(AP) -- AT&T Inc. caved to complaints that it's placing unreasonable limits on the "unlimited data" plans it offers smartphone subscribers.
The cellphone company said on Thursday that from now on, it will only slow down service for its "unlimited data" subscribers when they hit 3 gigabytes of usage within a billing cycle.
Previously, the company had been slowing down service when subscribers entered the heaviest 5 percent of data users for that month and that area.
There was no way for subscribers to find out ahead of time what the limit was. AT&T would send a warning by text message to people who approached the limit. The data throttling would then kick in a few days later.
"Our unlimited plan customers have told us they want more clarity around how the program works and what they can expect," AT&T said in a statement Thursday.
Several subscribers told The Associated Press that their data service had been throttled at just over 2 gigabytes of data use, lower than most people on AT&T's "limited" plans. Some of them said their phones were practically useless for two weeks out the month because the data service was slowed so drastically.
AT&T doesn't sell the "unlimited data" plan any more, but subscribers have been allowed to keep it. The company charges $30 per month for the same amount it charges for 3 gigabytes of data on a new "tiered" or limited plan.
AT&T has about 17 million "unlimited" smartphone subscribers, most of whom use iPhones.
The Dallas-based phone company said subscribers with "unlimited" plans and smartphones capable of using the new "LTE" data network would see the slowdown at 5 gigabytes rather than three. The LTE network is faster and doesn't have many users yet.
Explore further: Mobile provider TracFone to pay $40M in federal settlement