AT&T is loosening restrictions on Apple's FaceTime videoconferencing app once again by allowing all customers with a tiered data plan to use the service over the cellular network. It's yet another step in the right direction for the wireless carrier but because FaceTime over cellular is still not available to all AT&T customers (unlimited users still can't use it), consumer advocates are not yet satisfied.

If you recall, FaceTime was limited to Wi-Fi networks only when it was first introduced primarily due to bandwidth concerns. That all changed with iOS 6 which enabled all FaceTime compatible iPhones to run the app over a cellular network. The problem, however, is that AT&T didn't allow it over their network early on.

AT&T then said they would allow FaceTime over cellular, but only for customers that subscribed to one of their new shared data plans. The company changed their tune in November, allowing tiered data customers to use FaceTime but again, the feature was initially limited to customers with 4G LTE devices - the iPhone 5 and the new iPad. The most recent policy revision allows the feature to work on any compatible iPhones.

AT&T senior vice president Mark Collins said in a recent blog post that the carrier always intended to open the service up to more customers but doing it all at once wasn't an option. The reason it wasn't done from the beginning is because AT&T engineers couldn't effectively model usage of tens of millions of customers using the feature all at once. Flipping the switch without proper testing could have impacted the service of all customers if FaceTime exceeded expectations.