Digital signal hardware protection switching
CA 2083635 C · Owner: American Telephone And Telegraph Company · Inventors: Eng, Stephen Ka-Yee
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Protection switching of digital signal transmitting and receiving hardware is realized in a "hitless" manner. The hitless switch is obtained by employing hardware switching units which can individually determine the instant to switch from an active state to a standby state and vice versa. A switch is initialized by supplying a switch request signal from a control unit to a hardware switching unit in the active state. The active hardware switching unit upon detecting a prescribed, bit condition for example, a predetermined bit state of the digital signal being, supplied as an output therefrom supplies a predetermined synchronization pulse to the standby hardware switching unit. In response …
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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 November 24, 1992 and granted January 12, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 24, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 24, 2014.
- 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.