A Traffic Load Balancing Framework for Software-defined Radio Access Networks Powered by Hybrid Energy Sources

摘要

Dramatic mobile data traffic growth has spurred a dense deployment of smallcell base stations (SCBSs). Small cells enhance the spectrum efficiency andthus enlarge the capacity of mobile networks. Although SCBSs consume much lesspower than macro BSs (MBSs) do, the overall power consumption of a large numberof SCBSs is phenomenal. As the energy harvesting technology advances, basestations (BSs) can be powered by green energy to alleviate the on-grid powerconsumption. For mobile networks with high BS density, traffic load balancingis critical in order to exploit the capacity of SCBSs. To fully utilizeharvested energy, it is desirable to incorporate the green energy utilizationas a performance metric in traffic load balancing strategies. In this paper, wehave proposed a traffic load balancing framework that strives a balance betweennetwork utilities, e.g., the average traffic delivery latency, and the greenenergy utilization. Various properties of the proposed framework have beenderived. Leveraging the software-defined radio access network architecture, theproposed scheme is implemented as a virtually distributed algorithm, whichsignificantly reduces the communication overheads between users and BSs. Thesimulation results show that the proposed traffic load balancing frameworkenables an adjustable trade-off between the on-grid power consumption and theaverage traffic delivery latency, and saves a considerable amount of on-gridpower, e.g., 30%, at a cost of only a small increase, e.g., 8%, of the averagetraffic delivery latency.