Risks of Using AP Locations Discovered Through War Driving

  • Minkyong Kim
  • Jeffrey J. Fielding
  • David Kotz
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3968)


Many pervasive-computing applications depend on knowledge of user location. Because most current location-sensing techniques work only either indoors or outdoors, researchers have started using 802.11 beacon frames from access points (APs) to provide broader coverage. To use 802.11 beacons, they need to know AP locations. Because the actual locations are often unavailable, they use estimated locations from war driving. But these estimated locations may be different from actual locations. In this paper, we analyzed the errors in these estimates and the effect of these errors on other applications that depend on them. We found that the estimated AP locations have a median error of 32 meters. We considered the error in tracking user positions both indoors and outdoors. Using actual AP locations, we could improve the accuracy as much as 70% for indoors and 59% for outdoors. We also analyzed the effect of using estimated AP locations in computing AP coverage range and estimating interference among APs. The coverage range appeared to be shorter and the interference appeared to be more severe than in reality.


Median Error Actual Location User Location User Position Beacon Frame 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2006

Authors and Affiliations

  • Minkyong Kim
    • 1
  • Jeffrey J. Fielding
    • 1
  • David Kotz
    • 1
  1. 1.Department of Computer Science Dartmouth CollegeUSA

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