Method for monitoring the density and/or the movement of humans

The invention relates to a method (20) for monitoring the density and the movement of humans using a grid (100) of a plurality of luminaires (101a-d), each of the luminaires (101a-d) comprising an acoustic sensor (105), a motion sensor (107), preferably a Doppler sensor, a controller (109) supplied with output signals of said sensors (105, 107), and a wireless interface (111) for a communication between the controller (109) and a gateway (401) for forwarding sensor information signals (130) to a central database (403), wherein, based on the information in the database (403), the density and/or the movement of humans in an area covered by the grid (100) is estimated by generating a time series of sensor values, such as sound pressure, motion speed and/or motion intensity, of each luminaire (101a-d).