Description
An 802.11 Access Point (AP) is the infrastructure-side endpoint of a Wi-Fi link — typically a wall-mounted or ceiling-mounted device combining a Wi-Fi radio, an Ethernet uplink, and routing functions. For CSI sensing the AP plays one of two roles: transmitter of probe / data frames that another monitor station decodes, or monitor itself if firmware-patched. Common research APs include TP-Link N750/AC1750 (Atheros, OpenWrt-friendly), ASUS RT-AC86U (Broadcom, Nexmon-friendly), and any AP based on the atheros-csi-tool or nexmon-csi supported chipsets. The thesis deployment uses APs as the fixed CSI vantage points that observe the monitored area.
Specs / capabilities
- 802.11n/ac/ax depending on model
- Mounted at known coordinates → fixed Tx/Rx geometry, simplifies CSI processing
- Typically 2-4 antennas (2x2 / 3x3 / 4x4 MIMO)
- Wired backhaul (Gigabit Ethernet, PoE)
- Configurable channel, TX power, beacon interval
Quirks / known issues
- Stock vendor firmware almost never exposes CSI; OpenWrt + patched driver is the usual recipe
- Rooftop / ceiling mounting affects multipath profile vs station-at-desk-height — calibration must match deployment
- Many SOHO routers throttle CSI logging to maintain user data rates
Used by (papers)
- Used in any CSI deployment that places sensors at infrastructure points (i.e. essentially all of them)