Energy-Based Target Numeration in Wireless Sensor Networks

Target numeration is of great importance for activity monitoring applications in wireless sensor networks (WSNs); however it is also a challenging problem in a WSN only equipped with simple amplitude sensors. Only a few algorithms have been proposed to solve the problem of target counting, and their accuracy and computational complexity is not satisfactory. This paper provides a two- step energy-based target numeration (EBTN) algorithm that firstly groups the sensor nodes that detect a target into separate clusters, and then calculates the number of targets covered by each cluster based on the total signal energy collected over the cluster. A polynomial regression function is used to approximate the signal strength over a cluster, and the total energy is estimated by taking the integral of the function over the area. By combining with preliminary clustering step, energy-based target counting greatly improves the counting accuracy. Experiments also show that EBTN requires lower node density and computational complexity compared with other algorithms.