Performance Evaluation of Aerial Relaying Systems for Improving Secrecy in Cellular Networks

Unmanned aerial systems/vehicles (UAS/UAVs) are emerging in commercial spaces and will support many applications and services, such as smart agriculture, dynamic network deployment, and network coverage extension, surveillance and security. Emerging 5G terrestrial cellular communications networks will support UAS communications. This paper describes the communications security implications of integrating UAVs into cellular networks. We consider two roles for UAVs in a terrestrial cellular system—guardians and attackers—and analyze solutions against eavesdropping. Our approach leverages the mobility of UAV guardians that act as relays or jammers. The numerical analysis using common air-to-ground and air-to-air channel models demonstrates how the use of ground and aerial relay nodes can improve the secrecy rate in light of ground and UAV-based attacks. Specifically, the dependency on height and elevation angle between the ground and aerial communicating nodes is analyzed. The results show that the strategic use of single and multi-hop aerial relays can significantly increase the secrecy rate of ground cellular network users.