Method and apparatus for locating a wireless device

Abstract

Disclosed is a method and apparatus for locating a wireless device especially useful for locating a cellular telephone making a call from an unknown location. The call may be a request for emergency assistance, or for location-based commercial services, for example. Various embodiments may optionally include a mobile location component, a cellular telephone enabled to chirp-on-demand, and/or an interferometer link. A mobile location component may include a directional antenna. The directional antenna may be mounted on an antenna boom on top of an emergency vehicle, for example. The mobile location component may alternately or additionally comprise a hand-held unit. System elements may cooperate to generate a situation awareness map or other display. The mobile location component may be moved in the general direction of a first location calculation associated with a first circular error of probability. After being moved in the general direction, the mobile location component may cooperate with other elements to determine a second location calculation associated with a second circular error of probability. Second and subsequent location calculations are of increasing precision, enabling an emergency vehicle or attendant to zero in on a cellular telephone.

1 - 18 . (canceled)  
   
   
       19 . A method of determining a location of a mobile telephone and displaying the location on a map, the method comprising: 
 receiving, at a controller, a first location signal from a single cellphone tower in wireless communication with the mobile telephone;    receiving, at the controller, a second location signal from a non-tower source in wireless communication with the mobile telephone;    determining the location of the mobile telephone based solely on the first and second location signals;    generating a situation awareness map including the determined location and geographic map data for an area surrounding the determined location;    digitally displaying on a digital display device the situation awareness map showing the determined location of the mobile phone on a digital map of a geographic area surrounding the determined location.    
   
   
       20 . A system for determining a location of a mobile telephone and displaying the location on a map, the method comprising: 
 means for receiving a first location signal from a single cellphone tower in wireless communication with the mobile telephone;    means for receiving a second location signal from a non-tower source in wireless communication with the mobile telephone;    means for determining the location of the mobile telephone based on the first and second location signals;    means for generating a situation awareness map including the determined location and geographic map data for an area surrounding the determined location;    means for displaying the situation awareness map showing the determined location of the mobile phone on a map of the surrounding area.    
   
   
       21 . The method of claim  1  wherein the digital display device is a hand-held wireless communication device.