Try this if you cannot successfully connect to the Home Base Network.
INSTRUCTIONS & INFO
Check that you are connected to the AT&T Home Base Wi-Fi network. If connected via an Ethernet cable, ensure that the cables are properly attached (e.g. ATT-HOMEBASE-XXXX).
If connected via Ethernet, make sure the Ethernet cables are firmly attached to your Home Base and your computer (or other device).
Make sure you entered the correct Wi-Fi password.
Note: Your Wi-Fi password can be found on the bottom of your Home Base, if you have not changed it.