Telephone information service system using digital and out-of-band signaling
CA 2128388 C · Owner: American Telephone And Telegraph Company · Inventors: Backaus, Marjorie Susan; Davenport, Esther Lee; Fahrer, Harold
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A high-speed information service system is provided which uses Primary Rate Interface (PRI) Integrated Services Digital Networks (ISDN) signaling and temporary "out-of-band", signaling to improve information retrieval capability. ISDN signaling permits electronic addressing of information requested by the subscriber thereby eliminating the delays which, accompany DTMF signal processing. Communications between an information service provider and an individual information source are conducted using out-of-band signaling. That is call, setup and information request are processed using a channel other than the channel which carries data between the information service provider the information …
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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 20, 1994 and granted August 25, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 20, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 20, 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.