3Com WX2200 3CRWX220095A Switch User Manual

During radio operation, MSS periodically reevaluates the channel
and changes it if needed. (See “Channel Tuning” on page 313.)
Initial power assignment—The MAP sets a radio’s initial power
level to the maximum value allowed for the country code
(regulatory domain). In a deployment with few MAPs, the radio
remains at maximum power. Otherwise, the radio reduces power
until the power is just enough to reach the MAP’s nearest neighbor
that is on the same channel.
How Channels Are Selected
When a radio first comes up, if RF Auto-Tuning for channels is enabled,
the initial channel selected will follow a uniform distribution of channels
that spans the list of channels, rather than selecting the next sequential
channel number.
For example, the range of valid channels for 802.11a radios in the US is
as follows:
36, 40, 44, 48, 149, 153, 157, 161
On each WX, the first channel chosen will be random. Assuming that
channel 60 is the first channel selected, the order of the channel
selections will be as follows:
After these initial 8 channel selections are chosen, the pattern will repeat
Channel and Power
RF Auto-Tuning can change the channel or power of a radio, to
compensate for RF changes such as interference, or to maintain at least
the minimum data transmit rate for associated clients. A radio continues
to scan on its active data channel and on other channels and reports the
results to its WX switch.
Periodically, the switch examines these results to determine whether the
channel or the power needs to be changed.
Channel: 40 44 48 52 56 60 64 68