Enhancing CSI-Based Wireless Sensing With Open-Source Linux 802.11ax CSI Tool

Wireless sensing using channel state information (CSI) has gained wide attentions in the past decade. Despite this, the applications of existing systems are still limited by the CSI extraction tools, particularly for 802.11ax Wi-Fi devices. In this article, we present the development of IAX, an open-source CSI extraction tool based on Intel AX200/201/210/211 network interface cards (NICs). Our tool supports CSI extraction for 802.11ax 160-MHz high-efficiency (HE) encoded frames with up to 1992 subcarriers using a single packet. It can extract CSI from all orthogonal frequency-division multiplexing (OFDM) packets, which enables CSI capturing for all 802.11a/g/n/ac/ax standards. It supports CSI data extraction in three typical modes including station (STA), access point (AP), and Monitor. We verify the correctness of CSI data through three typical applications including intrusion detection, respiration sensing, and indoor localization. The experimental results demonstrate that IAX can achieve intrusion detection leveraging the surrounding wireless traffic, enable multiperson respiration sensing, and localize multiple devices. We believe that the release of this open-source tool will inspire further development of wireless sensing.