T-Mobile has made it known that it will double the speed of its HSPA+ 4G network from 21Mbps to 42Mbps. The carrier has also announced the markets that will offer these improved speeds.

New York City, Las Vegas, and Orlando will be the first cities to offer HSPA+ 4G with 42Mbps speeds. Then Chicago and Long Island/ Northern New Jersey will follow later this year. The carrier expected to offer the improved network in 25 markets by mid-year, covering some 140 million Americans.

T_Mobile has expanded its HSPA+ network across 5 more markets. The folks at Des Moines, Iowa; Gainesville and Panama City, Fla; Monterey, Calif.; and Savannah, Ga will not be able to enjoy the fast speeds of the carrier's 4G network. They will also be able to take advantage of this speed via the US 4G smartphones that are available on T-Mobile including the T-Mobile G2, Samsung Galaxy S 4G and myTouch 4G.

A new 4G smartphone will join the T-Mobile HSPA+ network this month. The carrier has announced that the Samsung Galaxy S 4G will be available on February 23. Interested consumers can purchase this US 4G smartphone for $199.99 with qualifying plan on two-year service agreement after a $50 mail-in-rebate card.

The Motorola Atrix 4G will hit the stores by March 6 or earlier for $199.99 with a two-year service agreement. That date is fast approaching so a number of tech sites have been given the green light to publish their Motorola Atrix 4G reviews. Experts have gotten their hands on the HSPA+ smartphone for AT&T and their opinions are now out on the web.

Here are some of the Motorola Atrix 4G reviews that have been published in the last few days. Check out the links to these reviews after the break.

The T-Mobile HSPA+ 4G network welcomes a new handset and 8 new markets. The Samsung Galaxy S 4G, which can use the carrier's 21Mbps HSPA+ network. will be available later this month.

T-Mobile’s network will also be delivering 4G speeds to Albany, Augusta, Columbus and Macon, Ga., and Chattanooga, Tenn., in the South region as well as in Champaign, Ill.; Lansing, Mich.; and Rochester, Minn., in the Midwest.

More on the Samsung Galaxy S 4G afer the break.

AT&T has reveled the release date for its first HSPA+ smartphone. The HTC Inspire 4G will be available starting Sunday, February 13, for $99.99 with a new two-year contract.

This upcoming AT&T 4G smartphone is the carrier's first handset to run the Android 2.2 platform and offer the mobile hotspot application. The Inspire 4G features a 4.3-inch super LCD display, and an 8-megapixel camera with HD video recording.

AT&T's first HSPA+ 4G smartphone will hit the market nexth month. Motorola CEO Sanjay Jha recently confirmed that the ATrix 4G for AT&T ;has been set for a launch at the end of February.

The Motorola Atrix 4G is a convertible superphone that features a dual-core Tegra 2 processor, a 4.3-inch 540 x 960-pixel display and an optional laptop dock that converts the device into a full-size smartbook.

AT&T has introduced a trio of HSPA+ 4G smartphones that will rival the other 4G handsets from T-Mobile Sprint and Verizon Wireless. The HTC Inspire 4G, Motorola Atrix 4G and Samsung Infuse 4G will carry the fight for the AT&T HSPA+ network.

Let's look into these new US 4G smartphones after the break.

It appears that tablets will be a major part of the US 4G war. Like its rivals, T-Mobile has promised to release 4G tablets next year. Here's the official statement:

“T-Mobile is working closely with the majority of our OEM partners to deliver 4G products by integrating HSPA+ into roadmaps in 2011 as the dominant global standard.  Consumers will continue to see HSPA+ fuel future innovation in a variety of mobile consumer electronics from smartphones and tablets to emerging devices. T-Mobile will continue to be at the forefront of wireless innovation, delivering an aggressive 4G product lineup in 2011, including 4G tablets.”

T-Mobile is focused on increasing its HSPA+ 4G footprints despite the attacks from its rivals. The carrier has recently launched 8 new markets with is fast 4G network.

More T-Mobile HSPA+ 4G details after the break.