Sony SGPT11 Series Help Manual page 177

Your tablet device cannot connect to a Wi-Fi network.
Make sure the Wi-Fi function is turned on.
Tap [ Apps] - [
box.
Make sure there are no obstacles blocking the signal between devices, and the distance between devices is
not too far [Details].
A connection may be made available by changing the channel settings of your access point.
Make sure the [Network SSID] and the [Security] of your access point are set correctly.
Settings] - [ Wireless & networks] - [Wi-Fi] in that order to put a check in the check