Isdn compound switching system
CA 2028141 C · Owner: Kurumisawa, Shinichi · Inventors: Kawamata, Kouji; Douzono, Masaaki; Funaki, Kenichi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
For example, in order to simplify the backup system of an on-line service system, according to the invention a host computer, a communication manager and, a number of ISDN compound switching units (I-SW) are installed on the part of a central controller unit. In addition, a terminal control unit and an I-SW remote manager are installed at the central controller unit or each of specific business offices. A plurality of ISDN compound switching units, a network terminal equipment, a digital service unit (DSU) a modem M, a, terminal control unit, a plurality of terminal equipment and automatic equipment, are installed in each business office. Using private lines, the communication manager unit …
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 February 28, 1990 and granted April 6, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 28, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 28, 2012.
- 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.