MSM7xx Controllers Configuration Guide v6.4.0

This setting only appears when Wireless mode is set to 802.11n/b/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. If the Interval parameter is set
to any value other than Time of day. and a wireless client is associated with the radio, automatic
channel selection is delayed. The AP will retry at one minute intervals until the radio is unused by
wireless clients.
• On the HP 425, MSM430, MSM460, MSM466, MSM466-R, HP 517: Scanning during the
channel selection process can cause interruptions to voice calls. This only occurs each time
the Interval expires. Therefore, HP does not recommend configuring a short Interval.
• 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 “Transmit
power control” (page 99).
Manual channel selection
If setting the channel manually, for optimal performance when operating in 2.4 GHz modes, select
a channel that differs from other wireless APs operating in neighboring cells by at least 25 MHz.
For example, if another AP is operating on channel 1, set the AP to channel 6 or higher.
When operating in 802.11a or 802.11n (5 GHz) modes, channels do not interfere with each
other, enabling APs to operate on two adjacent channels without interference.
HP APs support Dynamic Frequency Selection (802.11h) and Transmit Power Control (802.11d)
for 802.11a operation in European countries. These options are automatically enabled as required.
Channels used by dynamic frequency selection (DFS) for radar avoidance, are identified with an
asterisk "*".
• On the MSM410, MSM422 (radio 1), HP 425, MSM430, MSM460, MSM466, MSM466-R:
When Wireless mode is 802.11n/a and Channel width is Auto 20/40 MHz, the channel
numbers in the Channel list include either a (1)or (-1) to their right. A (1) indicates that the 40
92 Wireless configuration