KR19990024261A - Subscriber Line Tester of Optical Transmission System - Google Patents

Abstract

An apparatus for efficiently testing a subscriber line of an optical transmission system, comprising: an analog line interface unit for testing the characteristics of an analog line, a digital line interface unit for testing the characteristics of a digital line, the analog line interface unit, and the digital A digital signal processor that analyzes and tests data from a circuit interface unit, a memory for storing programs and data used in the digital signal processor, and a dual-port RAM for data communication with a host system. And a serial interface for command and result data communication with an operator, wherein the analog line interface unit includes a measurement mode selection unit including a relay to select a measurement target line, and a resistance connected to the measurement mode selection unit. With voltage divider circuit And a measurement voltage range selection section for selecting a measurement voltage range, and an analog-digital interface section for interfacing the analog signal from the measurement voltage range selection section and the digital signal processor.

Description

Subscriber Line Tester of Optical Transmission System

The present invention relates to a test apparatus that can determine the abnormality and failure of the subscriber line in the optical transmission system.

In general, a two-wire or four-wire copper wire is connected as a transmission medium between a telephone company and a general subscriber's home in a telephone communication network. This transmission medium serves as a service line for providing subscribers with voice and data signals provided from telephone stations. This copper line is to be connected separately from the exchange for each subscriber.

However, it is very inefficient in terms of cost or maintenance to connect each other by copper wire to a place where a large number of subscribers are concentrated such as a building or an apartment. Therefore, where a large number of subscribers are concentrated, as shown in FIG. 1, the signals from the switch 200 are combined and converted into optical signals using a telephone station optical conversion device (COT) 300 in the telephone station. Then, it is transmitted to the remote optical conversion device (RT) 400 installed in each building or apartment through the optical path 500, and the remote optical conversion device (RT) 400 again transmits an electric signal to each subscriber. It converts the data into separate subscribers and sends them to each subscriber.

However, since the optical transmission system replaces the line from the telephone station to the densely populated building with the optical transmission device, it is necessary to separately determine whether there is an abnormality in the final transmission section for the subscriber, that is, the section from the building to the subscriber side. Test equipment is required. In addition, subscribers supported by the remote optical conversion device (RT) 400 support analog equipment such as OCU, CSU, DSU, ISDN, as well as analog phones such as ordinary telephones and EMs, and thus, analog subscriber lines and digital subscriber lines. All equipment is required to be tested.

It is an object of the present invention to provide an apparatus for efficiently testing a subscriber line of an optical transmission system.

Another object of the present invention is to provide an apparatus capable of testing both analog and digital subscribers in an optical transmission system.

1 is a schematic diagram showing a network configuration of an optical transmission system;

Figure 2 is a block diagram showing the configuration of the test apparatus of the present invention,

Figure 3 is a block diagram showing in more detail the configuration of the analog test unit of the test apparatus of the present invention.

An apparatus of the present invention for achieving this object includes an analog line interface unit for testing the characteristics of an analog line, a digital line interface unit for testing the characteristics of a digital line, the analog line interface unit and the digital line interface. A digital signal processor for analyzing and testing data from a part, a memory for storing programs and data used in the digital signal processor, a dual-port RAM for data communication with an upper system, And a serial interface for command and result data communication with an operator, wherein the analog line interface unit includes a measurement mode selection unit including a relay to select a measurement target line, and a resistance voltage divider circuit connected to the measurement mode selection unit. Wire the measured voltage range And measuring voltage range selector configured to, analog-to interface with the analog signal from the voltage measuring range selection unit said digital signal processor characterized by comprising a digital interface.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. Figure 2 is a block diagram showing the configuration of the test apparatus of the present invention, Figure 3 is a block diagram showing the configuration of the analog test unit of the test apparatus of the present invention in more detail.

First, the controller of the test apparatus will be described. The controller of the test apparatus includes a digital signal processor 110 and a ROM (a memory for storing programs and data required for the operation of the digital signal processor). Read Only Memory (121), Random Access Memory (RAM) 122, and EEPROM (Electrically Erasable Programmable ROM) 123 are provided.

The digital signal processor 110 also controls the analog line test section 140 and the digital line test section for the analog line test and the digital line test. In this case, a control signal interface unit 160 is provided to interface the digital signal processor 110 and each test unit.

In addition, the test apparatus includes a dual port RAM 130 for data communication with an upper system, a terminal for transmitting and debugging a test command, and a serial interface 131 for data communication.

The analog line test unit 140 includes a measurement mode selector 141 which interfaces with an analog line and selects a measurement mode, a hold and -48V feeding selector 144 for level testing, and a level gain for level gain control. Converts the signal from the control unit 145, the measurement voltage range selection unit 142 for selecting the measurement voltage range, and the measurement voltage range selection unit 142 into a digital signal at high speed, and converts the digital signal from the digital signal processor. The analog-digital interface unit 143 converts the analog signal.

As shown in FIG. 3, the measurement mode selector 141 selects between the tip and the ring, the tip and the FGND, the ring and the FGND, and the like, according to the measurement mode. That is, when RL1 and RL2 are connected to M terminal, respectively, the signal between tip and ring is selected.When RL1 is M and RL2 is connected to B, between tip and FGND, RL1 is B and RL2 When connected to B, the signal between the ring and FGND is transmitted to the measurement voltage range selector 142.

The selected signal is transferred to the measurement voltage range selector 142 via an amplifier AMP. Since the voltage range that can be handled by the analog-digital interface unit 143 is limited, the measurement voltage range selection unit 142 selects a range to divide the input voltage according to the measurement voltage range. That is, as shown in Fig. 3, the MUX 147 for selecting the divided voltage circuit and the divided voltage range of the resistor is configured to transmit the signal of the desired voltage range to the analog-digital interface unit 143.

The transmitted signal is sampled at high speed in the analog-digital interface unit 143 and converted into a digital signal, and the converted signal is transmitted to the digital signal processor 110. The digital signal processor 110 performs digital filtering and the like from the signal from the analog-digital interface unit 143, and performs RT side line tests such as voltage measurement, resistance measurement, capacitance measurement, level transmission / reception test, and dial pulse. Exchange connection test (COT↔RT) such as transmission / reception test, EM line pulse transmission / reception test, Call Progress Tone test, noise (C-message, 3kHz, 15kHz) test and so on.

The digital test unit includes an RS-422 interface unit 150 and a control signal interface unit 160. The digital signal is converted to the TTL level used in the apparatus by the RS-422 interface unit 150 and transmitted to the digital signal processor 110 via the control signal interface unit 160.

In the digital test, a loop back test is performed, and the digital signal processor 110 performs a bit count, a block count, a bit error count, a block error count, a bit error rate, a block error rate, a measurement time, an error time (seconds), Error free time (seconds) is measured.

The test apparatus configured as described above is installed in both the COT 300 and the RT 400. Therefore, it is possible to generate certain conditions for testing in COT and to measure them in RT. That is, when a specific test is initiated in the COT, data indicating that the test is initiated is transmitted from the test apparatus 100 installed in the COT to the COT system via the dual port RAM 130, which in turn causes the optical transmission path 500 to return to the COT system. It is transmitted to the RT system through the dual port RAM 130 of the RT side test apparatus and transmitted to the digital signal processor 110 on the RT side. The RT side then sets up and makes measurements for this test. The data measured in the RT is transmitted to the RT system again via the dual port RAM 130, which is again transmitted to the COT system through the optical transmission line 500 through the dual port RAM 130 of the test device on the COT side It is delivered to the digital signal processor 110 on the COT side. Then, the digital signal processor 110 of the COT sends this data back to the terminal through the serial interface 131, so that the operator can easily know the test result in the country. However, in the case of a test with the operator's own country, the test result is not transmitted to the other party through the dual port RAM 130, but may be directly floated to the terminal through the serial interface 131.

Although the test apparatus of the present invention has been described with reference to a preferred embodiment, the present invention is not limited thereto, and various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the description of the claims.

According to the present invention, since the apparatus for centrally testing the analog line subscriber and the digital line subscriber accommodated in the optical transmission system is provided, the subscriber line of the optical transmission system can be efficiently tested remotely regardless of the circuit type. Will be.

In addition, according to the present invention, since the signal of the measurement voltage selector is connected to the digital signal processor through the analog-digital interface for the test of the analog line, the digital signal processor performs the measurement. Various measurements can be carried out, and it is effective in responding flexibly to changes in measurement specifications.

Claims (1)

An analog line interface unit for testing the characteristics of the analog line, Digital line interface part for testing characteristic of digital line, A digital signal processor for analyzing and testing data from the analog line interface unit and the digital line interface unit; A memory for storing programs and data used in the digital signal processor; Dual-port RAM for data communication with the system, It has a serial interface for command and result data communication with the operator, The analog line interface unit, A measurement mode selection unit including a relay to select a measurement target line; A measurement voltage range selection unit connected to the measurement mode selection unit and configured to select a measurement voltage range by including a resistance voltage divider circuit; And an analog-digital interface unit for interfacing the analog signal from the measurement voltage range selection unit with the digital signal processor.