Abstract: Respective location registration areas (A, B, C,) in a mobile communication network include a plurality of base station service areas (a.sub.1 -a.sub.n, b.sub.1 -b.sub.n, c.sub.1 -c.sub.n). By partially overlapping the respective location registration areas, each of the respective base station service areas, for instance, (b.sub.23, c.sub.23) belong to a plurality of location registration areas (B, C). The respective base station (b.sub.23, c.sub.23) transmits all the location registration codes (B, C) together with one designated primary location registration area code (B) to be selected by a mobile station. The mobile station begins communication after registering the designated area code. When, during communication, the mobile station moves beyond the location registration area boundary, no registration is updated so long as the mobile station stays within communication with a base station transmitting the designated registered area code.