Radiotelephone system for assignment of modems to support communications between subscriber stations and a base station
CA 2172972 C · Owner: Cooley, David M. · Inventors: Johns, Eric; Digiovanni, Joseph J.; Vessal, David
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A power-conserving time division multiple access (TDMA) radiotelephone system is disclosed in which a cluster of subscriber stations remote from a base station, employs a common pool of frequency-agile modems each of which digitally synthesizes on a time slot-by-time, slot basis, the different channel-identifying intermediate needed to support communications between several of the subscriber stations and the base station. Power conservation is facilitated inter alia by controlling the assignment of modems to calls maintaining, unassigned modems in a powered-down state and by controlling the number of calls using the same time slot. Delay in assigning a powered-down modem to a call is …
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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 July 21, 1994 and granted February 5, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 21, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 21, 2016.
- 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.