AT&T Throttling Heavy-Use Unlimited Data Subscribers In Early October

If you're an AT&T customer still holding onto an unlimited data plan, you may start noticing some changes in the coming months. It's rumored that AT&T will begin throttling data speeds for its heavy-use unlimited data subscribers starting the first week of October. This could be another sign that the iPhone 5 is indeed landing in September and that AT&T is anticipating major data network congestion soon thereafter.

The rumor comes from 9to5 Mac, who notes that AT&T's 3G network already took a hit when the first iPhone was introduced, with network capacity not being able to meet data demands, which makes sense of throttling data right after an iPhone 5 launch. Additionally, it's reported that AT&T will be retooling its insurance structure that same week, which could certainly signal the arrival of a high profile device around that time.

Throttling on AT&T should work similarly to what's been done recently on Virgin Mobile as well as Verizon. Heavy-users who surpass a certain data threshold, possibly somewhere between 2GB to 4GB, will see a significant decrease in data speed for the remainder of that billing cycle. The change should affect only 5% of subscribers, and to be in that top 5% who use roughly 30% of the bandwidth, it's said that you'd have to at least download "12,000 emails, 12,000 website views, 4 streaming movies, and 5 hours of streaming music."

Update: It's now official.

[via 9to5 Mac]