A Target Tracking System Using Directional Nodes in Wireless Sensor Networks

Some monitoring applications in wireless sensor networks (WSNs) may require that the target is tracked by at least <inline-formula><tex-math notation="LaTeX">$k$</tex-math></inline-formula> directional nodes in <inline-formula><tex-math notation="LaTeX">$m$</tex-math></inline-formula>-connected WSNs, where <inline-formula><tex-math notation="LaTeX">$k \geq 1$</tex-math></inline-formula> and <inline-formula><tex-math notation="LaTeX">$m \geq 1$</tex-math></inline-formula>. In this paper, we address the target tracking problem in term of the number and orientation of tracking region of directional nodes required to achieve <inline-formula><tex-math notation="LaTeX">$k$</tex-math></inline-formula>-target tracking in <inline-formula><tex-math notation="LaTeX">$m$</tex-math></inline-formula>-connected WSNs. We consider the different values of <inline-formula><tex-math notation="LaTeX">$k$</tex-math></inline-formula>, <inline-formula><tex-math notation="LaTeX">$m$</tex-math></inline-formula>, target range, tracking angle, communication range of nodes, and shape of the field of interest (FoI) for solving the problem. The FoI is divided into an equilateral triangle, square, and hexagon patterns to estimate the optimal side length of a polygon and tracking direction of the nodes for <inline-formula><tex-math notation="LaTeX">$k$</tex-math></inline-formula>-target tracking and <inline-formula><tex-math notation="LaTeX">$m$</tex-math></inline-formula>-connectivity of the network. Next, the optimal side length in a polygon is used to estimate the node locations required for the desired level of target tracking and connectivity. Finally, we select a regular deployment pattern, which requires the least number of nodes for the designed level of tracking and connectivity. We also propose a target tracking system using the proposed analysis for tracking the moving targets in the FoI.