JPH0771152B2 - PCM transmission line test method between time division exchanges - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention allows a maintenance person to perform a call continuity test function provided in advance in a time division exchange from the time division exchange side.
The present invention relates to a method for testing a PCM transmission line between time-division exchanges in which the PCM transmission line interposed between the opposing time-division exchanges can be tested.

[Conventional technology]

A conventional PCM transmission line test method will be described with reference to FIG. In a system using a time-division switch, a time-division including a subscriber circuit (SLIC) 2A accommodating a subscriber terminal 1A, a processor (CP) 9A, a line test equipment (LTD) 10A, and a monitoring test equipment (STD) 11A. A switchboard consisting of a switch section (TDSW) 3A and a digital interface (DIC) 4A is installed in the switchboard side wiring board rack (MD
F) 5A, PCM terminal repeater (LTE) 6A, transmission line side digital distribution board rack (DDF) 7A, PCM transmission path repeater 8A, PCM core, PCM transmission path repeater 8B, digital distribution board rack (DDF) It is connected to the exchange on the other side through 7B, PCM terminal repeater (LTE) 6B, and wiring board rack (MDF) 5B. The exchange on the other side also has a subscriber circuit (SLIC) 2B for accommodating the subscriber terminal 1B, a processor (CP) 9B, a line test device (LTD) 10B, and a monitoring test device (STD) 11B. TDSW) 3B and digital interface (DIC) 4B. Also, PCM terminal repeater
Between the 6A and 6B, a maintenance staff meeting line 13 and a fault repeater rating line 12 are provided.

In such a system, conventionally, the PCM terminal repeater 6A
Through the failure repeater evaluation line 12, the operating margins of the repeaters 8A and 8B are measured and the failed repeater is searched. For this reason, the PCM terminal repeater 6A is provided with a fault location tester (known) including an oscillator and a level meter. Then, a pulse trio (pulse train) modulated by a monitoring signal in the audio frequency band is sent from the oscillator in the fault location tester to the PCM transmission line, and the monitoring signal in the audio frequency band is extracted by the monitoring waveboard in the repeater. Then, the repeater is monitored depending on whether or not the extracted supervisory signal returns to the level meter in the fault point locating tester through the fault repeater locating line 12 at an appropriate level.

A PC when using a space division type exchange
The monitoring of the M transmission line is explained in Chapter 17 of "Toll-free telephone transmission" issued on November 20, 1972.

[Problems to be solved by the invention]

In the above-mentioned system, the maintenance person on the time-division exchange side has a problem that it takes time to repair because the search function is in the PCM terminal repeater even if it is known that the PCM transmission line has a fault. In particular, since the PCM transmission line is set to a large unit of 24 or 30 channels, a failure of the PCM transmission line will seriously hinder the smooth operation of the telephone network, so immediate action is required. It

An object of the present invention is to allow a maintenance person to easily test a PCM transmission line interposed between a time division exchange and an opposite time division exchange by using a communication path continuity test function provided in advance in the time division exchange. PC between permitted time division exchanges
M provides the transmission line test method.

[Means for solving problems]

The purpose of the above is that each of the time-division exchanges, based on the monitored test call path information from the monitoring test equipment, is controlled by the processor to pass through the call path as a forward path or a return path closed inside the time-division switch section. With the speech path continuity test section and the digital interface section connected, the test signal sent from the speech path continuity test section is returned to the digital interface section via the outgoing call path and then used as the return path. The signal level of the test signal is measured and judged by the communication path continuity test section through the communication path of, and the judgment result is displayed on the monitoring test device. PCM terminal repeater, digital wiring board rack, multiple repeaters, digital wiring board rack, PCM terminal repeater, digital interface A method for testing a PCM transmission line between time-division exchanges in which two-way PCM transmission is enabled between the time-division exchanges after being interconnected via With the common fault assessment line being pulled into the monitoring test equipment of each time-division switch, each time-division exchange has a PCM terminal repeater or multiple repeaters on the time-division exchange side as a monitored part. , Or the opposite time-division exchange side
To test the one-way PCM transmission line to the PCM terminal repeater,
Based on the monitored PCM transmission path information from the monitoring / testing equipment, under the control of the processor, the PCM transmission in the direction of the opposite time-division exchange can be performed via the speech path closed inside the time-division switch section and the digital interface section. In the enabled state, based on the monitored part information from the monitoring test device, the communication path continuity test part outputs a monitoring signal having a frequency corresponding to the monitored part, while the monitoring signal is The signal level of the monitoring signal is measured and judged by the communication path continuity test section through the common fault evaluation line and the above-mentioned monitoring test device, in addition to being able to be extracted only at the monitoring part, and the judgment result is the monitoring. It is achieved by being displayed on the test equipment.

[Action]

Unlike the conventional space-division type, the time-division exchange has an electronic communication path, and damage to one part makes many communication paths unusable. Therefore, a manual or automatic speech path continuity test (known) is performed for preventive maintenance of the speech path. There are various methods for conducting a speech path, but in principle, an oscillator and a level meter are connected to both ends of the speech path under test, and a test signal in the audio frequency band digitized by the oscillator is sent to the speech path under test. Then, the normality of the speech path is checked by checking the test signal sent by the level meter connected to the speech path.

In this way, the oscillator and the level meter prepared for the speech path continuity test of the time division exchange perform the same operation as the oscillator and the level meter in the fault location tester. Therefore, the PCM transmission line can be monitored by using the oscillator and the level meter prepared for the communication line continuity test of the time division exchange.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a system configuration diagram according to an embodiment of the present invention. The same devices as those illustrated in FIG. 3 are designated by the same reference numerals and will be described.

As shown, in the present embodiment, the fault repeater locating line 12
And the meeting line 13, via the digital wiring board rack 7A, 7B and the PCM terminal station relay device 6A, 6B, accommodated in the monitoring test device 11A, 11B for monitoring and testing in the time division exchange,
Digital interface unit 4A, 4B and PCM terminal repeater
6A and 6B are directly connected.

FIG. 2 is an explanatory diagram of a PCM transmission line test method in the system described above.

First, an example of an insertion passage continuity test in the time division exchange will be described. Now, the maintenance personnel of the time-division switch wants to test the communication path and digital interface section from the monitoring / testing equipment 11A.
When the information of 4A is sent to the processor 9A of the time division exchange, the processor 9A follows the information and the time division switch section 3A between the communication path continuity test section 20 and the digital interface section 4A.
Is controlled to close the communication path indicated by the broken line in the time divisional switch unit 3A. Next, the maintenance person instructs the monitoring test apparatus 11A to transmit the test signal in the voice frequency band to the oscillator OSC of the communication path continuity test unit 20. The test signal from the oscillator OSC returns to the level meter LM of the speech path continuity testing section 20 through the speech path of the time division switch section 3A and the contact t of the test lead-in relay of the digital interface 4A. The level meter LM checks whether or not the incoming test signal is correct, and displays the result on the monitoring test apparatus 11A. The maintenance person can check the normality of the communication path from the result displayed on the monitoring test device 11A.

Next, using the communication path continuity test in the time division exchange,
A method of monitoring the terminal repeater and the repeater of the PCM transmission line will be described. As shown in FIGS. 1 and 2, in a time division exchange in which the PCM terminal repeater 6A and the digital interface 4A are directly connected and the fault repeater locating line 12 is pulled into the monitoring and testing device 11A. The monitoring test device 11A sends information for connecting the digital interface unit 4A corresponding to the PCM transmission line to be monitored and the communication path continuity test unit 20 to the processor 9A of the time division exchange. According to the information, the processor 9A controls the time divisional switch unit 3A between the communication path continuity test unit 20 and the digital interface unit 4A, and closes the communication path indicated by the broken line in the switch unit 3A. Next, the maintenance person wants to monitor the PCM transmission line repeater 8A,
8C or the PCM terminal repeater device 6A, 6B, the communication path connection from the monitoring test device 11A to transmit the monitoring signal of the voice frequency band corresponding to any one of 6A, 6B through the predetermined PCM channel Instruct the oscillator OSC of the test unit 20. Table 1 shows an example of the frequency of the supervisory signal.

The first number is the monitoring corrugated board BPF (f _{0 to} f ₂₃ ) shown in Fig. 2.
Corresponding to, for example, if you want to monitor the repeater 8A in FIG. 2, if you send a monitoring signal of 2792Hz, f of the monitoring wave board BPF f
_The supervisory signal is extracted at ₁ and the extracted supervisory signal returns to the supervisory test device 11A in the time division exchange through the fault repeater locating line 12. The returned monitoring signal is sent to the level meter LM via the monitoring test device 11A and the contact s of the switching relay of the communication path continuity test unit 20. The level meter LM measures the incoming monitoring signal, checks whether it is at an appropriate level, and displays the result on the monitoring test device 11A.
Based on the result displayed on the monitoring test equipment 11A, the maintenance person of the time division exchange can know whether or not the path to the repeater 8A on the repeater of the PCM transmission line and the one-way PCM transmission line is normal. . Similarly, for example, to know whether or not the route to the PCM terminal station repeater 6B is normal, the PCM terminal station repeater 6
It suffices if a supervisory signal having a frequency corresponding to B is transmitted. This situation also applies to the opposite exchange, and it is easy for the opposite exchange to know whether the route on the reverse PCM transmission line is normal or not.

Next, P for maintenance work and fault search work of the PCM transmission line
The meeting line 13 used for meetings between CM terminal repeaters or between PCM terminal repeaters and intermediate repeaters will be described.
The meeting line 13 is pulled into the monitoring test equipment 11A in the time division exchange through the PCM terminal repeater 6A, so that the subscriber terminals 1A and 1B accommodated in the time division exchange (FIG. 1).
By using the call function (known) of the above, and sending a 16 Hz call signal to the meeting line 13, the maintenance person of the PCM transmission line can be called.

〔The invention's effect〕

According to the present invention, since the operating states of the PCM terminal repeater and the repeater of the PCM transmission line are monitored by the monitoring test device in the time division exchange, when the PCM transmission line fails, the transmission is performed on the time division exchange side. This has the effect of promptly taking measures to divert the call volume to a route to another route. Further, since the function for monitoring is performed by utilizing the existing function (call path continuity test function) in the time division exchange, there is an effect that the PCM terminal station relay device can be made inexpensive. Also, since the maintenance personnel of the time division exchange will monitor the PCM transmission path, there is an effect that the wiring board rack for the function of separating the time division exchange and the PCM terminal repeater can be deleted.

[Brief description of drawings]

FIG. 1 is a relay system diagram of a system according to the present invention, FIG. 2 is an explanatory diagram of a test method according to the present invention in the system, and FIG. 3 is a relay system diagram of a system according to a conventional technique. 1A ・ 1B …… Subscriber terminal (telephone etc.), 2A ・ 2B …… Subscriber circuit, 3A ・ 3B …… Time division switch section, 4A ・ 4B …… Digital interface section, 5A ・ 5B …… Wiring board rack ( Switch side), 6A / 6B ... PCM terminal repeater, 7A / 7B ... Digital wiring board rack (PCM side), 8A / 8B ... Repeater, 9A / 9B ...
… Processor, 10A ・ 10B …… Line test equipment, 11A ・ 11B…
… Surveillance test equipment, 12 …… Line for fault repeater orientation, 13 ……
Meeting line.

Claims (1)

[Claims] 1. Each of the time-division exchanges, based on the monitored test call path information from the monitor / test device, under control of a processor, a call path as a forward path or a return path closed inside the time-division switch section. With the communication path continuity test section and the digital interface section connected via the test path, the test signal sent from the communication path continuity test section is returned to the digital interface section via the outgoing call path and then returned to the return path. The signal level of the test signal is measured and judged by the communication path continuity test section through the communication path as the above, and the judgment result is displayed on the monitoring test device. , PCM terminal repeater, digital wiring board rack, multiple repeaters, digital wiring board rack, PCM terminal repeater, digital interface A method for testing a PCM transmission line between time-division exchanges in which two-way PCM transmission is possible between the time-division exchanges after being interconnected via With the common fault assessment line being pulled into the monitoring test equipment of each time-division switch, each time-division exchange has a PCM terminal repeater or multiple repeaters on the time-division exchange side as a monitored part. , Or the opposite time-division exchange side
To test the one-way PCM transmission line to the PCM terminal repeater,
Based on the monitored PCM transmission path information from the monitoring / testing equipment, under the control of the processor, the PCM transmission in the direction of the opposite time-division exchange can be performed via the speech path closed inside the time-division switch section and the digital interface section. In the enabled state, based on the monitored part information from the monitoring test device, the communication path continuity test part outputs a monitoring signal having a frequency corresponding to the monitored part, while the monitoring signal is The signal level of the monitoring signal is measured and judged by the communication path continuity test section via the common fault evaluation line and the monitoring test device, and the judgment result is the monitoring test. A PCM transmission line test method between time division exchanges that is displayed on the equipment.