JPH01241941A - Transmission line network switching system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a transmission line network switching system, and particularly to a method of controlling a transmission line network having working and protection transmission lines.

(Prior Art) Generally, a transmission line network is formed by a plurality of stations and transmission lines stretched between the stations.

Furthermore, in order to ensure communication in the section even if a failure occurs in the transmission path between certain stations, a backup transmission path and a switching device are provided, and if necessary, the system switches to the backup transmission path to supplement the failed section. Generally, a transmission line network switching system is introduced.

Fig. 2 is a diagram showing an example of a transmission line network in which a conventional transmission line network switching system has been introduced. This is the current transmission line installed between 1 and 3.

In this example, to simplify the explanation, one working transmission line is
Although only one is shown, in reality, there are other networks installed between each station. In addition, 3-1 to 3-7 indicated by broken lines in the figure are backup transmission lines laid out between the respective stations (that is, between the switching devices of the stations). 1
1 to 1-f3 are the supervisory control device 4 and the communication lines 5-1 to 5-f.
5-6. .

To explain the operation in this configuration, if a failure occurs in the machine transmission line 2 for some reason and the connection is interrupted, the switching devices 1-1 and 1-3 installed at the station (as described above) The station and the switching device installed at the station are collectively referred to as 1-1no+.
In order to ensure the transmission function between Switch to bus route.

In this case, the method of forming the bus route is from switching device 1-1 to 1.
Route leading to 1-3 via -2 or switching device 1-
There are many possible routes such as 1-4, 1-5, and 1-6 to reach 1-co3.

Therefore, in the past, as shown in FIG. 2, the switching device 1-1 of each station has been
The status of stations 1 to 1-6 was monitored via the communication lines 5-1 to 5-6, and control signals were transmitted to stations necessary for bus route formation-11 via the communication lines. .

However, in such conventional methods, the entire network is controlled by a single monitoring and control device, which requires an extremely large amount of processing power, which also places a heavy burden on the person.

Therefore, when the network becomes complex or large-scale, there is a drawback that the equipment for the monitoring and control equipment becomes enormous and becomes extremely expensive. .

Furthermore, even if the system has a relatively small number of stations, it is not possible to construct an economical system because a necessary basic configuration is required in order to satisfy the supervisory control function.

Furthermore, if this part is duplicated in order to avoid a functional outage in the event of a failure of the supervisory control station, the required cost will be even higher.

Tenth, system changes such as network expansion require a complete update of the database and modification of the entire control system such as programs 11'', resulting in a lack of flexibility for system expansion.

(Object of the Invention) The present invention has been made in view of the problems of the conventional transmission line network control and monitoring means as explained above. The purpose is to provide a road network switching system.

(Summary of the Invention) In order to achieve this object, the present invention provides a transmission line network system in which active and F transmission lines are installed between a plurality of stations equipped with a line switching device. When a failure occurs in the current transmission line, it is determined which route should be used to compensate for the failure, and for that purpose, the station switching device uses this communication line means to determine which bus route to switch to. What is the signal that instructs the station, and in what order should this command be transmitted to the station to which it should be transmitted?
The system is configured so that the signal is transmitted in a loop by transmitting a signal with the route and specifying the station from which the signal originates as the final fishing spot to which the signal is to be transmitted. It is a feature. .

Furthermore, if the station that previously received the command signal receives a peak or other command signal, the station that originated the signal will refuse to accept it, regardless of the transfer destination indicated by the command signal. A signal indicating this is added and sent back. .

(Example) Hereinafter, the present invention will be described in detail based on the drawings. .

FIG. 1 is a network diagram showing an embodiment of the present invention.

In this figure, 6-1 to 6-8 are transmission line switching devices of stations in the transmission line network, and between these stations there are protection transmission lines 7-1 to 7-9 and working transmission line 8-1 indicated by dotted lines. 〜8
-9 is installed.

These stations 6-1 to 6-8 can communicate with each other via communication lines 8T-1 to 8-9, respectively.

Now, suppose that some kind of failure occurs in the working transmission line 9 set between stations 6-1 and 6-3, and the connection is interrupted. : There are several possible combinations of routes connecting between 3 and 3 using backup transmission lines.

For example, a route in which a transmission path is set up in the order of stations 6-1.6-2.6-3 via backup transmission paths 7-1 to 7-2, or backup transmission path 7-1.7= 4.7-8.7-5
There may be a route for the gods, such as a route via . .

Among these multiple routes, for example, station 6-1.6-4.6
-5.6-6 in red 6-:□When forming a preliminary route to 3, station 6-1 sends a message indicating the content of the command to designate each of these stations in order to form the above route. (
(hereinafter referred to as a droop formation command) is first sent to the first station 6-
Send to 4.

This loop formation command is transmitted via each communication line, and the station that receives it (station 6-4 in this case) relays and transmits it to the next station 6-5 indicated in the loop formation command. .

Thereafter, the loop formation command is relayed and transferred in the same way to the stations that followed the loop formation command to the target station 6.
-3.

The final transfer destination of this loop formation command is designated as station 6-1, which is the originating point of the loop formation command, and is ultimately transmitted to this station 6-1, resulting in the signal being looped. Each station to which the loop formation command was transferred in this way controls its switching device to select a backup transmission path leading to the other station to which the signal was transferred, and the route to which the signal was transferred is A backup transmission line is formed along the line.

The above explanation shows the case where there is only one loop formation command issuing point, but in an actual transmission line network, there are many active transmission lines, and failures may occur in multiple of them. In many cases, the loop formation commands are issued independently from a plurality of stations on a transmission network in order to secure a backup route for each working transmission line. .

In this case, if the same station is selected, there is a possibility of system inconsistency.

Therefore, in order to avoid this problem, the following measures may be added.

When route formation commands are issued from multiple stations in order to form multiple backup routes for a "network", there is no problem if all the routes go through completely separate stations, but if any two or more -L route 1. If the same station is located in , the station that received the Loop Formation command will not send this to the other station until it receives the Loop Formation Command Cancellation command even if it receives the Loop Formation command. In response, the message (hereinafter referred to as NAC
(referred to as K) will be returned.

For example, as shown in FIG. 2, in the embodiment of FIG. 6-7 becomes a loop formation command issuing point and goes through station 6-5.6-6 to 6-
If it is assumed that a backup transmission line is to be formed along the route to station 8, two route formation commands will be passed through stations 6-5 and 6-6, resulting in a contradiction.

Therefore, if the second embodiment described above is used, if the command issued from station 6-7 is input after the command issued from station 6-1, the station 6-5 will not receive the command. The message is returned to the station 6-7 with information indicating that the message is rejected and that the message should be finally transmitted to the station 6-7. .

The station that receives the reception rejection message creates a backup route excluding the stations whose reception was rejected, or issues a formation command in the same way after the required time has elapsed. , in this example, 6-
The same command as the above route is issued after a route from 7 to 6-8 is selected or after some time has elapsed.

In this case, it is efficient to set the retransmission timing to a probabilistic time determined by taking into consideration the traffic state of the transmission network.

When a loop formation command is sent out and the loop formation is successful, the station that issued the command informs the necessary switching devices of other stations of the identification number of the switching device determined by the network and which switching device it is. Command information including information on whether such a connection should be removed is sent to the formed loop communication line.

A command containing the identification number of the switching device determined by the network 10 and information on what kind of connection the switching device should make is sent to the device over the formed loop communication line.

After forming the backup transmission line in this way, the command issuing station then sends out a loop formation release command to release the loop formation and open the communication line for other switching.

Below, to simplify the explanation, we have shown the case where there are only 8 stations, but
The same holds true even in the case of a multi-complex transmission line network, and the same holds true in the case of three or more command issuing points.

(Effects of the Invention) As described above, the present invention is configured such that a plurality of station numbers can function as control stations, and is an improvement over the conventional method of providing a large-scale monitoring and control device that monitors the entire system. In contrast, the initial cost is significantly lower, and since it is a distributed control method, the reliability of the entire system is increased.

Further, network expansion and other changes can be made extremely easily without changing the entire network database, and an economical transmission line network switching system can be constructed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention. FIG. 2 is a block diagram showing a conventional transmission line network switching system. . 6-1 to 6-8... Transmission line switching device 7-1 to 7-10... Backup transmission line 8-1 to 8-10... Communication line 9, IO... Current transmission line patent application People Toyo Tsushinki Co., Ltd.

Claims (2)

[Claims] (1) In a transmission line network system in which working and backup transmission lines are installed between multiple stations equipped with transmission line switching devices, communication lines are installed between the stations where the backup transmission lines are installed, and the required Sending a control signal for controlling the line switching device and a signal indicating a route to which the control signal should be transmitted from a station via the communication line, and transmitting the signal as the last station to which the signal is transmitted. A transmission line network switching system characterized in that the communication lines are connected in a loop by specifying a point, and the switching device is controlled via the communication lines connected in the loop. (2) If the transmission line switching device of the station that received the signal receives another signal before the signal command is canceled, the signal is received at the point where the signal originated, regardless of the transfer destination specified by the signal. 2. The transmission line network switching system according to claim 1, wherein the transmission path network switching system is configured to add a signal to the effect of rejecting the request and send it back.