@Ryan wrote:
Aligning APs vertically will get you into trouble with ARM. I don't recommend that. If you want to control RF propagation, use antennas that have the radiation pattern you want or leverage attenuation materials that will absorb a large amount of signal as it penetrates the ceiling.
To add to that, there is no feature on any controller or modification that will get you more out of Wifi than a good Rf design. Some people use a number of access points every say 60 feet to cover an area with a certain building material; that principle also would follow vertically. Do not have access points vertically 60 feet above each other. If you cannot move that access point, make it an air monitor so that clients will attach to a closer access point on the existing floor.
Adaptive Radio Management is mainly to simplify channel planning in a good RF design; it can only do so much being that clients ultimately decide where they will attach....
With that being said, there is nothing wrong with a client attaching to an access point on the floor above or below unless it is causing performance issues. Wifi is so bursty that the number of clients on an access point is a mere indicator of the potential of the loading of that access point. We need to look at something more concrete like utilization to determine which access points are truly loaded. Utilization is provided on the Dashboard in ArubaOS 6.1.x and above or in the radio tab in Airwave for that access point if Amon is enabled...