A method for a mobile station to access to a base station in a wireless communication system that uses selective acknowledgement mechanism, comprising: transmitting, an access probe from the mobile station to the base station, the access probe including a plurality of data frames; setting, a vector in the mobile station based on a message received from the base station, wherein the message indicates parts of the plurality of data frames in the access probe are not decoded by the base station; passing, the parts of the plurality of data frames that are not decoded by the base station from a MAC layer of the mobile station to a PHY layer of the mobile station according to the vector; and sending, by the mobile station to the base station, the parts of plurality of data frames that are not decoded by the base station.