Date Added: Jan 2011
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, the authors analyzed the errors in these estimates and the effect of these errors on other applications that depend on them. They found that the estimated AP locations have a median error of 32 meters.