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Expired Canadian patentCanada

Communications system

CA 2077458 C · Owner: Cedardell Limited · Inventors: Todd, Robert Edmund

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

A communications system comprises a plurality of transceivers capable of transmitting and receiving data from other transceivers in the system. At least one transceiver functions as a control module. Communication between the control module and the remainder of the communications modules occurs by consecutive communication between individual communications modules in the system. This means that low power transceivers can be used to form a system having a long range capability.

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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 March 4, 1991 and granted October 30, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 4, 2011.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 4, 2013.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMarch 4, 1991
GrantedOctober 30, 2001
Term endedMarch 4, 2011
Patent numberCA 2077458 C
Classification (IPC)H04B7/15 +1 more

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.