Users Guide

Dell PowerConnect ArubaOS 5.0 | User Guide Access Points | 133
Status Up; Mesh
Up time 9m:55s
Installation indoor
Configuring Channel Switch Announcement (CSA)
When an AP changes its channel, an existing wireless clients may “time out” while waiting to receive a new
beacon from the AP; the client must begin scanning to discover the new channel on which the AP is operating. If
the disruption is long enough, the client may need to reassociate, reauthenticate, and re-request an IP address.
Channel Switch Announcement (CSA), as defined by IEEE 802.11h, enables an AP to announce that it is
switching to a new channel before it begins transmitting on that channel. This allows the clients, who support
CSA, to transition to the new channel with minimal downtime.
When CSA is enabled, the AP does not change to a new channel immediately. Instead, it sends a number of
beacons (the default is 4) which contain the CSA announcement before it switches to the new channel. You can
configure the number of announcements sent before the change.
In the WebUI
1. Navigate to the Configuration > Wireless > AP Configuration page.
2. Select either the AP Group or AP Specific tab. Click Edit for the AP group or AP name.
3. Select RF Management in the Profile list.
4. Select the 802.11a or 802.11g radio profile.
5. Select Enable CSA. You can configure a different value for CSA Count.
6. Click Apply.
In the CLI
rf radio-profile <profile>
csa
csa-count <number>
20 MHz and 40 MHz Static Channel Assignments
With the implementation of the high-throughput IEEE 802.11n standard, 40 MHz channels were added in
addition to the existing 20 MHz channel options. Available 20 MHz and 40 MHz channels are dependent on the
country code entered in the regulatory domain profile.
The following channel configurations are now available in ArubaOS:
z A 20 MHz channel assignment consists of a single 20 MHz channel assignment. This channel assignment is
valid for 802.11a/b/g and for 802.11n 20 MHz mode of operation.
z A 40 MHz channel assignment consists of two 20 MHz channels bonded together (a bonded pair). This
channel assignment is valid for 802.11n 40 MHz mode of operation and is most often utilized on the
5 GHz frequency band.
If high-throughput is disabled, a 40 MHz channel assignment can be configured, but only the primary channel
assignment is utilized. The 20 MHz clients can also associate using this configuration, but only the primary
channel is utilized.
Note: Clients must support CSA in order to track the channel change without experiencing disruption.