Fingerprinting is way of determining the position by means of WLAN infrastructure. Instead of determining the distance between objects and reference points, the fingerprint technique searches for characteristic matches of signals such as RSSI (Received Signal Strength Indication) and MAC address (Media Access Control). For this purpose, first a database acting as a “map” is created with the characteristics of the existing WLAN signals at a specific location and at a specific time. Normally “broadcasts” sent out by WLAN routers are recorded. In later operation, the smartphone sends the signals received within the WLAN infrastructure to a server. There, the signal strength is compared with the signal strengths stored in the “map” and then the position is estimated. This is in turn continuously sent back to the smartphone.