The Sticky Client Problem:
A client is referred as “Sticky” when it does not roam or move to a nearby AP connection that has stronger signal strength. As illustrated in the above figure, when Optimized Roaming is disabled, the client will continue to stay with the AP at very weak signal strength, for example—lower than -86 dB. Lower signal strength will lead to increase in Airtime interference, thus reducing the overall performance.
Solution—Cisco Optimized Roaming:
The client will be allowed to rejoin the AP when the client RSSI value has increased to 6 dBm above the disassociation threshold. For example, if the Data RSSI threshold is -80 dBm, the client will be allowed to re-associate once the RSSI values is increased to -74 dBm.