A Hybrid Localization Algorithm for Wireless Sensor Networks

The continuously widening range of Wireless Sensor Networks (WSNs) applications requires exact node location which needs efficient and error free localization methods. Localization methods developed in the past are completely based on very fine numerical computation of various network parameters such as transmission range, propagation shape, transmitted or received power, sending or arrival time, connectivity information etc. These parameters are prone towards environmental situation and presence of obstacles in environment. Recently, research in localization is focused towards minimization of localization error in the available techniques. In this paper, the cause and behavior of errors in AOA and RSSI localization techniques have been mathematically analyzed. Based on the error analysis of both the existing techniques, a hybrid localization algorithm is proposed. The hybrid localization algorithm is based on existing Angle of Arrival (AOA) and Received signal strength indicator (RSSI). The algorithm is named as Minimum AOA Error with Minimum RSSI Error (MAE with MRE). Analysis of results obtained through simulation show that the hybrid localization algorithm performs better than AOA and RSSI techniques in terms of error percentage probability with varying number of known sensors, unknown sensors and shadowing effect percentage. (C) 2015 Published by Elsevier B.V.