Aerial base station

Lore & Background

Historically, UAVs were considered expensive toys used mainly for military purposes such as cargo delivery, remote surveillance, and armed attacks, with the primitive use recorded in 1849 at Venice when Austrians attacked Italy using unmanned balloons with explosives. Applications continued through the world wars and later for espionage and hostage search using wireless sensors. In the early 2000s, reduced costs and sizes led to civilian and commercial applications, with UAVs working as aerial user equipments (UEs) in coexistence with ground users, a technology called cellular-connected UAVs, exemplified by Amazon Air and Google's Project Wing.

Due to continuous miniaturization of wireless communication components, equipping UAVs with radio frequency transceivers and dedicated hardware to provide reliable, on-demand wireless links to ground users became a reality. Transceivers weighing less than 2 kilograms, such as universal software radio peripheral integrated with software-defined radio, can be mounted on aircraft using 3D printed supports. This new concept of UAV-assisted wireless communications supports fast-growing wireless data traffic, and ABSs are identified as an important component of 5G and beyond networks.

Key characteristics include high altitude (up to 100-120 meters) enabling broader coverage and reduced interference, 3D high mobility providing higher line-of-sight (LoS) channel probability crucial for millimeter-wave 5G and 3D MIMO, and scalability of FANETs using decentralized routing with the 802.11p protocol. However, ABSs face challenges including energy limitations, security monitoring, privacy and data protection, and the absence of unique legal regulation, with different agencies like FAA, NASA, EASA, and ICAO developing guidelines.

Reader's Guide

The significance of aerial base stations lies in their ability to allow mobile operators and network designers to create on-demand networks in bordered areas catering to particular clients and use cases. They can effectively accompany existing terrestrial systems in crowded areas like stadiums during events by providing additional capacity. ABSs enable information dissemination and collection in wireless sensor networks and IoT scenarios where long-range communications are not possible due to low transmitted power. They also facilitate information transmission among geographically separated data centers and deliver network coverage in hard-to-reach rural or suburban areas, where deploying ABSs is highly advantageous compared to expensive telecommunications towers or fiber links. In emergency situations such as terroristic attacks, ABSs provide fast connectivity restoration after infrastructure failure or data relaying, for example between the frontline and headquarters. Industry testing by Qualcomm, AT&T, and projects like Facebook Aquila, cell-on-wheels and wings (COW-W), Google SKYBENDER, Nokia F-Cell, and Huawei Digital Sky have explored the benefits of ABS services. A significant barrier remains the absence of unique legal regulation, with policies differing among countries and zones, split between UAV technology guidelines and telecommunications regulations.

Did You Know?

• The primitive use of a UAV was recorded in 1849 at Venice when Austrians attacked Italy using unmanned balloons furnished with explosives.
• ABSs can hover up to 100-120 meters, compared to typical terrestrial base stations at 10-20 meters in urban scenarios.
• Transceivers weighing less than 2 kilograms can be mounted on UAVs using 3D printed supports.
• FANETs use the 802.11p protocol, originally for vehicular communications, for information exchange among ABSs.