Cisco Cisco Aironet 1140 Access Point Guía De Diseño

40Mhz channels can also be statically configured on the Access Point radio much like the configuration 
of a 20MHz channel. In the below screenshot, the 802.11a/n radio is configured on channel 36 with a 
40MHz channel width. Although the actual channel selected in this configuration is 36, the radio, in fact, 
is utilizing both channels 36 and 40 to create a 40MHz-wide channel. This is showcased in the ‘Current 
Channel’ field which specifies both the control and extension channel used by this radio.

When selecting a statically assigned channel in 40MHz, the radio will automatically select the 
appropriate extension (or adjacent channel) to bond with the channel selected. In the above example, 
channel 36 was selected and channel 40 was automatically utilized as the extension channel. In another 
example, if channel 44 were selected, channel 48 would be selected as the extension channel. This 
applies to all channels across the 5GHz band configured for 40MHz operation and follows the 
convention that only adjacent channels can be bonded.

After ensuring that the WLAN infrastructure is appropriately configured for 802.11n operation, 
confirming that the client is utilizing 802.11n’s high throughput rates is simple. Checking the client’s 
mode of operation is accessible in the wireless LAN controller GUI by clicking ‘Monitor’ and then 
‘Clients’. As depicted in the screenshot below, the protocol field for each client will be populated with 
the type of connection the client is using. For 802.11n, this can be represented as ‘802.11n(5)’ which 
means an 802.11n connection on the 5GHz radio or ‘802.11n(2.4)’ which is indicative of an 802.11n 
connection on the 2.4GHz radio.