Opportunities for Physical Layer Security in UAV Communication Enhanced with Intelligent Reflective Surfaces

Unmanned aerial vehicles (UAVs) are an important component of next-generation wireless networks that can assist in high data rate communications and provide enhanced coverage.Their high mobility and aerial nature offer deployment flexibility and low-cost infrastructure support to existing cellular networks and provide many applications that rely on mobile wireless communications. However, security is a major challenge in UAV communications, and physical layer security (PLS) is an important technique to improve the reliability and security of data shared with the assistance of UAVs. Recently, the intelligent reflective surface (IRS) has emerged as a novel technology to extend and/or enhance wireless coverage by reconfiguring the propagation environment of communications. This article provides an overview of how the IRS can improve the PLS of UAV networks. We discuss different use cases of PLS for IRS-enhanced UAV communications and briefly review the recent advances in this area. Then, based on the recent advances, we also present a case study that utilizes alternate optimization to maximize the secrecy capacity for an IRS-enhanced UAV scenario in the presence of multiple Eves. Finally, we highlight several open issues and research challenges to realize PLS in IRS-enhanced UAV communications.

Introduction

The great demand for high data rates, massive connectivity, and protection from impending security attacks challenge next-generation wireless communication systems. In this regard, unmanned aerial vehicles (UAVs) can play a vital role in sup-porting reliable and secure communications with-out infrastructure coverage. UAVs provide several benefits in terms of cost-friendly rapid infrastruc-ture deployment in low signal coverage zones, mobile relay nodes to enhance coverage range, communication access points in emergency areas, and enabling physical layer security (PLS) [1]. Compared to traditional terrestrial communications, UAVs provide strong channel conditions due to line-of-sight (LoS) transmission links. Therefore, there is high demand for deploying large numbers of UAVs to support next-generation wireless networks [2]. UAVs can be used for different applications in transportation systems, cel-lular communications, agriculture, and emergency management. In addition, the use of UAVs will be an integral part of next-generation wireless net-works to support ultra-low-latency and extremely reliablev applications [3].