RSSI Fingerprinting

An indoor localization technique in which a device estimates its position by comparing the current pattern of received signal strengths (RSSI) from surrounding radio sources — most commonly Bluetooth Low Energy beacons or Wi-Fi access points — against a pre-collected map of signal strengths sampled at known positions. During a training phase, technicians walk the space collecting RSSI readings at labelled points; during use, algorithms such as K-nearest-neighbour match live readings to the closest fingerprints. RSSI fingerprinting is widely used in blind-navigation research (e.g., NavCog) because it yields sub-metre accuracy without structural modifications to the environment, though it requires ongoing map maintenance as radio conditions change.