A method and system varying super-frame length information in a wireless network according to characteristics of transmitted data frames and/or a channel status after a basic service set (BSS) is initiated. Characteristics of a data frame to be transmitted on a MAC layer after the BSS initiation is monitored, and if determined as a result of the monitoring that the super-frame length information needs to be changed due to a variation in a transmission duration of the data frame, the super-frame length information is changed.