JPH08274811A - Grid type network system and node connector - Google Patents

Abstract

PURPOSE: To extend the scale of the grid type network system by allocating a different packet transmission time slot for each column coordinate of each row group and each row coordinate of each column group. CONSTITUTION: A different packet transmission wavelength λn is allocated for each row group RGn (n=1, 2, 3). A different time slot Tn is allocated for each column coordinate in each row group RGn. The different packet transmission wavelength λn is allocated for each column group CGn (n=1, 2, 3). The different time slot Tn is allocated for each column coordinate in each column group CGn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lattice type network system for packet communication. The present invention also relates to a node connecting device suitable for constructing this system.

[0002]

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

[0003] The grid type network system groups a plurality of nodes arranged in a grid in each row and each column, transfers a packet in one hop between two arbitrary nodes belonging to the same group, and transfers the packets in different groups. Is a system configured to transfer a packet in two hops between any two nodes belonging to the group via nodes located at the intersections of the two groups to which they belong.

By the way, when constructing a network system, it is necessary to consider facilitation of network reconfiguration.

In a lattice type network system, in order to facilitate network reconfiguration, for example, all nodes are connected by one packet transmission line,
It is conceivable to transfer packets between nodes using different wavelengths in a shared packet transmission line.

According to such a configuration, by changing the wavelength used for packet transfer, it is possible to easily reconfigure the network without changing the physical connection of the transmission path.

Further, according to such a configuration, even if all the nodes share the packet transmission path, the wavelengths used for packet transfer are set to be different from each other.
It is possible to avoid collision of packets output from each node.

As a technique for avoiding packet collision by using different wavelengths in this way, conventionally, FIG.
The technique described in (1) is known.

Reference: “Virtual Topologies for WDM Sta
rt LANs-The Regular Structures Approach "Bo Li and
Aura Ganz IEEE INFOCOM'92 9B.3.1-9B.3.10 The technology described in this document outputs data from each node by assigning different packet transmission wavelengths to multiple nodes connected to one packet transmission path. It avoids packet collisions.

[0010]

However, such a configuration has a problem that it is difficult to increase the scale in terms of wavelength multiplicity and the amount of hardware of the node. This will be described below.

In the case of the above configuration, considering a N × N (N is an integer) lattice type network system, N × N packet transmission wavelengths are required. However, the number of wavelengths that can be multiplexed by the existing optical transmission technology is about 16. Therefore,
With the above configuration, only a 4 × 4 small-scale grid network system can be constructed.

Further, in the case of the above configuration, each node has at least (N-1) row side and (N-1) column side total of 2 nodes.
It is necessary to provide (N-1) wavelength filters. This is because each node needs to receive a packet from another node in the group to which the node belongs. As a result, in the above configuration, if the scale of the lattice type network system is increased, the amount of hardware of each node increases, which makes it difficult to increase the scale.

[0013]

In order to solve the above-mentioned problems, the lattice type network system according to claim 1 assigns different packet transmission frequencies to each row group and each column group, and to each column coordinate of each row group and A different packet transmission time slot is assigned to each row coordinate of each column group.

The node connection device according to claim 8 further comprises means for frequency-multiplexing packet transmission signals output from a plurality of nodes, means for separating the frequency-multiplexed output for each frequency, and each frequency separation output. A means for distributing is provided.

[0015]

In the lattice type network system according to claim 1, when the row side terminals of a plurality of nodes are connected by one star coupler, packet transmission signals output from two nodes belonging to different row groups are star couplers. Frequency multiplexed above. Also, packet transmission signals output from two nodes belonging to the same group are time-division multiplexed on the star coupler.

Thus, even if the above-mentioned connection is made, it is possible to prevent the collision of packets output from a plurality of nodes. This is the same on the row side.

Therefore, in the N × N lattice type network system, if the same packet transmission wavelength is used on the row side and the column side, the multiplicity of the packet transmission wavelength can be set to N, and if different packet transmission wavelengths are used. , 2N. Further, in any case, the number of wavelength filters provided in each node can be two.

As a result, it is possible to reduce the wavelength multiplicity and the amount of hardware of each node, so that it is possible to increase the scale of the lattice type network system.

According to another aspect of the node connecting apparatus of the present invention, the packet transmission signals output from the respective nodes are frequency-multiplexed and then separated for each frequency. Each separated output is appropriately distributed to a plurality of nodes.

Therefore, if this node connecting device is used to connect the nodes of the lattice type network system of claim 1, the wavelength filters can be deleted from each node and the number of wavelength filters to be used is N or 2N.
Can be reduced to individual pieces. This can contribute to increasing the scale of the grid network system.

[0021]

Embodiments of the present invention will now be described in detail with reference to the drawings.

(1) One Embodiment One embodiment of the present invention will be described.

(1-1) Configuration of One Embodiment (1-1-1) Outline of Lattice Network System First, an outline of a lattice network system to which the present invention is applied will be described.

FIG. 2 is a diagram showing a logical arrangement of nodes in the lattice type network system.

As shown in the figure, in the grid type network system, a plurality of nodes 100 are arranged in a grid. In the figure, a 3 × 3 lattice type network system is shown as a representative. Each node 100 is grouped by each row and each column. RG1 to RG3 indicate row groups, and CG1 to CG3 indicate column groups.

A packet is transferred in one hop between two nodes belonging to the same group. For example, between the nodes with node numbers 1 and 3 belonging to the row group RG1,
The packet is transferred in one hop.

On the other hand, between two nodes belonging to different groups, packets are transferred in two hops via the nodes located at the intersections of the groups to which they belong. For example, between the nodes 100 of the node numbers 1 and 6 belonging to the row groups RG1 and RG2, the node number located at the intersection of the column group CG1 to which the node 100 of the node number 1 belongs and the row group RG2 to which the node 100 of the node number 6 belongs The packet is transferred via the node 100 of No. 4. The above is the outline of the lattice type network system.

(1-1-2) Outline of One Embodiment Next, an outline of one embodiment of the present invention will be described.

Conventionally, packet collision is prevented by wavelength multiplexing as described above. On the other hand, in this embodiment, packet collision is prevented by combining wavelength division multiplexing and time division multiplexing. Therefore, in this embodiment, packet transmission wavelengths and packet transmission time slots are allocated.

FIG. 1 is a diagram showing allocation of packet transmission wavelengths and packet transmission time slots in this embodiment. In this embodiment, the packet transmission wavelength and the packet transmission time slot are assigned separately to the row side and the column side. FIG. 1A shows row-side allocation, and FIG. 1B shows column-side allocation.

On the row side, as shown in FIG. 1A, a different packet transmission wavelength λn is assigned to each row group RGn (n = 1, 2, 3). In the figure, the case where the wavelengths λ1, λ2, λ3 are assigned to the row groups RG1, RG2, RG3 is shown as a representative.

A different packet transmission time slot Tn is assigned to each column coordinate of each row group RGn. In the figure, node 100 with node numbers 1, 4, and 7
Is allocated to the column coordinate where the node number is arranged, the time slot T1 is allocated to the column coordinate where the node 100 having the node numbers 2, 5 and 8 is arranged, and the node 100 having the node number 3, 6 and 9 is arranged. The case where the time slot T3 is assigned to the defined column coordinates is shown as a representative.

By assigning different packet transmission wavelengths λn to the respective row groups RGn, even if the row side terminals of all the nodes 100 are connected by one star coupler, two nodes belonging to different row groups RGn It is possible to prevent collision of packets output from 100.

Also, by assigning different packet transmission time slots Tn to the respective column coordinates of each row group RGn, it is possible to prevent the collision of the packets output from these three nodes 100.

Although detailed description is omitted, each column group CGn is also displayed on the column side as shown in FIG. 1B.
A different packet transmission wavelength λn is assigned to each column, and a different packet transmission time slot Tn is assigned to each row coordinate of each column group CGn.

(1-1-3) Physical Configuration of One Embodiment Next, the physical connection configuration of one embodiment will be described with reference to FIG.

FIG. 3 is a block diagram showing a physical connection configuration of the lattice type network system of this embodiment.

As shown in the figure, the lattice type network system of this embodiment has a plurality of nodes 100, a node connecting device 200, and an external light source device 300.

Here, the node 100 has functions such as packet transmission, reception, relay, and discard. The node connecting device 200 has a function of connecting a plurality of nodes 100. The external light source device 300 has a function of supplying a carrier signal (optical signal) for packet transmission to the plurality of nodes 100.

The node connecting device 200 is provided separately on the row side and the column side. This is because, in this embodiment, the same packet transmission wavelength λn and the same packet transmission time slot Tn are used on the row side and the column side as described above.
However, for simplification of the drawing, only one node connecting device 200 is shown in the drawing.

The external light source device 300 is also provided separately on the row side and the column side. However, in order to simplify the figure,
Only one external light source device 300 is shown.

(1-1-4) Configuration of Node Connection Device 200 of One Embodiment Next, the configuration of the node connection device 200 of one embodiment will be described.

In the lattice type network system of this embodiment, as the node connecting device 200, for example, a device composed of one star coupler can be used as in the conventional case. In other words, a device having only the wavelength multiplexing function can be used. However, in the case of this configuration, it is necessary to provide two wavelength filters in each node 100. Therefore, the present invention is directed to the node connection device 200.
In addition, a wavelength multiplexing function, a wavelength separation function, and a signal distribution function are provided.

According to such a configuration, each node 100
Is supplied with only the packet transmission signal output from the node 100 in the group to which the own node belongs. Accordingly, it is not necessary to provide wavelength filters in each node 100, and N wavelength filters may be provided in the node connection device 200, so that the number of wavelength filters can be reduced.

FIG. 4 shows the node connection device 20 of this embodiment.
It is a block diagram which shows the structure of 0. The illustrated node connection device 200 includes a star coupler 211 and a wavelength filter 22.
1, 222, 223 and star couplers 231, 232,
233 and an optical switch 241.

Here, the star coupler 211 has a function of wavelength-multiplexing the packet transmission signal (optical signal) output from each node 100. Wavelength filters 221, 22
Reference numerals 2 and 223 have a function of separating the wavelength-multiplexed output of the star coupler 211 for each wavelength λn. Star coupler 2
The 31, 32, 233 and the optical switch 241 have a function of distributing the wavelength separation outputs of the respective wavelength filters 231, 232, 233 to the nodes 100 of the corresponding group.

Here, the star couplers 231, 232, 2
33 is the corresponding wavelength filter 231, 232, 233
It has a function of branching the wavelength demultiplexed output of 3 by the number of nodes belonging to each group. The optical switch 241 has a function of distributing the branched outputs of the star couplers 231, 232, 233 to the nodes 100 of the corresponding group.

(1-1-5) Configuration of Node 100 of One Embodiment Next, the configuration of the node 100 of this embodiment will be described.

FIG. 5 is a block diagram showing the configuration of the node 100. The illustrated node 100 includes an optical / electrical converter (O / E) 111, 112 and a packet processing unit 121.
And time slot control units 131 and 132 and external modulators 141 and 142.

Here, the optical / electrical converter 111 has a function of converting the optical signal of the packet supplied from the node connection device 200 on the row side into an electric signal. Similarly, the optical / electrical converter 112 has a function of converting an optical signal of a packet supplied from the node connection device 200 on the column side into an electric signal. The packet processing unit 121 has a function of fetching, relaying, generating, discarding packets and the like.

The time slot control unit 131 has a function of supplying the electric signal of the packet generated by the packet processing unit 121 to the external modulator 141 at the column side packet transmission time slot Tn assigned to its own node. .
Similarly, the time slot control unit 131 converts the electrical signal of the packet generated by the packet processing unit 121 into the row side packet transmission time slot Tn assigned to the own node.
Therefore, it has a function of supplying to the external modulator 142.

The external modulator 141 is an electric signal supplied from the time slot control section 131 and uses the external light source device 30.
It has a function of modulating an optical signal supplied from 0. This modulated signal is supplied to the node connection device 200 on the column side. Similarly, the external modulator 142 is an electric signal supplied from the time slot control unit 132 and uses the external light source device 30.
It has a function of modulating an optical signal supplied from 0. This modulated signal is supplied to the node connection device 200 on the row side.

(1-1-6) External Light Source Device 3 of One Embodiment
Structure of 00 Next, the structure of the external light source device 300 of one embodiment will be described.

FIG. 6 shows the external light source device 300 of this embodiment.
FIG. 3 is a block diagram showing the configuration of FIG. Illustrated external light source device 3
00 is a light emitting diode (LD) 311, 312, 31
3, a star coupler 321, 322, 323, and an optical switch 331.

Here, the light emitting diodes 311, 312,
Reference numeral 313 has a function of outputting optical signals of wavelengths λ1, λ2, and λ3, respectively. Star coupler 321,322,3
23 is the corresponding light emitting diode 311, 312, 31
It has a function of branching the optical signal output from the optical path 3 into three. The optical switch 331 includes star couplers 321 and 32.
It has a function of distributing the branch outputs of 2,323 to each group.

(2-1) Operation of One Embodiment (2-1-1) Packet Transmission Operation in Lattice Network System First, the packet transmission operation in the lattice network system will be described with reference to FIG. This behavior is
It is divided into row-side operations and column-side operations.

First, the packet transmission operation on the row side will be described. In the time slot T1, as shown in FIG. 1A, the optical signals of wavelengths λ1, λ2, and λ3 are output from the row-side output terminals of the node 100 having the node numbers 1, 4, and 7, respectively. In the time slot T2, the node number 2
Optical signals of wavelengths λ1, λ2, and λ3 are output from the row-side output terminals of the nodes 5 and 8 respectively. Further, in the time slot T3, the node 1 of the node numbers 3, 6, 9
From the row side output terminals of 00, wavelengths λ1, λ2, λ3, respectively.
The optical signal of is output.

The optical signal of the wavelength λ1 is supplied to the row side input terminals of the nodes 100 of the node numbers 1, 2 and 3 included in the row group RG1 via the row side node connection device 200. The optical signal of the wavelength λ2 is transmitted to the node connection device 200 on the row side
Node number 4, which is included in the row group RG2 via
It is supplied to the row-side input terminals of the nodes 100 of Nos. 5 and 6. The optical signal having the wavelength λ3 is supplied to the row side input terminals of the nodes 100 of the node numbers 7, 8 and 9 included in the row group RG3 via the row side node connection device 200. The above is the packet transmission operation on the row side.

Next, the packet transmission operation on the column side will be described. In the time slot T1, as shown in FIG. 1B, optical signals of wavelengths λ1, λ2, λ3 are output from the column-side output terminals of the nodes 100 having node numbers 1, 2, and 3, respectively. In the time slot T2, the node numbers 4,
Optical signals of wavelengths λ1, λ2, and λ3 are output from the column-side output terminals of the nodes 5 and 6 respectively. Further, in the time slot T3, the node 1 with the node numbers 7, 8 and 9 is
From the output terminals on the column side of wavelengths λ1, λ2, λ3
The optical signal of is output.

The optical signal of wavelength λ1 is supplied to the column side output terminals of the node numbers 1, 4 and 7 included in the column group CG1 via the column side node connection device 200. The optical signal of the wavelength λ2 is transmitted through the column-side node connection device 200 to the node 1 of the node numbers 2, 5 and 8 included in the column group CG2.
00 column side input terminal. The optical signal of wavelength λ3 is transmitted to the column group C via the node connection device 200 on the column side.
It is supplied to the column-side input terminals of the node 100 having the node numbers 3, 6, and 9 included in G3. The above is the packet transmission operation on the column side.

(2-1-2) Operation of Node Connecting Device 200 Next, the operation of the node connecting device 200 shown in FIG. 4 will be described.

First, the operation of the node connection device 200 on the row side will be described. In time slot T1, node number 1,
Wavelengths λ1, λ2 output from nodes 100 of 4 and 7
The optical signal of λ3 is wavelength-multiplexed by the star coupler 211. This wavelength division multiplexed signal is transmitted to the wavelength filters 221 and 22.
2, 223 separates each wavelength λ1, λ2, λ3. Each separated output is a star coupler 231, respectively.
It is branched into three by 232 and 233. This branch output is distributed to the nodes 100 of each row group RGn by the optical switch 241.

In this case, the input port and the output port of the optical switch 241 are connected as shown in FIG. 7 (a). As a result, the three optical signals of wavelength λ1 output from the star coupler 231 are supplied to the three nodes 100 of the row group RG1, respectively. The three optical signals of wavelength λ2 output from the star coupler 232 are supplied to the three nodes 100 of the row group RG2, respectively. Furthermore, the wavelength λ output from the star coupler 233
The three optical signals of 3 are supplied to the three nodes 100 of the row group RG3, respectively.

Similarly, in the time slot T2, the wavelengths λ1 output from the node 100 having the node numbers 2, 5 and 8
The optical signals of λ2 and λ3 are wavelength-multiplexed by the star coupler 211. The wavelength multiplex output is the wavelength filter 22.
1, 222, and 223 separate wavelengths λ1, λ2, and λ3. Each separated output is a star coupler 231,
It is distributed to the nodes 100 of each row group RGn by the optical switches 232 and 233.

Further, in the time slot T3, the wavelengths λ1, output from the node 100 having the node numbers 3, 6, 9
For the optical signals of λ2 and λ3, wavelength multiplexing processing, wavelength separation processing,
Receive signal distribution processing. The above is the node connection device 2 on the row side
00 operation.

Next, the operation of the node connection device 200 on the column side will be described. In this case, the star coupler 211, the wavelength filters 221, 222, 223, and the star coupler 23
The operations of 1, 232 and 233 are the same as those on the row side.

On the other hand, the connection between the input port and the output port of the optical switch 241 is as shown in FIG. 7 (b). Accordingly, the optical signal of wavelength λ1 is supplied to the three nodes 100 of the column group CG1, the optical signal of wavelength λ2 is supplied to the three nodes 100 of the column group CG2, and the optical signal of wavelength λ3 is supplied to the column group CG2. It is supplied to three nodes 100 of CG3. The above is the operation of the node connection device 200 on the column side.

(2-1-3) Operation of Node 100 Next, the operation of the node 100 shown in FIG. 5 will be described.

Optical signals supplied from the node connection devices 200 on the row or column side are converted into optical / electrical conversion units 111, 111, respectively.
It is converted into an electric signal by 112. This converted output is
It is supplied to the packet processing unit 121.

The packet processing section 121 analyzes the header of the input packet and processes the input packet based on the analysis result. That is, if the input packet is a packet addressed to its own node, this is taken in, if it is a packet to be relayed, it is relayed, and if it is another packet, it is discarded.

In packet relay, if the input packet is input from the row side, this input packet is supplied to the time slot control section 131 on the column side. On the other hand, if it is input from the column side, it is supplied to the time slot control unit 132 on the row side.

The packet processing section 121 also generates a transmission packet. This packet is supplied to the row side time slot control unit 132 if it is transmitted to the row side, and is supplied to the column side time slot control unit 131 if it is transmitted to the column side.

The electric signal of the packet supplied to the time slot control units 131 and 132 is supplied to the external modulators 141 and 142 in the time slot assigned to the own node. A carrier signal (optical signal) is further supplied from the external light source device 300 to the external modulators 141 and 142. This carrier signal is modulated by the electric signal and then supplied to the node connection device 200 on the row or column side. The above is the operation of the node 100.

(2-1-4) Operation of External Light Source Device 300 Next, the operation of the external light source device 300 shown in FIG. 6 will be described.

First, the operation of the row-side external light source device 300 will be described. Optical signals of wavelengths λ1, λ2, λ3 output from the light emitting diodes 311, 312, 313 are branched into three by the star couplers 321, 322, 323, respectively. Each branch output is supplied to the optical switch 331. In this case, the connection between the input port and the output port of the optical switch 331 is as shown in FIG.

As a result, the three optical signals having the wavelength λ1 output from the star coupler 321 are supplied to the row side external modulators 142 of the three nodes 100 of the row group RG1. In addition, the wavelength λ output from the star coupler 322
The three optical signals 2 are supplied to the row side external modulators 142 of the three nodes 100 of the row group RG2. Further, the three optical signals of the wavelength λ3 output from the star coupler 323 are supplied to the row side external modulator 142 of the three nodes 100 of the row group RG3. The above is the operation of the row-side external light source device 300.

Next, the operation of the external light source device 300 on the row side will be described. In this case, the light emitting diodes 311, 312,
The operations of 313 and the star couplers 321, 322, 323 are the same as those on the row side.

On the other hand, the connection between the input port and the output port of the optical switch 331 is as shown in FIG. 8 (b). Thereby, the star couplers 321, 322, 323
The three optical signals of wavelengths λ1, λ2, and λ3 output from are supplied to the column side external modulator 141 of the three nodes 100 of the column groups CG1, CG2, and CG3, respectively.
The above is the operation of the external light source device 300 on the row side.

(2-1-5) Network Reconfiguration (Group Change) Next, network reconfiguration will be described. In addition,
In the following description, as shown in FIG. 9, a case where the logical positions of the node 100 having the node number 1 and the node 100 having the node number 4 are exchanged will be described as a representative.

In this case, the wavelength of the optical signal output from the row-side output terminal of the node 100 with node number 1 is changed from λ1 to λ2, and output from the row-side output terminal of the node 100 with node number 4. It is necessary to change the wavelength of the optical signal from λ2 to λ1.

This change is as shown in FIG.
This is performed by switching the connection of the optical switch 331 of the external light source device 300 on the row side. In this case, one of the three optical signals of wavelength λ1 output from the star coupler 331 is supplied to the node 100 of node number 4, and one of the three optical signals of wavelength λ2 output from the star coupler 332 is output. One is supplied to the node 100 having the node number 1.

Further, the wavelength of the optical signal supplied to the row-side input terminal of the node 100 having the node number 1 is changed from λ1 to λ2, and the light supplied to the row-side input terminal of the node 100 having the node number 4 is changed. It is necessary to change the wavelength of the signal from λ2 to λ1.

This change is as shown in FIG.
This is performed by switching the connection of the optical switch 241 of the node connection device 200 on the row side. In this case, one of the three optical signals of wavelength λ1 output from the star coupler 231 is supplied to the node 100 of node number 4, and one of the three optical signals of wavelength λ2 output from the star coupler 232 is output. One is supplied to the node 100 having the node number 1.

Further, the time slot on the column side of the node 100 with the node number 1 is changed from T1 to T2, and the time slot on the column side of the node 100 with the node number 4 is changed from T2 to T.
Need to change to 1. This change is performed by the time slot control unit 131 on the column side.

In the case of the example in FIG. 9, the column group CG1
Since the positions of the two nodes 100 belonging to the column are exchanged, it is not necessary to change the transmission wavelength or the reception wavelength on the column side. Therefore, the connection state of the optical switch 331 of the external light source device 300 on the column side and the optical switch 2 of the node connection device 200 on the column side.
The connection state of 41 is not changed as shown in FIGS. 11 (a) and 11 (b), respectively.

Similarly, the time slots on the row side of these nodes 100 are not changed at all. (1-3) Effects of One Embodiment According to this embodiment described in detail above, the following effects can be obtained.

(A) First, according to this embodiment, a different packet transmission wavelength λn is assigned to each row group RGn, a different packet transmission wavelength λn is assigned to each column group CGn, and each column coordinate in each row group RGn is assigned. A different packet transmission time slot Tn is assigned to each row group, a different packet transmission time slot Tn is assigned to each column coordinate in each row group RGn, and the same packet transmission wavelength λn is used on the row side and the column side. Considering a × N grid-type network system, the wavelength multiplicity can be reduced from the conventional N × N to N. This makes it possible to increase the scale of the grid network system.

(B) Further, according to such a configuration,
Even if a device having only a wavelength multiplexing function, such as a star coupler, is used as the node connecting device 200, the number of wavelength filters provided in each node 100 is 2 (N-1) from the conventional two. Can be reduced to As a result, the amount of hardware of each node 100 can be reduced, so that the lattice type network system can be increased in scale.

(C) Further, according to this embodiment, since the device having the wavelength multiplexing function, the wavelength demultiplexing function, and the signal distribution function is used as the node connecting device 200, the wavelength filter is It suffices to provide N wavelength filters in each of the node connection devices 200 on the row side and the column side.

As a result, the number of wavelength filters can be significantly reduced as compared with the case where a device having only a wavelength multiplexing function is used as the node connecting device 100. Specifically, the number can be reduced from 2 (N-1) × N × N to N. As a result, the amount of system hardware can be reduced, which can contribute to the increase in scale.

(D) Further, according to this embodiment, the external light source device 300 having the signal distribution function to each node 10 is connected.
Since the carrier signal (optical signal) is supplied to 0, as the light emitting diodes, it is only necessary to provide N light emitting diodes on the row-side and column-side external light source devices 300, respectively.

As a result, the number of light emitting diodes is 2 × N as compared with the case where a light emitting diode is provided in each node 100.
It can be reduced from × N to 2 × N. as a result,
Since the amount of hardware in the system can be reduced,
It can contribute to the increase in scale.

(E) Further, according to this embodiment, since the optical switch 241 of the node connecting apparatus 200 is provided with the switching function of the distribution destination, it is possible to easily deal with the reconfiguration of the network.

(F) Further, according to this embodiment, since the optical switch 331 of the external light source device 300 is provided with the switching function of the distribution destination, it is possible to easily deal with the reconfiguration of the network.

(G) Further, according to this embodiment, the packet output from each node 100 is sent to this node 100.
Can be distributed to all other nodes in the group to which it belongs. In other words, each node 100 can broadcast the packet to other nodes in the group to which the node belongs. Therefore, by combining this broadcasting function and relay function, each node can
Broadcast to 0. As a result, according to this embodiment, it is possible to realize a network system such as a cable television system which performs broadcast communication.

(2) Other Embodiments Another embodiment of the present invention will be described.

(A) First, another embodiment of the lattice type network system of the present invention will be described.

For example, in the above embodiment, the case where the plurality of nodes 100 are connected by the node connecting device 200 having the wavelength multiplexing function, the wavelength demultiplexing function, and the signal distribution function has been described. However, in the lattice type network system of the present invention, connection may be made with a node connecting device having only a wavelength multiplexing function, such as a star coupler.

According to such a configuration, each node 100
Therefore, more wavelength filters are required than in the previous embodiment. However, since the number of wavelength filters that need to be provided in each node 100 is two, the amount of hardware of the node 100 is reduced as compared with the conventional configuration in which it is necessary to provide 2 (N−1) wavelength filters in each node. be able to.

Further, in the above embodiment, the case where the same packet transmission wavelength is used on the row side and the column side has been described. However, in the lattice type network system of the present invention, different packet transmission wavelengths may be used on the row side and the column side. With such a configuration, one node connection device 200 can be shared by the row side and the column side.

Further, in the above embodiment, the case where the same packet transmission time slot is used on the row side and the column side has been described. However, in the lattice type network system of the present invention, different packet transmission time slots may be used.

According to this structure, 1 is set on the row side and the column side.
One node connection device 200 can be shared. As a result, the number of wavelength filters can be reduced from 2N in the previous embodiment to N.

Further, in the above embodiment, the case where the external light source devices 300 are separately formed on the row side and the column side has been described.
However, in the lattice type network system of the present invention,
The light emitting diode and the star coupler may be shared on the row side and the column side, and only the optical switches may be separately provided.

As described in the above, when different packet transmission time slots are used on the row side and the column side,
One external light source device may be shared by the row side and the column side by providing a function of switching the distribution destination of the optical signal in synchronization with the switching of the time slots on the row side and the column side.

Further, in the above embodiment, the case where the light source such as the light emitting diode is provided outside the node 100 has been described. However, in the lattice type network system of the present invention, a light source may be provided for each node 100.

Further, in the above embodiment, the case where the lattice type network system of the present invention is applied to the N × N lattice type network system has been described. However, the lattice type network system of the present invention changes the number of wavelengths and the number of time slots on the row side and the column side to obtain M × N (M
And N are integers different from each other).

Further, in the above embodiment, the case where the lattice type network system of the present invention is applied to the network system using the optical signal as the transmission medium has been described.
However, the grid-type network system of the present invention can also be applied to a communication network system using electric signals.

Further, the lattice type network system of the present invention is a communication system for transmitting digital signals,
The present invention can be applied to both a communication system that transmits an analog signal and a communication system that transmits a digital signal and an analog signal.

(B) Next, another embodiment of the node connecting device of the present invention will be described.

In the above embodiment, the case where the node connecting device of the present invention is applied to the node connecting device of the lattice type network system has been described. However, the node connecting device of the present invention can be applied to a network system having three or more transmitting / receiving directions. For example, it can be applied to a node connecting device of a cube type network system as shown in FIG.

(C) In addition to the above, it is needless to say that the lattice type network system and the node connecting device of the present invention can be variously modified without departing from the scope thereof.

[0112]

According to the lattice type network system of the first aspect, different packet transmission frequencies are assigned to each row group and each column group, and each column coordinate of each row group and each row coordinate of each column group are respectively assigned. Since different packet transmission time slots are assigned, the wavelength multiplicity can be reduced and the amount of hardware of each node can be reduced as compared with the related art. This makes it possible to increase the scale of the grid network system.

According to the node connecting device of the eighth aspect, since the frequency multiplexing function, the frequency separating function and the signal distributing function are provided, it is possible to connect the nodes of the lattice type network system of the first aspect. If used, the wavelength filter can be deleted from each node and the number of wavelength filters used can be reduced. This can contribute to increasing the scale of the grid network system.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an outline of an embodiment of the present invention.

FIG. 2 is a diagram for explaining an example of a lattice type network system to which the present invention is applied.

FIG. 3 is a block diagram showing a physical configuration of an example.

FIG. 4 is a block diagram showing a configuration of a node connection device according to an embodiment.

FIG. 5 is a block diagram showing a configuration of a node according to an embodiment.

FIG. 6 is a block diagram showing a configuration of an external light source device according to an embodiment.

FIG. 7 is a block diagram for explaining the operation of the node connecting device according to the embodiment.

FIG. 8 is a block diagram for explaining the operation of the external light source device of the embodiment.

FIG. 9 is a diagram illustrating an example of network reconfiguration.

FIG. 10 is a diagram for explaining the operation of network reconfiguration.

FIG. 11 is a diagram for explaining the operation of network reconfiguration.

FIG. 12 is a diagram showing the configuration of another embodiment of the present invention.

[Explanation of symbols]

100 ... Node 200 ... Node connection device 300 ... External light source device 111, 112 ... Optical / electrical converter 121 ... Packet processing unit 131, 132 ... Time slot control unit 141, 142 ... External modulator 211, 231, 232, 233 321, 322, 3
23 ... Star coupler 221, 222, 223 ... Wavelength filter 241, 331 ... Optical switch 311, 312, 313 ... Light emitting diode

Claims (8)

[Claims] 1. A plurality of nodes arranged in a grid are grouped for each row and each column, and a packet is transferred in one hop between any two nodes belonging to the same group, and any node belonging to a different group is transferred. In a lattice type network system configured to transfer a packet between two nodes in two hops through a node located at an intersection of two groups to which these two nodes belong, a packet transmission frequency different for each row group. Is assigned to each column group, a different packet transmission frequency is assigned to each column group, a different packet transmission time slot is assigned to each column coordinate within each row group, and a different packet transmission time slot is assigned to each row coordinate within each column group. Lattice characterized by being configured to be assigned Network system. 2. The packet transmission frequency is the same on the row side and the column side, and the packet transmission time slot is the same on the row side and the column side. 1. The lattice type network device described in 1. 3. A node connecting means for connecting the plurality of nodes, frequency multiplexing means for frequency-multiplexing packet transmission signals outputted from the plurality of nodes, and frequency-multiplexed output of the frequency multiplexing means for each frequency. 2. The lattice type network system according to claim 1, further comprising frequency separating means for separating and signal distributing means for distributing each frequency separated output of the frequency separating means to a node of a corresponding group. 4. A carrier signal generating means for generating a carrier signal for transmitting the packet, a plurality of signal generating means for generating a carrier signal having the same frequency as the packet transmission frequency, and the plurality of signal generating means. 2. The lattice type network system according to claim 1, further comprising signal distribution means for distributing a plurality of carrier signals output from the means to nodes of a corresponding group. 5. The lattice type network according to claim 1, wherein the node is configured so that the time slot for packet transmission can be changed in accordance with a change in coordinates where the own node is located. system. 6. The signal distribution means of the node connection means is configured so that a distribution destination of the frequency separation output can be changed in accordance with a change in coordinates where the node is located. The lattice type network system according to claim 3. 7. The signal distribution means of the carrier signal generation means is configured to be able to change the distribution destination of the outputs of the plurality of signal generation means in accordance with the change of the coordinates where the node is located. The lattice type network system according to claim 4, wherein. 8. A frequency multiplexer for frequency-multiplexing packet transmission signals output from a plurality of nodes, a frequency separator for separating the frequency-multiplexed output of the frequency multiplexer for each frequency, and each of the frequency separators. A node connection device comprising: a signal distribution unit that distributes a frequency separated output to corresponding nodes.