Non-Terrestrial Networks in a Nutshell

Non-terrestrial networks (NTNs) have been proposed by the 3rd Generation Partnership Project to fill the gaps in cellular coverage and meet the need for more mobile access connectivity. This novel, cost-effective, and flexible network architecture opens up the way for ubiquitous and widespread broadband connectivity. This is made possible thanks to the high capacity and long-range communications of satellites and to the high flexibility of unmanned aerial vehicles (UAVs). This article aims to raise the awareness of the research community about the high potential of NTNs through an up-to-date study of their main features. First, we describe the different scenarios for the use of UAVs in NTNs. Then we present the envisioned NTN architecture and its main challenges in terms of connectivity and quality of service requirements. Finally, we discuss some technical and regulation challenges and point out the main open issues facing the deployment of NTNs.