PURPOSE: To avoid disable use of all radio terminal equipments due to a fault in a database by storing and updating position registration information to a database of a home exchange in its own area to which each radio terminal equipment is subscribed and registered distributing on every movement of the terminal equipment.

CONSTITUTION: Every time a terminal equipment 4 moves to other area, position registration information representing to which exchange the terminal equipment 4 moves is stored and updated in a database 14 of a home exchange 1 to which the terminal equipment 4 is subscribed and registered. When a terminal equipment 5 calls the terminal equipment 4, a caller exchange 3 makes a call to the exchange 1 and the exchange 1 retrieves position registration information of the terminal equipment 4 in the database 14. When the movement of the terminal equipment 4 is confirmed, the exchange 3 makes a 2nd call to the exchange 2 of a moving destination to connect the terminal equipments 4, 5.