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Call-waiting tone detection technique

  • US 6,496,572 B1
  • Filed: 12/20/2001
  • Issued: 12/17/2002
  • Est. Priority Date: 05/26/1998
  • Status: Expired due to Fees
First Claim
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1. A communications device comprising:

  • a telephone-line communications interface;

    a call-waiting tone detector coupled to the telephone-line communications interface, the call-waiting tone detector correlating a received signal with a phase-shifted version thereof to identify call-waiting tone therein, wherein the phase-shift corresponds to a period of the call-waiting tone.

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