Time division multiplex switching system for interconnecting telephone circuits which operate in accordance with different signalling systems and call formats
CA 2074447 C · Owner: Gueldenpfennig, Klaus · Inventors: Gueldenpfennig, Klaus; Breidenstein, Charles J.; Caplan, Jerome S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A time division multiplex switching system converts call formats and signalling protocols so that calls can be interchanged between circuits originating in different networks thereby providing a gateway for telephone transmissions originating from sources (e.g. foreign countries) having differences in transmission (signal attenuation characteristics and companding laws) and signalling and numbering plans or protocols. This switching system is characterized by a processor which is programmed to identify the circuits requiring interconnection and to process signalling messages in accordance with the signalling systems and formats used in the circuits, while translating the signalling messages …
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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 July 23, 1992 and granted January 19, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 23, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 23, 2014.
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Timeline
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.