Guest Editorial: Coexistence of Drone and Terrestrial Networks

While drones have found use in military applications for decades, they have recently entered the commercial application arena, with substantial market investments coming up over the next decade. They are prevalent in application domains like public safety, surveillance, package/goods delivery, and first responders, to name a few. They are being seen as wireless services on the fly that can augment or complement the capabilities of the current terrestrial wireless communication networks. Drones require a radio frequency spectrum to connect and communicate with the ground base stations, irrespective of the underlying application. Terrestrial wireless networks can support low-altitude drone communications and can thereby help improve the reliability, security, and safety of drone operations. However, transmission from drones to terrestrial networks has the potential to interfere with a large number of terrestrial nodes because of their larger coverage footprint. This leads to a plethora of research challenges related to the coexistence of drone and terrestrial networks. Primarily, we need to understand the rules and regimes under which it makes sense for drone networks to share spectrum with terrestrial networks. Likewise, it is also essential to study situations in which it will be suitable for drones to operate over licensed frequency bands. Therefore, even though integrating drones with terrestrial networks is inevitable and will likely inspire a new suite of applications, many challenges must be tackled before this becomes a reality. For example, existing cellular networks were not designed or optimized to serve or support aerial devices, which demands a significant rethinking in the design and operation of these networks if we are to support these new aerial services reliably.