While WiFi connection is unstable, please try to
1. If the connection of SSID "VTC-Student" is disconnected/connected frequently, please try to change the position/location of mobile device because the mobile device is located at a overlap coverage for roaming.
2. If the connection is changed to one (Y5Zone) from another (VTC-Student), please try to change the position of the mobile device because the mobile device is closed to a strong signal SSID which was succeed to connect in the past. Or you can disconnect/forget either SSID you want.