A method and apparatus for reducing interference between systems when a plurality of wireless access systems are co-located are disclosed. To support CLC mode, an MS in the CRC mode transmits a handover request message to a first Base Station (BS) to initiate a handover process, receives a handover command message acknowledging the handover request message from the first BS, transmits a ranging request message to second BS at network reentry after handover, and receives from the second BS a ranging response message including CRC start time information that set by the second BS.