Allied Telesis AT-WA7400/EU - Manual (Page 70)

Chapter 6: Channel Management
70
Understanding Channel Management
When channel management is enabled, the AT-WA7400 Management
Software automatically assigns radio channels used by clustered access
points to reduce mutual interference (or interference with other access
points outside of its cluster). This maximizes WiFi bandwidth and helps
maintain the efficiency of communication over your wireless network.
Note
You must start channel management to get automatic channel
assignments; it is disabled by default on a new access point. See
“Stopping or Starting Automatic Channel Assignment” on page 73.
How it Works in
a Nutshell
At a specified interval (the default is one hour) or on demand (click
Update), the Channel Manager maps access points to channel use and
measures interference levels in the cluster. If significant channel
interference is detected, the Channel Manager automatically reassigns
some or all of the access points to new channels per an efficiency
algorithm (or automated channel plan).
Overlapping
Channels
The radio frequency (RF) broadcast channel defines the portion of the
radio spectrum that the radio on the access point uses for transmitting and
receiving. The range of available channels for an access point is
determined by the
IEEE 802.11 mode (also referred to as band) of the
access point.
IEEE 802.11b / 802.11g modes (802.11 b/g) support use of channels 1
through 11 inclusive, while IEEE 802.11a mode supports a set of non-
consecutive channels (36,40,44).
Interference can occur when multiple access points within range of each
other are broadcasting on the same or overlapping channels. The impact
of this interference on network performance can intensify during busy
times when a large amount of data and media traffic competing for
bandwidth.
The Channel Manager detects which bands (b/g or a) clustered access
points are on, and uses a predetermined collection of channels that will
not mutually interfere. For the “b/g” radio band, the classical set of non-
interfering channels is 1, 6, 11. Channels 1, 4, 8, 11 produce minimal
overlap. A similar set of non-interfering channels is used for the “a” radio
band, which includes all channels for that mode since they are not
overlapping.