06614349 is referenced by 281 patents.

A communication module for an asset to be monitored operates to periodically receive a signal from a monitoring facility via a first wireless communication system, and in response to the absence of the signal at an expected time, communicating with the module via a second wireless system. The first system may be a short range system operating inside a limited facility, and the second system may be a cellular phone system. The module may include a global positioning receiver, so that the module may report its location via the second system to the monitoring system when it is taken from the transmission range of the first system.

Title
Facility and method for tracking physical assets
Application Number
9/677486
Publication Number
6614349 (B1)
Application Date
October 2, 2000
Publication Date
September 2, 2003
Inventor
Andrew J Rimkus
Bainbridge Island
WA, US
Rod L Proctor
Seattle
WA, US
Agent
Stoel Rives
US
Assignee
Airbiquity
WA, US
IPC
G08B 13/14
View Original Source