Exploring Presence Patterns in an Educational Setting Through Electromagnetic Activity

Congestion in parts of the radio spectrum presents an opportunity to explore presence patterns, potentially providing valuable insights into smart living environments. However, the relationship between human presence and Electromagnetic (EM) activity remains poorly understood. Our research focuses on an innovative approach to estimate presence patterns using EM activity within an educational setting. We concentrate specifically on the frequency bands corresponding toWi-Fi channels 1 and 11. Experiments were conducted in a computer classroom with student participation, accompanied by detailed ground-truth manual counting to validate the sensing methods. As a key contribution, we extend prior studies conducted in large, open environments to a confined computer classroom. This enables analysis under different environmental and propagation conditions.We further compare EM activity-based presence estimation with two commonly used alternatives, namely an attenuation-based device-free sensing method andWi-Fi Media Access Control (MAC) address counting. The analysis revealed significant, weak-to-moderate, positive correlations between EM activity in the Wi-Fi channels and an attenuation-based device-free crowd-size sensing method, while correlations with the number of detected Wi-Fi MAC addresses were relatively weaker. Comparisons with the ground-truth manual counts confirm these observations, indicating that EM activity reflects occupancy dynamics but with reduced sensitivity compared to the attenuation-based approach. These findings indicate that EM activity provides complementary information to existing presence-detection approaches and may be used as a supplementary indicator of occupancy dynamics in smart environments. The potential implications of this work extend beyond the experiment performed, offering valuable insights for applications in crowd behaviour and occupancy analysis. However, further refinement of the sensing methods is necessary to improve accuracy and real-time data processing.