Backhaul-Aware Placement of a UAV-BS with Bandwidth Allocation for User-Centric Operation and Profit Maximization.

Addressing the Quality-of-Service (QoS) requirements of users is crucial for service providers to improve the network performance. Furthermore, the transformation from the network-centric to user-centric service paradigm requires service providers to focus on improving the Quality-of-Experience (QoE) which is expected to become an important objective in Next Generation Cellular Networks (NGCNs). Managing QoE is not only a technical issue but also a marketing ability to improve profitability. An efficient strategy to improve the profitability is to apply price differentiation for different service levels. Unmanned Aerial Vehicle Base Stations (UAV-BSs) are envisioned to be an integral component of NGCNs and they create opportunities to enhance the capacity of the network by dynamically moving the supply towards the demand while facilitating services that cannot be provided via other means efficiently. However, building a reliable wireless backhaul link via optimized resource allocation is a key issue for the placement of UAV-BSs. In this paper, we consider a UAV-BS and a terrestrial network of Macro-cell Base Stations (MBSs) that the UAV-BS rely on for backhauling. The problem is to determine the 3D location of the UAV-BS and the bandwidth allocations to each user to maximize the profitability of service provided in terms of achievable data rate levels. We develop a Mixed Integer Non-Linear Programming (MINLP) formulation of the problem. To overcome the high complexity, we propose a novel search algorithm that is very efficient in terms of solution quality and time. The analysis performed through numerical evaluations reveal that offering multiple data rate options to users improves the QoE and at the same time allows the service providers to increase the total profit.