Modeling and optimization of self-organizing energy-saving mechanism for HetNets

Energy efficiency in future green cellular wireless networks poses a challenge to operators and researchers. An effective method of providing energy savings (ES) in base stations (BSs) is to switch off idle BSs or put them into sleep mode and subsequently migrate the traffic loads to active BSs in their neighborhood. The intrinsic issue related to such methods applied to heterogeneous networks (HetNets) is that the optimal selections of various types of BSs during both energy-saving and coverage-compensating (CC) processes are difficult to determine. In an attempt to resolve the insufficiency of existing strategies, we propose a novel traffic-aware self-organizing ES mechanism that enables efficient resource allocation and interference management in multi-level networks. To further develop optimal energy conservation procedures for BSs, a new constraint model is proposed. We employ coverage gaps and over-provisioning as the optimization objectives and analyze the effects of their weights. The performance in terms of energy savings is evaluated in an urban Long-Term Evolution (LTE) scenario with different types of BSs. The simulation results show that the proposed mechanism can maximize energy efficiency in heterogeneous cellular networks while guaranteeing the quality of service. This algorithm is autonomous in terms of decision making and execution.