SR TSV 002578 : ISSUE 1

Defines an innovative method & apparatus developed at Bellcore for detecting a dual tone signal in the presence of speech. A general tutorial describing in-band tone signalling & its performance related problems is initially presented to familiarize the reader with the subject matter. A brief description of some new services for which this tone detection technology is needed & the signalling problems specific to these services is provided. Signal recognition issues are discussed & a basis for the choice of the alerting signal chosen is presented. A detailed discussion of the detector block diagram follows. Several filter pilots are provided to describe various filtering sections within the detector. Two signal timing algorithms are also described in detail. Includes flow charts of both algorithms.