ADAPTIVE CALL PROGRESS TONE DETECTION SYSTEM

摘要

A system and apparatus for enabling communications devices to recognize call progress tones that may be used in foreign countries. The call progress tone detection system includes a communications device (50) having one or more frequency decoders (113) for determining the frequency of call progress tones, a cadence decoder (126) for determining the on/off pattern for the call progress tones and a table (122) for storing the call progress tone frequencies and the cadences. Recognition of call progress tones is accomplished by enabling the communications device (50) to receive one or more foreign call progress tones, enabling the user to associate the type of call progress tone for each call progress tone received and storing each call progress tone to a table (122) for later cross reference when initiating a call.