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Expired Canadian patentCanada

Method and apparatus for monitoring and correcting individual wavelengthchannel parameters in a multi-channel wavelength division multiplexer system

CA 2196817 C · Owner: Koch, Thomas Lawson · Inventors: Koch, Thomas Lawson

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Abstract From the Canadian patent

A system and associated method for determining if a channel signal carried by a discrete wavelength channel is properly centered for that wavelength channel. A signal generator is provided that superimposes a secondary signal over the original signal in a signal channel. Tone detectors are provided at a point after the superimposition of the secondary signal. The tone detectors detect the superimposed tone signal at wavelengths that are longer and/or shorter than the wavelength assigned to the wavelength channel. By measuring the degree of balance between wavelengths longer than the wavelength assigned to the wavelength channel and the wavelengths shorter than the wavelength assigned to 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 February 5, 1997 and granted December 19, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 5, 2017.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 5, 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.
FiledFebruary 5, 1997
GrantedDecember 19, 2000
Term endedFebruary 5, 2017
Patent numberCA 2196817 C
Classification (IPC)H04J14/02 +1 more

Timeline

Timeline From CIPO dates

1998200020022004200620082010201220142016Application filedFeb 5, 1997Patent grantedDec 19, 2000Term endedFeb 5, 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.