A client has existing 11g and 11n wireless users. His concern was to have the AP run on 11n mode.
My understanding on this is when you have an 11g and 11n users on the same AP, the AP radio operates at 11g mode to cater both the 11n and 11g users. To run the AP in 11n mode, you have to evade the 11g users from connecting the AP. If I have to set the AP in 11n mode only, 11g users can't connect to the AP.