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Expired Canadian patentCanada

Data communications with alternation of signaling constellations

CA 2010998 C · Owner: American Telephone And Telegraph Company · Inventors: Rauchwerk, Michael David; Chung, Hong Yang

CIPO record

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

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Abstract From the Canadian patent

Abstract, Primary and secondary data are communicated from a transmitter to a receiver in a communication system. The value of an individual primary data word is communicated by transmitting an individual one of first plurality of channel symbols associated with that value while the value of a combined data word comprising an individual primary data word and an individual secondary data word is communicated by transmitting an individual one of second plurality of channel symbols associated with that value. In the receiver both the primary and secondary, data word values are recovered from the channel symbols thus transmitted. The approach of alternating two sets of channel symbols for …

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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 February 27, 1990 and granted October 5, 1993. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 27, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 27, 2012.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledFebruary 27, 1990
GrantedOctober 5, 1993
Term endedFebruary 27, 2010
Patent numberCA 2010998 C
Classification (IPC)H04L5/00 +1 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedFeb 27, 1990Patent grantedOct 5, 1993Term endedFeb 27, 2010

Sources & verification

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