A simple base station device is installed in the entrance or the like of a
building and a power OFF signal is supplied. A portable telephone set
that has received the signal informs the simple base station of its
telephone number, also informs a position management server of the same
via a public base station device to register it, the position management
server being located in a radio network, and switches OFF power for a
radio section. An incoming call operation to the portable telephone set
is carried out by referring to the registered content of the position
management server. Thus, a power supply for a portable telephone set in a
use prohibition area is reduced and no incoming call control is
performed.