A survey on the role of UAVs in the communication process: A technological perspective

Recently, the use of unmanned aerial vehicles (UAVs) has extended to include many aspects of life such as the commercial, military, search and rescue, monitoring and communications aspects, to name a few. It is unthinkable nowadays to imagine life without robust and far-reaching communication systems. This has become quite evident with the recent COVID-19 pandemic that has struck humanity with profound effects like no other. Many of the human activities had to be switched from being face-to-face activities to the online mode. Therefore, the use of UAVs to extend the reach of communication systems will prove invaluable to many citizens of the world. We see that UAVs can assume different functional roles in the communications process. In this study, we present a novel classification of UAV-related communications along two axes. First, this classification examines the role of the UAV in the communications process where it classifies the UAV as a provider of communications, a relay (service extender) of communications or a consumer of the communications. Second, it examines the communication technologies most used in conjunction with UAV utilization. We provide a critical discussion of the studies that deal with different applications as well as the issues encountered in using a certain technology with UAVs as they assume a specific role. Finally, we present the lessons learned as well as the future directions for using the UAVs in their different roles in connection to the different communication technologies.