Time since last fix annunciation system for GPS-based wireless rescue system
First Claim
1. In a wireless location system in which a wireless phone is provided with a GPS receiver for receiving GPS satellite signals and means for annunciating the position derived from said GPS receiver and for transmitting said annunciated position to a remote location by said wireless phone, means at said wireless phone for ascertaining when in time said GPS receiver acquires a position fix from said GPS satellites, means for ascertaining present time, means for calculating time since said fix, means for annunciating said time since said fix, and means for transmitting said annunciated time since said fix to said remote location with said position annunciation such that the validity of said annunciated position can be ascertained at said remote location.
7 Assignments
0 Petitions
Accused Products
Abstract
In a wireless emergency location system in which a cellular phone is utilized to communicate the location of an individual or vehicle by announcing position based on the output of a GPS receiver, time since last fix is computed and annunciated to permit emergency personnel to ascertain if the position information is valid. In a one embodiment, velocity and direction of travel are also annunciated for permitting emergency personnel to calculate the location of the phone and thus a stricken individual. Time since last fix as well as velocity and direction annunciation is also used to enable location of stolen or hijacked vehicles assuming location information is no longer available at the phone or satellite fix has been lost.
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Citations
7 Claims
- 1. In a wireless location system in which a wireless phone is provided with a GPS receiver for receiving GPS satellite signals and means for annunciating the position derived from said GPS receiver and for transmitting said annunciated position to a remote location by said wireless phone, means at said wireless phone for ascertaining when in time said GPS receiver acquires a position fix from said GPS satellites, means for ascertaining present time, means for calculating time since said fix, means for annunciating said time since said fix, and means for transmitting said annunciated time since said fix to said remote location with said position annunciation such that the validity of said annunciated position can be ascertained at said remote location.
Specification