RSSI range estimation for indoor anchor based localization for wireless sensor networks

Range estimation using RSSI (received signal strength indicator) for localization application for wireless sensor networks is a challenging task. Interference from the shared 2.4GHz channel and fading due to multipath propagation and shadowing deteriorate the process of range estimation. In this work an estimation of these noise levels that are present in the environment is being carried out by anchor nodes which are placed throughout the sensing field. These anchor nodes will compare the actual distance between them with distance computed from the measured RSSI. Four different techniques have been devised that applies a smoothing coefficient on the measured RSSI taking into consideration information about the environment from the anchor nodes. Simulation shows that even when the error introduced is equivalent to 100% of the transmission range, the error in range estimation was around 25%.