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Expired Canadian patentCanada

Integrated packet switching and circuit switching system

CA 1237185 A · Owner: American Telephone And Telegraph Company · Inventors: Hiller, Thomas L.; Van Dine, Gilbert A.; Davis, James A.

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

Abstract, An integrated packet switching and circuit switching system comprising a number of switching modules each connected to a different plurality of user terminals. Each switching module includes a time-slot interchange unit for providing circuit-switched communication channels and a control unit that controls the operation of the time-slot interchange unit. Each switching module also includes a packet switching unit used both to provide packet-switched communication channels among the user terminals connected to that switching module, and to switch control information between the user terminals and the control unit to establish circuit-switched calls and packet-switched calls.

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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 May 24, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 24, 2005.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledApril 24, 1985
GrantedMay 24, 1988
Term endedMay 24, 2005
Patent numberCA 1237185 A
Classification (IPC)H04Q11/04 +1 more

Timeline

Timeline From CIPO dates

1986198819901992199419961998200020022004Application filedApril 24, 1985Patent grantedMay 24, 1988Term endedMay 24, 2005

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.