A method for transiting basic service sets (BSSs) in a wireless communications system is provided. A wireless station first detects an integrity of a real-time flow from an access point in a first BSS. The wireless station then sends a request frame to the access point. The request frame comprises a communication condition of the wireless station. The access point responds with information of a plurality of APs and a set of parameters that used to select the APs. The wireless station then determines which AP to be associated according to the information of the plurality of APs and the communication quality of the wireless station.
