Coalitional Planning for Energy Efficiency of HetNets Powered by Hybrid Energy Sources

In this paper, we focus on the problem of planning heterogeneous cellular networks powered by renewable energy sources, which are a good alternative for dealing with the growth of mobile data traffic while minimizing energy consumption. The paper proposes a method based on a coalitional game in which small cells are players, with the Shapley value determining the contribution of each potential small cell to the global performance of the system. The characteristic function of the game is based on three key performance indicators: percentage of users served, reduction of grid consumption, and average transmission rate. The success of the coalitional game-based planning process is considered from an energy efficiency perspective, which means a reduction of on-grid consumption and an improvement of network performance according to renewable energy availability. The efficiency of the coalitional design is compared with other heuristic and optimal alternatives in two simulation examples. Our results show that the proposed coalitional planning scheme produces an efficient use of energy compared to other strategies.