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:
Apr. 06, 1999
Filed:
Sep. 16, 1996
Andrew L Norrell, Nevada City, CA (US);
Christopher R Hansen, Grass Valley, CA (US);
U.S. Robotics Access Corp., Skokie, IL (US);
Abstract
A full-duplex modem having improved transmission speeds over voice grade telephone circuits that extends the concepts of asymmetric transmission to include echo cancellation techniques. The preferred modem has a high speed forward channel and an overlapping low speed back channel and is capable of transmitting or receiving over either of the channels, depending on the relative data rates. A narrow band echo canceler substantially cancels all or part of reflected transmit signals. Because the echo cancellation technique employed is narrow band, there is a significant reduction in the complexity and computational requirements for the modem.