different wavelength, interposed between each of the first interface means and the first server; A terminating hub for exchanging data between the first server and each of the first interface means; and an intervening hub interposed between the wavelength multiplexing device and the second server for transmitting an electric signal to each of the first interfaces. An electrical / optical converter that converts an optical signal having a wavelength different from the wavelength of the optical signal output by the face unit; and N terminals as the second device disposed on the other end of the optical fiber; A branch coupler that is interposed between the other end of the optical fiber and the terminal, and that performs multiplexing and branching of an optical signal; and an electric signal that is interposed between the branch coupler and each of the terminals. Interface with optical signals, each with a different Is set to output the optical signal of the wavelength, and further,
N first interface means and N second interface means set to output an optical signal having a different wavelength from the electric / optical converter, wherein the first server addresses the terminal. When the data is transmitted and the data is unilaterally distributed from the second server to each of the terminals, the first server transmits an electric signal including data addressed to the terminal to the terminal hub, The terminal hub transmits the electric signal sent from the server to first interface means corresponding to the terminal of the destination, and the first interface means transmits the electric signal sent from the terminal hub. Is converted to an optical signal and supplied to the wavelength multiplexing device. The second server transmits an electric signal including data to be unilaterally distributed to each of the terminals to the electric / optical converter. The converter converts the electrical signal transmitted from the second server into an optical signal and supplies the optical signal to the wavelength multiplexing device. The wavelength multiplexing device includes one or more of the first interface means and the The optical signal transmitted from the electric / optical converter is multiplexed and supplied to the optical fiber, and the branching coupler converts the optical signal transmitted from the wavelength multiplexing device through the optical fiber into N. Distributes and supplies the signal to each of the second interface means. The second interface means converts the optical signal sent from the branching coupler into light from the corresponding first interface means. When the signal is demultiplexed into a signal and an optical signal from the second server, each is converted into an electric signal and supplied to a terminal, and the terminal transmits data addressed to the first server, Data addressed to the first server Transmitting an electric signal including the data to the second interface means, the second interface means converts the electric signal sent from the terminal into an optical signal, and supplies the optical signal to the branch coupler; The branch coupler multiplexes optical signals sent from one or more of the second interface units and supplies the multiplexed optical signal to the optical fiber. The optical signal sent from the branching coupler is split into an optical signal output by the second interface means and supplied to the corresponding first interface means, and the first interface means comprises: The optical signal transmitted from the wavelength multiplexing device is converted into an electric signal and transmitted to the terminal hub. The terminal hub transmits the electric signal transmitted from the first interface means to the first server. Send And wherein the optical communication system. 7. The optical communication system according to claim 1, wherein an Ethernet system is used as a communication system.