T-Mobile USA

T-Mobile announced today that it added five new metro areas to its list of U.S. cities served by 4G (HSPA+) on its faster 1900 network, including Chicago, Reno, and three regions in California.

"T-Mobile has now enhanced the network in 23 metro areas, and we have already reached 100 million people with this improved network experience," T-Mobile USA's chief technology officer Neville Ray said in a statement. "These upgrades will now provide voice and data enhancements, improved signal strength and in-building coverage for customers."

One of the devices that the carrier specifically highlighted to get the faster 4G coverage is the unlocked iPhone. According to T-Mobile, customers with iPhones in these cities get a faster and cheaper service than they would on other carriers like AT&T.

"Internal tests of unlocked iPhone 4S devices running over 4G (HSPA+) on our 1900 MHz network recorded on average 70 percent faster download speeds than iPhone 4S devices on AT&T's network," Ray said.

Unlike AT&T, which is an official iPhone carrier, T-Mobile doesn't sell the device just yet. However, rumors floated last week that the carrier is looking to strike a deal with Apple sometime in 2013. Up until now, T-Mobile has encouraged customers to use its service with unlocked iPhones.

T-Mobile does not yet have 4G LTE. Instead, it offers 4G (HSPA+), which it says is fast enough to be called 4G. While the carrier has said it will develop a 4G LTE network, it doesn't plan to start until next year. By comparison, AT&T has roughly 100 4G LTE markets covered, Sprint Nextel is in nearly 50 cities, and Verizon has covered almost 500 U.S. markets.

Here's the list of cities where users can now get on T-Mobile's 4G HSPA+ 1900 MHz network:

Chicago, including the surrounding areas of: Aurora, Berwyn, Chicago Heights, Cicero, Des Plaines, Downers Grove, Evanston, Evergreen Park, Naperville, Oak Park, Schaumburg, Wilmette, and Winnetka.

Reno, Nevada

Sacramento, California, including the surrounding areas of: Antelope, Citrus Heights, Elk Grove, Fair Oaks, Folsom, Loomis, North Highlands, Rancho Cordova, Rio Linda, Rocklin, Roseville, Vacaville, and West Sacramento.

Fresno, California

Southern California, including: Alhambra, Anaheim, Claremont, Culver City, El Monte, Encino, Garden Grove, Granada Hills, Inglewood, Irvine, La Crescenta, Laguna Niguel, Monrovia, Monterey Park, Newport Beach, North Hills, North Hollywood, Paramount, Pasadena, Redlands, Reseda, Rosemead, Santa Ana, San Fernando, San Gabriel, Santa Monica, South El Monte, Temple City, Torrance, Upland, Valley Village, Van Nuys, Westminster, and Wilmington.

Updated December 14 at 6:20 p.m. PT to clarify that the five new metro areas already have 4G coverage but are now getting enhanced coverage on the 1900 MHz network.