Satellite positioning needs a clear view of the sky. Indoors, location comes from other signals, and the method determines both accuracy and privacy.
The four techniques
- Wi-Fi fingerprinting: matches visible networks against a database. Works widely, accurate to several metres, needs a survey.
- Bluetooth beacons: cheap and precise to a few metres, requires installed hardware.
- Ultra-wideband: centimetre accuracy, expensive, excellent for asset tracking.
- Dead reckoning: accelerometer and gyroscope, drifts within a minute, useful only in short bursts.
Privacy implications
Wi-Fi fingerprinting can work without the device transmitting anything identifiable, while beacon systems usually log which tag passed which receiver. Ask who holds the log.
What is realistic
For finding a room, Wi-Fi is enough. For finding a pallet in a warehouse, UWB. For finding your keys, Bluetooth.
Bottom line: match the technique to the accuracy you need, then ask where the history lives.
