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:
Nov. 17, 1998
Filed:
Jun. 27, 1996
Applicant:
Inventors:
Heping Ding, Kanata, CA;
Scott McClennon, Ottawa, CA;
Assignee:
Northern Telecom Limited, Montreal, CA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
379409 ; 379390 ; 379420 ;
Abstract
A telephone terminal having handsfree functionality is provided with an audio system which controls echo return loss while permitting virtual full-duplex operation. The system, which has a variolosser in both the transmit and receive path and an acoustic echo canceller, also has a complementary variolosser which introduces additional echo return loss only when required and as a function of the state of the system.