Improved range estimation method in WSN for human intruder localization

Considering wide applications of Wireless Sensor Networks (WSNs) this paper presents an improved range estimation method which can be used in WSNs to improve their efficiency while keeping low system requirements. Generally three range estimation methods are used Time of Arrival (ToA), Angle of Arrival (AoA) and Received signal strength Indicator (RSSI). RSSI requires minimum system requirement when compared with ToA and AoA but on the same time lacks in accuracy. In this research accuracy of RSSI in increased by introducing Virtual Reference Tags (VRTs) in the surveillance area. VRTs are previously used in Radio Frequency Identification (RFID) systems to increase their accuracy. Using Ultra Wide Band (UWB) frequencies, when VRTs are used with RSSI, the accuracy of localization increases from 2-4 meters to 0.2-0.4 meters. The integration of RSSI with VRTs, its design and accuracy are discussed in this research.