This invention provides an improved radio communication system performing a soft hand-off procedure between the first and second base stations for a mobile station and performing asynchronous packet communication between a base station controller and each base station. The first and second base stations assign hand-off exclusive bandwidths to respective communication lines between the base station controller and themselves during the soft hand-off procedure. Accordingly, the first and second base stations can simultaneously receive packet signals sent by the base station controller, and then the mobile station can accurately perform site diversity.