AT&T now lets customers with unlimited data plans use 22 GB before throttling them

AT&T Mobility (NYSE: T) quietly increased the amount of data customers on its legacy unlimited data plans can burn through before they see their speeds throttled. Previously, the upper limit was 5 GB but the carrier has increased the threshold to 22 GB in a change that takes effect today.

"As always, Unlimited Data Plan smartphone customers will still have the comfort of knowing that, no matter how much data they use in a billing cycle, they will continue to pay a single monthly flat rate," AT&T said in a notice on its website. "That is the essential promise of the Unlimited Data Plan, and we are pleased to continue honoring that promise. Further, speed reductions will occur only when the customer is using his or her device at times and in areas where there is network congestion and only for the remainder of the current billing cycle after the customer has exceeded the 22 GB data usage threshold."

AT&T said it will notify customers with unlimited data plans during each billing cycle when their data usage reaches 16.5 GB (75 percent of 22 GB) "so they can adjust their usage to avoid network management practices that may result in slower data speeds."

In a statement to FierceWireless, the carrier said that it is "raising the high speed data usage threshold for our legacy unlimited plan users to 22 GB because our network is stronger than ever before." AT&T said that "due to the investments we've made to strengthen our network, we are now able to provide a better experience for our legacy unlimited data customers on 3G/4G or LTE. Most major wireless companies manage network resources in a similar fashion."

Previously customers with legacy unlimited data plans who have 3G or HSPA+-only phones saw their speeds reduced after they hit 3 GB of data usage in a billing cycle and customers on LTE phones could be throttled after hitting 5 GB. Speeds can be reduced at times and in places where there is network congestion, AT&T said, but once the congestion subsides or the customer moves to an uncongested site, speeds return to normal.  

AT&T noted that "reduced speeds and increased latency may cause websites to load more slowly or affect the performance of data-heavy activities such as video streaming or interactive gaming. The degree of reduced speeds and increased latency will vary depending on the amount of congestion. Congestion can start and stop over a very short time period (often measured in fractions of a second), further minimizing customer impact."

The carrier added that "because the amount of congestion at a cell site can vary significantly, the performance impact for affected unlimited data plan customers may also vary significantly. Standard speeds and latency will resume once the cell cite is no longer congested, or the customer's data session moves to an uncongested cell site. In addition, speeds and latency will return to normal at the start of the customer's next billing cycle."

The disclosures about how customers might be affected are notable because of the FCC's proposed $100 million fine against AT&T over its throttling practices, which AT&T is contesting. The FCC accused AT&T of violating the transparency rule of its 2010 Open Internet order on net neutrality. Although a federal court tossed most of those rules out last year before the FCC drew up new ones, the court let the transparency rule stand and it has been in effect since 2011. The FCC said that although AT&T disclosed its throttling policy in a July 2011 press release and notices to customers, it did not provide information on when or after using how much data customers would see their speeds throttled, how much their speeds would be reduced or how those speed reductions would affect their ability to use apps on their phones.

It's unclear how many AT&T customers still have grandfathered unlimited data plans. AT&T said in July that as of the end of the second quarter around 87 percent of its postpaid smartphone subscribers were on usage-based data plans (tiered data, Mobile Share and other plans).

In May AT&T had changed its policy and said it would throttle the data speeds of customers on legacy unlimited data plans only when they are connected to congested cell sites, regardless of the kind of smartphone they have.

Previously, customers who had 3G or HSPA+ phones as well as legacy unlimited data plans were throttled for the remainder of their billing period after they exceeded 3 GB of data in a month, but only "at times and in areas that are experiencing network congestion." However, while LTE customers with grandfathered unlimited plans did not see their speeds throttled until they reached 5 GB of data usage in a month, their speeds were slowed down for the remainder of their billing cycle at all times -- regardless of whether the network was congested. 

For more:
- see this AT&T website
- see this 9to5Mac article 

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