AT&T may charge users of FaceTime over 3G, the updated version of Apple's video calling system which, as of iOS 6, will allow for calls over 3G connections instead of solely WiFi. Screenshots of AT&T handsets running the iOS 6 beta shared in the MacRumors forums show an error message similar to that given when users without a compatible data plan try to activate tethering.
For tethering, AT&T - like many other carriers - requires that subscribers pay for an extra data plan. It's suggested that, given FaceTime will likely increase the amount of 3G traffic users consume, the carrier will demand they cough up another fee to cover it.
Interestingly, 9to5Mac found that Verizon handsets do not give the same error message as AT&T devices running iOS 6, though it's not conclusive proof that the carrier will not be demanding an extra tithe for FaceTime 3G calls.
Whether AT&T's fee is in the form of a set allowance for FaceTime 3G traffic, a pay-per-call charge, or a flat fee covering "unlimited" use each month (though likely with a "fair use" policy) remains to be seen. "We're working closely with Apple on the new developer build of iOS 6" AT&T said in a statement, "and we'll share more information with our customers as it becomes available."
It's exact form could have a significant impact on those AT&T subscribers still clinging onto their older, now-discontinued unlimited data plans. If AT&T demands an all-new data package that covers FaceTime 3G, rather than simply adding the service as an account add-on, such users may have to choose between their grandfathered plans or the ability to make video calls over cellular data connections.