JPH04282921A - Line changeover device - Google Patents

Abstract

PURPOSE:To obtain an output waveform satisfying a specified mask by presetting a gain of an amplifier compensating the attenuation of a changeover switch provided to a receiver side and a connection cable or the like connecting to the changeover switch. CONSTITUTION:A fault takes place in a current line II, an output signal of a standby line is fed to an amplifier 701 via a receiver side changeover switch 601. Then the signal is amplified at the amplifier 701 up to a required level and the result is outputted from a switch 602. The gain of the amplifier 701 to compensate the attenuation in the switches 601, 602 and a connection cable or the like is set. Thus, a signal of an output waveform with a specified mask is fed to an output terminal.

Description

[Detailed description of the invention]

0001

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

0002

2. Description of the Related Art FIG. 2 is a block diagram of a conventional example (in the case of 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 the working lines I and II. A data signal given as a working I data input passes through a transmitter switch (hereinafter referred to as TXSW) 101 to a modulator 201 , a transmitter 301 , a receiver 401 , and a demodulator 5
01, and the receiving side switch (hereinafter, RXS
601 (referred to as W), and is given to the downstream end-of-carrier equipment, etc. as the current I data output. Here, when the line quality of the current line I deteriorates due to propagation failure or equipment failure, T
The connection modes of XSW 101 and RXSW 601 are switched, and the data input of the working line I is applied to the protection line III. That is, the data input of the current line I is transmitted to the modulator 203, the transmitter 303, and the receiver 403.
, demodulator 503, and output from the RXSW 601. The same operation as the current line I is performed for the current line II, and the output signal is sent to the RXSW60 via the RXSW601.
Output from 2.

0003

[Problems to be Solved by the Invention] However, in such a conventional example, when a signal on the protection line is output to the working line M, it passes through the cable connecting the M RXSWs and the switch. There is a drawback that the signal is attenuated and the waveform deteriorates, making it impossible to satisfy the specified waveform mask. In particular, as the number of N increases, the deterioration increases.

SUMMARY OF THE INVENTION The present invention aims to eliminate these drawbacks, and aims to provide a line switching device equipped with means for amplifying signals attenuated by receiving switches, connecting cables, and the like.

[0005]

[Means for Solving the Problems] The present invention provides N (N≧1)
A first input that is provided on the receiving side of a digital radio line that has a backup line for the main working line, is connected to each output end of the working line, and receives a signal via this working line as input. a terminal, a second input terminal that inputs a signal via the protection line, a first or second output terminal connected to the first or second input terminal, and a control terminal, When this control terminal is in the first state of the first and second states, the first input terminal is connected to the first output terminal, and when the control terminal is in the second state, the above-mentioned second input terminal is connected to the first output terminal. In a line switching device equipped with N switches connected to an input terminal and a first output terminal, the second output terminal of the above switch and the first input terminal of another switch are sequentially connected (N- 1) It is characterized by including an amplifier inserted in the circuit means.

[0006]

[Operation] The gain of the amplifier is set in advance so as to compensate for the amount of attenuation due to the changeover switch provided on the receiving side and the connection cable connecting the changeover switch. This provides an output waveform that satisfies the prescribed mask.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block configuration 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 backup line III is provided for two working lines I and II, and a backup line III is provided for each of the working lines I and II. a first input terminal connected to the output end of the circuit and receiving a signal via the working line;
A second input terminal receives a signal via the protection line, a first or second output terminal connected to the first or second input terminal, and a control terminal. is in the first state of first and second, the first input terminal is connected to the first output terminal, and when in the second state, the second input terminal and the first In addition, as a feature of the present invention, the second output terminals of the switches 601 and 602 and the first input terminal of the other switch are connected to the output terminals of the switches 601 and 602. It includes an amplifier 701 inserted into one circuit means connected in sequence.

Next, the operation of this embodiment will be explained. For example, if a failure occurs in the working line II, the output signal of the protection line is supplied to the amplifier 701 via the RXSW601, where it is amplified to the required level, and
Output from 02. Here, RXSW601, 6
By setting the gain of the amplifier to compensate for the amount of attenuation due to 02 and the connecting cable, it becomes possible to make the output waveform satisfy the prescribed mask.

[0009]

As described above, the present invention uses an amplifier between the switches to compensate for the attenuation caused by the switches and connecting cables, so that it is possible to supply a specified signal to the output terminal.

[Brief explanation of the drawing]

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

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

[Explanation of symbols]

101 , 102 Transmission switch 105 Pilot signal generator 201 , 202 , 203 Modulator 301 , 3
02, 303 transmitter 401, 402, 40
3 Receivers 501, 502, 503 Demodulators 601, 602 Reception switch 605 Pilot signal detector 701 Amplifier 801 Line monitoring control device

Claims (1)

[Claims] [Claim 1] Provided on the receiving side of a digital radio line in which a protection line is provided for N (N≧1) working lines, connected to the output end of each of the working lines, and connected to the output end of each of the working lines. a first input terminal to which the signal passing through the protection line is input; a second input terminal to which the signal passing through the protection line is input; and a first or second input terminal connected to the first or second input terminal. having an output terminal and a control terminal, and connecting the first input terminal to the first output terminal when the control terminal is in a first state of the first and second states;
In a line switching device comprising N switches that are connected to the second input terminal and the first output terminal when in a second state, the second output terminal of the switch is connected to the second output terminal of the other switch. A line switching device comprising an amplifier inserted in (N-1) circuit means for sequentially connecting first input terminals.