Device-free crowd counting is the problem of estimating the number of people present in a monitored area using ambient wireless signals, such as WiFi Channel State Information (CSI), without requiring individuals to carry or interact with any dedicated device. It matters for the field because it enables passive, scalable, and privacy-preserving occupancy monitoring in indoor environments using low-cost commodity hardware, with broad applications in crowd management, emergency response, and smart building systems. Key variants include count-only estimation, as demonstrated in FreeCount using a pair of WiFi routers, and joint counting with localization, as in Wi-CaL, which simultaneously predicts crowd size through regression and crowd zone through classification within a unified sensing framework.
Source Papers
- A Novel Device-Free Counting Method Based on Channel Status Information ↗ — A Novel Device-Free Counting Method Based on Channel Status
- CRPF-QC: An Efficient CSI Recurrence Plot-Based Framework for Queue Counting ↗ — CRPF-QC: An Efficient CSI Recurrence Plot-Based Framework fo
- Guiding Wi-Fi Sensor Placement for Enhanced CSI-Based Sensing in Stationary Crowd Counting ↗ — Guiding Wi-Fi Sensor Placement for Enhanced CSI-Based Sensin