Energy-Saving Transmission for Green Macrocell–Small Cell Systems: A System-Level Perspective

Energy minimization has been one of the major research challenges for access networks striving for green communication. Macrocell base stations (MBSs) are the main contributors to energy consumption, and the situation has become worse as more MBSs are being deployed to cope with the ever-increasing data traffic. Therefore, it will be crucial in the near future to minimize the energy consumption of MBSs. Based on various academic and industrial surveys, cellular systems involving both MBSs and small cell base stations (SBSs) are predicted to be the key network architecture for reducing the total energy consumption of access networks. In this paper, an efficient energy-saving transmission algorithm is proposed to minimize power consumption for transceivers in both MBSs and SBSs in cellular systems with a green deployment policy. The proposed algorithm enables grouped SBSs to be smartly activated/deactivated, according to dynamically fluctuating traffic loads, while maintaining the predetermined data rate requirements of all served users. Simulations of various traffic scenarios show that the presented approach performs better in terms of energy saving than the conventional approaches, providing an average improvement of around 20% under the employed real-world traffic pattern.