MULiving: Towards Real-time Multi-User Survival State Monitoring Using Wearable RFID Tags

Human presence detection is crucial in various scenarios, from law enforcement surveillance to smart health-care systems. Traditional methods like cameras and acoustic signals face challenges such as privacy concerns, the need for line of sight (LoS), and susceptibility to environmental noise. This paper proposes MULiving, a real-time RFID-based system designed to monitor the survival status of multiple users simultaneously. Unlike previous RFID-based solutions, MULiving addresses two key challenges: achieving real-time detection and accurately identifying stationary users. By leveraging a signal threshold-based approach that adapts automatically to non-living states, MULiving can distinguish between living and non-living users, even during periods of minimal movement(e.g., sleep). Extensive experiments using Commercial off-the-shelf (COTS) RFID devices demonstrate that MULiving is not only highly accurate but also robust across different users, RFID tags, and behaviors. The results confirm MULiving as a promising solution for real-time multi-user survival monitoring, with significant potential for practical deployment in real-world applications.