Struggling U.S. wireless carrier T-Mobile has unveiled a new unlimited data plan that promises not to throttle when you start using more data than it would like, the company announced today.

Unlimited data plans offered by wireless carriers almost always have limitations, including slowing down your speeds after you use a certain amount of data. T-Mobile is skirting this trend by promising to not slow down anyone on the “Unlimited Nationwide 4G Data” plan. T-Mobile is clearly feeling the hurt from being the only major carrier that doesn’t carry the iPhone, so it continues offer the best overall value in plan prices of the big four wireless carriers.

It’s important to note that T-Mobile’s “4G” data isn’t the same as what Verizon, AT&T, and Sprint are offering with their 4G data. T-Mobile’s 4G is HSPA+ rather than LTE and isn’t next-generation technology. HSPA+ from T-Mobile claims speeds up to 42 Mbps in some U.S. markets, and can be quite speedy if your phone is compatible. Still, T-Mobile plans to start offering 4G LTE in 2013.

The Unlimited Nationwide 4G Data plan runs $20 per month on top of a Value voice and text plan or $30 a month on top of a Classic voice and text plan. For example, a single-line Classic plan with unlimited talk, text and data will cost $89.99.

The new plan will be available on Sept. 5.

Screenshot: T-Mobile/YouTube