AT&T is feeling the heat of competition and as a result has lowered the price of its unlimited data plan from $100 to $90 a month, also improving it by adding 10GB of high-speed tethering data. AT&T today also announced a $60-per-month option for customers who are willing to accept slower speeds of no more than 3Mbps.

Until recently, AT&T only sold its $100-per-month unlimited smartphone data plan to customers who also subscribed to DirecTV or U-verse TV. After unlimited data announcements from Verizon and T-Mobile USA, AT&T made its unlimited plan available to any customer but initially did not change any of its annoying limitations. Unlimited data users thus couldn't use their phones as mobile hotspots to get Internet access for other devices.

Today's announcement cut the monthly price from $100 to $90 and renamed the plan "Unlimited Data Plus." Customers will get 10GB of high-speed tethering each month. After the 10GB is used, tethering speeds are reduced to 128kbps. There were no changes to this plan on the HD video front: the best video quality is still disabled by default, but customers can watch video in HD by disabling the "Stream Saver" option, AT&T told Ars.

AT&T also created an "Unlimited Choice" plan that costs $60 a month and also has no data caps and overage fees. However, this plan doesn't include any tethering capability, and video is always reduced to about 480p resolution or a maximum bandwidth of 1.5Mbps. Overall speeds on the $60 plan are reduced to a maximum of 3Mbps, whereas the more expensive plan provides "our fastest speed."

Fastest speeds vary by location, but crowdsourced data from OpenSignal last year measured AT&T's average 4G download speeds at 7.93Mbps.

The $90 and $60 prices require customers to get paperless bills and make automatic payments with a bank account or debit card, as credit card payments are not eligible for those prices. Without the autopay discount, the price rises $5 for single-line plans and $10 for multiline plans.

Unlimited data plans don't have any data caps or extra fees for using too much data, but they're not entirely without monthly limits. With both the $90 and $60 plans, customers may see slower speeds for the rest of the month after they use 22GB on a line, but speeds will only be slowed "during times of network congestion." (AT&T subsidiary Cricket Wireless has reportedly also started throttling after 22GB.) This is similar to the policies of other carriers, although T-Mobile sets the limit at 28GB.

AT&T has special pricing for customers who bundle mobile plans with DirecTV or U-verse TV. Unlimited Plus customers will get a $25 monthly credit on TV packages. This also applies to the DirecTV Now online streaming service, which starts at $35 a month. As a result, you can get a single line of unlimited data with DirecTV Now for $100 a month.

This chart provided by AT&T has a summary of the plans, including prices for multiple lines: