This object specifies the number of time slots (plus a SIFS duration) that a QAP (Quality AP/Access Point) must wait with the medium idle before transmitting or executing backoff for a specific Access Category in EDCA (Enhanced Distributed Channel Access). This parameter controls the medium access priority and timing for Wi-Fi 802.11 quality-of-service. WLAN administrators adjust this value to tune the priority and fairness of different traffic types on their wireless networks.