@Cellcom thank you, i have used to assign different SSID for each AP, the situation is somehow better. There is a noticed problem at the roaming technology at the TP LINK controller model. thank you...

@Cellcom this is a living for university students with two floors (1 OC200 and 10 EAP 225 APs), EAP225 APs are installed at the corridor in each floor. first of all, i'm wanna to isolate each floor...

@Cellcom thank you for the update. i will check at the OC200, but i don't thing that i have this option, i will check it and i will check if i have to upgrade firmware for it many thanks

@Cellcom i'm facing the same issue also with controller OC200 and 10 EAP 225. clients are facing an issue that bad signal and speed, i have found that those clients are connecting to far APs...