Communication set and method
CA 1207030 A · Owner: Racal Acoustics Limited · Inventors: Smith, Peter L.; Gorman, Anthony G.; Barrett, Paul Q.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A telephone communication method provides simultaneoulsy duplex channels between respective pairs of stations over a single wire pair highway by frequency division multiplexing. Each duplex channel has a predetermined pair of carrier frequencies but only carrier, frequency pairs of channels in use for communication are present on the highway at any time. On initiating a call, a station seeks for a free channel and reserves it by generating the "go" carrier of the free channel modulated with the call sign of the desired station and, also generating an alert signal. Quiescent stations respond-to the alert by seeking a "go" carrier with call sign data and, on identifying their own call sign …
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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
- Granted July 2, 1986. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 2, 2003.
- 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.