JPH0653980A - Order wire signal transmission system - Google Patents

Abstract

PURPOSE:To enable automatic simultaneous communication between plural stations at all the stations without requiring manual work at the stations unrelated to a fault at the time of a transmission line fault by providing a means for terminating order wire signals at a fault detection station at the time of the transmission line fault and the means for monitoring an overhead at all times and connecting the cut order wire signals when the communication of a transmission line changeover request is performed. CONSTITUTION:When the transmission line faults of both active and standby systems are generated between the stations 2 and 3, the changeover request is transferred from the station 2 through the stations 1 and 4 to a direction indicated by 5 by the overhead, also simultaneously, the changeover request is transferred from the station 3 through the stations 4 and 1 towards the direction indicated by 6 to the station 2 and a main signal is saved by the changeover of the transmission line. Since the signals are not transmitted at the fault detection stations 2 and 3, the ring of the order wire signals are automatically cut and thus the order wire signals are terminated at the fault detection stations utilizing this. At the station 1, the above-mentioned communication of the changeover request using the overhead of an overhead transmission line frame is monitored, the occurrence of the fault can be recognized and the cut signals at the time are connected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an order wire signal transmission system, and more particularly to an order wire signal transmission system when a transmission line failure occurs in a synchronous network ring system.

[0002]

2. Description of the Related Art Conventionally, in a ring system in which each station is connected by two sets of bidirectional transmission lines, one set is used as an active system and the other is used as a standby system, and the transmission line is switched to a standby system when a failure occurs in the active system. The protection method is adopted to rescue the signal, and when both the active system and the standby system have a failure, the active system received signal is sent to the standby system transmission line and the standby system received signal is sent to the active system transmission line to rescue the signal. There is.

In this case, the transmission line switching control is always performed by performing communication in the ring using the transmission line switching control overhead. When a failure occurs, the stations at both ends of the failure point detect the failure, and at the same time, the overhead of the main signal is used to communicate with the opposite station to switch the transmission path.

Regarding the order wire signal, at each station, the working system is selected from the order wire signals received from the upstream working system and the protection system transmission line, and the signals of its own station are combined and sent to the working system and the protection system transmission line at the same time. Similarly, the order wire signal from the downstream is also sent to the upstream.

Further, in the ring system, since the transmission line is connected in a ring shape, the signal transmitted from the own station does not go around all the stations in the ring and return to the own station. By disconnecting the ring state of the signal and adopting the above configuration, it is possible to make a voice call between multiple stations at the same time.

[0006]

However, in this conventional order wire transmission system, when the failure occurs in only the active transmission line, the receiving side can switch to the standby system for voice communication, but the active system and the standby system can be used. At the time of failure of both systems, the order wire signal is originally disconnected at any station so that it does not form a ring configuration, and the order wire signal is disconnected even at the failure point, and the station configuring the ring takes 2 minutes for the order wire signal. Therefore, there is a case where communication via the order wire is impossible between them.

In order to prevent this, it is necessary to connect the order wire signal at the station that originally disconnected the order wire signal at the time of failure. This connection is done manually and requires manpower.Furthermore, if the station is not related to the failure, the connection will not be made without noticing the failure and communication between the separated stations will not be possible. There was a problem that it might become.

The present invention has been made in view of the above-mentioned conventional circumstances, and therefore an object of the present invention is to provide a novel order wire signal transmission system capable of solving the above-mentioned problems inherent in the prior art. To do.

[0009]

In order to achieve the above object, an order wire signal transmission system according to the present invention is a means for terminating an order wire signal at a failure detection station when a transmission line failure occurs and originally disconnecting the order wire signal. If the communication for switching the transmission path between the opposite stations was performed due to the overhead at the station that had the transmission path failure, if the communication for the transmission path switching request was made by constantly monitoring the overhead. And means for connecting the disconnected order wire signal.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of order wire signal transmission according to the order wire transmission system of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which (a) is a flow chart of the order wire signal in a normal state, and (b) is a flow chart of the order wire signal when a failure occurs between the stations 3 and 4. is there.

In FIG. 1, reference numerals 1 to 4 indicate stations that form a ring. The stations are connected to each other by two sets of bidirectional transmission lines to form a ring, and the outer two lines are active transmission lines. The two inner lines are backup transmission lines. Reference numeral 7 is a signal synthesizing means for synthesizing signals.

In the normal state (a), the station 3 selects the order wire signal from the station 2 which has passed through the active transmission path, and the signal synthesizing means 7 synthesizes its own signal to the station 4. At the same time as transmitting to both the active system and the standby system, the signal from the station 4 is also combined with the signal of the own station by the signal combining means 7 to make the station 2
Transmit to. The signals from the stations 2 and 4 are combined and output to the station 3 itself. The same applies to the station 4.

At the station 1, the transmission signal from the station itself is station 4 → station 3
→ In order to prevent the signal from the station 4 from being returned to the station via the station 2, the output is stopped and disconnected so that the signal from the station 4 is not accepted and the signal from the station 4 is not transmitted to the station 4.

By the means described above, it is possible to make a call by using an order wire between arbitrary plural stations.

As shown in (b), when a failure occurs in both the active system and the standby system between the stations 2 and 3, the station 2 switches via the stations 1 and 4. The request is transferred in the direction indicated by 5 by overhead, and at the same time, the switching request is transferred from the station 3 through the station 4 and the station 1 to the station 2 in the direction indicated by 6, and the main signal is transferred by switching the transmission line. Be relieved.

At this time, since the fault detection stations 2 and 3 do not transmit signals, the ring of the order wire signal is automatically cut. Therefore, by utilizing this, the fault detection station terminates the order wire signal. To do.

In the station 1 which originally cut the signal in order to prevent the order wire signal from becoming a ring state, the communication of the switching request using the overhead of the overhead transmission path frame described above is monitored and a failure occurs. You can know and connect the signal that was disconnected at this time.

In this way, the transmission of the order wire signal is performed only when the disconnection point of the order wire signal, which is the only disconnection between the stations 1 and 4 at the normal time, is moved to the faulty station 3 or 4. It is possible to make simultaneous calls by order wire between arbitrary stations without changing from the normal state.

[0020]

As described above, according to the order wire transmission method of the present invention, it is possible to automatically perform simultaneous communication between a plurality of stations at all stations without requiring manpower at a station unrelated to the failure at the time of transmission line failure. Become.

[Brief description of drawings]

1A and 1B are views showing an embodiment of the present invention and are diagrams showing movement of an order wire signal disconnection point and a flow of an order wire signal at a normal time and a failure by the order wire transmission method according to the present invention. .

[Explanation of symbols]

1 to 4 ... Stations 1 to 45 constituting the ring ... Switching request transfer direction due to overhead (clockwise
..Station 4 → Station 3) 6 ... Switching request transfer direction due to overhead (counterclockwise ... Station 3 → Station 4) 7 ... Signal combining means

Claims (1)

[Claims] 1. A system comprising three or more stations, each station comprising two sets of two transmission lines for transmitting signals in mutually opposite directions, a total of four transmission lines, one set being a working system and the remaining one being a system. In a ring system having a set as a backup system, means for terminating and terminating the ring connection of the order wire signal at any one station in the ring system, and each station configuring the ring system receives the order wire signal of its own station. A means for sending out in both directions after synthesizing in the received order wire signal of the direction, and when a failure occurs in both the active system and the standby system transmission line between the stations, the order wire signal ring connection is made at the failure detection station. Disconnection means, and means for connecting the points that were disconnected and terminated in order to prevent ring connection of the order wire signal in the normal state by communication using overhead. Order wire signal transmission system.