If you are purchasing any new Access Points (AP) for use in the United States, they are now no longer an A regulatory domain, but have been moved to the B domain. Any new access points that you get will now be B domain. Unfortunately, this means that the Wireless LAN Controller (WLC) will not support these new APs. If you select to connect the APs to the controller, you will see them connect and then drop and reboot. They will go into a continuous cycle of trying to connect.
The fix to allow the new B domain AP to connect, is to upgrade the WLC to a version release after 4/19/16. Cisco released the 126.96.36.199 WLC software.
After upgrading the WLC, both regulatory domains A & B can work on the controller. The APs can both be attached and work in the same AP groups together.
Jason Howe, PEI