This paper proposes a framework for interference mitigation in multi-BSS infrastructure 802.11 WLANs. Our interference mitigation approach is based on Access Point (AP) Coordination. With this approach, interfering BSSs negotiate and switch from the 802.11 CSMA/CA to a time slotted mechanism if users’ QoS is observed to be degraded, diagnoses conclude that the cause is high interference, and the switch to the time slotted modus is expected to be useful and feasible. The proposed algorithms within the framework are driven by measurements. We utilize the wireless bandwidth and improve the fairness among WLAN users. We present results of detailed simulation experiments as well as real implementation.