Massive MIMO and Secrecy Guard Zone Based Improving Physical Layer Security in UAV-Enabled uRLLC Networks

Ultra reliable low latency communications (uRLLC) is a new service category for sixth-generation (6G) wireless networks. The security and confidentiality of information transmission faces more challenges in the context of uRLLC because of the openness nature of wireless medium. By using the inherent characteristics of wireless medium, physical layer security (PLS) can be used as a promising solution to ensure the security of wireless communications. Unmanned aerial vehicle (UAV) communications is frequently characterized by line-of-sight (LoS) and dynamic propagation conditions. Since UAV can provide a strong line-of-sight link with strong reliability and speed, it is widely used in various wireless communication scenarios. Much previous work ignored the role of UAVs in PLS research in uRLLC. In this paper, we consider the line-of-sight/non-line-of-sight (NLoS) path-loss model for UAV-aided air-to-ground (A2G) wireless channel. Furthermore, massive MIMO technology is adopted in the deployment of transmitter-receiver pairs. In terms of performance measurement, we introduce the network insurance framework for network users. Under this framework, this paper deduces the closed expressions of connection outage probability (COP) and secrecy outage probability (SOP) for the above UAV-enabled network scenarios. Finally, the secrecy guard zone is proposed to further protect the confidentiality. Simulations validate our derived theoretical results, and indicate that communication security increases with the radius of the guard zone, while eavesdropper density has a detrimental effect.