Cisco Cisco 2106 Wireless LAN Controller

The following new features and changed information are included in controller software release 
4.1.185.0.

These radio resource management (RRM) features have been added to controller software release 
4.1.185.0.

These new CLI commands have been added to configure the dynamic channel allocation (DCA) 
algorithm:

To control the DCA sensitivity with respect to changes in the environment, enter this command:

config advanced {802.11a | 802.11b} channel dca sensitivity {low | medium | high}

The DCA algorithm determines whether to make a channel change based on how much better a new 
channel would be for the radio with the worst DCA metric in the radio band. The DCA metric is 
comprised of noise, interference, channel load, and overlapping neighbors (other radios on the same 
channel). Previously, a channel change would occur if another channel was 5 dBm better than the 
current channel of the radio with the worst DCA metric. This new command allows you to control 
how sensitive the DCA algorithm is to environmental changes, such as signal, load, noise, and 
interference, when determining whether to change channels. 

 shows the three available DCA 

sensitivity levels.

For example, if the radio with the worst DCA metric in the 2.4-GHz band has a metric of –60 dBm 
on its current channel and the DCA algorithm finds that the metric would be –80 dBm on another 
channel (which is an improvement of 20 dBm), the DCA algorithm would change the channel if the 
DCA sensitivity is set to high or medium. It would not change the channel if the sensitivity is set to 
low.

To define the time when DCA starts, enter this command:

config advanced {802.11a | 802.11b} channel dca anchor-time hour

where hour is an hour in the day from 0 to 23 (12:00 a.m. to 11:00 p.m.).

High

High sensitivity to
environmental changes

5

5

Medium (default)

Moderate sensitivity to
environmental changes

15

20

Low

Low sensitivity to
environmental changes

30

35