The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 25, 1994
Filed:
Apr. 13, 1992
Isaac Shpancer, Edina, MN (US);
Jon M Silverman, Minneapolis, MN (US);
Merv L Grindahl, Waseca, MN (US);
RACOTEK, Inc., Minneapolis, MN (US);
Abstract
A data communications system is overlaid on a voice-based trunked radio system. Digital data packets are transmitted over available radio channels, thereby enabling data communication between a host dispatch system and mobiles and a base station in the trunked radio system. Radio channels associated with trunked channel groups are accessed when available by a communications controller. The communications controller is configured to communicate with various mobile units of the trunked radio system over available radio channels through multiple radio communication links. Radio channels are monitored to detect when the radio channels are presently unused for voice transmission and thereby accessible for data overlay. In particular, when the data overlay system detects that the transmission of analog voice information ceases over a particular radio channel, the trunked channel group association of that particular radio channel is caused to be switched from a voice group to a data group. Data packets are then transferred over the available radio channel.