A radio control apparatus 10 is provided with a call management system 18 configured so that, when a mobile station in communication with a first base station by a first communication link requests diversity handover with a second base station, the call management system 18 retrieves a potential information rate that is not higher than an information rate of the first communication link and that is highest, from an information rate table 31 storing information about information rates of communication links securable in the second base station under other radio control apparatus; and a link management system 20 configured so that, when the potential information rate is lower than that of the first communication link, the link management system 20 instructs the first base station to change the first communication link to a second communication link communicable at the potential information rate; the call management system 18 requests the other radio control apparatus to secure a third communication link communicable at the potential information rate and to instruct the second base station to perform communication with the mobile station by the third communication link.