How can I enforce only G & A radio clients from being able to connect to my 1131AG Access Points?
I know that when a B client connects it automatically brings all the G clients down to B due to the fact that G is backward compatible but does not operate at 54 mbps with a mix of B clients.
Here is one method;
To set the 2.4-GHz, 802.11g radio to serve only 802.11g client devices, set any Orthogonal Frequency Division Multiplexing (OFDM) data rate (6, 9, 12, 18, 24, 36, 48, 54) to Basic.
Note: The client must support the basic rate that you select or it cannot associate to the wireless device. If you select 12 Mbps or higher for the basic data rate on the 802.11g radio, 802.11b client devices cannot associate to the wireless device's 802.11g radio.
From this good doc;
Hope this helps!