A Topology-Oriented Solution Providing Accuracy for Outdoors RSS-Based Tracking in WSNs

As tracking applications for moving objects become more challenging, demands for accurate and reliable tracking methods using wireless sensor networked devices increase. The use of received signal strength (RSS) of the propagated signals, provided by most sensor radios, is the popular means of achieving such a task. Despite the great RSS variation, which may result in inaccurate estimation of the mobile object position, the advantage is that RSS does not require any additional hardware as in cases like radar and ultrasound techniques and may lower the cost and the size of WSN devices. Parameters such as height from the ground and distance between nodes are examined for their impact on RSS in outdoor environments using the Tmote-Sky platform. Optimal parameter ranges are derived for solving major problems caused by node mobility as well as fading and reflection phenomena of the propagated signal.