JP3320571B2 - Node device and network system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a node device and a network system, and is applicable to, for example, a high-speed multi-hop network system for performing packet communication, an optical network system, and the like.

[0002]

2. Description of the Related Art In recent years, a multi-hop network system has attracted attention as an optical network system for packet communication suitable for high speed and large scale.

[0003] Here, multihop Pune Tsu network system A, there are a few <br/> group of nodes that can be transferred in one hop within a group, the transfer outside the group, through a number of times the relay node (1 This is a system in which two relays are performed two times, two relays are three hops, and so on.

As such a network system, for example, there has been a network system as shown in FIGS. Reference: IEEE INFOCOM'9
2, 9B. 3.1-9B3.10, "Virtual
Topologies for WDM Stars
LANs-The Regular Structural
es Approach. "

FIGS. 2 and 3 respectively show FIG. 3 and FIG.
FIG. 7 is an explanatory diagram of the system described in FIG. 6. In these systems, a system in which all nodes are connected by one star coupler is adopted as a node connection system. Wavelength allocation of these systems, a method for allocating a transmission wavelength to each path is adopted.

The logical configuration of the network system shown in FIG. 2 is a shuffle (FIG. 2A) , which constitutes a multi-hop network system. FIG.
The logical configuration of the network system shown in FIG. 1 is a lattice type network (FIG. 3A) , and constitutes a multi-hop network system.

Further, in the of these systems, as the addressing scheme of the packet (scheme which defines the destination of the packet), a method of transmitting a wavelength corresponding to each packet to its destination is employed.

[0008]

However, in the above-mentioned conventional system, since wavelengths are allocated only for one-hop transmission, when relaying, a packet is received and temporarily taken into an electric signal buffer. Since the relay is performed after analyzing the packet header, there is a problem that the relay takes a long time.

In other words, in addition to the transfer information, the information of the relay process must be transferred, so that there is a problem that the transfer efficiency is reduced. In addition, since a preamble (data containing a clock component) is transferred before packet transfer in order to synchronize clocks, header analysis is performed after synchronization, so that there is a problem in that relay processing takes time. .

[0010] In view of the above, there is a demand for providing a node device and a network system that can transfer signals between node devices at a higher speed than before.

[0011]

A node device according to the present invention and
The network system may have characteristics or
Whether to provide the characteristics that define the relay node independently and relay
Each node device determines whether or not the header of the received signal
This is made possible without performing analysis.

[0012]

According to the present invention, a characteristic indicating the necessity of relaying or
Whether to relay based on the characteristics that define the relay node
Since the determination is made, it is not necessary to provide an address in the header part of the transmission signal, information necessary for transfer other than data can be reduced , and transfer efficiency can be improved.

[0013]

Next, a preferred embodiment of the present invention will be described with reference to the drawings. "First Embodiment": In the first embodiment, in a lattice type network system, optical transmission using a subcarrier multiplexing method (SCM: electric frequency multiplexing method) is performed, and several lightwaves existing in one wavelength of light are transmitted. The addressing of the packet is performed by using the electric frequency of (1).

[0014] With such a configuration, it is not necessary to provide an address in a header portion of each packet, it is possible to reduce the information required to transfer the non-data, so that better transfer efficiency of the transfer information (information / data transfer) Can be . Moreover, the frequency of the received signal, the reception is intended by relaying decisions Unisuru.

[Node Connection Configuration] First, the configuration of the lattice network system (4 × 4 network) of the first embodiment will be described. FIG. 4 is a diagram showing a logical node arrangement and physical node connections of this network. As in FIG. 4, the logical, <br/> node 100 of the plurality (16) are arranged in a grid, not have each of the nodes
Re or of belonging to the row and column groups.

[0016] Physically, all of Roh in one group
Over de is Ru Tei is connected in a star shape by star coupler 101. Each node is connected to a row star coupler and a column star coupler, respectively.

[Allocation of Wavelengths] Next , allocation of wavelengths and electric frequencies in the lattice network system of the first embodiment will be described. Optical wavelength (transmission wavelength) (no collision signal) that can be parallel transfer so Ru allocation <br/>. Each node in the group is connected via a star coupler
Since the subsequent transmission paths are the same, different wavelengths are assigned to avoid signal collision.

Since transmission paths are different for different groups,
The same combination of wavelengths may be assigned to different groups . FIG. 5 shows an example of optical wavelength assignment. λx is the light wavelength.

The electric frequency is allocated within the optical wavelength band. This frequency indicates the address of the destination node . Row <br/> direction frequency F1 to F4, assigned the frequency F1 to F4 in a column direction, the destination address is a two-dimensional array (row direction frequency,
Column direction frequency). Also, F0 is assigned as the frequency indicating the relay. Therefore, the frequencies are shown in a three-dimensional array (frequency in the row direction, frequency in the column direction, relay frequency).

[Internal Configuration of Node] Next, the internal configuration of a node in the lattice network system of the first embodiment will be described. FIG. 1 is an internal configuration diagram of this node.

First, the row side will be described. The receiving unit is an optical input terminal 401, a coupler 402, an optical wavelength filter 403 to
405, and optical / electrical converters (O / E) 406-408.

The packet processing unit comprises electric frequency filters 409 to 417 assigned to the own address, a frequency judgment unit 418, and a packet generation / disassembly unit 419. The transmission unit is a frequency converter (FMx to z) 4
20 to 422, a frequency multiplexer (Max) 423, switches (SW) 424 and 425, a laser diode (LD) 426, and an output terminal 427.

The configuration on the column side is the same as that on the row side. That is, the receiving unit includes the optical input terminal 501, the coupler 502,
Optical wavelength filters 503 to 505, an optical / electrical converter (O /
E) 506-508.

The packet processing unit comprises electric frequency filters 509 to 517 assigned to the own address, a frequency judgment unit 518, and a packet generation / disassembly unit 519. The transmission unit is a frequency converter (FMx to z) 5
20 to 522, a frequency multiplexer (Max) 523, switches (SW) 524 and 525, a laser diode (LD) 526, and an output terminal 527.

Further, when relaying line side input, since sent from the row side to the column side, the switch (SW) 424 is Ru Tei is connected to a switch (SW) 525. In the case of the column side input, since the data is sent from the column side to the row side, the switch (SW)
524 Ru Tei is connected to a switch (SW) 425.

"Packet Structure": Next, a first embodiment
Structure of Packets in Grid Network System
Will be described. Figure 6 shows this grid-type network system.
Shows the structure of the packet in the system. PaK
The preamble and the beginning of the data for synchronization
It consists of a frame bit and information dataAnd
You.

[Operation]: (Transfer operation between nodes):
The transfer operation between nodes will be described.

In FIG. 4, each optical signal (wavelength) output from each node 100 in the same group is multiplexed by the star coupler 101 and distributed to each node in the same group. In other words, each node of each node in the same group
All the optical signals transmitted by the card are received. At this time, even if the destination (electrical frequency) is the same, the signals do not collide because the wavelengths of light are different.

(Operation in Node) Next, the operation in the node will be described.

((Transmission operation)): FIGS. 1, 5, and 7
The transmission operation will be described with reference to FIG. Since the row side and the column side have the same operation , the transmission operation to the row side will be described.

The signal (packet) formed by the packet generation / decomposition unit 419 is transmitted to the frequency modulators 420 to 420 according to the destination.
Modulated at 422, multiplexed at the frequency multiplexer 423, and assigned to the own node by the laser diode LD426.
The signal is converted into an optical signal having a certain wavelength, and output from the output terminal 427.

[0032] Here, the optical signals becomes what SCM signal is intensity-modulated by the laser diode LD.
FIG. 7 shows this state. That is, the frequency F0,
The signals of F1 and F2 are multiplexed to obtain an SCM signal. laser
The diode LD is intensity-modulated according to the SCM signal.
The obtained optical signal of the wavelength λ1 is obtained. In this example, the address (F
1, F2) node 2-hop (located relayed to the) is to send packets at. Here, in the transmission operation described above, the switch (SW) 425 is connected to the frequency multiplexer 423.

((Reception Operation)) Next, the reception operation will be described with reference to FIG. Since the row side and column side have the same operation,
The receiving operation from the row side will be described.

The optical signal received from the input terminal 401 is distributed to each optical filter 403-405 by the coupler 402, the optical filter is set in its own filter to select a light wavelength Ru Tei, optical / electrical (O / E) Converters 406-40
8 converts the optical signal passing through the filter into an electric signal.

This electric signal is supplied to a filter (Filter x, Filter y) set to its own address,
Filter set to the relay frequency (Filter z)
Is filtered by

[0036] ((frequency determining section)): 8 whether the frequency determination (own node addressed to the frequency determination unit 418,518
Ru Description Zudea showing the operation of Kano determination).

In FIG . 8, in the row side determination (S1), filters x (Filterx) 409, 412,
415 determines whether the packet has passed (S2), to be appropriate to discard the packet (S5). If applicable, then the electric frequency filter z (Filter z) 41
It is determined whether the packet has passed through 1, 414 , 417 (S3). Receiving processes the packet if Re pass Shinake
( Receive the output of the filter x ) (S6). fill
If the signal passes through the filter z, the relay processing is performed ( the output of the filter y is relayed ) (S4).

In FIG. 8, the column side determination (S1
In 0), the filter y (Filter y) 51
It is determined whether the packet has passed 0 , 513 , 516 (S11). If not, the packet is discarded (S15). If applicable, filter z (Filter
z) Whether the packet has passed 511 , 514 , 517
It is determined whether or not it is (S12). If it has passed, relay processing is performed ( output of filters x509, 513, and 515 is relayed ) (S13). If the signal does not pass through the filter z, reception processing is performed ( filters y510, 513, and 5).
16 is received ) (S16).

The packet from the row side (or column side)
When receiving (self addressed packet), the row side (or column
Side), and in the case of relaying, the data is passed to the column-side transmission device (or row-side transmission device) by a switch.

That is, in the case of reception, the packet is passed to the packet generation / decomposition units 419 and 519, where the packet is decomposed . In the case of relaying, the switches 424 and 524 are switched to the row side.
(Or from the line side) . Here, in the case of relay, since only one packet can be transmitted, it is omitted from the block diagram of FIG. 1, but is selected by a competing circuit. Packets that were lost in the conflict, this device Ru is discarded because it does not have the buffer of the relay. (Effects of First Embodiment): According to the lattice network system of the first embodiment described above, SC
M (electric frequency multiplexing) is performed, and the reception and relay processing is performed using the electric frequency as the destination address of the packet. Therefore, there is no header part for performing the packet processing for determining the destination and the relay . Therefore, the packet length is shorter than before (the data portion is not changed), and the transfer efficiency is improved.

As a result, the signal transfer between the node devices can be performed at a higher speed than before.

(Other Embodiments) (1) By changing the configuration in the nodes (the number of transmitters, the number of receivers, the determination method, etc.) of the grid type network system of the first embodiment, It can be applied to the illustrated shufflenet.

(2) Furthermore, although each group assigns wavelengths using the same combination of optical wavelengths, optical wavelengths may be assigned so that all nodes transmit different wavelengths. In this case, one star coupler may be provided throughout the entire system .

The "second embodiment": distinguishing for the second embodiment to solve the conventional problem, in application to a multi-hop network system, by changing the frequency of the electrical during optical signal transmission, the reception and relay However, in the case of relaying, the relay is performed without taking in the buffer by judging the frequency.

With this configuration, when a packet is converted from light to electricity, relaying can be determined at the electric frequency without analyzing the header, so that high-speed relay processing can be performed.

[0046] As a specific example, in a multi-hop network, (relay once) 2-hop transfer is also described an embodiment of a lattice-type network for. In the following description, the lattice type
The network system has a 4 × 4 configuration.

[Node Connection Configuration] First, the configuration of the system (4 × 4 network) of the second embodiment will be described . Logical node arrangement and physical node connection network of the second embodiment are also intended to be represented by Figure 4 according to the first embodiment described above. That is, each node is divided into a row-side group and a column-side group and arranged in a lattice. One node is always included in any one row-side group and any one column-side group.

[Wavelength Assignment] Next, assignment of wavelengths and electric frequencies in the system of the second embodiment will be described. Optical wavelengths (transmission wavelengths) are allocated so that parallel transfer is possible (no signal collision ) . In the group
The transmission wavelength of each node is assigned a different wavelength to avoid signal collision. In different groups, it may be assigned the same combination of wavelengths.

FIG. 9 shows an example of assignment of optical wavelengths (transmission wavelengths) . Note that λx (x = 1 to 4) is the light wavelength. In FIG. 9, F0 is assigned to the electric frequency in the case of one-hop transfer. In other words, the frequency F0
Represents one-hop transfer. For two-hop forwarding, to indicate which node is to relay assigns a reception frequency. FIG. 9 shows an example of electric frequency allocation. Fx (x = 1 to 4) is the electric frequency. In other words, frequency F1~F4 within the Group
Which node relays. "Configuration in Node": Next, the internal configuration of the node of the second embodiment will be described. FIG. 10 is an internal configuration diagram of the node according to the second embodiment.

Referring to FIG . 10, first , the configuration on the row side will be described. The receiving unit includes an optical input terminal 201, a coupler (1 ×
3) 202, an optical wavelength filter 203-205, coupler (1 × 2) 206 - 208, the optical / electrical converter (O / E variant
And a changer) 209 to 211 Metropolitan.

The packet processing unit includes electric frequency filters (Fx: x represents an assigned frequency indicating that the own node performs a relay operation ) 212 to 214, and a frequency determination unit 215.
And a packet generation / disassembly unit 216.

The relay section is an optical fiber delay line 219-22.
1. Optical switch (SW) 222, O / E converter 223
, A frequency modulator (F0) 224, and a laser diode (LDx: x represents a transmission wavelength from the own node ) 225
It is composed of

The transmitting section includes a variable frequency modulator (F0 to F
4) 217, a laser diode LDx218, a coupler (2 × 1) 226, and an output terminal 227.

The column side has the same configuration as the row side described above. That is, the receiving unit on the column side is the optical input terminal 30
1, coupler (1 × 3) 302, optical wavelength filter 303 to
305, couplers (1 × 2) 306 to 308, and optical / electrical (O / E) converters 309 to 311.

The packet processing unit includes electric frequency filters (Fx: x represents a self-assigned frequency) 312 to 314.
, A frequency determination unit 315, and a packet generation / decomposition unit 316
It is composed of

The relay units are optical fiber delay lines 319 to 32.
1. Optical switch (SW) 322, O / E converter 323
, A frequency modulator (F0) 324, and a laser diode (LDx: x represents its own transmission wavelength) 325.

The transmitting section includes a variable frequency modulator (F0 to F
4) 317, a laser diode LDx318, a coupler (2 × 1) 326, and an output terminal 327.

[Operation]: (Transfer operation between nodes):
The transfer operation between nodes will be described. 4, each optical signal (wavelength) output from a node 100 in the same group is multiplexed by a star coupler 101 and distributed to each node in the same group. That is, each node receives all the optical signals transmitted by the nodes in the same group. At this time , even if the electric frequency is the same, the signals do not collide because the wavelengths of light are different.

(Operation in Node): Next, the operation in the node will be described.

[0060] ((transmission operation)): the transmission operation will be described with reference to FIG. 10. Since the row side and the column side perform the same transmission operation , the row side transmission operation will be described here.

The signal (packet) formed by the packet generation / decomposition unit 216 is modulated by the variable frequency modulator 217 to the frequency F0 in the case of one-hop transmission, and is modulated by two-hop transmission .
In the case ( when relaying ) , at which node to relay,
A frequency is selected (F1 to F4) and frequency modulation is performed.
This modulated electrical signal of the laser diode (LDx)
At 218, it is converted into an optical signal. The output includes an optical signal coming from the relay unit, and is output from the output terminal 227 via the coupler 226.

Here, the transmitting unit and the relay unit do not output simultaneously. Although not shown in FIG. 10, selection control is performed on the self-originated packet and the relay packet.

((Reception Operation)) Next, the reception operation will be described with reference to FIG. Is the same reception dynamic <br/> operates in a row side and the column side, will be described here the receiving operation of the row side.

The optical signal received from the input terminal 201 is distributed to each of the optical filters 203 to 205 by a coupler 202, and each optical filter selects a set optical wavelength, and
The signals are distributed to the receiving unit and the relay unit via 6 to 208. The optical signals distributed to the receivers are O / E converters 209 to 211
Is converted into an electric signal.

These electric signals are distributed to electric frequency filters 212 to 214 for relay processing and a packet generation / decomposition unit 216. The packet generation / disassembly unit 216 discards packets other than those addressed to the own node. Also described below
The relay determination process, even if the determination that relaying,
The packet arriving at the packet generation / decomposition unit 216 is discarded.

((Relay processing)): In FIG.
The operation of the relay process will be described. Electric frequency filter 212
When the frequency assigned to the own node is detected by the to -214, the information is passed to the frequency determination unit 215, and the frequency determination unit 215 competes for which one of the electric frequency filters 212 to 214 to relay the packet. , And whether a 1-hop packet is being transferred (self
To determine whether the packet transmission), the optical switch (SW) 2
Switch 22.

[0067] The optical switch (SW) 222 is, usually,
The output side is not connected. That is, it is configured to be discarded. Switch to the output side only when relaying. The optical fiber delay lines 219 to 221 delay the relay determination time and the switching time of the optical switch ( SW ) 222. Output from the optical switch ( SW ) 222
The relayed signal is converted into an electric signal by the O / E converter 223, and the frequency (F
0) , is converted into an optical signal transmitted from the own node by the laser diode ( LDx ) 225, passes through the coupler 326, and is output from the output terminal 327.

((Transfer)) Next, a transfer example will be described with reference to FIG . In FIG. 11, (1) is one-hop transfer from node 1 to node 3. Node 1 is shown in FIG.
The variable frequency modulator 217 modulates the packet at the frequency F0 and outputs it (signals of F0 and λ1). The node 3 receives the signal and outputs the signal to the electric frequency filter 21 related to the wavelength λ1.
It can not detect a signal in 2, the packet generating decomposition unit 2
At 16, the signal is analyzed and if it is addressed to the own node, it is stored in the reception buffer.

FIG. 11B shows a case where the node 1
6 is a two-hop transfer. Since node 1 transmits a packet to node 4 relays, allocation periphery of the variable frequency modulator 217 frequency F4 (node 4 packets of 11
(Wave number) and output (signal of F4, λ1).

The node 4 receives this signal and changes the wavelength to the wavelength λ1.
Such an electric frequency filter (pass frequency is F4 band) 212
When the signal is detected by the switch, the optical switch SW222 is switched. At this time, the same packet arriving at the packet generation / decomposition unit 216 is discarded. Optical switch (SW) 222
Is output from the frequency F0 for one hop and the
The signal is converted to the transmission wavelength λ4 (signals of F0 and λ4) and output from the output terminal 327.

[0071] Node 16 receives this signal (F0, .lambda.4), can not detect a signal at electrical frequency filter 3 12 according to the wavelength .lambda.4, analyzes the signal in the packet generating decomposition unit 3 16, if the own node addressed This is stored in the reception buffer.

(Effect of the Second Embodiment) According to the second embodiment, the relay node information is transferred by modulating the electric frequency in the transmission light wavelength, so that the header analysis by the relay is eliminated. The packet can be relayed without storing the packet in the electric buffer, and the relay process can be performed at high speed.

Therefore, the signal transfer between the node devices can be performed at a higher speed than in the related art.

(Other Embodiments) (3) In the above-described second embodiment, which relates to a lattice network, the configuration in a node (the number of transmitters and the number of receivers, etc.) is changed. Thus, the present invention can be applied to other multi-hop networks requiring relay.

(4) In the above-described embodiment, each group assigns a wavelength using the same combination of optical wavelengths. However, an optical wavelength may be assigned so that all nodes transmit different wavelengths. good. In this case, the star coupler is 1
One is good.

(5) Further, in the above-described embodiment, the electric signal is converted into the optical signal allocated so that the wavelength is different from the optical signal of the other node. It is also effective to convert the signal to a modulation mode signal, convert to a modulation mode signal, convert to an amplitude signal, or convert to a polarization signal.

(6) Further, in the relay processing, an electric frequency is allocated, and the relay processing is determined based on the frequency. In addition, any one of power, amplitude, phase, modulation mode, and polarization is used. It is also effective to judge the relay processing on the condition.

(7) In the above-described embodiment, conversion between electricity and light is performed. However, in addition to this, a system using only electric signals, a system performing conversion between electricity and sound, The present invention can also be applied to a system that performs conversion between a signal and a wireless signal.

(8) The present invention is not limited to packet transfer, but is also effective when applied to cell transfer, frame transfer, block transfer, and the like.

[0080]

As described above, according to the present invention, the relay
Based on the characteristics that indicate the need for
To determine whether to relay based on the
It is not necessary to provide an address in the
Information required for data transfer, improving transfer efficiency.
Can be made.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a lattice network system according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a conventional network system.

FIG. 3 is an explanatory diagram of a conventional network system.

FIG. 4 is a diagram showing a logical node arrangement and physical node connections of the grid type network system of the first embodiment.

FIG. 5 is a diagram illustrating an example of assignment of optical wavelengths according to the first embodiment.

FIG. 6 is a configuration diagram of a packet according to the first embodiment.

FIG. 7 is an explanatory diagram of a transmission signal according to the first embodiment.

FIG. 8 is an operation flowchart of the frequency determination unit of the first embodiment.

FIG. 9 is an explanatory diagram of assignment of optical wavelengths and electric frequencies according to the second embodiment.

FIG. 10 is an internal functional configuration diagram of a node according to a second embodiment.

FIG. 11 is an explanatory diagram of a transfer example according to the second embodiment.

[Explanation of symbols]

1 to 16, 100... Nodes, 201, 301, 401,
501 ... optical input terminal, 202, 302, 402, 502
... Couplers, 203-205, 303-305, 403-
405, 503 to 505 ... optical wavelength filters, 206 to 2
08, 226, 306 to 308, 326 ... coupler, 20
9 to 211, 223, 309 to 311, 406 to 40
8, 506 to 508: optical / electrical conversion (O / E) device, 21
2-214, 312-314, 409-417, 509
-517: electric frequency filter, 215, 315, 41
8, 518... Frequency determination units, 216, 316, 419,
519: Packet generation / decomposition unit, 217, 317 ... Variable frequency modulator, 218, 225, 318, 325, 42
6, 526 ... Laser diode LDx, 219-22
1, 319 to 321: optical fiber delay line, 222, 32
2. Optical switches SW, 224, 324, 420 to 42
2, 520 to 522... Frequency modulators, 227, 327,
427, 527 ... output terminals, 423, 523 ... frequency multiplexers, 424, 425, 524, 525 ... switches.

Continuation of the front page (72) Inventor Tetsuya Akahoshi 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (56) References JP-A-5-304504 (JP, A) JP-A-5-304 167583 (JP, A) JP-A-8-84147 (JP, A) JP-A-7-202846 (JP, A) JP-A-7-99495 (JP, A) JP-A-6-318947 (JP, A) JP-A-8-107394 (JP, A) JP-A-8-107393 (JP, A) JP-A-7-99496 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04L 12/28 H04L 12/44-12/46 H04L 12/00-12/26 H04L 12/50-12/66

Claims (5)

(57) [Claims] A first star coupler connected to the first star coupler;
And another node device connected to the first star coupler.
The first group together with the second star cap.
Form a second group together with other node devices connected to the
The first group and the second group to which the own node device belongs.
The wavelength that is different from the other node devices
Node device assigned to the transmission wavelength from
Te, all nodes of the network to which the node device belongs instrumentation
In the first group as destination address information.
The first frequency for identifying the node device and the
A second cycle for identifying the node device in the two groups
Wave number and the entire network
A third frequency that indicates whether a common relay is needed for
It is defined as the destination address information to the other node device of the transmission destination.
The assigned first frequency and the assigned second frequency
And a third frequency indicating whether relaying is necessary.
The transmission signal is subcarrier multiplexed, and this multiplexed signal is
To an optical transmission signal of the transmission wavelength assigned to the
In other words, other nodes in the first group or the second group
Transmitting means for transmitting to the node device, and another node device of the first group or the second group.
Receives optical transmission signals transmitted from the device and converts them into electrical signals
Receiving preprocessing means, and the first signal in the electric signal obtained by the receiving preprocessing means.
Filter means for extracting the component of the frequency to the third frequency
And based on the extraction result by the filter means,
To determine if it is necessary to relay to another node device, and
The reception processing for the electric signal obtained by the reception pre-processing means
And relaying to another node device is required
The transmission means obtains the pre-reception processing means.
The electric signal is re-converted into an optical transmission signal, and the second group
Alternatively, a reception to be transmitted to another node device of the first group is performed.
A node device comprising: a communication relay unit . 2. The first and second star couplers are connected to each other.
And another node device connected to the first star coupler.
The first group together with the second star cap.
Form a second group together with other node devices connected to the
The first group and the second group to which the own node device belongs.
The optical characteristics that are different from the other node devices
Node equipment assigned to the transmission light characteristics from the
And all node devices of the network to which the node device belongs.
Stipulates that the node will be the node that performs the relay operation.
Are assigned to the first relay characteristic
A second indicating that a common relay is not required for the entire network
The relay characteristic of the second relay characteristic, which indicates that relaying is unnecessary, or the relay operation
The other node devices assigned to the
1 to have one of the relay characteristics and
Optical signals that have transmission optical characteristics specific to
Transmitting means for converting the transmission signal and transmitting the converted signal, and another node device of the first group or the second group.
The optical signal transmitted from the device is collected according to the transmitted optical characteristics.
And the relay of the optical signal extracted by the reception preprocessing means is required.
In this case, the first relay characteristic of the optical signal is changed to the second relay characteristic.
Converted to relay characteristics, the second group or the first group
The relay transmitting means for transmitting to another node device in the loop and the optical signal extracted by the reception pre-processing means,
Whether the assigned first relay characteristic exists
The relay characteristic discriminating means for discriminating at least the relay characteristic discriminating means and the relay characteristic discriminating means.
If it is determined that the first relay characteristic does not exist, the receiving
The received optical signal is converted according to the destination information of the converted electrical signal.
Of the signal content of the
When it is determined that the first relay characteristic described above exists.
In the above, the relay permission / non-permission judgment to make the relay transmitting means operate effectively
Node device characterized by comprising a means. 3. The transmission light characteristic for distinguishing a transmission source node.
3. The node device according to claim 2, wherein: is any one of wavelength, power, phase, modulation mode, and polarization . 4. The method according to claim 1, wherein the first and second relay characteristics are optical signal
Frequency of the electrical signal, power of the optical signal,
Depending on the phase of the signal, the modulation mode, or the polarization of the optical signal,
4. The node device according to claim 2, wherein said node device has different transmission light characteristics . 5. A system comprising the node device according to claim 1, wherein a plurality of node devices arranged in a grid form each row,
A plurality of the first and second groups are provided for each row.
A network system configured to transmit a signal between a plurality of node devices.