Errors in determinstic wireless fingerprinting systems for localisation

Fingerprinting is a technique that records vectors of received power from several transmitters, and later matches these to a new measurement to position the new user. This paper examines data used in earlier fingerprinting experiments in a WiFi network to characterize the eventual positioning errors. The implied relationship between real distance and ldquovectorrdquo distance between fingerprints is tested and found to be poor. However, because fingerprinting algorithms use nearest neighbour techniques, these nearby fingerprints were examined and found to be better behaved.