An approximation algorithm for General Energy Restricted Sweep Coverage problem

Abstract

Considerable attention has been paid to sweep coverage in Wireless Sensor Networks (WSNs) for the past few years. In sweep coverage, mobile sensor nodes are scheduled to visit Points of Interests (POIs) periodically. Due to the limited energy of mobile sensors, energy consumption poses an important challenge in sweep coverage. In this paper, we extend the Energy Restricted Sweep Coverage to the General Energy Restricted Sweep Coverage (GERSC) by assuming the unit energy consumption of mobile sensors varies in different road sections. The goal of GERSC is also to minimize the required number of mobile sensors in sweep coverage under the energy constraint. In GERSC, the approximation ratio of the state-of-the-art algorithm named ERSweepCoverage is no longer guaranteed. Therefore, we devise a constant-factor approximation algorithm named IERSC for GERSC. The approximation ratio of IERSC is β[3αmin(θ,1−θ)+1]. θ is the predefined parameter of IERSC ranging from 0 to 1. With θ being 12, IERSC has the best approximation ratio of (6α+1)β. Finally, the promising experimental results demonstrate the effectiveness and efficiency of the proposed algorithm.