Disclosed is a handover system in a BWA communication system. In the system, a serving BS broadcasts neighbor BS information including BS identifiers of a plurality of neighbor BSs and reference signal indices indicating reference signals used by the neighbor BSs, a MS receives the neighbor BS information and requests a scanning interval to the serving BS at a timing point at which the MS wants to perform a scanning, the serving BS allocates the scanning interval to the MS in response to a request for the scanning interval, and the MS scans reference signals received from the neighbor BSs during the scanning interval in response to the neighbor BS information.