Wavelength-time-space division switching system
CA 2045797 C · Owner: Nishio, Makoto · 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 switching network comprises a plurality of optical splitters coupled respectively to inlet highways for receiving wavelength-time division multiplex (WTDM) signals through the respective inlet highways, each of the multiplex signals comprising a series of WTDM signals each being identified by a unique wavelength and a unique time slot. A like plurality of sets of tunable wavelength filters are provided. The filters of each set are coupled to respective outputs of the splitters for selecting the wavelength of one of the WTDM signals. A like plurality of time-space switches are associated respectively with the sets of the tunable wavelength filters. Each of the time-space switches …
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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 June 27, 1991 and granted August 23, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 27, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 27, 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.
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.