Self-Calibrating RSSI-based Indoor Localization with IEEE 802.15.4

The received signal strength indicator (RSSI) based localization techniques are attractive because of their simplicity. Since RSSI has become a standard feature in most wireless devices, RSSI-based localization techniques does not require additional hardware, and does not have a significant impact on local power consumption, sensor size and thus cost. The path loss exponent, and the wall attenuation factor are the key parameters in the distance estimation based on RSSI. Existing techiniques, exploit both RSSI and distance measurements to calibrate the parameters. This procedure is very expensive in terms of time as it requires human intervention. In this paper we propose a selfcalibration procedure which only exploits the measurements of the RSSI between pairs of anchors. In particular we propose two heuristics for self-calibration and we evaluate their performance with respect to an ad-hoc calibration campaign by performing measures in an indoor environment with an IEEE 802.15.4 sensor network.