Verification of subscriber lines prior to cutover to a new switching system
CA 2080107 C · Owner: American Telephone And Telegraph Company · Inventors: Dennison, Bernard Michael; Miller, Jerry Gorman; Turner, James Lee
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract The present invention addresses an improved solution to the problem of cutover verification testing where a new digital switching system is to replace an existing switching system that serves at least a group of subscribers via continuous wire lines. It permits a plurality of existing wire lines to be concurrently connected to channel units associated with the new switching system without adversely impacting the existing service and automatic testing under the control of the new system.
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 October 7, 1992 and granted August 30, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 7, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 7, 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.