US 8,509,421 B2 · Method and device for checking a subscriber line

Abstract

In a method for checking a subscriber line with a first and a second electrical line, wherein each line is connected to an encoder/decoder via a subscriber line circuit, the first line is connected to ground, a resistance of the second line is increased, an audio signal is outputted from the encoder/decoder to the first line; and a first frequency-selective signal is measured at a point at which the encoder/decoder is connected to the first line. Further, the second line is connected to ground, a resistance of the first line is increased, a further audio signal is output from the encoder/decoder to the second line, and a second frequency-selective signal is measured at a point at which the encoder/decoder is connected to the second line. An amplitude difference between the first and second frequency-selective signals is ascertained.

Claims6

Dependent claims

A method for checking a subscriber line circuit with a first and a second electrical line, wherein each line is connected to an encoder/decoder of a codec via a subscriber line circuit, the codec including a frequency selective measuring unit, the method comprising:

connecting the first line to ground;
increasing a resistance of the second line;
outputting from the encoder/decoder an audio signal to the first line;
measuring, via the measuring unit, a first frequency-selective signal at a point at which the encoder/decoder is connected to the first line;
connecting the second line to ground;
increasing a resistance of the first line;
outputting from the encoder/decoder a further audio signal to the second line;
measuring, via the measuring unit, a second frequency-selective signal at a point at which the encoder/decoder is connected to the second line;
ascertaining, via the measuring unit, an amplitude difference between the measured first and second frequency-selective signals;
and
ascertaining an asymmetry at inputs of the subscriber line, via the measuring unit based on the amplitude difference circuit.

8 more elements

Dependencies are inferred from the claim text.

Method and device for checking a subscriber line

Life of this patent

Method and device for checking a subscriber line

Life of this patent

Abstract

Claims6