Barrier coverage is an appropriate coverage model for intrusion detection by constructing sensor barriers in wireless sensor networks. In this paper, we focus on the problem how to relocate mobile sensors to construct k sensor barriers with minimum energy consumption. We first analyze this problem, give its Integer Linear Programming(ILP) model and prove it to be NP-hard. Then we devise an approximation algorithm AHGB to construct one sensor barrier energy-efficiently, simulations show that the solution of AHGB is close to the optimal solution. Based on AHGB, a Divide-and-Conquer algorithm is proposed to achieve k-barrier coverage for large sensor networks. Simulations demonstrate the effectiveness of the Divide-and-Conquer algorithm
