US Patent No. 9,094,497


Patent No. 9,094,497
Issue Date July 28, 2015
Title Dtmf Circuit And Method Of Relaying Dtmf Digits In A Dtmf Circuit
Inventorship Robert E. Geis, Lenexa, KS (US)
Siddharth Oroskar, Overland Park, KS (US)
Gerald Baylis Prince Young, Olathe, KS (US)
Assignee Sprint Communications Company L.P., Overland Park, KS (US)

Claim of US Patent No. 9,094,497

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.