Integrated Sensing and Covert Communication In Low-Altitude Networks: A Smart Radio Environment Perspective

The rise of low-altitude economies and 6G is driving the evolution of low-altitude networks (LANs), making communication security a pressing concern. Unlike traditional security approaches, covert communication offers enhanced protection by hiding the transmission behavior itself. Integrated sensing and communication (ISAC), a key technology of 6G, efficiently supports both sensing and communication tasks through hardware integration, thereby promising significant gains for covert communication. Nevertheless, the complexity and dynamics of urban environments pose critical challenges. Drawing on the latest advances in smart radio environment (SRE) technologies, this paper introduces them into integrated sensing and covert communication (ISACC) to suppress covert channel fading and counteract sensing precision loss in LANs. We first survey the applications and state-of-the-art findings of ISACC in LANs, highlighting key practical challenges. Subsequently, we introduce the core concept of SRE and elaborate on its enabling techniques across four dimensions. To deliver more insights, we explore potential pathways for integrating SRE into ISACC. To maximize covert throughput, a reinforcement learning-based case study is conducted by jointly optimizing flight trajectory, jamming power, movable antenna position, bandwidth allocation, and beamforming vectors. Simulation results show that the proposed scheme achieves superior performance compared to the benchmark. Finally, some open challenges and potential directions are discussed.