JPS63283236A - System for switching spare device - Google Patents

Abstract

PURPOSE:To rapidly recover a transmission line even when a fault without issuing alarm is generated at a transmission terminal, by transmitting and switching information representing the fact of the generation of abnormality in both reception signals current in use and spare from a reception terminal to the transmission terminal with an inverse line. CONSTITUTION:When the abnormality is generated in a transmission signal due to the fault of a modulation part 4 current in use, a monitoring circuit 16 detects the fact of the generation of the abnormality in both signals current in use and spare at the reception terminal. The monitoring circuit 16, in the case of detecting the continuance of the abnormality of the signal exceeding a prescribed time, transmits the information of the fact from a transmitter 17 to a receiver 18 via the inverse line. A control circuit 19 allows a switch 7 to switch connection to a transmission part 5 on a spare side by controlling the switch 7 corresponding to the above operation. Consequently, the transmission terminal begins to transmit the transmission signal without the abnormality outputted from the transmission part 5 on the spare side to the reception terminal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device backup switching system, and more particularly to a device backup switching system for switching between working and backup transmitting devices in a standby device backup system.

[Conventional technology]

In the conventional device backup switching system of this type, as shown in FIG.
) The signal is guided to two transmitting devices, a working and a standby consisting of a processing section 3, a modulating section 4, and a transmitting section 5, and the transmitting power of the transmitting section 5 is detected by a detector 6, and the presence or absence of the transmitting power and the modulating section 4 are detected.
In this method, the switch 7 is switched depending on whether or not an alarm is issued. At the receiving end, the received signal of the antenna 9 is branched by a no-1 hybrid 10 and sent to the respective receiving sections 1, 1 and demodulating section 1.
2 and a baseband (BB) processing unit 13, and detects whether there is an abnormality in the signal passing through each receiver, and switches the switch 14 according to the detection result. Switch.

[Problem that the invention seeks to solve]

In the conventional device backup switching method described above, for example, the modulation section 4
If a no-alarm failure occurs, such as one in which the device does not output an alarm and the signal is interrupted, switching control between active and standby is not performed at the transmitting end, which can easily lead to service failures over a long period of time, and The disadvantage is that the discovery and recovery measures are delayed.

[Means for solving problems]

The system of the present invention includes a switching means for connecting an output signal of one of two transmitting circuits, a working circuit and a standby transmitting circuit, to a transmission path, and detecting a signal abnormality in the transmitting circuit to generate a first alarm signal. a first alarm means for generating a second alarm signal, and a second alarm signal for generating a second alarm signal when a signal abnormality is detected in both the working and standby receiving circuits that receive the signal passing through the transmission path and reaching the receiving end. alarm transmitting means for transmitting the second alarm signal from the receiving end to the transmitting end;
and control means for switching the connection of the switch in response to the first and second alarm signals.

〔Example〕 Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention.
The transmitting end is shown in the upper half, and the receiving end is shown in the lower half. The baseband signal applied to input end 1 of the transmitting end is
The signal is branched at the hybrid 2 and input to each of the working and standby baseband (BB) processing units 3. 4 is a modulation section, and 5 is a transmission section. 6 is a detector that detects the output power of the transmitter. The output signal of the transmitter 6 passes through a switch 7 and a duplexer 8, and is transmitted from an antenna 9.

↓9 is a control circuit that controls the switch 7.

On the other hand, the signal received by the antenna 9 at the receiving end passes through the duplexer 8, is split into two by the hybrid 10, and is input to each of the working and standby receiving sections 11. 12 is demodulator 1
3 is a baseband (BB) processing section. BB processing section 1
The output signal No. 3 is outputted from the output terminal 15 via the working/standby switching switch 14. 16 is a circuit that monitors the continuity of the transmission signal. 17 is a transmitting device for the reverse line, that is, a line going from the receiving end to the transmitting end, and 18 is a receiving device for the reverse line.

At the transmitting end, the detection results from both the active and standby detectors 6 indicate that the output power of the transmitter 5 is normal, and both modulators 40 are not issuing alarms. However, it is assumed that an abnormality has occurred in the transmitted signal due to a failure in the currently used modulator 4. In this state, the transmitting end cannot detect any abnormality, so the switch 7 remains on the active side. In this case, at the receiving end, the monitoring circuit 16 detects that an abnormality has occurred in both the working and standby signals. If the device at the transmitting end is malfunctioning, this state will continue for a long time. When the monitoring circuit 16 detects that the signal abnormality continues for a predetermined period of time, the monitoring circuit 16 transmits the information from the transmitting device 17 to the transmitting end through the reverse line. The data is transmitted to the receiving device 18 of.

When this information regarding the continuation of the signal abnormality is given from the receiving device 18, the control circuit 19 controls the switching device 7 accordingly,
The transmission section 5 on the standby side is caused to switch the connection. As a result, the transmitting end starts transmitting the normal transmission signal output from the backup side transmitter 5 to the receiving end.

〔Effect of the invention〕

As explained above, according to the present invention, information indicating that an abnormality has occurred in both the working and standby received signals is transmitted from the receiving end to the transmitting end via the reverse line and switching control is performed.
Even if a no-alarm failure occurs at the transmitting end, the transmission line can be quickly restored by performing active/standby switching at the transmitting end.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional device backup switching system. 1.--Input end, 2.10...Hybrid, 3゜1
3... Baseband (BB) processing section, 4... Modulation section, 5... Transmission section, 6... Detector, 7.14... Switching device, 8... Transmission/reception duplexer, 9...Aerial line, 11...
Receiving section, 12... Demodulating section, 15... Output end, 16.
... Monitoring circuit, 17... Transmitting device, 18... Receiving device, 19... Control circuit.

Claims (1)

[Claims] a switching means for connecting an output signal of one of two transmitting circuits, a working and a standby transmitting circuit, to a transmission line; and a first switching means for detecting a signal abnormality in the transmitting circuit and generating a first alarm signal. a second alarm signal that generates a second alarm signal when a signal abnormality is detected in both the alarm means and the two receiving circuits, a working and a standby receiving circuit that receives signals passing through the transmission path and reaching the receiving end;
alarm means for transmitting the second alarm signal from the receiving end to the transmitting end; and control means for switching the connection of the switch in response to the first and second alarm signals. A device backup switching system characterized by comprising: