Patent Yard Sign in
Expired Canadian patentCanada

Integrated communications system for hdlc variable-length data packets and fixed-length voice/video packets

CA 2009237 C · Owner: Tsuzuki, Kazuo · Inventors: Tsuzuki, Kazuo

CIPO record

Overview

Drawings and full text

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

Open the CIPO record

Abstract From the Canadian patent

In an integrated communications system HDLC variable-length, packets and non-HDLC fixed-length packets are decomposed into cells and a cell identifier is generated for each of the cells for identifying its type. A frame sync code is transmitted from one end of a transmission channel, and the cell identifier and each of the cells are assembled into a field and a plurality of such fields are assembled into a frame for transmission. The frame sync code is detected at the other end of the transmission channel as a timing reference and the frame is deassembled into fields in response to the timing reference and each field is deassembled into a cell identifier and a cell. According to each …

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 2, 1990 and granted July 26, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 2, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 2, 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.
FiledFebruary 2, 1990
GrantedJuly 26, 1994
Term endedFebruary 2, 2010
Patent numberCA 2009237 C
Classification (IPC)H04Q11/04 +2 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedFeb 2, 1990Patent grantedJuly 26, 1994Term endedFeb 2, 2010

Sources & verification

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