Patent ID: 6978007
Filing Date: 2005-12-20
Classification: H04M

Abstract:
1. A communications system with a transmission network for transmitting useful signals, comprising: (a) at least one subscriber terminal for inputting call numbers; (b) at least one subscriber line unit connected between said at least one subscriber terminal and the transmission network of the communications system, said at least one subscriber line unit including a coding device, a filter unit, an analog-digital/digital-analog converter, an amplifier unit, and an impedance matching unit; (c) a separate recognition unit connected to the transmission network for recognizing a particular call number pattern and for outputting a control signal corresponding to a recognized particular call number pattern; and (d) a separate control unit connected between said recognition unit and said subscriber line unit, said separate control unit adjusting a coding characteristic of said coding device, a frequency response of said filter unit, a conversion characteristic of said analog-digital/digital-analog converter, a gain/attenuation of said amplifier unit, and an impedance of said impedance matching unit in dependence on the control signals output by said recognition unit.