Optical wavelength selection control system in optical networks
CA 2125422 C · Owner: Nec Corporation · Inventors: Nishio, Makoto
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical wavelength selection control system in an optical network includes an optical center node device and a plurality of terminal devices each comprised of a work station and an interface. The optical center node device includes a control circuit, a plurality of optical switches and a plurality of tunable wavelength filters. When there occurs a collision among the plurality of terminal devices wherein a plurality of terminal devices send simultaneously optical packets to the same terminal device, the control circuit operates to control the optical switches and the tunable wavelength filters such that they select only one optical packet, based on information relating to, for example, a …
Read the whole patent
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 June 8, 1994 and granted April 22, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 8, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 8, 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.