Developing a pervasive interactive smart space requires continuous detection of human presence and their activities. Existing literature lacks robust wireless sensing mechanisms capable of continuously monitoring multiple users’ activities without prior knowledge of the environment. Developing such a mechanism requires simultaneous localization and tracking of multiple subjects. In addition, it requires identifying their activities at various scales, some being macro-scale activities like walking, lunges, squats, etc., while others are micro-scale activities like typing or playing guitar, etc. In this paper, we develop a holistic system called MARS using a single Commercial off-the-shelf (COTS) MillimeterWave (mmWave) radar, which employs an intelligent model to sense both macro and micro activities. In addition, it uses a dynamic spatial time-sharing approach to sense different subjects simultaneously at a room-scale. A thorough evaluation of MARS shows that it can sense up to 5 subjects overan 8 × 5 m2 space with an average accuracy of 98% and 94% while identifying macro and micro activities, respectively.
More details on the experimental setup for different room experiments R1:office-cabin(4mx3m), R2:study-room(5mx8m) and R3:laboratory(12mx6.5m), different obstacles wooden-chairs, tables, metal-wardrobes, fiber-desks, desktop-computers, etc., users performing macro-micro activities together etc.is provided here.