Performance Analysis of a UAV-based Non-Terrestrial Network (NTN) using NB-IoT

Unmanned Air Vehicles (UAVs) in wireless communications are mainly used to support existing terrestrial links when they are overloaded. UAV-based Non-Terrestrial Networks (NTNs) are being envisioned to meet the increased network demand incurred by the advent of Internet of Things (IoT). A primary wireless communication technology being considered for UAV-based NTNs is the Narrowband IoT (NB-IoT), which is inherently designed to provide improved coverage for a large number of low-throughput, low-power devices with low cost. In this work, communication procedures are proposed for a UAV-based NTN scenario employing the UAV as a relay between the NB-IoT User Equipments (UEs) and a terrestrial Base Station (BS). It is ensured NB-IoT UEs only interact with the UAV over Line of Sight (LoS) communication links and a simple energy based active user detection mechanism is proposed. Finally, it is demonstrated that the energy efficiency of the UEs in the proposed UAV-based NTN scheme is better than that of the conventional NB-IoT system where the UEs directly access the terrestrial BS.