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Cisco Wireless LAN Controller Configuration Guide
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Chapter 11 Configuring Radio Resource ManagementWireless Device Access
Configuring an RF Group
RF Group Leader
The members of an RF group elect an RF group leader to maintain a “master” power and channel scheme
for the group. The RF group leader is dynamically chosen and cannot be selected by the user. In addition,
the RF group leader can change at any time, depending on the RRM algorithm calculations.
The RF group leader analyzes real-time radio data collected by the system and calculates the master
power and channel plan. The RRM algorithms employ dampening calculations to minimize system-wide
dynamic changes. The end result is dynamically calculated optimal power and channel planning that is
responsive to an always changing RF environment.
The RRM algorithms run at a specified updated interval, which is 600 seconds by default. Between
update intervals, the RF group leader sends keep-alive messages to each of the RF group members and
collects real-time RF data.
Note
Several monitoring intervals are also available. See the
“Configuring RRM” section on page 11-9
for
details.
RF Group Name
A controller is configured with an RF group name, which is sent to all access points joined to the
controller and used by the access points as the shared secret for generating the hashed MIC in the
neighbor messages. To create an RF group, you simply configure all of the controllers to be included in
the group with the same RF group name.
If there is any possibility that an access point joined to a controller may hear RF transmissions from an
access point on a different controller, the controllers should be configured with the same RF group name.
If RF transmissions between access points can be heard, then system-wide RRM is recommended to
avoid 802.11 interference and contention as much as possible.
Configuring an RF Group
This section provides instructions for configuring RF groups through either the GUI or the CLI.
Note
The RF group name is generally set at deployment time through the Startup Wizard. However, you can
change it as necessary.
Note
When the multiple-country feature is being used, all controllers intended to join the same RF group must
be configured with the same set of countries, configured in the same order.
Note
You can also configure RF groups using the Cisco Wireless Control System (WCS). Refer to the
Cisco
Wireless Control System Configuration Guide
for instructions.
