My company have some APs (combine AIR-CAP2602E-E-K9 and AIR-LAP1142N-A-K9 ). Cisco Wireless Controller 2500 manage all APs. However, sometimes, I mornitor on Wireless Controller, some APs disconect, and I must reconnect power adapter to set AP run at normal status. What's the cause of this event? Thanks in advandce