RF-based sensing is the practice of detecting people or activity by analyzing changes in wireless radio signals, rather than using a camera, microphone, or dedicated motion sensor. A Wi‑Fi or other RF signal can reflect off bodies and objects; when someone moves, the signal pattern shifts. Software can infer presence, walking, breathing, or movement from those shifts.
This matters in cyber security because it creates a new kind of surveillance surface. Even when no image is captured, RF-based sensing can reveal occupancy, routines, or movement patterns, which has privacy implications and can support physical-security awareness. Defenders may use it for passive home monitoring, but attackers could also abuse similar signal analysis to learn when a building is occupied. As with any sensor feature, the security question is what is collected, who can access it, and whether the inference is accurate enough to trust.