Multi-tier Drone Architecture for 5G/B5G Cellular Networks: Challenges, Trends, and Prospects

摘要

Drones (or unmanned aerial vehicles [UAVs]) are expected to be an importantcomponent of fifth generation (5G)/beyond 5G (B5G) cellular architectures thatcan potentially facilitate wireless broadcast or point-to-multipointtransmissions. The distinct features of various drones such as the maximumoperational altitude, communication, coverage, computation, and endurance impelthe use of a multi-tier architecture for future drone-cell networks. In thiscontext, this article focuses on investigating the feasibility of multi-tierdrone network architecture over traditional single-tier drone networks andidentifying the scenarios in which drone networks can potentially complementthe traditional RF-based terrestrial networks. We first identify the challengesassociated with multi-tier drone networks as well as drone-assisted cellularnetworks. We then review the existing state-of-the-art innovations in dronenetworks and drone-assisted cellular networks. We then investigate theperformance of a multi-tier drone network in terms of spectral efficiency ofdownlink transmission while illustrating the optimal intensity and altitude ofdrones in different tiers numerically. Our results demonstrate the specificnetwork load conditions (i.e., ratio of user intensity and base stationintensity) where deployment of drones can be beneficial (in terms of spectralefficiency of downlink transmission) for conventional terrestrial cellularnetworks.