JP5156983B2 - Optical network interface configuration - Google Patents

Description

  The present invention provides a new configuration of a network interface that converts Ethernet electrical signals into light to transmit and receive large-capacity information between remote multipoint computers. Recent advances in Ethernet technology have been remarkable, and 10 Mbps, 100 Mbps, 1000 Mbps, and 10 Gbps Ethernet global standards have been established and have become a broadband communication infrastructure. In particular, in the optical network, 1 gigaser is popular, and the demand for 10 gigaser is also expanding.

  An Ethernet electrical signal is transmitted from a personal computer (PC) via a network interface card (NIC) to an RJ-45 (Registered Jack, 8-pole 8-core modular jack) using a UTP cable (Unshielded Twisted Pair Cable). Sent and received. As shown in FIG. 1, PC data is suitable for UTP cable transmission via the MAC layer (Media Access Control, medium access control unit) and PLS (Physical Layer Signaling, physical layer signaling unit) by NIC. Converted to signal format. Data communication between PCa and PCb is transmitted and received by electrical wiring using U1 cables of a1 and b1. In ordinary Ethernet, an auto-negotiation function between PCa and PCb devices is introduced. This auto-negotiation function is a mechanism for realizing plug-and-play (user setting-free) connection. By exchanging signals called fast link pulls (FLP), information on communication modes supported by each other can be obtained. Replace and automatically select the optimal communication mode. The normal auto-negotiation procedure is as follows: (1) Announce the support mode of the local station by FLP, (2) Receive the FLP from the partner station, recognize the support mode of the partner station, and (3) Priority resolution ( A mode that enables higher-speed communication is selected, and (4) a communication mode selected by each other is FLP-announced, and (5) a link is established.

A UTP cable for Ethernet of 100 Mbps or more is composed of four twisted pair wires of 8 poles and 8 cores. Using this UTP cable, full-duplex communication can be performed even in 100Base-T and in a transmission / reception method of 1000Base-T or more. In particular, full-duplex communication is used in Ethernet communication through an optical fiber.
As shown in FIG. 2, a physical layer conversion circuit (PHY) that converts UTP electrical signals into low-voltage digital differential signals (LVDS) for transmission and reception is used for mutual communication between remote locations using optical fibers. Use. This is an O / E converter that receives an optical signal from the side to be transmitted as an optical digital signal by an E / O converter a4 for modulating a light source and converts it into a low voltage digital differential signal (LVDS). It consists of the input side from a5. FIG. 2 shows a configuration for performing Ethernet communication between PCs using two optical fibers. With this configuration, auto-negotiation is established by exchanging FLP signals from both sides, and Ethernet communication can be executed.

  2. Description of the Related Art In conventional Ethernet communication using an optical fiber, a transmission side optical fiber and a reception side optical fiber are used as shown in FIG. In future Ethernet communication using optical fiber networks, not only such straight two-core optical fibers but also optical splitters that branch from one optical fiber to n optical fibers and optical couplers that connect to one from n optical fibers, etc. It is also necessary to cope with expansion to complicated optical fiber connection networks such as an optical fiber network in which an optical multiplexing / demultiplexing circuit is introduced and an optical fiber network in which an optical switch is inserted in the middle. When transmitting and receiving Ethernet signals through such a complex optical fiber network, it is necessary to consider a new network configuration according to the application.

  The problem to be solved by the present invention is to transmit an Ethernet signal to a destination PC connected by a single optical fiber, connect an optical splitter or optical hub device to one optical fiber, and connect to the output fiber In some cases, such as multicast communication of Ethernet signals to a plurality of PCs that have been established, it is not possible to cope with the start of transmission by establishing auto-negotiation by exchanging FLP between PCs. In FIG. 3, transmission fiber connection is performed, but when the reception-side fiber connection is not performed, since the auto-negotiation is not established, Ethernet communication cannot be performed. In the configuration of FIG. 4, it is not possible to transmit an Ethernet signal to two PCs PCb and PCc by connecting the 1 × 3 optical splitter 9 to the transmission fiber of PCa because auto-negotiation cannot be established. The present invention provides a configuration that enables Ethernet communication even in such an optical fiber network.

  First, in the configuration of FIG. 4, as shown in FIG. By connecting one output of the splitter 9 to the light receiving O / E converter a5 through the optical fiber a7, the FLP from the PCa is transmitted through the optical fiber a6, the splitter 9, the optical fibers a7 and a5, and the LVDS a3. It was experimentally confirmed that the auto-negotiation between the FLP from the transmitting side of the mobile station and the FLP from the transmitting side of the local station is established, and the Ethernet transmission from the PCa is established. The condition for establishing this auto-negotiation is that the Ethernet communication mode of the PCb and PCc NICs matches the Ethernet communication mode of the PCa. For the PCa, if the FLP transmitted from the PCa and the received FLP are FLPs from the own station, auto-negotiation is established, and an Ethernet signal is transmitted from the PCa as its communication mode. The Ethernet signal from PCa can be received. A condition for establishing this communication mode is when multicast communication or broadcast communication is performed when the network is set to the UDP / RTP mode.

  FIG. 6 shows a first configuration diagram of the present invention. In this configuration, the Ethernet card NIC used for each PCa, PCb, and PCc is required to be in the same communication mode (such as 1000Base-T). In this configuration example, an optical hub device 10 having three inputs and three outputs is connected, an optical input from the PCa is connected to one input c, and an optical fiber a7 connected to the output a ′ of the optical hub is connected. Negotiation is established, and data from PCa can be distributed by multicast or broadcast to PCb and PCc via Ethernet communication. This optical hub device can be applied to any scale of n inputs and m outputs.

  FIG. 7 shows a drawing in which all ports are interconnected with optical fibers in the configuration of FIG. This figure shows a configuration in which optical fibers output from PCa, PCb, and PCc are connected to the input of the optical hub device 10, and all outputs of the optical hub device 10 are connected to inputs of PCa, PCb, and PCc. In this case, since all the first link pulses FLPa, FLPb, FLPc from each PC are input to each light receiving unit, the auto-negotiation becomes unstable due to interference, and the Ethernet communication cannot be normally performed. Become.

The second configuration of the present invention is the configuration of FIG. 8A, FIG. 8B, and FIG. 9, and this configuration makes it possible to establish Ethernet communication. However, it is assumed that all of the NICs of PCa, PCb, and PCc use the same communication speed communication mode.
Optical wavelength multiplexing O / E conversion and E / O conversion as shown in FIG. 9 are introduced into each O / E conversion unit and E / O conversion unit. The operation when FIG. 9 is applied as the O / E conversion unit a4 and the E / O conversion unit a5 will be described. The LVDS signal from PHYa8 shown in FIG. 8A is branched into two by the distributor S1, one is connected to the light source drive a2 in FIG. 9, and the other is connected to the switch S2 having two inputs and one output through the path af of the LVDS. Connect and select s2-Loop to return to PHYa8 to establish auto-negotiation for this path.
FIG. 8B has a selection function of disconnecting the path af and passing the received signal a3 by selecting the switch s2 as s2-pass.
In FIG. 9, the input a2 is connected to ao by the switch S3, emits the optical wavelength λa, and is output to the optical fiber a6 through the optical multiplexer m1. The E / O converters ao, bo, and co have a function of turning on and off the respective optical outputs by the control signals Txa, Txb, and Txc. Only the Txa is turned on and the others are turned off.
On the other hand, the side that receives light at a7 demultiplexes λa, λb, and λc with an optical demultiplexer, and O / E converts them with O / E converters ae, be, and ce, and the LVDS signal switch S4 , Λa, λb, λc, and has a function of selecting and outputting from a3.
The O / E converters ae, be, and ce have a function of outputting monitor signals from Rxa, Rxb, and Rxc as to whether or not λa, λb, and λc exist.
The following functions can be realized by using the configurations of FIGS. 8 and 9 having the functions as described above.
(1) Ethernet multicast communication can be performed from PCa to PCb and PCc.
(2) Two-way Ethernet communication between PCa and any other PC is possible.
To realize (1), select the connection (s2-Loop) in FIG. 8, and in FIG. 9, the transmitting side connected to PCa selects λa by switch s3, and the receiving side PCb, PCc Selects λa.
To realize (2), for example, when the reception of Rxb other than Rxa is monitored in the configuration of FIG. 9 of the path connected to PCa during the state of (1), the switch of FIG. By selecting s2-pass of s2, it is possible to switch to bidirectional communication between PCa and PCb that transmits from λa, receives from λb, receives from λb, and transmits from λb, and receives from λa. .
This is because, when multicast communication is performed also from the PCb side, the Rxb received signal is confirmed from FIG. 9 connected to the PCa. As a result, the PCa determines that the PCb has selected bidirectional communication. This is an example of switching to.
The above is an embodiment of the present invention in which multicast communication and bidirectional communication using three wavelength and 3 × 3 optical hub devices are performed between three PCs. In the case of four PCs, multicast communication and bi-directional communication between the PCs can be similarly performed by using an optical hub device of 4 wavelengths and 4 × 4. Similarly, multicast communication and bi-directional communication between each PC are possible using n wavelength and nxn optical hub devices.

  As can be understood from the above description, the present invention has an effect that can be realized by selecting Ethernet multicast communication or bidirectional communication in an optical network including an optical hub device. In addition, bidirectional communication with a specific partner is also possible by selecting the optical wavelength.

  In order to implement the present invention, by preparing optical network interfaces having different optical wavelengths for each terminal, broadcast and multicast distribution from each terminal can be performed, and bidirectional communication between the terminals as necessary. You can also. Further, when it is sufficient to be able to broadcast such as distance education or video distribution, it can be realized by light of one wavelength. Economical network design is possible by reducing the number of wavelengths according to the application.

An embodiment of the present invention is shown in FIG. It is an example of the high-definition optical local network which can be used when having a high-definition camera and a high-definition display at four locations or having only one of them. This optical local network is realized by using the optical network interface box ONIB11 of the present invention as shown in FIGS. 8 and 9 as an interface to the optical network, and connecting the optical hub 10 with 4 inputs and 4 outputs for optical fiber connection. .
Each of the four terminals is composed of a high-definition camera and a high-definition display connected to a personal computer PC, and ONIB. The video of the high-definition camera of the terminal a can be simultaneously transmitted to the other three high-definition displays. This is realized by multicast distribution by the above method (1). In this example, the wavelengths of the light sources of the four terminals each have four wavelengths, and are configured to be selectable depending on the usage method and time synchronization. This can be conveniently used when delivering a lecture at one place to many places as distance learning. In addition, it can be distributed to specialists at other multiple locations such as special medical sites and used for group medical care. When the specialist at the point of the terminal c requests mutual communication with the medical site of the terminal a, mutual communication is possible by switching the setting. As described above, the present invention has the feature that it can cope with a plurality of uses by switching the setting by using ONIB having the same configuration, and can be conveniently used for distance education, cyber hospital, and the like.
In addition, when monitoring images from a plurality of high-definition cameras on a single high-definition display, it can be realized by switching the settings in time synchronization. this is,
It can be used when monitoring on a high-definition screen for crime prevention and disaster prevention. In the above description, it has been explained that communication can be performed centering on the HDV image of the high-definition camera, but of course, it can also be used for communication of a normal DV image or the like.

    As can be understood from the above-described embodiments, the present invention can transmit images taken by a high-definition camera at a plurality of points to a high-definition display at a plurality of other points. It is characterized by. Its features may be useful for future remote medical treatments such as cyber hospitals, viewing event information remotely, remote sales of new cars, and distance learning.

Ethernet configuration diagram using conventional UTP cable connection between PCs Ethernet configuration diagram using conventional UTP cable and optical fiber connection between PCs In FIG. 2, a configuration diagram in which the bidirectional optical fiber connection is connected in only one direction. Configuration diagram in which an optical splitter is connected to the optical fiber of the output of the sending personal computer, and the optical input of the sending personal computer is cut off In FIG. 4, an optical network interface configuration diagram in which the output of the optical splitter is connected to the optical input of the transmitting personal computer side Optical network interface configuration diagram when distributed from one PC connected with the optical hub device of the present invention and received by other PCs Optical network interface configuration diagram when transmitting and receiving from each terminal PC in an optical network interface configuration to which the optical hub device of the present invention is connected (A) Optical network interface configuration diagram for performing only transmission according to the present invention (B) Optical network interface configuration diagram for transmitting and receiving according to the present invention Configuration of Optical Wavelength Multiplexing Select Switch, Electro-Optical (E / O) Conversion Unit, Photoelectric (O / E) Conversion Unit, and Optical-Electric Conversion Unit Having Optical Demultiplexing (DEMUX) Multiplexing (MUX) Figure Examples of the present invention

Explanation of symbols

PCa, PCb, PCc, PCd Personal computer 1, a1, b1, c1, 12 Ethernet electrical cable (such as UTP)
2 Network interface card (NIC)
3 Personal computer (PC)
4 Media access control unit (MAC)
5 Physical layer signal converter (PHY)
6 Media access unit (MAU) and RJ-45 connector FLP Fast link pulls a ', b', c 'Output terminals a, b, c of optical splitter and optical hub Input terminals a2, b2, c2 of optical hub device Light source drive Electric signal LVDS
a3, b3, c3 Light reception electric signal LVDS
af, a3f Light source drive electrical signal LVDS feedback signals a4, b4, c4 Electro-optical converter (E / O)
a5, b5, c5 photoelectric conversion part (O / E)
a6, b6, c6 Output optical fiber a7, b7, c7 Input optical fiber 11 Optical fiber connection a8, b8, c8 Physical layer signal converter (PHY)
s1 2 distributor s2 2x1 switch s3 1x3 switch s4 1x3 switch m1 optical multiplexer (MUX) d1 optical demultiplexer (DEMUX)
7 LVDS electrical signal for light source drive 8 Optical fiber 9 Optical splitter 10 Optical hub a, b, c Optical splitter / optical hub input a ′, b ′, c ′ Optical splitter / optical hub output FLPa, FLPb, FLPc Each PCa, Fast link pulse from PCb, PCc 11 Optical network interface box (ONIB)
13 Optical fiber connection network

Claims (4)

In a network interface that converts Ethernet electrical signals to light and transmits and receives between computers at multiple points, an optical hub device that outputs signals from each input equally to all multiple outputs in a multi-input and multi-output optical circuit In an optical network in which the optical output from the multipoint is connected to the input of the optical hub device and the output of the optical hub device is connected to the input of the network interface of the multipoint, one output of the optical hub device is distributed Optical network interface configuration characterized in that broadcast distribution and multicast distribution are performed by connecting to the input of the network interface In order to convert the physical layer specification of the Ethernet electrical signal into light, the electrical output of the physical layer circuit for converting into the physical layer specification of light is divided into two, and the LD light source is modulated by the one electrical output. An optical Ethernet output signal, and the other electrical output is connected to an input of a physical layer circuit to perform broadcast distribution or multicast distribution through the optical network without connecting the optical input. Interface configuration 3. The signal according to claim 2, wherein the wavelength-multiplexed LD light source is configured to select and modulate a wavelength, and a signal obtained by selecting and modulating a specific wavelength from a terminal having a network interface having the same configuration at another point. In the configuration of an optical network connected to the optical input through an optical network having one optical hub device, when light having a mixed wavelength from each point arrives at the optical input, to connect to a specific point At the same time, the electrical signal receiving the light wavelength at a specific point is selectively connected to the input of the physical layer, and at the same time, the circuit connecting the output from the physical layer to the input is disconnected by an electrical switch. Optical network interface configuration characterized by connecting Ethernet line to other points 4. The configuration for modulating the wavelength of the LD light source according to claim 3, wherein the light source is forcibly turned off and the light output is not forcibly output by an instruction input from the outside even when a modulation signal is input. Optical network interface configuration characterized by having a function of switching on operation to emit light, and a function of notifying the outside of a signal notifying the reception of light when a specific optical wavelength is received

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