Method to reduce distortion of a digital data signal by a POTS ringing signal, and related telephone ringing signal generator

摘要

To reduce the distortion of digital data due to on/off switching of the ringing of a Plain Old Telephone Service (POTS) signal (RINGING1, RINGING2) transmitted simultaneously with the digital data over a single line (LINE), the telephone ringing signal generator (POTS-RING GENERATOR 1, POTS RING GENERATOR 2) produces a digital data friendly ringing signal (RINGING1, RINGING2). The telephone ringing signal generator (POTS-RING GENERATOR 1, POTS RING GENERATOR 2) thereto applies a transient smoothening window (WINDOW1, WINDOW2) to a sine or cosine shaped signal (SINE1, SINE2).