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3.4.4.1 Roaming (Client based Fast Roaming)
The feature can be applied in Wireless client mode, configured WLAN setting to 2.4G or 5G Radio Frequency, then
you can find the command in Advance WLAN setting page.
There are two major setting, Roaming Threshold (dbm) and Roaming difference.
Roaming Threshold(dbm):
While there are some APs, the client checks the signal strength, listens the available APs,
and start to connect new AP while reaching the Roaming Threshold. You can check and measure the performance in
the site, then type the suitable value for your environment.
Roaming Min Diff:
It is practical to install multiple APs with overlapping coverage, this is gray or red zone area. In
this area, the client with Fast Roaming can find other available APs, check better signal connectivity and then quickly
switch to new AP. However, to avoid frequently switch the connected AP among the available APs, it is better to
reserve a minimum gray area before switching from the connected AP to new AP.
Figure 3.4.4.4-1: Fast Roaming Architecture
For example in above, the “Roaming Threshold” is configured as -55dbm and the “Roaming Min Diff” is 5. The client
starts Fast Roaming mechanism while the signal strength of other available AP is -55dbm. The Client continuously
check the signal strength of the available APs, however, it still connects to original AP until the signal strength of the
original AP is lower than -60(-50-5)dbm. Refer to below overlapped area between AP1 and AP2.
While the client is moving and signal strength is lower than -60dbm, it start to connect new available AP which has
better signal (>Roaming min Diff) than original AP. To reach high fast roaming performance, the frequency channel
scanning feature is restricted to 3 specific channel, you can select the channels you’d applied in web GUI.
