Patent ID: 6597768
Filing Date: 2003-07-22
Classification: H04L,H04M

Abstract:
A method of coupling a voiceband modem circuit to a common phoneline connector, the common phoneline connection having a ring line connection and a tip line connection which couples a ring/tip line pair to a subscriber loop circuit, the voiceband modem circuit operating in a voiceband modem operating frequency band and having a voiceband modem interface ring line and a voiceband modem interface tip line, comprising:coupling the voiceband modem interface ring line to the ring line and coupling the voiceband modem interface tip line to the tip line connection by inserting, between the ring line connection and the voiceband modem interface ring line and between the tip line connection and the voiceband modem interface tip line, a series pair of inductors, a first inductor of the series pair having a low inductance and a high self-resonant frequency and a second inductor of the series pair having a high inductance and low self-resonant frequency, the low inductance, the high self-resonant frequency, the high inductance and the low self-resonant frequency being each determined to locate a filtering cutoff point between the voiceband modem operating frequency band and a digital subscriber line operating frequency band.