User's Manual

Wireless Array
336 Configuring the Wireless Array
Roaming Assist
Roaming assist is a Xirrus feature that helps clients roam to Arrays that will give
them high quality connections. Some smart phones and tablets will stay
connected to a radio with poor signal quality, even when there’s a radio with
better signal strength within range. When roaming assist is enabled, the Array
“assists” the device by deauthenticating it when certain parameters are met. This
encourages a client with a high roaming threshold (i.e., a device that may not
roam until signal quality has seriously dropped) to move to an Array that gives it
a better signal. The deauthentication is meant to cause the client to choose a
different radio. You can specify the device types that will be assisted in roaming.
The roaming threshold is the difference in signal strength between radios that will
trigger a deauthentication. If the client’s signal is lower than the sum of the
threshold and the stronger neighbor radio’s RSSI, then we “assist” the client. For
example:
Threshold = -5
RSSI of neighbor Array = -65
RSSI of client = -75
-75 < (-5 + -65) : Client will roam
Another example:
Threshold = -15
RSSI of neighbor array = -60
RSSI of station = -70
-70 > (-15 + -60) : Client will not roam
Procedure for Configuring Roaming Assist
1. Enable Roaming Assist: Use the Yes and No buttons to enable or disable
this feature.
2. Backoff Period: After deauthenticating a station, it may re-associate to
the same radio. To prevent the Array from repeatedly deauthenticating
the station when it comes back, there is a backoff period. This is the
number of seconds the station is allowed to stay connected before another
deauthentication.