The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 06, 1998
Filed:
Dec. 30, 1994
John R Zabel, Canton, NY (US);
James E Neil, Ogdensburg, NY (US);
Mitel, Inc., Reston, VA (US);
Abstract
A method of dialing digits using dual tone multifrequency (DTMF) signals comprised of generating a digit from a DTMF generator comprised of a first pair of signals forming a DTMF signal, one signal of the first pair of signals being in a low frequency band and one signal of the first pair of signals being in a high frequency band, and applying the DTMF signal to a telephone line connected to a central office, detecting the first pair of signals in an auxiliary circuit and immediately applying a third signal in either of the low or high bands to the telephone line at the same time as the first pair of signals, and detecting the presence of the pair of signals and the third signal at the central office and preventing processing of the DTMF signal at the central office as a result thereof.