Channel Extension - HP MSM3xx Management And Configuration Manual

The channel selected on the radio page is the primary channel and the secondary (or
extension) channel is located adjacent to it. The secondary channel is either above or below
depending on which channel was selected as the primary. In the 5 GHz band, the channels are
paired: 36 and 40 are always used together, 44 and 48 are always used together, etc. It works
slightly differently in the 2.4 GHz band: there you choose whether the extension channel
should be above or below the beacon using the Channel extension parameter. See the
Channel parameter for more information.

Channel extension

Supported on: MSM410, MSM422 (radio 1), E-MSM430 (radio 2), E-MSM460 (radio 2),
E-MSM466 (radio 2)
Not available in Sensor mode.
This setting only appears when Wireless mode is set to 802.11n (2.4 GHz), 802.11n/b/g, or
802.11 n/g and Channel width is set to Auto 20/40 MHz.
This setting determines where the second 20 MHz channel is located.
 Above the beacon (+1): The secondary channel is located on a channel above the
currently selected channel.
 Below the beacon (-1): The secondary channel is located on a channel below the
currently selected channel.
Channel
Select channel (frequency) for wireless services. The channels that are available are
determined by the radio installed in the AP and the regulations that apply in your country.
Automatic channel selection
Use the Automatic option to have the AP select the best available channel. Control how
often the channel selection is re-evaluated by setting the Interval parameter.
 On the E-MSM430, E-MSM460, E-MSM466: Scanning during the channel selection
process can cause interruptions to voice calls. This only occurs each time the Interval
expires. Therefore, configuring a short Interval is not recommended.
 On the MSM310, MSM320, MSM335, MSM410, MSM422: Scanning is continuously
performed on all the channels in the currently selected Operating mode, even though
the channel is only re-evaluated each time the Interval expires. (If Interval is set to
Disabled, continuous scanning is not performed.) Continuous scanning can cause
interruptions to voice calls. On dual-radio APs, you can avoid interruptions by setting one
radio to operate in Monitor mode. For example, if radio 1 is set to Automatic and radio 2
is in Monitor mode, scanning occurs on radio 2 and interruptions on radio 1 do not
occur.
Caution
When using the Automatic option with an external antenna in the 2.4 GHz band, all channels
must be set to the lowest acceptable value for your regulatory domain. See
control on page 3-31.
Wireless configuration
Radio configuration
Transmit power
3-23