Method for the dynamic monitoring of a mobile entity group

The method involves determining proximities of a group of wireless mobile communication entities e.g. Bluetoothtype radio transmitters/receivers. The entities present in each proximity are detected, and a massage containing identifiers of the entities is transmitted to the detected entities. The messages are collected. An identifier list is drawn up from the identifiers in the messages, and the list is compared to a stored identifier list. The group is declared as coherent if the lists are equal, and the group is declared as non-coherent, if the lists are not equal.