JPS6231226A - Circuit supervision switching system - Google Patents

Abstract

PURPOSE:To supervise the quality of a transmission side by forming a switching circuit for selectively outputting any one of outputs of two modulating circuits and inputting the output to any one of two demodulating circuits and supervising the quality of a transmission line by the switching circuit. CONSTITUTION:If the quality of a transmission line used as a circuit is deteriorated and an alarm is generated in a demodulating circuit 9A, a switch 8 is connected as shown by a dotted line when the other transmission line which is not selected as a circuit and looped back within its station is normal. If no alarm is generated in a demodulating circuit 9B after said switching, a reception switching circuit 10 is switched and a switch 7 is simultaneously connected as shown by a broken line. Said operation saves the receiving circuit through the transmission line passing a receiving circuit 6B and the demodulating circuit 9B. When a receiving alarm is generated from the opposite station, the receiving circuit can not be saved by the switching of the receiving side in the opposite station and the transmitting side is switched in a terminal station, a transmission switching circuit 5 is switched and a switch 3 is connected as shown by a broken line. Consequently, the transmission circuit can be saved by a modulating circuit 2B and a transmitting circuit 4B.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a line monitoring switching system, and more particularly to a line monitoring switching system for a one-to-one set backup hot standby carrier communication line.

[Conventional technology]

If radio frequency allocation is small, one-to-one allocation to wireless communication lines
A set-preparation hot-standby method is often used.

FIG. 2 is a block diagram showing an example of a terminal station of such a line using a conventional line monitoring switching system.

The terminal station shown in FIG.
A branching hybrid 1, modulation circuits 2C and 2D that output IP-multiplied signals modulated by the output of the hybrid 1, four transmission circuits and 4B that frequency convert and power amplify the output of the modulation circuits 2C and 2D, and transmission circuits 4A and 4B. A transmission switching circuit 5 selects one of the outputs and outputs it as a transmission F signal 102, and a transmission switching circuit 5 which converts and amplifies the frequency of the received RF signal 103 and converts the received RF signal 103 to an IF.
6-person receiving circuit 6B that outputs double signal, and 6-person receiving circuit 6B.
9 demodulation circuits that demodulate 6B output, 9B, and demodulation circuit 9
The receiving baseband switching circuit 10 selects either the human output or the 9B output and outputs it as the reception baseband 104.

The demodulator circuit 9/9B constantly monitors the reception quality of the two receiving side rows and issues an alarm if the quality deteriorates. However, there is no means for monitoring transmission quality on the sending side.

If an alarm occurs in only the one selected by the reception switching circuit 10 (currently used) among the nine demodulation circuits/9B, the reception switching circuit 10 is switched to rescue the reception line.

If an alarm occurs in both the demodulation circuits 9 and 9B, the portion corresponding to the transmission switching circuit 5 of the opposing station is switched. However, since the opposing station cannot monitor the transmission path quality of the transmitting system that has not been selected for the line, it may not be possible to rescue the line even if the opposing station performs a transmission switching operation. In other words, a transmission switching operation may be performed even for a silent fail on the transmitting side, and an alarm may remain on the receiving side even after switching.

[Problem that the invention seeks to solve]

As explained above, the conventional line monitoring switching method cannot monitor the quality of the transmission path on the transmitting side, so there are cases where the line cannot be rescued by switching the transmission, and in this case, the fault is on the transmitting side, but it is not possible to repair the line on the receiving side. The disadvantage is that it takes a lot of time to discover the faulty part because it is not known whether there is a problem or not.

SUMMARY OF THE INVENTION In order to solve the above drawbacks, it is an object of the present invention to provide a line monitoring switching system that can also monitor the transmission line quality on the transmitting side.

[Means for solving problems]

The line monitoring switching method of the present invention includes a line monitoring switching method for a one-to-one set backup hot standby carrier communication line, selects and outputs either one of the outputs of two modulation circuits, and selects one of the outputs of two demodulation circuits. On the other hand, it is provided with a switch circuit for inputting ζ, and is configured to monitor the quality of the transmission line configured by the switch.

〔Example〕

The present invention will be described in detail below with reference to drawings showing embodiments.

FIG. 1 is a block diagram showing four stations according to an embodiment of the line monitoring switching system of the present invention.

The terminal station shown in Figure 1 consists of a hybrid 1, two modulation circuits/2B that output two IFi signals modulated by the hybrid 1 output, a switch 3, and one each of the modulation circuits 2/2B output. Transmission circuits 4N and 4B that input, transmission switching circuit 5, reception circuit 6 and 6B, and switches 7 and 8
, demodulation circuits 9A and 9B, and a reception switching circuit 10. Parts 2 in FIG. 1 with the same reference numerals as in FIG. 2 have the same functions as 2 in FIG.

The switches 3-7-8 all have the same structure, and have four terminals a to d in the structure shown in the switch 3. When terminal a connects to terminal 1 and terminal C connects to terminal d (called a solid line connection), and when terminal a connects to terminal d and terminal 1 connects to terminal C (called a broken line connection) ) there are two connection states.

One fan of the switch 3 is terminated, and the other three terminals are connected to the output terminals not connected to the two modulation circuits, the four transmitting circuits of 2B, and the switch 7, which are not connected to 4B. The other three terminals of switch 7 are 6 receiver circuits, 9A demodulator circuit,
It is connected to switch 8. The other two terminals of the switch 8 are connected to the receiving circuit 6B and the demodulating circuit 9B, and the remaining terminals are terminated.

The operation of the terminal station shown in FIG. 1 will be explained below.

When switches 3, 7, and 8 are all connected with solid lines and the line is normal, the transmission switching circuit 5 outputs the output of the four transmission circuits,
The reception switching circuit 10 selects the output of the demodulation circuit 9 and selects 2 outputs.
The transmission baseband signal 101 is sent to the transmission station F via two hybrid modulation circuits, four transmission circuits, and a transmission switching circuit 5.
The received RF signal 103 becomes a received baseband signal 104 through six receiving circuits, a switch 7, nine demodulating circuits, and a receiving switching circuit 10, and is output as a received baseband signal 104.

Therefore, in this case, two modulating circuits and four transmitting circuits are selectively used on the transmission side, and a receiving circuit 6A and nine demodulating circuits are selectively used on the receiving side.

In this case, the modulation circuit 2B output is looped back to the demodulation circuit 9B via switches 3, 7, and 8, and the demodulation circuit 9B monitors the quality of this loop. Meanwhile, nine demodulators are monitoring the quality of the transmission line currently being used.

When the quality of the transmission line operated as a line deteriorates and an alarm is issued to the nine demodulator circuits, if the transmission line that is not selected as a line and is looped back at your own station is normal, first switch. Connect 8 with the broken line. If no alarm is issued in the demodulation circuit 9B after this switching, the reception switching circuit 10 is next switched, and at the same time, the switch 7 is connected as indicated by the broken line.

Through this operation, the receiving line is relieved through the transmission line from the receiving circuit 6B to the demodulating circuit 9B. At this time, the modulation circuit 2B output is looped back to the demodulation circuit 9 via switches 3 and 7, and the quality of this loop is determined by the investigation of the cause of the reception quality deterioration.
This is used. When the switch 8 is changed and the alarm remains in the demodulation circuit 9B for a certain period of time or more, the switch 8 is returned to the solid line connection and the opposite station is switched to the H transmission side.

When a receiving alarm occurs at the opposite station and cannot be relieved by switching to the receiving side of the opposite station and switching to the transmitting side at the terminal station shown in FIG. Make the connection a dashed line. Through this operation, the transmission line is relieved by the variable circuit 2B and the transmission circuit 4BIC. At this time, the output of the two modulating circuits is sent to the limiting circuit 9 via switches 3, 7, and 8.
Bt is looped back, and the quality of this loop is used to investigate the cause of the previous transmission quality deterioration.

In addition, the switch circuit provided in the unreleased device can be constructed if the line has a function to connect the modulation circuit/demodulation circuit 1-11 that is not selected. It is not limited to connections.

The actual L & example of the present invention has been described above using the terminal stations shown in FIG. 1 as a column.

〔Effect of the invention〕

The line monitoring switching method of the present invention, which has been explained in detail in Rule 1 above, is effective in inputting the output of a modulation circuit that is not selected for a line to a demodulation circuit that is not selected for a line via a switch circuit. Since the transmission line product This has the advantage of being able to prevent faults, and the quality of the demodulation circuit or modulation circuit that is used as a backup when switching to the receiving side or switching to the transmitting side can be immediately monitored, making it easier to find faulty parts. Furthermore, it is economical because the quality on the transmitting side can be monitored by simply adding an inexpensive IF band switch circuit without adding an expensive modulator quality monitoring circuit.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a terminal station according to an embodiment of the line monitoring switching method of the present invention, and Fig. 2 is a block diagram showing an example of a terminal station using the conventional line monitoring switching method◇ 1.・・・-Hybrid, 2A/2B・・・・・・
Modulation circuit, 3/7/8... switch, 4A/4
B...--Transmission circuit, 5...Transmission switching circuit, 6A/6B...Reception circuit, 9 people/9B...
... Demodulation circuit, 10 ... Reception switching circuit. Agent: Patent Attorney Otoki Uchihara, Tsukasa L

Claims (1)

[Claims] In a line monitoring switching system for a one-to-one set backup hot standby carrier communication line, a switch selectively outputs one of the outputs of two modulation circuits and inputs the output to one of two demodulation circuits. 1. A line monitoring switching system comprising a circuit for monitoring the quality of a transmission line configured by the switch circuit.