Optimal matching between energy consumption of Base Stations and traffic load in green cellular networks

Energy efficiency has become significantly important in designing future green mobile communication systems. In this paper, a novel energy efficiency metric, which is per energy per area capacity, is proposed to quantify the matching degree between energy consumption of Base Stations (BSs) and the traffic load. Based on BS power consumption model and Shannon capacity formula, the deployment strategies of different base station types are discussed, and the matching degree maximization is formulated as a convex optimization problem. The optimal cell size is proved to be the solution, which can be obtained by our presented iterative algorithm. Through theoretical inference and experimental simulations, we find that macro BS outperforms micro BS when the traffic density is pretty low, while it becomes reversed if the value exceeds the boundary. Besides, the heavier traffic demand results in a smaller optimal cell size.