T-Mobile US Inc. 's 4G Long Term Evolution (LTE) deployment in 2013 could nearly double the download speed offered on the operator's fastest current mobile broadband service. (See T-Mobile Will Launch LTE in 2013.)

"T-Mobile's initial LTE deployment in 2013 will deliver theoretical peak speeds of 72 Mbit/s on the downlink," a T-Mobile spokeswoman tells Light Reading Mobile. The operator currently offers a high-speed packet access-plus (HSPA+) service, marketed as 4G, that tops out at 42 Mbit/s, as well as a 21Mbit/s flavor. (See T-Mobile's Fighting Spirit.) Users are unlikely to get close to these theoretical maximums; there too many variables on a real-world network to guess what average download speeds are going to be, says Daryl Schoolar, Ovum Ltd. 's principal analyst for infrastructure. He believes that you can expect to get half of the theoretical peak or less.

As LTE radio and backhaul technology improves, however, operators are definitely able to crank the speeds on these faster mobile data services. Schoolar says he has been getting very fast downloads on a test handset on the new AT&T Inc. (NYSE: T) LTE network in Phoenix. (See AT&T Turns Up 11 More LTE Markets.) "I was hitting up to 32 Mbit/s on the downloads," Schoolar says. "I was surprised."

T-Mobile is deploying the LTE network on advanced wireless services (AWS) spectrum (1700/2100MHz), some of which came from the aborted merger with AT&T and some of which was T-Mobile's own. The operator expects to have nationwide LTE coverage by the end of 2013. (See T-Mobile's Race to Faster 4G.)

— Dan Jones, Site Editor, Light Reading Mobile