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Expired Canadian patentCanada

Geolocation method and apparatus for satellite based telecommunications system

CA 2202827 C · Owner: Trw Inc. · Inventors: Upton, Eric L.; Stephens, Scott A.

CIPO record

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Abstract From the Canadian patent

A method for determining the geolocation of a user terminal within a telecommunications system having a constellation of satellites which relay communications signals between earth stations and user terminals over preassigned channels. The method performs synchronization upon the telecommunications signals to calculate timing and frequency update information for the user terminals. The timing and frequency update information is also used within the earth station to calculate the geoposition of the user terminal. To do so, the earth station calculates a distance between the satellite and a user terminal based on the corresponding propagation time therebetween which is obtained from the …

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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 April 16, 1997 and granted August 28, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 16, 2017.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 16, 2019.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledApril 16, 1997
GrantedAugust 28, 2001
Term endedApril 16, 2017
Patent numberCA 2202827 C
Classification (IPC)H04B7/18 +1 more

Timeline

Timeline From CIPO dates

1998200020022004200620082010201220142016Application filedApril 16, 1997Patent grantedAug 28, 2001Term endedApril 16, 2017

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