JPH0223727A - Service channel transmission system - Google Patents

Abstract

PURPOSE:To improve the reliability of a radio station, to lower the operation frequency of a diode switch used for an intermediate frequency attenuator and to obtain the stability of an operation by eliminating that all the switching of service channels at the time of switching become interrupted due to the equipment fault of the transmission equipment of a host standby system. CONSTITUTION:The branching circuit 30 of the transmission equipment of radio relaying branches a main signal Sin which an input transmits into a present system 10 and a standby system 20. The present system 10 pre-amplifies one main signal branched in the circuit 30, and the standby system 20 does the other main signal. Present and standby service channel signals SC1 and SC2 are simultaneously inserted as the modulation signals IF1 and IF2 of an intermediate frequency. When the present signal SC1 is disconnected by the fault occurrence of the present system 10, a directional coupler 40 gives less attenuation to the high frequency output RF1 of the transmitter 13 in the present system and specified high frequency attenuation A required for the high frequency output RF2 of the standby system 20. The coupler 40 is driven by a control signal C and intermediate frequency attenuation B is given to an intermediate frequency attenuator 14.

Description

[Detailed Description of the Invention] [Summary] A telephone signal for a maintenance meeting when a standby radio in microwave radio relay is prepared in a so-called hot standby standby system that can directly replace the working radio in the event of a failure. Regarding the service channel transmission method for transmitting supervisory control signals, the main input source is The signal is split into two and the intermediate carrier wave is modulated with each main signal to form an intermediate frequency modulation signal, which is mixed with a local carrier wave and converted into the high frequency main signal.
It has two sets of transmitters with the same configuration that modulate and insert the service signal SC of a wired telephone, etc., and outputs a high-frequency main signal and a service signal. In a service channel transmission method in which the service signal SC2 of the other protection system is transmitted in place of the service signal SC2 when the connection is interrupted, the attenuation is small for the transmission output of the working system, and the necessary constant level is maintained for the transmission output of the protection system. a directional coupler that provides a high frequency attenuation of , and an intermediate frequency attenuation B that is driven by a control signal C and is sufficiently larger than a constant high frequency attenuation A of the directional coupler for a modulation signal of an intermediate frequency of the current system. The intermediate frequency attenuator is provided with an intermediate frequency attenuator to apply an intermediate frequency attenuator, and the intermediate frequency attenuator is driven by a control signal C generated due to a fault in the working system when the current service signal SC, is interrupted, and the intermediate frequency attenuator is driven by a control signal C generated by a fault in the working system when the current service signal SC is interrupted. It is configured to apply frequency attenuation to suppress the transmission output of the working system and to transmit the protection system service signal SC2 instead.

[Industrial application field]

The present invention relates to a service channel transmission method for transmitting maintenance worker meeting telephone signals and supervisory control signals in microwave radio relay, and in particular to a so-called hot standby backup method in which a backup radio can directly replace a working radio in the event of a failure. The present invention relates to a service channel transmission method in the case of

[Conventional technology]

As shown in Fig. 3, the wireless relay transmitter using the true standby backup system splits the input main signal Sin to be transmitted into two using a hybrid H30A, pre-amplifies and modulates one of the main signals, and then outputs power. A working system 10A that amplifies and transmits and a standby system 2OA that similarly processes and transmits the other main signal are prepared, and the high frequency output of the transmitter TX 13^ of the working system 10A and the transmitter TX of the standby system 20A are prepared. The switch SW 40A that switches the high frequency output of 23A is the active system 1
0A preamplifier TDP IIA, modulator MOD I2
A, transmitter TX 13A and preamplifier TDP 21A of standby system 20A, modulator MO022A, transmitter TX
The fault information ALM of 23A is AND-processed by gates 15A and 25A, and an alarm is output, and the control unit C0NT 50
A control signal C is generated at A and driven and switched by the control signal C. As the switch SW 40A, a two-power, one-output type switch is normally used that is constructed of a diode with low passing loss in a high frequency band.

The service channel signal SC that transmits the telephone signal and supervisory control signal of the wireless station maintainer to the other wireless station is
For analog wireless relay, the modulator MOD 12 shown in the figure
A. MOD 22A or transmitter TX 13A, 23
It is sent to the next radio station as an analog service channel ^SC which is analog-modulated by PM modulation to a transmitting local oscillator (not shown) inside A (in the case of hetero gain relay), and is sent to the next radio station as an i-key 11M0D 12 in digital radio relay.
A, MOD 22A performs digital processing to generate a pulse signal synchronized with the frame of the main signal, inserts it into the main signal as a digital service channel DSC, and sends it to the active system 10A and protection system 2OA transmitters TX 13A and TX 238. and transmits it to the next radio station.

And the working SC3 and standby SC2 of the service channel SC.
The switching is performed in dependence on the switching of the main signal by the two-man power one-output switch SW 40A.

[Problem to be solved by the invention]

As mentioned above, the conventional service channel transmission method in wireless relay uses the working channel SC1 and the protection channel SC1.
, is performed in dependence on the switching of the main signal by the two-manpower one-output switch SW 40A, so the switch 5-
40 becomes an obstacle, the path with the least passing loss will be fixed to either the active side 10A or the backup side 20^, but it is not always fixed to one side, so if the active side 10A
When A becomes a failure and the current service channel S61 becomes unavailable, the switch 5-40^ also becomes a failure and the path with less passing loss is fixed to the current side 10A.
There is a problem in that switching from the active service channel SC4 to the backup SC2 is not performed, resulting in a blind state in which the service channel SC is completely disconnected, making it impossible to transmit telephone signals and supervisory control signals to the next radio station. be.

The present invention aims to solve the above problems.

[Means to solve the problem]

This problem is solved by the conventional high-frequency diode switch S.
Instead of W 40A, as shown in FIG. 1, the high frequency output RPI of the transmitter 13 of the active system 10 has less attenuation and is passed through, and the output RF2 of the transmitter 23 of the protection system 20 is used.
For this purpose, a directional coupler 40 is used which provides attenuation of a certain amount AdB necessary to avoid adversely affecting the transmission of the working system 10. Furthermore, when the intermediate frequency signal IFI output from the modulator 12 is normally not driven, the attenuation is zero and it is passed through, and when driven by the control signal C in the event of a failure, the backup system transmission of the directional coupler 40 is performed. An intermediate frequency attenuator 14 that provides an attenuation amount BdB that is sufficiently larger than an attenuation amount AdB to the output RF2 of the device 23 is provided, and the intermediate frequency attenuator 14 is
This problem is solved by the present invention, in which the control unit 50 is configured to drive an active system alarm, which collects failure information ALM of each part of the active system 10, as a control signal C.

In the principle diagram of FIG. 1 showing the configuration of the service channel transmission system of the present invention, 10 is a branch circuit 3 for transmitting an input main signal Sin to be transmitted.
0, one of the main signals is preamplified to become an intermediate frequency modulation signal IFI, and at the same time, the active part of the service channel signal SC+ is inserted into the main signal, mixed with the local carrier wave, and frequency converted to a high frequency signal. This is the active system of the transmitter that amplifies the power and transmits it.

20 splits the input main signal Sin into two at the branch circuit 30, amplifies the other main signal and converts it into an intermediate frequency modulation signal, and at the same time inserts the spare part SCz of the service channel signal into the main signal, thereby converting the frequency into a high frequency signal. This is a backup system of the transmitter that converts, amplifies, and transmits power.

30 is an input main signal Sin to be transmitted to the working system 10.
This is a branch circuit that branches into two to the standby system 20.

40 has low attenuation for the high-frequency transmission output RFI of the active system 10 and passes through to the transmission specific power RF of the protection system 20.
2 is a directional coupler that provides attenuation of a certain amount A dB necessary to avoid adversely affecting communication in the working system 10.

14 is the intermediate frequency signal output from the modulator 12 in the working system.
Compared to F5, when not driven, there is less attenuation and it becomes a through,
When driven by the control signal C, the directional coupler 40
Attenuation amount AdB for the output RF2 of the standby transmitter 23 of
This is an intermediate frequency attenuator that provides a sufficiently larger attenuation amount BdB.

Reference numeral 50 denotes a control unit that collects and gates operation information ALM of each part of the active system 10 and generates a fault information alarm for the active system, and uses the generated alarm for the active system as a control signal C to send to an intermediate frequency attenuator. 14.

[Effect]

In the radio relay transmitting device of the present invention, the branch circuit 30 sends an input main signal Sin to be transmitted to the active system 10 and the standby system 20.
The working system 10 preamplifies one main signal branched by the branch circuit 30, and the protection system 20 preamplifies the other main signal, respectively, and converts them into intermediate frequency modulation signals rFl and IP2, and simultaneously outputs the working and protection service channels. The signals SC+ and SCz are inserted into the respective main signals, mixed with a local carrier wave, frequency-converted to a high-frequency signal, and power amplified by the transmitter 13. Send to next station.

The directional coupler 40 has little attenuation for the high frequency output RFI of the transmitter 13 of the working system 10 and passes through it, and attenuates the high frequency output RF2 of the transmitter 23 of the protection system 20 by a certain amount AdB. Therefore, the output R of the standby system 20
F2 does not interfere with the transmission quality of the active system 10 during normal operation.

The intermediate frequency attenuator 14 has little attenuation and passes through the intermediate frequency signal IFI output from the modulator 12 of the working system when it is not driven normally, so there is no problem with transmission by the normal working system, and the intermediate frequency signal IFI output from the modulator 12 of the working system When driven by the control signal C from the control unit 50 at the time of system fault alarm, the attenuation B dB which is sufficiently larger than the attenuation amount A dB of the directional coupler 40 for the output of the standby system transmitter 23 is applied to the intermediate frequency of the active system 10. Since it is added to the signal IFI to suppress it, it does not adversely affect the transmission by the protection system 20.

The control unit 50 separately collects and processes the failure information ALM of each part of the active system 10 and the backup system 20 and generates an alarm for the active system and an alarm for the backup system separately, and controls the generated alarm for the active system. intermediate frequency attenuator 14 as signal C
to drive.

In the case of a digital type, the service channel SC is input in parallel to the intermediate frequency modulator 14 of the working system 10 and the intermediate frequency modulator 24 of the protection system 10, and is digitally processed, respectively, and is synchronized with the frame of the main signal. A pulse signal digital service channel DSC, and its active output DS
C, and a preliminary output DSC, are inserted into each main signal.

The working output OSC is then connected to the working transmitter 13 and the directional coupler 40 via the intermediate frequency attenuator 14 of the working system 10.
The signal is then sent to the next station.

In addition, in the case of an analog type, the service channel SC includes a local oscillator for frequency conversion to a high frequency signal inside the intermediate frequency modulator 12 of the active system 10 or the transmitter 13, and an intermediate frequency modulator of the protection system 10. It is input in parallel to the local oscillator of the transmitter 22 or the transmitter 23 and subjected to analog modulation such as FM modulation, and becomes an analog service channel signal ASC.The working output ASCl and standby output ASC2 are inserted into the respective analog modulated main signals, and the working output The output ASC is similarly sent to the next station via the intermediate frequency attenuator 14, the current transmitter 13, and the directional coupler 40.

In both digital and analog systems, when the active system 10 issues failure information ALM and the active service channel SC1 becomes disconnected, the control signal C generated by the control unit 50 due to the active system alarm is activated. The intermediate frequency attenuator 14 inserted in the working system 10 is driven, and the working output SC of the intermediate frequency IFI, which is the output of the working modulator 12, is suppressed by the sufficiently large attenuation BdB of the intermediate frequency attenuator 14, and the working output SC, which is the output of the working modulator 12, is suppressed. Since the service channel S62 of the output IF2 of the backup modulator 22 is sent to the next station by the transmitter 23 of the backup system 20 via the directional coupler 40, the service channel SC is no longer disconnected and the problem is solved.

〔Example〕

FIG. 2 shows a digital relay service channel transmission method according to the first embodiment of the present invention, and FIG. 3 shows a wireless relay service according to the second embodiment of the present invention. This is an example of an analog channel transmission method.

In the transmitter in the digital embodiment shown in FIG. 2, the branch circuit 30 is configured as a hybrid, and the active
0 and the preamplifiers 11 and 21 of the backup system 20 are the preprocessor TD.
P, intermediate frequency modulator 12.22 is 4-phase PSK
The intermediate frequency attenuator 14 is composed of a single-manufactured one-output switch using an intermediate frequency diode.

Then, the branch circuit 30 receives the input main signal Sin to be transmitted.
is branched into two into the active system 10 and the backup system 20, and the active system 10 is
The branch circuit 30 preprocesses one of the main signals branched, and the backup system 20 preprocesses the other main signal in each TDP of the preamplifier 11.21, and outputs it to MOD of PSK modulation of the intermediate frequency modulator 12.22. A PSK modulated signal is obtained. Then, the intermediate frequency modulator 12.22 of the FSX modulation MOD simultaneously inserts the working and backup service channel signals DSC, , DSC, into the respective PSK main signals, and the transmitter 13.23 converts them into high frequency signals. Frequency converted and power amplified high frequency signals RF1, R
F2 is output and transmitted to the next station via the directional coupler 40.

The directional coupler 40 is configured with a directional coupler having a coupling degree of 30 dB, for example, and has little attenuation for the high-frequency output RFI of the transmitter 13 of the active system 10 and passes through the transmitter 23 of the protection system 20. Since a certain amount of attenuation of 30 dB is given to the high frequency output RF2 of the protection system 20, the output RF2 of the protection system 20 does not interfere with the transmission quality of the normal working system 10.

The intermediate frequency attenuator 14 is composed of a single-power, single-output switch using an intermediate frequency diode whose attenuation amount B during operation is, for example, 60 dB, which is twice the coupling degree of 30 dB of the directional coupler 40. When the intermediate frequency signal IFI output from the modulator 12 is normally not driven, attenuation is small and the signal is passed through, so there is no problem in transmission by the working system. When driven by the control signal C from the control unit 50 when the active system 10 has a failure, the attenuation 60 of the directional coupler 40 with respect to the output RF2 of the standby system transmitter 23 is sufficiently larger than 30 dB.
dB as the intermediate frequency signal I of the output of the modulator 12 of the working system 10
Since it is applied to the FI and suppressed, it does not adversely affect the transmission by the backup system 20. Note that when the intermediate frequency attenuator 14 itself fails, there is no problem because the attenuation only becomes a very large value.

The control unit 50 controls the preamplifiers 1 of the working system 10 and the standby system 20.
1.21, intermediate frequency modulator 12, 22, transmitter 13
．． 15.2 Operation information ALM of each part of 23
5 are individually collected and processed to generate a working system alarm and a standby system alarm separately, and only the generated working alarm generates a control signal C to drive the intermediate frequency attenuator 14.

The service channel DSC includes a modulator 14 of the intermediate frequency PSK of the working system 10 and an intermediate frequency PSK of the protection system 10.
A digital service channel DSC is an intermediate frequency pulse signal synchronized with the main signal frame of each PSK, which is input in parallel to the K modulator 24 as DSC and DSC2, and is digitally processed. DSC2 is inserted into the main signal of each PSK. The working output DSC is then connected to the working transmitter 13 and the directional coupler 40 via the intermediate frequency attenuator 14 of the working system 10.
The signal is then sent to the next station.

Also, in the case of the analog type, as shown in FIG. 3, the configuration and operation of the directional coupler 40 and intermediate frequency attenuator 14, which are the main parts of the present invention, are exactly the same as in the digital type shown in FIG. be. However, the service channel SC includes the intermediate frequency modulator 12 of the active system 10 or the local oscillator T, LOG for frequency conversion to a high frequency signal inside the transmitter 13, and the intermediate frequency modulator 22 of the protection system 10. Alternatively, it is input in parallel to the local oscillator T and LOG of the transmitter 23 as the working ASC, and the standby ASC2, and is subjected to analog modulation such as FBI modulation to become an intermediate frequency analog service channel signal ASC, and the working output ASC, standby output ASC, are respectively inserted into the analog modulated main signal, and the current output ^SC1 is sent to the intermediate frequency attenuator 14 as in the case of the digital system.
The signal is sent to the next station via the current transmitter 13 and directional coupler 40.

In both digital and analog systems, the preamplifier 11 . Intermediate frequency modulator 12
．． When the current service channel SC1 is disconnected due to a failure in any of the parts of the transmitter 13, the control signal C generated by the control unit 50 in response to the current system alarm output from the AND gate 15 causes the current system 10 to be disconnected. drives the intermediate frequency attenuator 14 inserted in the intermediate frequency attenuator 14 to reduce the attenuation amount 60
The intermediate frequency IFI of the output of the current modulator 12 in dB
The output RF of the current transmitter 13 by attenuating the
I is suppressed by 60 dB, and the directional coupler 40 sends out the backup service channel S02 to the next station using the backup output RF2 whose level is 30 dB higher than the current output RFI. Therefore, in both the case of the digital system shown in FIG. 2 and the case of the analog system shown in FIG. 3, although the level of the service channel SC is low, there is no problem because it is never interrupted.

〔Effect of the invention〕

As explained above, according to the present invention, service channel switching is never interrupted when switching due to a device failure in a real standby protection type transmitting device, so the reliability of maintenance services for wireless stations is improved. Effects can be obtained. In addition, the directional coupler for switching the high frequency output of the transmitter output is cheaper and more reliable than the conventional high frequency operation and high attenuation diode switch, and the intermediate frequency attenuator. The diode switch used for this has a low operating frequency, simple configuration, and can easily achieve high attenuation, which is effective in reducing costs. Furthermore, since only the current alarm system is sufficient for generating the control signal for driving the intermediate frequency attenuator, there is an effect of further cost reduction.

[Brief explanation of the drawing]

FIG. 1 is a principle diagram showing the configuration of the service channel transmission system of the present invention, FIG. 2 is a block diagram showing the configuration of the service channel transmission system of the first embodiment of the invention, and FIG. FIG. 4 is a block diagram showing the configuration of the service channel transmission system according to the second embodiment, and FIG. 4 is a block diagram of the conventional service channel transmission system. In the figure, 10 is a working system, 20 is a backup system, 12.22 is an intermediate frequency modulator, 14 is an intermediate frequency attenuator,
13.23 is a transmitter, 30 is a branch circuit,

Claims (1)

[Claims] The input main signal (Sin) is branched into two, and an intermediate carrier wave is modulated with each main signal to generate intermediate frequency modulation signals (IF1, IF
2) A service signal (SC) such as a meeting telephone is modulated and inserted into the main signal of the high-frequency signal which is mixed with a local carrier wave and frequency converted, and a high-frequency main signal and a service signal are output (RF
1, RF2), and when the active service signal (SC_1) is interrupted due to a failure in one active system (10), the other backup system (2
In the service channel transmission method in which the service signal (SC_2) of the active system (10) is transmitted in place of the service signal (SC_2), there is little attenuation with respect to the transmission output (RF1) of the working system (10), and the service signal (SC_2) of the protection system (
a directional coupler (40) that provides a necessary constant high frequency attenuation (A) to the transmission output (RF2) of the active system (10); and an intermediate frequency modulation signal (IF1) of the working system (10).
On the other hand, the directional coupler (
The intermediate frequency attenuator (14) provides an intermediate frequency attenuation (B) that is sufficiently larger than the constant high frequency attenuation (A) of 40), and when the current service signal (SC_1) is interrupted, the current system (
The intermediate frequency attenuator (14) is driven by the control signal C generated due to the failure in the current system (10), and a sufficiently large attenuation (B) is applied to the intermediate frequency modulation signal (IF1) of the current system (10). A service channel transmission system characterized by suppressing the transmission output (RF1) of the system (10) and transmitting the service signal (SC_2) of the protection system (20).