Polling method in a radio data packet communication system
CA 2059239 C · Owner: Nec Corporation · Inventors: Kasugai, Teruaki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A central station 101 continuously transmits a slot of predetermined time length which comprises a polling frame Pxx and a downward data frame Ixx. After receiving the upward data frame Dxx, it sequentially and repeatedly carries out an individual polling of upwardly communicating terminal stations 102 and 103 at a time interval which is more than the predetermined time interval for the polling frame Pxx. Unspecified polling is carried out of unspecified terminal stations by a polling frame Po which does not carry out this individual polling. Independently of the polling frame Pxx the downward data, frame Ixx is repeatedly transmitted to downwardly communicating terminal stations 104 and …
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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
- Filed January 13, 1992 and granted October 13, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 13, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 13, 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.