User Guide

292 Configuring RF Auto-Tuning
320657-A
Initial Channel and Power Assignment
The following process is used to assign the channel and power to an AP radio when it is first enabled:
• If RF Auto-Tuning is disabled for both channel and power assignment, the radio uses the channel and power
settings in the radio profile that manages the radio. After this, the channel and power do not change unless you
change the settings in the radio profile, or enable RF Auto-Tuning.
• If RF Auto-Tuning is enabled for channel and power assignment, the radio performs an RF scan and reports the
results to the WSS switch that is managing the AP the radio is on. The scan results include third-party access ports.
Based on the scan results, WSS Software sets the channel and power on the radio. WSS Software always selects
channel and power settings that are valid for the country of operation.
● Initial channel assignment—WSS Software determines a radio’s initial channel based on RSSI
values, interference levels on each valid channel, and other parameters.
WSS Software periodically reevaluates the channel and changes it if needed.
● Initial power assignment—The AP determines a radio’s initial power level by inspecting the RSSI
values of probe responses the radio receives as it actively scans channels. After all channels are
scanned, the AP selects the highest RSSI value of all probe responses, and designates its sender as
the radio’s nearest neighbor AP. The AP determines the power level at which the nearest neighbor
AP’s probe response was sent, and uses this value and the RSSI to compute the minimum transmit
power required to reach the nearest neighbor AP. This power level becomes the radio’s default
power level.
The radio can temporarily increase its power level based on client needs but returns to its default
power level when clients no longer need the higher power level.
WSS Software periodically reevaluates the default power level and changes it if needed.