Actuating Sensor For Determining The Direction Of Arrival Using Maximal RSSI

Abstract In this paper we proposed an actuating device that can identify the direction of arriving DOA radio signal using its maximum receive signal strength RSSI that is suitable for localization as well as localization aided fundamental network services such as network routing topology control coverage boundary detection and clustering. The device determine the direction of arrival by identifying the maximal received signal strength indicator RSSI measurement based on MRF24J40MA ZigBee embedded monopole antenna radiating characteristics. Localization from distance estimation alone is a challenging problem but helpful if we know the relative angular position measurements between pairs of nodes. AOA measurements using directional antenna or phased array antenna are unsuitable for wireless sensor networks due to cost size complexity and energy demanding limitation. The device and the algorithm we proposed is compact and simple enough to be suitable for deployment in WSNs. Our prototype scheme is based on low cost 8 bit Atmega micro-controller embedded with Microchip ZigBee MRF24J40MA shield and rotational support provided by servo motor. Our experimental results verify the optimality of smart sensor for estimating the DOA with less than an error of 6 to 7 degree in both indoor and outdoor environments including varying height of transmitting anchor.