JPH0319442A - Equal loss switching system - Google Patents

Abstract

PURPOSE:To prevent a signal level sent to a carrier terminal station from being changed by selecting a unipolar/bipolar(U/B) converter when the active channel switch of a fault active channel is reset and turning on a standby channel switch. CONSTITUTION:N active channel switches 3 are provided on the active channel, and a select conversion means 4 having N U/B converters and a selector using a unipolar switch(USW) and N standby channel switches 5 whose passing loss is nearly the same as that of the active channel switches are provided on a standby channel. Then 1st and 2nd driving signals and a selecting signal are applied simultaneously to control the two switches and the selector, thereby switching a faulty active channel into the standby channel. In this case, the passing loss of the active and standby channel switches is the same. Then even when any active channel is switched to the standby channel, the signal level sent to the carrier terminal station is unchanged.

Description

[Detailed Description of the Invention] [Summary] For example. Regarding the equal-loss switching method used in a multiplex radio system with N working channels and 11 reserve channels, the purpose is to ensure that the signal level sent to the carrier terminal station does not change no matter which working channel is switched to the reserve channel. Digital multiplexing! In the Ii # line system, the receiving side includes a working channel switcher that passes or blocks the output of the working univola/bipolar converter according to the input first drive signal, and a built-in N
A selection/conversion means that selects a corresponding unipolar/bipolar converter from among the unipolar/bipolar converters and converts the unipolar pulse taken out in the spare channel into a bipolar pulse, and a passage loss that is almost the same as that of the current channel switch. It has A spare channel switching device and a control unit are provided to pass or block the output of the selection/conversion means according to the inputted second drive signal, and when a failure occurs in the working channel, the control unit uses the inputted failure information to The first and second drive signals and the select signal are simultaneously sent to turn off the working channel switch of the faulty working channel and select the unipolar/bipolar converter. Be prepared to turn on the backup channel switch.

[Industrial application field]

The present invention relates to an equal-loss switching method used, for example, in a multiplex radio system having N working channels and one protection channel.

In general, important equipment on the transmission path is equipped with spares to compensate for deterioration in transmission quality or line disconnection caused by fading in the transmission path or failure of equipment that composes the transmission path.

One method of arranging this backup equipment is to prepare a backup channel using a different frequency in addition to the working N channel in advance, and then switch to the backup channel when a failure occurs in the working channel. It is necessary to ensure that the signal level sent to the carrier terminal station does not change no matter which working channel is switched to the protection channel.

[Conventional technology]

FIG. 3 shows a line configuration diagram. The operation will be explained below assuming that the number of active channels is If and the number of backup channels is 1.
Since the operation is the same for each channel, it is performed for the current channel H.

Note that 8 working channels M2~gate. and spare channel P
The configuration of is the same as that of the l1 working channel, so it is omitted. Also, the AT working channel is abbreviated as the M1 channel, and the protection channel is abbreviated as the P channel.

(i) In the case of normal operation of the Ml channel, first. The bibolar pulse train (hereinafter abbreviated as B pulse) sent from the transmitting carrier terminal station is sent to the Ill transmission parallel switch T on the transmitting side.
SW, (hereinafter abbreviated as TSW), is applied to the code processing circuit l1, and an internal bibular/unipolar converter 111 (hereinafter abbreviated as B/U converter) converts the unipolar pulse train (hereinafter, U pulse) into )
After the signal is converted into , code processing such as serial/parallel conversion and addition of a frame synchronization signal for the wireless section and a digital control signal is performed.

Then, the code-processed signal is sent from the transmitting section of the wireless transmitting/receiving device l2 to the receiving side at a predetermined frequency and power.

On the receiving side, the receiving section of the wireless transmitter/receiver 13 extracts the U pulse from the received signal and applies it to the code processing circuit 14. Here, after performing the reverse processing to the transmitting side through the #1 unipolar switch (hereinafter abbreviated as USW) composed of an IC to be described later, the unipolar/bipolar converter 1
41 (hereinafter abbreviated as U/B converter) into 8 pulses, and #l reception switch circuit (hereinafter referred to as RSl'lI
(abbreviated as ) to the receiving carrier terminal station.

(2) In the case of a failure in the Ml channel When the line switching device 18 on the receiving side detects a failure in the H channel, the information is sent to the supervisory control device 16, so this control device determines whether the P channel is normal or not. After confirming that it is unused, it sends a sending end parallel request signal to the sending end via the digital control line. Therefore. The transmitting side uses a drive signal from the line switching control device l5 to switch off the faulty line. That is, by driving ↑S- of the M1 channel, the B pulse from the transmitting carrier terminal is also sent to the P channel. As a result, the receiving side knows that 8 pulses have been sent to the P channel. For example, after confirming with RS'flll, RSW. driving the moon,
Switching from channel to P channel is completed. In a digital multiplex radio system, synchronization is lost and code errors occur when lines are switched due to fading, but in order to prevent this, synchronization is established between the working channel and the backup channel in advance, and the While maintaining synchronization using υSW. It is designed to switch lines without any interruption. Next, FIG. 4 shows an example of a conventional configuration diagram of a receiving side switching circuit, which is the receiving side RSII part in FIG. 3. In the figure, RSW is a coaxial type relay for turning on/off the B pulse, and the contacts rlI-. ~rl, 1. It consists of four contacts, two input terminals and two output terminals, and the input signal from the five terminals IN-1 can be output from the terminal OUT-1. The input signal from terminal IN-2 can be output from terminal OUT-1 or OUT-2.
There is a loss of B. Furthermore, the configuration of RSHt-RSW■ is RS
It is the same as W.

[Problem to be solved by the invention]

Here, from Fig. 4, we calculate the RSWI passing loss before and after the I'll channel switches to the P channel. In the former case, it passes through two contacts of r l l-1 + r l I-4, so it is approximately 0.6 dB, and in the latter case, r i r-t
Since it passes through two contacts: +rl r-z, it does not change by about 0.6 dB.

However, if we calculate the passing loss for the +MI1 channel in the same way as above. In the former case, approximately 0.6 dB passes through two contacts.
, in the latter case, it passes through the l2 contact and becomes about 3.6 dB, resulting in a change in passing loss of about 3 dB.

That is. There is a problem in that the signal level sent to the carrier terminal station changes depending on which working channel is switched to the protection channel. The purpose of the present invention is to prevent the signal level sent to the carrier terminal station from changing no matter which working channel is switched to the protection channel. [! ! ! Means for Solving the Problem] Figure 1 shows a block diagram of the principle of the present invention. In the figure, numeral 3 denotes a current channel switch that passes or blocks the output of the current unipolar/bipolar converter depending on the input first drive signal. In addition, 4 uses the input select signal to select the corresponding unipolar/bipolar converter (412) from among the N built-in unipolar/bipolar converters, and converts the unipolar pulse extracted from the spare channel into a bipolar pulse. 5 is a spare channel switch which has almost the same passing loss as the current channel switch and passes or blocks the output of the select/convert means according to the input second drive signal; 1 6 is the control section.

When a fault occurs in the working channel, the control unit uses the input fault information to simultaneously send out the first and second drive signals and a select signal to turn off the working channel switch of the faulty working channel. , select the unipolar/bipolar converter, turn on the backup channel switch, and switch the faulty working channel to the backup channel.

[Effect]

In order to make the passing loss in the working channel the same as the passing loss when switching from the working channel to the backup channel, the present invention is designed to match the number of switching from the output side of the 1/B converter to the B pulse output end (A). All you have to do is let it happen. For this reason, a selection/conversion means 4 having N working channel switchers 3 for the working channel and a selector using the aforementioned USW and N υ/B converters for the backup channel.
and N spare channel switchers 5 having almost the same passing loss as the current channel switcher, and control the two switchers and the selector by simultaneously applying the first and second drive signals and the select signal. The failed working channel is now switched to the backup channel.

At this time, since the pass-through loss of the working and protection channel switchers is the same, the signal level sent to the carrier terminal station does not change no matter which working channel is switched to the protection channel. [Embodiment] FIG. 2 shows a block diagram of an embodiment of the present invention.

here. Relay contact RLI-1RLI-! ．． Resistance RI
+ The hybrid 31 is a component of the current channel switch 3, AND gates 411, 4111, U/B converter 412. 4112 is a component of the selection/conversion means 4, and a relay contact RL+-x. RL+-4.
Rz indicates a control section of the backup channel switch 5. still,
The same symbols indicate the same objects throughout the figures. Further, the control section is not shown as it is included in the supervisory control device in FIG.

The operation shown in FIG. 2 will be described below, but since the operation of the working channel and the switching operation from the working channel to the protection channel are the same, the operation will be performed for the M1 channel.

(1) M. In the case of normal channel operation, on the receiving side, the receiving section of the wireless transmitter/receiver (not shown) extracts the pulse from the received signal, performs the reverse code processing as on the transmitting side, and then sends it to the U/B converter 21. In addition, convert it to B pulse. Contacts RL+-+, RL+-z. It is sent to the carrier terminal station via the hybrid 31.

At this time, the contacts RLI-:l and RLI-4 are in the solid line state, so the hybrid 3l is not connected to the U/B converter 412. (2) When a failure occurs in the L channel If a failure occurs in the M1 channel. The first one from a supervisory control device (not shown). With the second drive signal, contact RLI-,
~RL, -4 becomes a dotted line state and H level I
JSW, the select signal is applied to AND gate 4l1, so this gate is turned on. Therefore, the connection between the υ/B converter 21 and the hybrid 31 is disconnected, but A
Since the ND gate 411, the U/B converter 412, and the hybrid 3l are connected, the pulse from the P channel is converted into a B pulse and sent out via the hybrid 31. Here, in the case of +Ml1 channel, U/B converter 21
The number of contacts from 1 to hybrid 311 and the number of contacts from υ/B converter 4112 to hybrid 311 are both two, and the same is true for the other channels. This results in
No matter which working channel is switched to the backup channel, the signal level sent to the carrier terminal station does not change. In the figure, 2 is a unipolar/bipolar converter, 3 is a working channel switch, 4 is a selection/conversion means, and 5 is a backup channel switch.

〔Effect of the invention〕

As explained in detail above, the present invention has the effect that the signal level sent to the carrier terminal station does not change no matter which working channel is switched to the protection channel.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the principle of the present invention; Fig. 2 is a block diagram of an embodiment of the present invention.
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Claims (1)

[Claims] It has N working channels (N is a positive integer) and 1 spare channel, and when the working channel is operating normally, the transmitting side converts the input bipolar pulses into unipolar pulses, performs code processing, and sends them out. However, on the receiving side, after extracting the unipolar pulse from the received signal and performing reverse code processing,
The bipolar converter (2) converts it into a bipolar pulse and outputs it. In a digital multiplex radio system that switches the failed working channel to a backup channel when a working channel failure occurs, the first drive signal input to the receiving side A current channel switch (3) that passes or blocks the output of the current unipolar/bipolar converter, and a corresponding unipolar/bipolar converter ( 412
) and converts the unipolar pulse taken out in the spare channel into a bipolar pulse; - A backup channel switch (5) and a control unit (6) are provided to pass or block the output of the conversion means, and when a failure occurs in the working channel, the control unit uses the input failure information to switch the first channel to the first one. , simultaneously transmits the second drive signal and the select signal to turn off the working channel switch of the faulty working channel, selects the unipolar/bipolar converter, and turns on the spare channel switch to turn the faulty working channel into a spare channel. An equal-loss switching method characterized by switching.