Patent ID: 9094497
Filing Date: 2015-07-28
Classification: H04M,H04Q

Abstract:
1. A first Dual Tone Multi Frequency (DTMF) circuit for relaying DTMF digits, the first DTMF circuit comprising: a communication interface adapted to exchange one or more DTMF digits over a communication link; a storage system configured to store a sampling window size, a DTMF test sequence, a returned DTMF sequence, and the one or more DTMF digits, with the one or more DTMF digits to be transferred to a second DTMF circuit by the first DTMF circuit; and a processing system coupled to the communication interface and the storage system, with the processing system configured to receive the one or more DTMF digits via the communication interface and an input sampling window, generate the DTMF test sequence and transmit the DTMF test sequence as DTMF tones to the second DTMF circuit, compare the DTMF test sequence to a returned DTMF sequence received as DTMF tones within the input sampling window back from the second DTMF circuit, and if the returned DTMF sequence includes a different number of DTMF digits than the DTMF test sequence, then adjust the sampling window size of the input sampling window.