In a radio communication system with at least one radio network control
device, at least one base station is connected to at least one user
station by a radio communication interface. The base station(s) and the
radio network control device are components of a base station subsystem.
The radio network control device is connected to an access device for a
core network. The radio network control device and the user station(s)
have a service specific key that is preferably valid for several user
stations, or in other words, the service specific key is not user
specific.