Energy-efficient user association for heterogenous cloud cellular networks

Energy efficiency is an important issue in radio cellular network planning due to the increasing awareness of environmental protection and cost-efficiency. Heterogenous cloud computing technology is introduced to cellular networks in recent years, which can improve energy utilization by employing lower power cells to reduce the distance between users and base stations, as well as simplifying the system architecture to reduce energy consumption of supporting facilities of base stations. In this paper, we study the energy-efficient user association scheme in heterogenous cloud cellular networks. We try to minimize the total power cost of cellular systems while satisfying users´ traffic demands. The optimization task is formulated as a mixed integer nonlinear programming problem that is generally hard to tackle. We develop a distributed algorithm for power optimization and a centralized one for load balancing. Simulation results show our proposals can fully exploit the advantages of the heterogenous cloud cellular networks, achieving high energy utilization.