System and method of using an AP to individually controlling RTS/CTS duration thresholds for multiple STAs in a WLAN. In response to a STA's association request, the AP determines a duration threshold specific to the STA and encloses this information in an association request response for transmission to the STA. By using a broadcast frame, the AP may instruct multiple STAs to uniformly update their stored duration thresholds. For example, if the duration threshold field in the beacon frame is set to 0, the multiple STAs preserve their current duration thresholds; if the field is set to a non-zero value less than 1023, the multiple STAs all update their duration thresholds to the non-zero value; if this field is set to 1023, the multiple STAs disable the RTS/CTS transmissions. Based on a current threshold and pertinent policies, an STA can decide whether to initiate an RTS/CTS transmission sequence.