Energy-efficiency-aware flow-based access control in HetNets with renewable energy supply

Abstract

Software defined networking (SDN) is revolutionising the telecommunication networking industry by providing flexible and efficient management. This paper proposes an energy-efficiency-aware flow-based management framework for relay-assisted heterogeneous networks (HetNets), where the relay nodes are powered by renewable energy. Due to the dynamic property of user behaviour and renewable energy availability, the flow-based management layer should enhance not only the instantaneous energy efficiency but also the long-term energy efficiency, while satisfying the transmission rate demand for each user. We first formulate the energy efficiency problem in HetNets as an optimisation problem for instantaneous energy efficiency and renewable energy allocation, and propose a heuristic algorithm to solve the optimisation problem. According to the proposed algorithm, we then design a dynamic flow-table configuration policy (DFTCP) which can be integrated as an application on top of an SDN controller to enhance the long-term energy efficiency. Simulation results show that the proposed policy can achieve higher energy efficiency compared with current distributed relay strategy, which chooses the nearest or strongest signal node to access, and obtain better performance for the overall relay network when the user density and demand change.