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:
Jul. 17, 1984
Filed:
May. 13, 1982
Ronald J Canniff, Naperville, IL (US);
Gordon K Lin, Naperville, IL (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
A dual tone multifrequency and dial pulse receiver that receives 8000 digital data words per second, each of the data words including eight PCM bits representing the analog signal transmitted from a subscriber set and also including a line status bit indicating the DC status of the line. The receiver includes a time-shared processor which processes the PCM bits of 4000 words per second to detect tone-pairs and which also processes the line status bit of 4000 words per second to detect valid dial pulse sequences. The time-shared processor stores one of a first plurality of code words in a register when a tone-pair is detected and stores one of a second plurality of code words in the register when a valid dial pulse sequence is detected. Advantageously, the receiver can detect either dual tone multifrequency or dial pulse signaling from a subscriber even though the type of signaling to be used by the subscriber is not known a priori.