Positioning with coverage area estimates generated from location fingerprints

We present a method to estimate the coverage areas of transmitters, and a method to use a database of such coverage areas for personal positioning. The coverage areas are modelled as ellipsoids, and their location and shape parameters are computed from reception samples (fingerprints) using Bayesian estimation. The position is computed as a weighted average of the ellipsoid centers, with weights determined by the ellipsoid shape parameters. The methods are tested using a subset of a prototype wireless sensor network (TUTWSN) consisting of 30 nodes deployed indoors on one floor of a university building. The network nodes use low power commercial off-the-shelf components including a 2.4GHz radio.