Characterizing Mobile Telephony Signals in Indoor Environments for Their Use in Fingerprinting-Based User Location

摘要

Fingerprinting techniques have been applied to locate users in indoor scenarios using WiFi signals. Although mobile telephony network is used for outdoor location, it is widely deployed and their signal more stable, thus being also a candidate to be used for fingerprinting. This paper describes the characterization of GSM/UMTS signals in indoor scenarios to check if their features allow to use them for constructing the radio maps needed for fingerprinting purposes. We have developed an Android application to collect the received signal information, such that makes the measurement process cheaper and easier. Measurements show that changes in location and device orientation can be identified by observing the received signal strength of the connected and neighboring base stations. Besides, detecting this variability is easier by using the GSM network than with UMTS technology. Therefore mobile telephony network seems suitable to perform fingerprinting-based indoor location.