Specifications

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Cisco Wireless LAN Controller Configuration Guide
OL-21524-02
Chapter 4 Configuring Controller Settings
Configuring Client Roaming
Figure 4-25 802.11a > Client Roaming Page
Step 2
If you want to fine-tune the RF parameters that affect client roaming, choose Custom from the Mode
drop-down list and go to Step 3. If you want to leave the RF parameters at their default values, choose
Default and go to Step 8.
Step 3 In the Minimum RSSI text box, enter a value for the minimum received signal strength indicator (RSSI)
required for the client to associate to an access point. If the client’s average received signal power dips
below this threshold, reliable communication is usually impossible. Therefore, clients must already have
found and roamed to another access point with a stronger signal before the minimum RSSI value is
reached.
The range is –80 to –90 dBm.
The default is –85 dBm.
Step 4 In the Hysteresis text box, enter a value to indicate how much greater the signal strength of a neighboring
access point must be in order for the client to roam to it. This parameter is intended to reduce the amount
of roaming between access points if the client is physically located on or near the border between two
access points.
The range is 3 to 20 dB.
The default is 3 dB.
Step 5 In the Scan Threshold text box, enter the minimum RSSI that is allowed before the client should roam
to a better access point. When the RSSI drops below the specified value, the client must be able to roam
to a better access point within the specified transition time. This parameter also provides a power-save
method to minimize the time that the client spends in active or passive scanning. For example, the client
can scan slowly when the RSSI is above the threshold and scan more rapidly when the RSSI is below the
threshold.
The range is –70 to –77 dBm.
The default is –72 dBm.
Step 6 In the Transition Time text box, enter the maximum time allowed for the client to detect a suitable
neighboring access point to roam to and to complete the roam, whenever the RSSI from the client’s
associated access point is below the scan threshold.
The Scan Threshold and Transition Time parameters guarantee a minimum level of client roaming
performance. Together with the highest expected client speed and roaming hysteresis, these parameters
make it possible to design a wireless LAN network that supports roaming simply by ensuring a certain
minimum overlap distance between access points.
The range is 1 to 10 seconds.
The default is 5 seconds.