Minimal Exposure Path Algorithms for Directional Sensor Networks

As a fundamental problem of wireless sensor networks, the minimal exposure path problem corresponding to the sensor network´s worst-case coverage plays an important role in the applications for detecting intrusions. However, most existing works about minimal exposure path are based on omnidirectional sensors. In contrast, this paper studies the minimal exposure path problem for directional sensor networks. We first develop a directional sensing model: directional sensitivity model. Then, we formulate the minimal exposure path problem by using two sensing intensity functions: all-sensor intensity function and maximum-sensor intensity function, and generate two weighted grids to convert the minimal exposure path problem into two discrete geometric problems. Based on the above weighted grids, we also develop two approximation algorithms to find the minimal exposure path for the directional sensitive model. We conduct extensive simulations to validate and evaluate our proposed models and algorithms.