Association of Small Cell Base Stations with UAVs in HetNets

Abstract

Small cell networks (SCNs) offer a cost-effective coverage solution to wireless ap plications demanding high data rates. However, in SCNs, a challenging problem is the proper management of backhaul links to small cell base stations (SCBSs). To make a good backhaul link, perfect line-of-sight (LoS) communication between the SCBSs and the core network plays a vital role. Traditionally, the traffic of SCBSs is routed to ground core network via fiber optics. However, the de ployment cost and time is a huge concern when the number of SCBSs increases. Therefore, in this thesis, we use the scalable idea of employing unmanned aerial vehicles (UAVs) to provide connectivity between SCBSs and the core network. In particular, we focus on the association of SCBSs with UAVs by considering multiple communication-related factors including data rate limit and available bandwidth resources of the backhaul. Specifically, we address the optimum placement of UAVs to serve a maximum number of SCBSs while considering available resources using the unsupervised k-means algorithm. Afterward, we provide a two layer-based algorithm to maximize the sum rate and energy efficiency of the overall network while associating the SCBSs with UAVs. Simulation results show that the proposed methods outperform the conventional approach used in literature in terms of associated SCBSs, bandwidth consumption, available link utilization sum rate, and energy efficiency maximization