Originally Posted by bethany66
So you say: "Xperia™ Pro sold in the US is not compatible with T-Mobile's 3G frequencies." Is that also true for AT&T frequencies? I bought an unlocked one and have not yet been able to get the data working. The phone works, and the data works via WiFi, but not via the cellular network.
Assuming you got the Xperia Pro MK16a (UMTS 850 / 1900 / 2100), AT&T 3G is supported. In order to get cellular data working, you need to manually input the APN. You also need to do this if you want to be able to send/receive MMS.
Go to Settings » Wireless & networks » Mobile networks » Access Point Names and create a new APN.
The following settings work for my Xperia Active:
Name: <anything you want>
Proxy: <Not set>
Port: <Not set>
Password: <Not set>
MMS proxy: <Not set>
Authentication type: <Not set>
APN type: default,suppl,mms