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.

Date of Patent:
Dec. 09, 2003

Filed:

Feb. 04, 2000
Applicant:
Inventors:

Younes Djadi, Austin, TX (US);

Vijayakumaran V. Nair, Austin, TX (US);

Yan Zhou, Austin, TX (US);

Assignee:

Legerity Inc., Austin, TX (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04M 1/00 ; H04M 3/00 ; H04M 9/00 ; H04M 9/08 ;
U.S. Cl.
CPC ...
H04M 1/00 ; H04M 3/00 ; H04M 9/00 ; H04M 9/08 ;
Abstract

A line card for interfacing with a plurality of subscriber lines includes a plurality of data processors and a tone detector. Each of the data processors is associated with one of the subscriber lines. The tone detector is adapted to detect one of a plurality of activation tones on a selected subscriber line. The plurality of activation tones include a first activation tone having an active portion and a silent portion. The active and silent portions repeat periodically at a first frequency having a first period. A second activation tone has a phase reversal portion repeating at a second frequency and having a second period. The tone detector is further adapted to sequence between the subscriber lines at a predetermined interval. The predetermined interval is based on the first and second periods. The tone detector is adapted to signal the data processor associated with the selected subscriber line in response to detecting one of the activation tones.


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