Energy-efficient roadside units deployment in Vehicular Ad hoc Networks

With the rapid development of the highway and railway, more and more people pay attention to the Vehicular Ad hoc Networks (VANETs) in recent years. Meanwhile, there are many challenging problems in this research area and the deployment of roadside units (RSUs) is one of the most important. In this paper, we study the energy-efficient RSU deployment problem in VANETs, where some RSUs are deployed to seamlessly cover the road with the purpose of minimizing the transmit power. The formulated problem is hard to solve since the minimum function is nonconvex. To address this difficulty, we transform the primal problem into a standard convex problem, by applying the methods of linear approximation, the S-Procedure and Semidefinite relaxation. Then an energy-efficient RSU deployment algorithm is proposed to solve the relaxed problem, where the initialization and update of the parameters are described. Finally, the simulations are conducted and the results show the performance of our proposed algorithm.