Opportunities and Challenges of Wireless Human Sensing for the Smart IoT World: A Survey

Wireless human sensing plays a crucially important role in the human-computer interaction context, in which human activities and even emotions can be recognized and understood by computers. A batch of academic efforts have been proposed to use wireless techniques such as WiFi, RFID, Bluetooth, Radar, and Zigbee to address the human sensing problem. Each kind of sensing technology has its own characteristics and advantages and thus is suitable for specific application scenarios. For example, WiFi-based solutions can achieve non-intrusive human sensing, and RFID-based solutions can enable individual human sensing for multi-person scenarios. To let users better understand the existing wireless human sensing solutions and choose the most suitable one according to their demands, this article presents a comprehensive survey of the existing wireless human sensing approaches. Specifically, we discuss promising human sensing applications and partition them into three categories: vital sign monitoring, gesture recognition, and activity recognition. For each category of applications, we further conduct a taxonomy of the existing solutions and summarize their ideas, characteristics, pros, and cons from various perspectives, such as design approaches, system configuration, wireless technology, and used information. Finally, we discuss some technical challenges and problems that have not been noticed yet and point out the potential opportunities in the future study of wireless human sensing.