JPH0748717B2 - Line switching device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a line switching device in a synchronous multiplex wireless transmission system in which digital transmission signals in multiple columns are synchronized and transmission control signals such as frame synchronization signals are transmitted. In particular, the present invention relates to a line switching device that distinguishes between synchronous switching due to line quality deterioration and system switching due to equipment failure.

[Conventional technology]

 A conventional technique will be described below with reference to the drawings.

FIG. 3 is a block diagram showing an example of the configuration of a line switching device in a synchronous multiplexing wireless transmission system according to the present invention, and FIG. 4 is a frame synchronization circuit 1 and a receiving part of a receiving side device 102 of the conventional line switching device. 3 is a block diagram showing details of a synchronization switching circuit 2 and a reception signal processing circuit 3. FIG.

The line switching device of the synchronous multiplex wireless transmission system is generally composed of a working N (N is a positive integer) and a spare 1 system, but in the following description, for convenience of explanation, a line switching device of a working 1 and a spare 1 system is mainly used. Will be described. In FIG. 3, a transmission code processing circuit 4a, a transmission synchronization switch 9, a wireless section 5
The a, the frame synchronization circuit 1a, the reception distribution circuit 10, and the reception code processing circuit 3a form a standby system, and the other circuits form an active system.

Referring to FIG. 3, the multiplexed digital data signal .alpha. From the carrier terminal is input to the g terminal and is divided by the branch circuit 6 into a working system and a standby system (or line). The transmission switch 7 switches the data signal α between the working system and the backup system. The x, y, z terminals indicate connection terminals with other active systems. Reference numerals 4 and 4a denote transmission code processing devices that insert a parity signal, a frame synchronization signal, a line supervisory control signal, etc. into the data signal α from the i1 and i2 terminals and perform signal processing. Reference numeral 9 is a transmission synchronization switching circuit, and 2 is a reception synchronization switching circuit. Reference numerals 5 and 5a represent wireless sections, which are sections including modulation, demodulation, high-frequency transmission, high-frequency reception, radio wave propagation, etc., and are sections in which line quality deterioration and intermediate relay station failures occur. 1, 1a is a frame synchronization circuit, which establishes frame synchronization of the transmitted signal α1. Reference numeral 10 is a reception distribution circuit that distributes the transmission signal from the standby system to the active system when switching the synchronization. 3,
Reference numeral 3a is a reception code processing circuit, which removes the signal inserted in the transmission code processing circuit 4 and also performs signal processing, and outputs a data signal α from the terminal h to the carrier terminal station via the reception switch 8. . The reception switch 8 switches between the active system and the standby system. Reference numeral 101 denotes a transmitting side device, and 102 denotes a receiving side device.

The c1 and c2 terminals output line monitoring information for synchronous switching, and the d1 and d2 terminals output line monitoring information for system switching. Further, the i1 and j1 terminals input the line control signal for synchronous switching, and the k and 1 terminals input the line control signal for system switching.

And the wireless section 5 and the frame synchronization circuit 1 of the active system
When the transmission signal is route A, that is, the transmission synchronization circuit 9, the wireless section 5a, the frame synchronization in the standby system Synchronous switching through the circuit 1a and the reception distribution circuit 10 is performed.

At this time, line control information for synchronous switching is generated based on the line monitoring information output from the c1 terminal of the frame synchronization circuit 1, and the line control information is transmitted to the transmission code processing circuit 4.
Input from the i1 terminal and the j1 terminal of the reception synchronization switching circuit 2,
The transmission synchronization switching circuit 9 and the reception switching circuit 2 are switched from the working system to the backup system.

On the other hand, in the case of a device failure in the reception synchronization switching circuit 2 and the reception code processing circuit 3 of the active system, the transmission signal passes through the B route, that is, all circuits of the standby system by switching the transmission switching device 7 and the reception switching device 8. The system is switched.

At this time, line control information for system switching is generated based on the line monitoring information output from the d1 terminal of the reception code processing circuit 3, and the line control information is sent to the k terminal of the transmission switching device 7 and the reception switching device 2. Input from 1 terminal and send switch 7
Also, the reception switch 8 is switched from the active system to the standby system.

In the receiving side apparatus of FIG. 4, the frame synchronization of the transmitted signal α1 is established by the frame synchronization processing circuit 41 and becomes the signal α11. Next, the signal α11 is collated by the first parity collating circuit 42 with the parity signal inserted in the data signal α in the transmission code processing circuit 4. The parity collation output signal α2 of this collation result is output to the c terminal, and becomes the line monitoring information for monitoring the deterioration of the line quality, the failure of the intermediate relay station, and the like.

Similarly, the second parity matching circuit 45 of the reception code processing circuit 3 also performs the matching with the parity inserted in the transmission code processing circuit 4, and the signal α11 passes through the reception synchronization switching circuit 2 to cause a failure of that circuit. The parity collation output signal α21 of the signal α3 that may have caused an error due to the above is output as line monitoring information, and the system switching is performed as a result of an equipment failure according to the result.

[Problems to be Solved by the Invention]

The above-mentioned conventional line switching device uses the parity signal inserted in the transmission code processing device 4 as a method for monitoring the deterioration of line quality, the failure between intermediate relay stations, and the device failure of the device, and the synchronous switching section and the system switching. Parity matching was performed in the same way in each of the sections, and the results were used for synchronous switching and system switching.

For this reason, if the line quality deteriorates and there is a failure between the intermediate relay stations, the device is also determined to be at the same time defective.

Therefore, an object of the present invention is to provide a line switching device capable of completely distinguishing between synchronous switching due to line quality deterioration and failure between intermediate relay stations and system switching due to equipment failure.

[Means for Solving the Problems]

In order to achieve the above object, a line switching device according to the present invention is a line switching device of a synchronous multiplexing wireless transmission system in which a digital multiplexed signal sequence is transmitted, wherein a transmitting side device transmits a frame synchronization signal or a parity signal to a data signal. Means for inserting and transmitting, means for extracting a frame synchronization signal at the receiving device side to establish frame synchronization, means for first parity matching for detecting line quality deterioration and a failure between intermediate relay stations, A means for switching the synchronization by the signal output by the above-mentioned parity collation, a means for adding / generating a signal for monitoring in the device to the received signal with the frame synchronization established, and transmitting the signal And a means for extracting and collating the monitoring signal in the device.

〔Example〕

Next, a first embodiment of the line switching device according to the present invention will be described with reference to FIGS. 1 and 3.

FIG. 1 is a block diagram showing details of the frame synchronization circuit 1, the reception synchronization switching circuit 2, and the reception signal processing circuit 3 in the reception side device 102 of the line switching device shown in FIG.

The transmission code processing circuit 4 inserts a parity signal or the like obtained by performing a parity operation into the signal sequence of the input signal α from the carrier terminal device. The frame synchronization processing circuit 11 is a means for establishing frame synchronization of the reception signal α1 that has passed through the wireless section 5, and the reception synchronization switching circuit 2 has a function of switching the signals of the working system and the standby system without interruption. The reception signal processing circuit 14 outputs the data signal α from which the signal inserted in the transmission code processing circuit 4 is removed, from the output terminal b to the reception terminal 8 through the reception switch 8 to the carrier terminal apparatus.

Here, as shown in FIG. 1, the received signal α1 input from the a terminal becomes a signal α11 with frame synchronization established in the frame synchronization processing circuit 11, and the parity calculation is performed in the first parity collation circuit 12 so that the transmission side device 101 It is collated with the parity signal inserted by the transmission code processing circuit 4. The resulting parity collation output signal α2 is output to the c terminal as line monitoring information for monitoring the deterioration and failure of the line quality of the wireless section 5 and the frame synchronization circuit 1, and the synchronous switching is performed based on the result.

In the parity calculation circuit 13, the signal α11 after the frame synchronization is established
A parity operation is performed on the obtained parity signal α4, and the resulting parity signal α4 is output to the second parity matching circuit 15 through the reception synchronization switching circuit 2. on the other hand. The signal α11 passes through the reception synchronization switching circuit 2, and the data signal α3 in which an error may have occurred due to a device failure is also input to the second parity matching circuit 15.
The second parity check circuit 15 performs a parity operation on the data signal α3, and the data signal α11 passed through the frame synchronization processing circuit 11.
The parity check output signal α5 is output from the d terminal to obtain the line monitoring information for monitoring the device failure.

As a result, the synchronous switching (route A) due to the deterioration of the line quality in the wireless section 5 and the failure between the intermediate relay stations and the system switching (route B) at the time of a device failure of the device are completely distinguished.

Note that terminals e and f in FIGS. 1, 2, and 4 indicate input terminals (A route) for receiving signals and parity signals from the standby system at the time of synchronous switching. Has a function other than the parity check of the reception code circuit 3.

FIG. 2 shows a second embodiment of the line switching device according to the present invention, and FIG. 2 shows the receiving side device of the line switching device shown in FIG.
3 is a block diagram showing details of a frame synchronization circuit 1, a reception synchronization switching circuit 2, and a reception signal processing circuit 3 of 102. FIG.

In FIG. 2, the received signal α1 input to the a terminal is subjected to frame synchronization in the frame synchronization processing circuit 21 and then the first parity collation circuit collates the parity signal of the signal α11.
The parity collation output signal α2 is output to the c terminal and used as the line monitoring information for synchronous switching. Further, the signal α11 after the frame synchronization is established is subjected to parity calculation in the parity calculation circuit 23,
The output is reinserted into the parity signal part of the signal α11 by the parity insertion circuit 26, and the signal is transmitted to the reception synchronization switching circuit 2. The inserted parity signal is the second
The parity collation circuit 25 detects and collates, and becomes the parity collation output signal α51. The parity collation output signal α51 is output from the d terminal and becomes line monitoring information for equipment failure, and system switching is performed based on this. Therefore, the parity check by the second parity check circuit 51 handles only the original equipment failure, and the system switching due to the equipment failure can be performed separately from the failure in the wireless section 5.

〔The invention's effect〕

As described above, according to the present invention, by using the in-apparatus supervisory signal for detecting the device failure of the switching device, it is possible to determine that the device failure is present at the same time, although it is only the deterioration of the line quality and the failure between the intermediate relay stations. Therefore, there is an effect that the synchronous switching and the system switching can be completely distinguished and monitored and switched.

[Brief description of drawings]

FIG. 1 is a block diagram showing a part of the configuration of a receiving side device of an embodiment of a line switching device according to the present invention, and FIG. 2 shows a part of the configuration of a receiving side device of another embodiment according to the present invention. Block diagram, FIG. 3 is a block diagram showing a configuration of a line switching device in a synchronous multiplexing wireless transmission system according to the present invention, and FIG. 4 is a block diagram showing a part of a configuration of a receiving side device of a conventional embodiment. is there. 1, 1a: Frame synchronization circuit, 2 ... Reception synchronization switching circuit,
3,3a ... Reception code processing circuit, 4,4a ... Transmission code processing circuit, 5,5a ... Wireless section, 6 ... Branching circuit, 7 ... Transmission switch, 8 ... Reception switch, 9 ... … Transmission synchronization switching circuit, 10
...... Reception distribution circuit, 11,21,41 …… Frame synchronization processing circuit, 12,22,42 …… First parity matching circuit, 13,23 …… Parity calculation circuit, 14,24,44 …… Reception signal processing Circuit, 15,2
5,45 …… Second parity matching circuit, 26 …… Parity insertion circuit.

Claims (3)

[Claims] 1. A means for inserting a frame synchronization signal and a parity signal into a data signal in a transmitting side device to convert it into a transmission signal, and a receiving side device for establishing frame synchronization of the transmission signal and generating a synchronization establishment signal. Circuit for digital synchronous multiplexing wireless transmission system having means for extracting and collating the parity signal and outputting a parity collation output signal for collation, and means for performing synchronous switching and system switching by the parity collation output signal. In the switching device, the receiving side device includes means for generating a monitoring signal from the synchronization establishment signal, and means for extracting the monitoring signal and generating a signal for detecting an abnormality in the receiving side device. A line switching device. 2. The supervisory signal is composed of the synchronization establishment signal and a signal generated by performing a parity operation from the synchronization establishment signal, and the supervisory signal is extracted to generate a signal for detecting an abnormality in the receiving side apparatus. The line switching device according to claim 1, wherein the means for performing is a means for performing a parity check on the two signals. 3. The line switching device according to claim 1, wherein the supervisory signal performs a parity operation on the synchronization establishment signal and inserts the output into the parity signal part of the synchronization establishment signal.