Simple and Effective Online Rssi Calibration Method in Wireless Sensor Networks Wsns

Abstract

The Received Signal Strength Indicator (RSSI) of a radio channel provides a feasible way of estimating distance between sensor nodes. It is preferred to use this distance measurement technique because the sensor nodes do not require any additional hardware but only a radio transceiver. Both medium characteristics and node hardware consistency influences RSS measurement results. The calibration method proposed in this paper considers both these error generating factors. It is proposed an online calibration method that based on the known distance between anchor nodes adjusts the distance measurement equation by introducing a calibration factor. How the measurements are influenced by different number of iterations is also analyzed in this paper. It is proven that for an indoor WSN scenario the error is reduced between 60% and 96% after the online calibration method is applied.