Mobile communication systems and methods consistent with the present invention include a central station, a mobile unit and a plurality of radio base stations. The mobile unit communicates with the central station through one of the radio base stations. The central station receives from the mobile unit registration information identifying the radio base station the mobile unit is currently communicating with. This registration information is then stored in a registration database located at the central station. Files are then transferred from the central station to the mobile unit using the radio base station identified by the registration information stored in the registration database.