I hope someone can help me. I installed 4 AP's in our house, 1 AP(EAP110) on each Floor (2nd,3rd,4th  floors), and another 1 AP (EAP 225-Outddor) on 1st floor resto. 
my problem now is that on my main router/modem and the AP(EAP 225) it gives me 400-500 mbps, on the 3 AP(EAP 110) it only gives 20-35 mbps max.

what could be the possible problem?

btw. I'm using POE for all AP's

diagram: MODEM - GIGABIT SWITCH - ACCESS POINTS