A comprehensive solution is provided for multi-carrier scanning and handover operations in OFDM wireless systems. A multi-carrier scanning is any scanning operation that involves multi-carrier radio frequency carriers. In one embodiment, a mobile station communicates with a serving base station over a primary carrier, and performs scanning over one or more determined carriers. A multi-carrier handover is any handover operation that involves multiple radio frequency carriers. In a first embodiment, a break-before-entry (BBE) handover procedure with fast synchronization is provided. In a second embodiment, an entry-before-break (EBB) handover procedure through unavailable intervals is provided. In a third embodiment, EBB handover procedures for both inter-FA and intra-FA using multiple carriers are provided. Finally, in a fourth embodiment, intra-BS handover procedures are provided. The multi-carrier handover procedures may be applied to 2-to-2 or N-to-N carriers handover situation. The overall scanning time and handover interruption time may be reduced through the provided procedures.