Strings in the iOS 5.1 firmware make reference to 4G phone calling, and using FaceTime over 4G, notes Cydia developer Krishna Sagar. One message in the code reads, "Enabling 4G will end your phone call. Are you sure you want to enable 4G?" Others refer to enabling and disabling 4G on FaceTime calls, as well as regular voice ones.
The code appears to back up regular reports that Apple is working on an LTE iPhone. More unusual is the reference to FaceTime, since even LTE-equipped iPads are still unable to make FaceTime calls over cellular networks. The restriction is typically blamed on wireless carriers, who are likely worried about bandwidth congestion as well as people opting out of higher-... »read more

More at: Electronista Add additional source