Green-energy Aware and Latency Aware user associations in heterogeneous cellular networks

Green communications has received much attention recently. For cellular networks, the base stations (BSs) account for more than 50 percent of the energy consumption of the networks. Therefore, reducing the power consumption of BSs is crucial to greening cellular networks. With the development of green energy technologies, BSs can be powered by green energy in order to reduce the on-grid power consumption, and subsequently reduce the carbon footprints. In this paper, we have proposed a distributed scheme to enable Green-energy Aware and Latency Aware (GALA) user-BS associations in heterogeneous cellular networks whose BSs are powered by both on-grid power and green energy. The GALA algorithm considers both the traffic delivery latency and the green energy generation rate in BSs for determining the user-BS association. We have proved that the GALA algorithm converges to the optimal solution which minimizes the summation of the weighted latency ratios of BSs. The simulation results show that the GALA algorithm enables the trade-off between the on-grid power consumption and the average traffic delivery latency, and saves a significant amount of on-grid power in heterogeneous cellular networks that are powered by both on-grid power and green energy.