Patent ID: 6075847
Filing Date: 2000-06-13
Classification: H04N

Abstract:
In a fax system wherein a calling fax machine communicates with a called fax machine by sending a calling tone to the called fax machine and wherein the called fax machine sends information flags to the calling fax machine, a method for detecting a fax call comprising the steps of:(a) initialing a detection threshold;(b) detecting whether the calling tone has been transmitted from the calling fax machine to the called fax machine;(c) decrementing the detection threshold if the calling tone has been detected in step (b);(d) generating a flag measure by monitoring, with a detector, signals sent from the called fax machine, wherein the flag measure is representative of a number of information flags detected by the detector;(e) comparing the flag measure to the detection threshold; and(f) detecting the fax call in accordance with the result of step (e).