Digital telephone, cable tv system and local exchange bypass network
CA 2118911 A1 · Owner: Baran, Paul · Inventors: Baran, Paul
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Cordless telephones (38) generate call relay packets. Packets from each cordless telephone are polled by an upstream polling unit avoiding multi-unit interference. Cell packets are transmitted via a cable TV system (36). Radiated frequencies of the cordless telephones are shifted in frequency as they enter or leave the TV feeder cable to allow frequency reuse. The upstream polling unit appends header information on the cell packets and converts them into standard SONET ATM protocol packets. The cell relay packets are switched by a cell relay type switch to create a cost-effective, alternative telephone system.
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 September 16, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 16, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 16, 2014.
- 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.