JP3116399B2 - Line switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital radio line receiving side switch having protection lines for N working lines.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram of a conventional example (when N = 2). As shown in FIG. 2, line I is the first working line,
Line II is a second working line, and line III is a protection line provided for working lines I and II. The data signal provided as the working I data input passes through a transmission-side switch (hereinafter, referred to as TXSW) 101, is reproduced through a modulator 201, a transmitter 301, a receiver 401, and a demodulator 501, and is reproduced. RXSW) 601 and working I
The data output is provided to a downstream end device or the like. Here, when the line quality of the working line I is deteriorated due to a propagation failure or equipment failure, the connection mode of the TXSW 101 and the RXSW 601 is switched based on the control of the line monitoring controller 801 and the data input of the working line I is performed. Provided to spare line III. That is, the data input of the working line I is reproduced through the modulator 203, the transmitter 303, the receiver 403, and the demodulator 503 and output from the RXSW 601.
The same operation as that of the current line I is performed for the current line II, and the output signal is output from the RXSW 602 via the RXSW 601.

[0003]

However, in such a conventional example, when the signal of the protection line is output to the working line M, it passes through the cable connecting the M RXSWs and the switches. There is a disadvantage that the signal is attenuated or the waveform is deteriorated, so that a prescribed waveform mask cannot be satisfied. In particular, the deterioration increases as the number of N increases.

An object of the present invention is to provide a line switch provided with a means for amplifying a signal attenuated by a receiving switch, a connection cable, and the like.

[0005]

According to the present invention, there is provided an image processing apparatus comprising: N (N ≧ 2 )
A first input, which is provided on the receiving side of a digital wireless line having a protection line with respect to the working line, is connected to each output terminal of the working line, and receives a signal passing through the working line as an input. A terminal, a second input terminal for inputting a signal passing through the protection line, a first and second output terminal connected to the first or second input terminal, and a control terminal, to the control terminal a first of said <br/> first output terminal the first input terminal when the state of the first and second states, said first and said second input terminal Second appearance
And N switches for connecting the second input terminal to the first output terminal when in the second state, the N switches being respectively connected to the second terminal.
In the line switch in which the output terminal of the switch is connected to the first input terminal of the next stage , the second output terminal of the switch is connected to the other output terminal.
The first input terminals of the two switches are sequentially connected (N-
1) Each switch and their inserted into one circuit means
It is characterized by including an amplifier for compensating signal attenuation due to a connecting cable .

[0006]

The gain of the amplifier is set in advance so as to compensate for the attenuation caused by the changeover switch provided on the receiving side and the connection cable connecting the changeover switch.
As a result, an output waveform satisfying the specified mask is obtained.

[0007]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of this embodiment. As shown in FIG. 1, this embodiment is provided on the receiving side of a digital radio line in which a spare line III is provided for two working lines I and II, and each of the working lines I and II A first input terminal for inputting a signal passing through the working line, a second input terminal receiving a signal passing through the protection line, and a first or second input terminal. A first or second output terminal connected to the terminal, and a control terminal, and when the control terminal is in the first state of the first and second states, the first input terminal is connected to the second input terminal. Two switches 601 and 602 which are connected to one output terminal and are connected to the second input terminal and the first output terminal when in the second state. The second output terminals of switches 601 and 602 and one other switch. First inserted sequentially one circuit means for connecting the input terminal amplifier 701
including.

Next, the operation of this embodiment will be described. For example, when a failure occurs in the working line II, the output signal of the protection line is supplied to the amplifier 701 via the RXSW 601 where it is amplified to a required level and output from the RXSW 602. Here, by setting the gain of the amplifier so as to compensate for the amount of attenuation caused by the RXSWs 601 and 602 and the connection cable, it becomes possible to satisfy the output waveform with the specified mask.

[0009]

As described above, the present invention compensates for the attenuation caused by the switch and the connecting cable by using the amplifier between the switches, so that a specified signal can be supplied to the output terminal.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing the configuration of a conventional example.

[Explanation of symbols]

 101, 102 Transmission switch 105 Pilot signal generator 201, 202, 203 Modulator 301, 302, 303 Transmitter 401, 402, 403 Receiver 501, 502, 503 Demodulator 601, 602 Reception switch 605 Pilot signal detector 701 Amplifier 801 Line monitoring and control device

Claims (1)

(57) [Claims] 1. A receiving side of a digital radio line having a protection line for N (N ≧ 2 ) working lines, connected to each output terminal of the working line, and A first input terminal that receives a signal passing therethrough, a second input terminal that receives a signal passing through the protection line, and first and <br / connected to the first or second input terminal. > a second output terminal, a control terminal and has a first of the first when the state is the input terminal a first output terminal of the control terminal first and second states The second above
Are connected to the second output terminals, respectively ,
Comprises N switch for connecting the second input terminal to the first output terminal when a second state, respectively the N switches, the second output terminal is the next stage
In the line switching device connected to the first input terminal, the second output terminal of the switch and the first input terminal of another switch are sequentially connected and inserted into (N-1) circuit means. Each switch and the cables connecting them
A line switch comprising an amplifier for compensating for signal attenuation caused by the line switch.