Determining wireless device locations

Abstract

Wireless network devices can obtain their geographical location by triangulating with access points that have precise time information. In response to a location prompt, a wireless device can send a transmission to multiple access points that are within its range. The different times at which the transmission is received at different access points can be collected and forwarded to a server, which can compute the location of the wireless device using triangulation techniques. The access points can calibrate their own time bases from time services received from global position satellites.

We claim:  
     
         1 . An apparatus comprising: 
 an access point including: 
 a wireless communication interface to communicate data with a wireless mobile device; and  
 logic coupled to the wireless communication interface to receive a time signal from the wireless mobile device through the wireless communication interface.  
   
     
     
         2 . The apparatus of  claim 1 , wherein: 
 the time signal is a ping signal broadcast by the wireless mobile device.    
     
     
         3 . The apparatus of  claim 1 , wherein: 
 the wireless communication interface includes a common antenna for said communicating data and said receiving the time signal.    
     
     
         4 . The apparatus of  claim 1 , wherein: 
 communicating data includes communicating with an Internet browser.    
     
     
         5 . An apparatus comprising: 
 an access point including: 
 a wireless communication interface to communicate data with a wireless mobile device; and  
 logic coupled to the wireless communication interface to transmit a time signal to the wireless mobile device through the wireless communication interface.  
   
     
     
         6 . The apparatus of  claim 5 , wherein: 
 the time signal is a pseudo-GPS signal to use in calculating location in the wireless mobile device.    
     
     
         7 . The apparatus of  claim 5 , wherein: 
 the wireless communication interface includes a common antenna for said communicating data and said transmitting the time signal.    
     
     
         8 . The apparatus of  claim 5 , wherein: 
 said communicating data includes communicating with an Internet browser.