Method and apparatus for switching frequency assignment in wireless communicaton system

PURPOSE: A method and an apparatus for switching an assigned frequency in a wireless communicaton system are provided to enable a base station to effectively switch frequency assignment for communication with a mobile terminal, thereby continuously receiving a service without deterioration of service quality in the mobile terminal. CONSTITUTION: A base station determines switching to FA(Frequency Assignment) 2(320). The base station transmits a MOB NBR-ADV(Mobile Neighbor Advertisement) message to the mobile terminal(322). The base station transmits a MOB SCN-RSP(Mobile Scanning Interval Allocation Response) message to the mobile terminal(324). The mobile terminal identifies FA2 through an FA identifier in the MOB NBR-ADV message. The mobile terminal scans quality of a preamble signal through FA2(326). The mobile terminal transmits the scanning result to the base station(328).