JPH0260257A - Ring transmission line - Google Patents

Abstract

PURPOSE:To absorb the increase of traffic and the temporal and spatial variation of the traffic in a network by performing communication between nodes under a logical ring different from physical arrangement by using a switch device interposed in physical ring transmission line. CONSTITUTION:Optical fiber pairs 12, 14 connecting respective optical switches 151, 152,...156 form a ring optical fiber transmission line, and the optical fiber pair 12 is a clockwise optical fiber pair, and the optical fiber pair 14 is a counter-clockwise optical fiber pair. When a signal transmission request between the adjacent nodes occurs between the nodes 41 and the node 44, the electric switches of the optical switches 151 and 154 are turned on. Thus, a separated ring transmission system is recomposed so that the node 41 and the node 44 can perform signal transmission/reception equivalent to the adjacent nodes.

Description

[Detailed Description of the Invention] [Summary] A logical ring is flexibly set within a physical circular transmission path in which two nodes with a large amount of communication are logically adjacent to each other for communication. A ring transmission line consisting of a clockwise ring transmission line group and a counterclockwise ring transmission line group, and a node for controlling signal exchange between the ring transmission line for transmitting signals, and a established,
Selective connection for signal exchange between the node and the desired ring transmission path of the clockwise ring transmission line group and the counterclockwise ring transmission line group, and the clockwise connection other than the target of the selective connection. a switch device for selective connection for signal transmission between a ring transmission line and a counterclockwise ring transmission line; and a connection control means for causing each switch device to make the selective connection for each switch device. It was configured by setting up.

[Industrial application field]

The present invention relates to a circular transmission line in which two nodes with a large amount of communication are logically adjacent to each other and communicate.

A local area network is one type of information communication system. This is intended to connect a plurality of workstations set up in a certain area, for example, a business office, and to make advanced use of the system. When constructing such a system, it is necessary to take into consideration the network configuration, the amount of traffic loaded on the network, its spatial traffic fluctuations, temporal traffic fluctuations, etc., in order to make the system highly usable.

[Conventional technology]

An example of a conventional local area network is shown in FIG. This is an example of a ring-type local area network, and the circular transmission line (optical fiber) 50 constituting the network is a clockwise circular transmission line 50. and a counterclockwise circular transmission path 50 □, and a plurality of nodes 521 on the circular transmission path 50 .

52! ,... 52. is interposed, and each node 52=
The network is configured such that a terminal device 54° is connected to (i=1.2, . . . , 6).

The clockwise circular transmission line 501 or the counterclockwise circular transmission line 50
Use either one of g for network operation,
The other is used as a standby. That is, for example, when communicating between the terminal device 54 and the terminal device 54□, the terminal device 54. Communication is transmitted from the terminal device 54□ through the clockwise circular transmission path 50. carried out through
The transmission line 50. If a failure occurs in the transmission line, for example, if a transmission line failure occurs at point A, a transmission system as shown by the dashed-dotted line in the figure is formed within the system to ensure communication and ensure the reliability of the transmission system. is increasing.

Because this network maintains its physical transmission arrangement in a fixed manner both during normal operation and in the event of a failure, in order to transmit the desired communication, the delay at the sending node is greater than the delay at the receiving node. It is unavoidable that the reception delay in the network increases, and this becomes more noticeable as the network becomes larger. Also, each node intervening from the receiving node to the transmitting node may be unable to communicate at all depending on the bandwidth usage of the transmission path of the transmitting/receiving node, and the efficiency of the network may be affected due to communication failure due to nodes intervening between the transmitting/receiving nodes. Cannot be used.

One means by which the network can be freed from this problem is also being considered.

The local area network is as shown in Figure 7, and the main point is that, as shown by the dotted line ■ in Figure 7, the standby counterclockwise circular transmission line 50□ is converted into a transmission form under the conventional system. It will not be incorporated into the operational system unless a request for this occurs. This makes it possible to solve the above-mentioned transmission delays and poor usage efficiency.

Note that the reference numbers in FIG. 7 are the same as in FIG. 6.

Further, in order to transmit and receive signals between nodes in each of the above-mentioned conventional examples, information for controlling each node is given to each node from the master node, with one node in the network serving as a mask node.

[Problem to be solved by the invention]

The latter local area network described above can be a solution to the technical problems that exist in the former local area network between physically adjacent terminal devices, but the manner in which traffic occurs in the local area network is , the more advanced the system is, the more it occurs in various manners other than those occurring under the transmission system configuration that provides the solution described above. In other words, traffic occurs in various forms both spatially and temporally.

In such traffic, the latter local area network described above has not been able to solve the technical problem that is the problem with the former local area network described above.

The present invention was created in view of such problems, and an object of the present invention is to provide a logical ring setting method for a circular transmission path that can flexibly set a logical ring within a physical circular transmission path. .

[Means to solve the problem]

FIG. 1 shows a block diagram of the principle of the present invention. In this figure, reference numeral 2 denotes a ring-shaped transmission line consisting of a clockwise ring-shaped transmission line group 21 and a counter-clockwise ring-shaped transmission line group 22.

43.4□,...,4. , are nodes for controlling signal exchange with the ring transmission path 2 that transmits signals. 61.6□,... 6. 1 is a switch device provided corresponding to a node, and is a switching device for selectively transmitting and receiving signals between the node and a desired ring transmission path of the clockwise ring transmission path group 21 and the counterclockwise ring transmission path group 22. The connection and selective connection for signal transmission between ring transmission lines other than those to be selectively connected are made. Reference numeral 8 denotes a connection control means for causing each switch device to make the selective connection for each switch device. By this connection control means 8, each switch device 61.6□,...
6. The present invention allows a logical ring (a physical circular transmission line with a logically different connection form) to appear in the circular transmission line 2 by causing desired switching to occur in the circular transmission line 2.

[For production]

In normal operation, for example, the clockwise ring transmission line group 2 of the ring transmission line 2. However, if you want to operate the transmission system differently from this operation, for example, if you want to directly communicate between distant nodes, the connection control means 8 will cause the related switch device to perform the following operations. Produces switching action. That is, in each node-compatible switch device interposed between the two nodes, the clockwise circular transmission path is directly connected to the next switch device in the clockwise direction, and the signal transmission from the receiving node in the clockwise direction to the transmitting node in the clockwise direction is Therefore, a switching connection is made from the receiving node to the desired counterclockwise circular transmission line, and the switching device corresponding to each node interposed in the counterclockwise circular transmission line also connects the counterclockwise circular transmission line in the same way as the clockwise circular transmission line. Makes a direct connection to the next switch device.

Then, in order to make it possible to take in the signal transmitted from the clockwise receiving node (counterclockwise transmitting node) via the counterclockwise circular transmission path to the clockwise transmitting node, In a switch device corresponding to a receiving node (a transmitting node in a clockwise direction), the counterclockwise circular transmission line is switched and connected to a receiving node in a counterclockwise direction.

By changing the connection of this circular transmission path, the clockwise transmitting node (counterclockwise receiving node) and the clockwise receiving node (counterclockwise transmitting node) are logically adjacent to each other. It can be viewed as a node and communicated with it.

Therefore, even if the nodes are physically separated, communication can be performed between the two nodes without the above-mentioned transmission delay or reduction in utilization efficiency.

〔Example〕

FIG. 2 shows an embodiment of the invention. This example is an example implemented in a local area network, with 12
．． 14 indicates an optical fiber pair within the optical fiber cable.

Each light switch 15. ．． 152,... 15h (1st
This corresponds to the switch devices 61.6□, . . . 66 in the figure. ) A pair of optical fibers 12 and 14 connecting the two optical fibers form a ring-shaped optical fiber transmission line 11, which corresponds to the ring-shaped transmission line 2 in FIG. Optical fiber pair 12 is a right-handed optical fiber pair, and optical fiber pair 14 is a left-handed optical fiber pair. 41.4t
,... 46 are nodes, and between each of these nodes and the corresponding optical switch, there are also two pairs of optical fibers 16.
．． 18. ．． 16□, 18□,... 16. , IEz, are stretched out. 207.20□,...,20. is the control line. According to the prior art, control information on these control lines is provided from the master node of the network to each node via a circular optical fiber transmission line. Under this conventional technique, a system for transmitting control information from a master node to each node and then to a node-compatible optical switch corresponds to the connection control means 8 in FIG. As before, the terminal device 22. ．．
222, . . . 226 are connected.

Each optical switch is a 6×6 optical switch as shown in FIG. Optical fiber 1. , It,... ■, are six optical fibers 01.0□,..., 0. Of these, it is selectively connected to an optical fiber for signal exchange or signal transmission via a matrix switch section 30. This selective connection is the control line 2
0 to the matrix switch section 30. In addition, the input fibers of the optical switch and the corresponding matrix switch inputs IN, , INN,
... IN, there is a photoelectric conversion unit 32i1.32 between
12,...,32. h is provided, while the matrix switch unit outputs OUT, , ou'rt, ..., OU
There is an electro-optic converter 341 between T and the corresponding optical output fiber.
2.34.2, . . . , 34=h are provided.

Each input fiber II of the optical switch, Ls...■
, are each optical fiber t2 . of the clockwise optical fiber pair 12 in each optical switch in the embodiment of FIG. ．． 122 and each optical fiber 141.14□ of the counterclockwise optical fiber pair 14
and each optical fiber l6!1 of the optical fiber pair 16.
．． Represents the output end side of 16it, each output fiber 01.0
□, . . . , 0° indicates each optical fiber 12 . of the right-handed optical fiber pair 12 in each optical switch in the embodiment of FIG.
．． 122 and each optical fiber 1 of the counterclockwise optical fiber pair 14
4+, 14□, and the incident end side of each optical fiber 185 1.1812 of the optical fiber pair 18i.

Matrix switch section 30. is 3 as shown in Figure 4.
The matrix switch section input IN, , IN! ,...
. A switching signal is given to each electric switch from the control section 38□. The control section 38 is connected to the control line 20. is connected.

An example of forming a logical ring and transmitting signals within the local area network configured as described above will be described below.

During operation of the physical local area network configuration shown in FIG. 2, a request for signal transmission between adjacent nodes as described in FIG. 7 is received, for example, from node 4. and node 4! shall be deemed to have occurred between.

In that case, a switching signal that turns on the electric switches 36trh, 36□, and 36t, 36333 of the optical switches 15□, 153 is sent to the control units 38□, 38. Electrical switch from 36□1 & , 3631th and 36t
z3.36s: given to +3. those light switches 1
The output end of the input right-handed optical fiber 12+ at 5g and 15s is coupled (selectively connected), left-handed optical fiber 14+
The output end of is coupled to the input end of a left-handed optical fiber 14I coupled to the optical switch via optical/electrical-electrical/optical conversion.

As a result, the separate ring transmission system is reconfigured so that the nodes 41 and 4t can transmit and receive signals in the same way as the adjacent nodes described in FIG. 7.

In other words, the notebook 4I and the node 4□ are placed in a logical ring in which signals can be exchanged in the same manner as between physically adjacent nodes. .

Note that node 4 in this case. and a corresponding optical switch 15 for the above-mentioned signal transmission and reception at the node 44. ．． 15
．． The switching control performed on each electric switch is the same as in the conventional case explained in FIG. or,
In FIG. 5, node 4. and Note 41, as well as a logical ring configuration in which node 46 and node 4□ perform the same communication between adjacent nodes as above, but this is also formed by providing the same switching as above to the physical ring. It is what was done. Communication between other nodes is performed under the same transmission path configuration as in FIGS. 6 and 7, which follows the physical ring arrangement order.

Note that the above embodiment shows a case where a ring transmission line is configured with two optical fiber pairs, and an optical switch is provided for each node in the ring transmission line to form a desired logical ring. Therefore, it will be clear to those skilled in the art that the present invention is not limited thereto. For example, the above-mentioned uplink and downlink transmission paths are formed using time-division transmission paths, and electrical switches connected to optical switches are provided on the transmission paths.

[Effects of the Invention] As described above, according to the present invention, communication between nodes can be performed under a logical ring that is different from the physical arrangement using a switch device installed in a plurality of physical ring transmission paths. . As a result, the system can be given a degree of freedom (flexibility) that can appropriately absorb increases in traffic in the network and temporal and spatial fluctuations in traffic, and can respond to desired communication requests.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the principle of the present invention; Figure 2 is a diagram showing an embodiment of the invention; Figure 3 is a diagram showing the configuration of an optical switch; Figure 4 is a diagram showing the configuration of a matrix switch; Figure 5 is a diagram showing the configuration of an optical switch. FIGS. 6 and 7 are diagrams showing a configuration example of a logical ring in an embodiment of the present invention, respectively, and are diagrams showing conventional local area networks. 1 and 2, 2 is a ring transmission line (ring optical fiber transmission line 11), 2 is a clockwise ring transmission line group (clockwise optical fiber pair 12), and 22 is a counterclockwise ring transmission line group (clockwise optical fiber pair 12). Counterclockwise glowing fiber pair 14
), 4 ・ ・ ・ 4. , is a node, 6...
6. , is a switch device (optical switch 151, . . .
156), 8 is a connection control means (a system for transferring control information from the master node to each node and providing it to the corresponding optical switch). Hitsuzumo P Moon n Atsuri Ichi Majesty Hata's Abduction Figure 1 Light, Sui L+ Figure 3 MaF117 Sunu 4zuchi leaves Figure 4 'L#n/F's Loka I Reesoachi..., F Work No. Figure 4 &-i'sIzo-'s Row n Rue 7 Ryo Itozu L Work Tate 7
figure

Claims (1)

[Claims] (1) Signal exchange control between the circular transmission line (2) consisting of the clockwise circular transmission line group (2_1) and the counterclockwise circular transmission line group (2_2) and the circular transmission line (2) that transmits signals a node (4_i) (i=1, 2, ..., n) for each node, and a node (4_i) (i = 1, 2, ..., n), which is provided for each node, and connects the node with the clockwise circular transmission line group (2_1) and the counterclockwise circular transmission line group ( 2_2) selective connection for signal transmission and reception with the desired ring transmission line, and selective connection for signal transmission between the clockwise ring transmission line and the counterclockwise ring transmission line other than the target of the selective connection. a switch device (6_i) for connection; and a connection control means (8) for causing each switch device to make the selective connection for each switch device (6_i).
).