Place Lab: Device Positioning Using Radio Beacons in the Wild (Pervasive 2005)

Present the architecture. Requires positions of beacons, which can be found through simple techniques such as centroid.

Collected traces from 3 areas, show 100% GSM coverage and 90% WiFi coverage.

Achieved 100-200m accuracy based only on the srongest-cell technique (WiFi achieves 15-20m accuracy)

GPS provides median accuracy of 10m.