A base station includes an adjacent cell interference amount calculator and an adjacent cell interference amount notifier. The adjacent cell interference amount calculator calculates an adjacent cell interference amount caused by an adjacent cell adjacent to an original cell managed by the base station. The adjacent cell interference amount notifier notifies the mobile station of the adjacent cell interference amount. A mobile station includes radio resource associators, a selector, a propagation loss calculator, and a radio resource assigner. The radio resource associators associate a radio resource with a propagation loss in the radio packet communication. The selector selects a radio resource associator in accordance with the adjacent cell interference amount. The propagation loss calculator calculates a propagation loss in the radio packet communication. The radio resource assigner assigns the radio resource associated with the calculated propagation loss to the radio packet communication, based on the selected radio resource associator.