Adaptive rate control for echo cancelling modem
CA 2004476 A1 · Owner: Sridhar, Manickam R. · Inventors: Sridhar, Manickam R.; Bargoot, Carol Ann; Payton, John L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An echo cancellation modem for full-duplex communication over a channel with a remote device in accordance with one of several possible modulation schemes suitable for different channel qualities respectively. The modem includes an echo canceller for reducing echo components appearing in the channel signal while leaving a residual echo component in the echo reduced channel signal, a monitor for determining the quality of the channel based on an analysis of the residual echo component, and a controller for selecting an acceptable modulation scheme, based on the analysis of the monitor. The modem selects the acceptable modulation scheme prior to data communication and it also requests changes …
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed December 4, 1989. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 4, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 4, 2011.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.