Description
Smartphones are the consumer-host platform that participates in indoor sensing in two roles: as moving probe that scans BLE beacons and measures Wi-Fi RSSI for self-localization, and as RF target whose passive presence perturbs the CSI on infrastructure-side monitors. The thesis explicitly leverages smartphones as the carrier of ble scanning during BLE-calibration campaigns (a student-game mobile app feeds back BLE / Wi-Fi observations alongside the student's known position). Most modern smartphones expose Wi-Fi RSSI scan results and BLE advertisements to apps but do not expose CSI — that remains the domain of patched commodity NICs (see nexmon-csi for the Nexus 5/6P exception).
Specs / capabilities
- Wi-Fi 5 / 6 / 6E radios (varies by model)
- BLE 5.0+ (most post-2019 models)
- Inertial sensors: accelerometer, gyro, magnetometer (PDR pairing)
- GPS + GNSS for outdoor truth; useless indoors
- Camera + IMU for visual-inertial baselines (rarely used in thesis, but available)
Quirks / known issues
- Wi-Fi RSSI scan rates throttled by Android / iOS to ~1 scan / 30 s on battery
- CSI is not exposed by stock smartphones (modem firmware is closed)
- BLE advertisement scan can be backgrounded but iOS restricts to foreground
- Nexus 5 / Nexus 6P historically supported Nexmon CSI on the BCM4339 / BCM4358 chip — niche
Used by (papers)
- BLE / Wi-Fi RSSI fingerprinting baselines
- Crowdsourced mobile-side localization datasets
- Thesis BLE-calibration campaigns