Telecommunications networks
CA 2188052 C · Owner: Arya, Deepak · Inventors: Saunders, Martyn; Hoy, Michael Davey; Mason, Stuart
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In a telecommunications network comprising digital main switching units (1) and local exchanges (3) the local exchange (3) is, arranged to permit alternative alert signals to consumer premises (4) by way of the local loop (5). The alternative signals may be cadenced to provide information to apparatus connected in a consumer's premises (4) without causing activation of traditional telephone facsimile, or answering machines. Such information may be supplemented by the presence or absence of a line polarity reversal before the activation signal is sent and by modulated signals such as FSK signalling.
Read the whole patent
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 April 12, 1995 and granted March 27, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 12, 2015.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 12, 2017.
- 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.