Echo cancellation in the network for data applications
CA 2250641 C · Owner: Duttweiler, Donald Lars · Inventors: Duttweiler, Donald Lars; Shaw, David Goodwin
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A network-based CODEC (coder-decoder) includes an echo canceler. This CODEC recognizes the presence of a data call by detecting predefined signaling portions, of a modem handshaking process. For each detected data call the CODEC uses a , stored, channel model for performing echo cancellation during the data call. The CODEC trains, off-line during selected segments of the modem call and then stores the new channel, model for use in a future data call.
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 October 14, 1998 and granted April 9, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 14, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 14, 2020.
- 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.