Controllerless Networks

IDS/IPS typically occur at management rates. At those lower rates, the frames go further. It is estimated that you deploy one AM for every AP.

What exactly are you trying to do?  That will determine your strategy.

Again, if you have already surveyed for client coverage, you need 1/4 of the already deployed APs to cover your WIDS foot print.  Those will be dedicated air monitors, but regular APs also participate in WIDS...

 

You will also need the RFProtect license for that controller that matches the number of APs on that individual controller.  That will add the ability to deny access to clients, EXCEPT the ones on your network.  Before you go down that path, however, you should engage some legal opinions, because some business have chosen to block foreign user WLAN traffic and have been fined by the FCC....

http://community.arubanetworks.com/t5/Wireless-Access/The-FCC-has-clarified-their-stance-on-wireless-containment-but/m-p/226342#M46143

Correct.