JPH04324721A - Line changeover device - Google Patents

Abstract

PURPOSE:To implement changeover uninterruptibly and to avoid deterioration in the line quality. CONSTITUTION:An output signal string from an active transmission/reception code conversion circuit 21a and a standby transmission/reception code conversion circuit 21b is subjected to 1/n frequency division by 1/n frequency divider circuits 31a, 31b respectively into n-sets of signal strings to widen a one bit width. A selector 32 changes over simultaneously n-sets of signal strings of an active line and n-sets of signal strings of a standby line.

Description

[Detailed description of the invention]

0001

FIELD OF INDUSTRIAL APPLICATION The present invention is applied to a line switching device for digital wireless communication. In particular, an n-divider circuit is installed before the selector to switch the line to the working side (0 system) when a failure occurs in the signal train from the multiplex converter or when performing equipment maintenance.
The present invention relates to a line switching device that switches from a line to a standby side (system 1) without momentary interruption.

0002

2. Description of the Related Art FIG. 2 is a block diagram of a conventional line switching device.

Conventionally, line switching equipment switches the working line to a protection line using a selector in the transmission code processing circuit of the line switching equipment when a failure occurs in the signal train on the working side or when maintenance is performed on the equipment. was.

In FIG. 2, 11a is a multiplex conversion device 1
Transmission/reception code conversion circuit on the active side (0 system) in 0, 11b
21a is a transmitting/receiving code converting circuit on the protection side (1 system) in the multiplex converter 10, 21a is a transmitting/receiving code converting circuit on the working side (0 system) in the line switching device 20, and 21b is a transmitting/receiving code converting circuit on the active side (0 system) in the line switching device 20.
A transmitting/receiving code converting circuit on the protection side (system 1) and a transmitting code processing circuit 30 include a selector 32 for selecting a working line or a protection line.

[0005] In the above-mentioned digital radio communication, switching of the signal train between the multiplex conversion device 10 and the line switching device 20 is performed by the transmission code processing circuit 30.

[0006]

[Problem to be Solved by the Invention] However, in such conventional line switching equipment, the switching of the signal train between the multiplex converter and the line switching equipment was performed only by the selector, and therefore, the switching between the working line and When there is an absolute fixed phase difference in the protection line, there is a problem that switching is not performed without momentary interruption and the line quality deteriorates when maintenance is performed.

[0007] The present invention solves the above problems.
It is an object of the present invention to provide a line switching device that can perform switching without momentary interruption and does not deteriorate line quality.

[0008]

[Means for Solving the Problems] The present invention provides a working transceiver code conversion circuit that receives a signal train transmitted from a multiplex converter via a working line and performs code conversion, and a standby code converter circuit that receives a signal string transmitted from a multiplex converter via a working line and converts the code. Select a protection transmission/reception conversion circuit that receives and code-converts the signal string transmitted via the line, and selects the working system code-converted signal string to be input and the protection-system code-converted signal string to be input. In the line switching device, the transmission code processing circuit divides the output signal of the active transmission/reception code conversion circuit by a predetermined frequency division number n. The output signal strings of the working system's n frequency dividing circuit, which provides the code-converted signal string of the working system, and the transmission/receiving code conversion circuit of the protection system are divided by the predetermined frequency division number n, It is characterized in that it includes a preliminary n-divider circuit that provides a code-converted signal sequence.

Further, in the present invention, the predetermined frequency division number n is such that the 1-bit width of the output signal string of the n frequency division circuit sufficiently absorbs the absolute fixed phase difference between the working line and the protection line. It is desirable that this is set.

0010

[Operation] The transmission code processing circuit divides the output signal sequence of the transmission/reception code conversion circuit of the current system into n signal sequences by using the n frequency division circuit of the current system, divides it into n signal sequences, widens the width by 1 bit, It is given to the selector as a code-converted signal string, and a backup n frequency divider divides the output signal string of the backup transmitting/receiving code conversion circuit by n, divides it into n signal strings, widens the width by 1 bit, and outputs it as a backup. It is given to the selector as a code-converted signal sequence of the system. The selector switches these n signal strings simultaneously.

Further, the predetermined frequency division number n is set to a number such that the 1-bit width of the output signal string of the n frequency division circuit sufficiently absorbs the absolute fixed phase difference between the working line and the protection line.

[0012] As described above, switching can be performed without instantaneous interruption, and the line quality can be prevented from deteriorating.

[0013]

Embodiments Examples of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a line switching device according to an embodiment of the present invention.

In FIG. 1, the line switching device includes a working transmitting/receiving code converting circuit 21a that receives a signal string transmitted from the transmitting/receiving code converting circuit 11a of the multiplex converter 10 via the working line and converts the code. , a protection transmission/reception conversion circuit 21b that receives the signal string transmitted via the protection line from the transmission/reception code conversion circuit 11b of the multiplex conversion device 10 and performs code conversion, and an input working system code-converted signal string. The transmission code processing circuit 30 includes a selector 32 that selects and outputs an input preliminary code-converted signal sequence.

Here, the feature of the present invention is that the transmission code processing circuit 30 is the transmitting/receiving code converting circuit 21 of the active system.
a current system n frequency divider circuit 3 which divides the output signal sequence of a by a predetermined frequency division number n and provides it as a current system code-converted signal sequence;
1a, and a standby n frequency division circuit 31b which divides the output signal train of the standby transmitting/receiving code conversion circuit 21b by a predetermined frequency division number n and provides the standby code-converted signal train. There is a particular thing.

Further, the predetermined frequency division number n is determined by the n frequency division circuit 31a.
, 31b is set to a number that sufficiently absorbs the absolute fixed phase difference between the working line and the protection line.

The operation of the line switching device having such a configuration will be explained.

In FIG. 1, n frequency divider circuits 31a, 31
b is the distance of the working line (0 system) from the transmitting/receiving code converting circuit 11a to the input of the transmitting code processing circuit 30 and the distance of the protection line (1 system) from the transmitting/receiving code converting circuit 11b to the input of the transmitting code processing circuit 30. By absorbing the difference in distance (absolutely fixed phase difference) (by the widened bit width), it is possible to prevent phase shift due to switching, and to perform uninterrupted switching.

[0019]

As explained above, the present invention has the excellent effect of being able to perform switching without momentary interruption and without degrading the line quality.

[Brief explanation of drawings]

FIG. 1 is a block configuration diagram of a line switching device according to an embodiment of the present invention.

FIG. 2 is a block configuration diagram of a conventional line switching device.

[Explanation of symbols]

10 Multiplex conversion device 11a, 21a Transmission/reception code conversion circuit (currently used 0 system) 1
1b, 21b Transmission/reception code conversion circuit (spare 1 system) 20
, 20A line switching device 30, 30A transmission code processing circuit 31a, 31b n frequency division circuit 32 selector

Claims (2)

[Claims] 1. A working transmission/reception code conversion circuit that receives a signal string transmitted from a multiplex conversion device via a working line and performs code conversion, and a signal transmitted from the multiplex conversion device via a protection line. A transmitter including a backup transmission/reception conversion circuit that receives a sequence and performs code conversion, and a selector that selects and outputs an input working system code-converted signal sequence and an input protection system code-converted signal sequence. In the line switching device comprising a code processing circuit, the transmission code processing circuit divides the output signal sequence of the working transmitting/receiving code converting circuit by a predetermined frequency division number n, and performs code conversion of the working system. The output signal strings of the active system's n frequency dividing circuit and the protection system's transmitting/receiving code conversion circuit are divided by the predetermined frequency division number n to provide the signal string as the protection system's code-converted signal string. 1. A line switching device comprising: a standby-system n frequency divider circuit. 2. The predetermined frequency division number n is set to a number such that the 1-bit width of the output signal string of the n frequency division circuit sufficiently absorbs the absolute fixed phase difference between the working line and the protection line. The line switching device according to item 1.