Smartphones with WiFi functionality (WLAN) regularly send probe requests - so-called pings. These signals are sent out when the devices search for a WiFi network to which they can connect. During the probe requests, the smartphone transmits various parameters. These are recorded by the Event Metrics sensors with a time stamp and signal strength.
The data is then anonymized in a multi-stage process so that it is impossible to draw conclusions about a specific person. The data is used to calculate aggregated movement metrics. Examples of such key figures are: Number of visitors at a location at a specific time.