KR940005861B1 - Trunk testing apparatus - Google Patents

Abstract

This system provides a testing apparatus and a method for BER testing and finds out a digital transmission quality. The apparatus comprises of; a system matching sec. (11) which matches a exchange (12) and two testing points of junction lines; a common control sec. (12) which controls all the parts of testing apparatus, communicates with a matching sec., analyses a receiving message and generates a 8Khz FS; a digital matching sec. (13) which performs a T1/CERT matching function; a digital signal processor sec. (14) which generates a pseudo random testing pattern, transmits it to digital matching sec., receives it from digital matching sec., compares this pattern and counts the error of testing pattern.

Description

Construction method for BER test of repeater test equipment and repeater during electronic exchange

1 is a detailed block diagram of a test apparatus.

2 is a BER test path diagram of the switching center trunk.

3 is a sequential chart.

* Explanation of symbols for main parts of the drawings

11: system matching unit 12: common control unit

13: digital matching unit 14: digital signal processor

The present invention relates to a repeater test apparatus for performing a BER test for inspecting the digital transmission quality of a repeater received in an electronic switch and a configuration method for the BER test of the repeater.

The automatic trunk line test system currently in operation in Korea is the Centralized Automatic Reporting On Trunks (CAROT) system developed by AT & T, which is a remote office test line (ROTL) located in the Toll / Tandem office. It provides only the analog characteristic test for trunk under test (TUT) with 56 A type FER (Far End Responder) in the remote trunk test unit (RTTU) and the '105 test line' in the country. However, considering that the general public telephone network is gradually becoming digitalized, the code 105 test, which is an analog transmission characteristic test of the existing network, cannot perform the maintenance function of the relay network. In a digital communications system, bit errors are a direct cause of signal distortion or data loss, and are the biggest contributors to poor service quality and efficiency.

An object of the present invention is to provide a repeater test apparatus and a repeater test configuration method for measuring a bit error, which is a direct cause of deterioration of digital communication, for a relay line accommodated during an electronic switching period without relying on a separate test apparatus. .

The default parameters for evaluating error performance are BER (Bit Error Rates), and appropriate parameters such as ES (Errord Second) including information indicating how errors are distributed over time for more useful and meaningful performance measurements. have. According to the present invention, the parameter of the BER that can be performed is% ES of the received ES (Erroed Second) and the percentage having at least one of the total number of transmitted bits, bit error / error rate, and measurement time, and one error occurs. Error free second (EFS) and percentage% EFS, the total number of blocks in the pseudo random test pattern, and block error / error rate.

The present invention will be described in detail with reference to the accompanying drawings as follows.

FIG. 1 is a detailed block diagram of the trunk line test apparatus 1, which includes a system matching unit 11, a common control unit 12, a digital signal processor (DSP part) unit 14, and a digital matching unit 13. As shown in FIG. The system matching unit 11 performs matching between the switch 12 and the two trunk line measuring units, and performs a TD (Telephony Device) bus communication for communication with the maintenance processor (ASMP) of the switch. It has three RS-232C ports for self-maintenance and matching with the trunk line measuring section, RS-232C ports 0 and 1 are connected to the common control section 12 of each thread measuring section, and port 2 matches the system. It is used as a local monitor port for self maintenance of the unit 11. The main function of the system matching unit 11 located between the maintenance boss processor and the measurement unit performs an interface converter function between the real measurement unit of RS-232C communication and the maintenance processor performing TD-bus communication. Change the data format of the file to the corresponding format. Under the control of the common control unit, the common control unit, the digital signal processor unit (DSP part), and the digital matching unit are mutually connected to each other by a standard VME bus communication and an internal test bus linked to the PCM to transmit and receive a test pattern. The common control unit 12 controls all parts of the trunk line test apparatus, performs RS-232C communication with the system matching unit 11, and performs standard VME bus communication with its unit.

In addition, the common control unit 12 performs all external communication, received message analysis and error detection, and generates a main frequency (2.048 MHz) and an FS of 8 KHz of the PCM link, which is an internal test bus. The digital matching unit 13 performs a T1 / CEPT matching function of the relay line DS1 (Digital Speed 1) and has a built-in digital test port for occupying the relay line under test.

The digital signal processor 14 generates a 2047 bit pseudo random pattern required for the BER test, and transmits the test pattern necessary for the test under the control of the common controller to the transmitter of the digital matching unit at a speed of 56 kbps. After receiving the pseudo random test pattern looped back from the receiving side exchange to the receiving end of the digital matching unit 13, the error of the test pattern is counted by comparing with the transmitted pseudo random test pattern.

Figure 2 shows the BER test path of the electronic exchanger for the digital characteristic test. In case the same station is the same switchboard, at the request of the operator of the calling switchboard, the measured trunk line channel is occupied, and the transmission and reception of the occupied trunk line channel are performed by a time switch (TSW). It is connected to the transmitting and receiving end of the repeater test apparatus through the T1 / E1 link. At the request of the calling exchange, the receiving exchange loops back the measured trunk line transmission channel to the measured trunk line receiving channel at the back of the TSW and connects the trunk line transmitting channel to the receiving end of the TPC test equipment. Form a measurable loop path.

In the figure, the dotted line represents the BER test path, DT1 represents a digital T1 interface block, DCI represents a digital CEPT interface block, ASMP represents an access switching maintenance boss processor, and DTIP represents a digital trunk interface processor.

3, the trunk line channel to be measured is occupied by TLT (Trunk Line Test), which is a relay line tester control S / W block of the exchange, to form a test path as shown in FIG. 2. FIG. This is a test flow chart showing the loopback of the trunk line channel under test by the block. When the test request by the operator is input, the TLT occupies the channel of the repeater to be measured through the TSW, connects it to the digital matching part of the repeater test apparatus, and corresponds to the 'BER test preparation request' with the receiving exchange (subject) through the same channel. Dial the special number '163'. When the receiving exchange receives a special number '163' from the calling exchange, it notifies the TLT in charge of the relay line test, and the TLT loops back the transmitting channel and receiving channel at the back of TSW and 'call connection completed'. Send the signal to the calling exchange. The source exchange recognizes the 'call connection complete' signal as 'BER test ready' and the TLT requests the BER test to the trunk line tester. At this time, the repeater test apparatus transmits a 2047-bit pseudo random test pattern at a speed of 56 kbps to the transmitting end of the digital matching unit, receives a pseudo random test pattern that is looped from the receiving exchange (at the station) to the receiving end, and then returns the BER on the measured repeater. Measure The measurement results are output to the operator through the TLT as parameters of various BER.

Claims (4)

A system matching unit means 11 for transmitting / receiving data connected to the upper processor of the electronic switchboard by the TD bus, and a common control unit 12 for performing a BER test according to a reception command from the matching unit means, and a digital signal processor. The unit 14 and the digital matching unit 13 are connected to each other via a VME bus and an internal PCM test bus, and have a digital relay line matching function, and generate a pseudo random test pattern to form a real measuring unit means for measuring BER. Trunk line tester. A system matching unit means 11 for transmitting / receiving data connected to the upper processor of the electronic switchboard by the TD bus, and a common control unit 12 for performing a BER test according to a reception command from the matching unit means, and a digital signal processor. The unit 14 and the digital matching unit 13 are connected to each other by a VME bus and an internal PCM test, and have a digital relay line matching function, and generate a pseudo random test pattern to generate a pseudo random test pattern. In the first step of receiving a test request by an operator, the channel is connected to the digital matching unit 13 by occupying the channel of the relay line under test, and dialing the special number "163" to the receiving exchange in the same channel. Receives a special number "163" from the calling exchange and notifies the calling exchange, and the receiving exchange switches the same channel to the time switch. A second step of looping back the transmitting channel and the receiving channel and transmitting a " call connection complete " signal to the calling exchange, and the calling exchange recognizes the " call connection complete " signal as " BER test ready " A repeater test method comprising a third step of requesting a BER test as a repeater test device. 3. The method of claim 2, wherein the third step transmits a pseudo random test pattern of 2047 bits to a transmitting end of the digital matching unit at a speed of 56 kbps and loops back from a receiving exchange. Repeater test method characterized in that it further comprises the step of measuring the BER on the relay line to be measured after receiving by the receiving end. 4. The method of claim 3, wherein the BER measurement in the third step is an ES (Erroed Second) and a percentage%, which is the number of seconds having at least one error among the total number of bits transmitted, the bit error / error rate, and the measurement time for the measured trunk line. ES, trunk line test method comprising the measurement of the number of seconds FES (Errored Free Second) and the percentage% EFS, the total number of blocks of the pseudo random test pattern, the block error / error rate, the number of seconds that no error occurred.