T-Mobile USA is getting ready to launch the next generation of 4G Long Term Evolution (LTE) in the U.S. in 2013. Here's where the operator is likely to go first and what LTE-Advanced is all about.
What T-Mobile has said so far
T-Mobile plans to have 4G LTE service up and running in the vast majority of the top 50 markets in the U.S. by the end of 2013. It will launch LTE on Advanced Wireless Services (AWS) spectrum next year and move its High-Speed Packet Access-Plus (HSPA+) service, which is marketed as "4G," to 1900MHz.
The operator is testing next-generation Release 10 -- aka LTE-Advanced -- equipment this summer, with an eye on launch next year. "The ability to launch with this next version of LTE technology is one advantage of launching next year," stated SVP of Technology Dave Mayo, in a blog post in June. (See T-Mobile Upgrades HSPA+, Trials LTE .)
There's no solid word on how fast LTE-Advanced will be once deployed on the network. T-Mobile said in February that theoretical maximum downloads on its initial LTE launch would be 72Mbit/s. Data speeds can get lowered quite a bit, however, between the test lab and the network tower. (See T-Mobile Promises Multi-Megabit Peaks on LTE.)
What is LTE-Advanced, anyway?
LTE-Advanced is defined in the 3GPP release 10 of the LTE specification. The specification is focused on using several techniques to further increase the transmission speeds and spectral efficiency of the 4G standard.
The 3GPP is gunning for maximum download rates of 3Gbit/s and uploads of 1.5Gbit/s. Clearly these speeds will be far less when translated into the real world, particularly as the 3GPP suggests the specification could use up to 100MHz of spectrum in bonded channels. This amount of bandwidth is a pipe dream for most carriers around the world. T-Mobile will have a maximum of 20MHz to play with, and less in some markets.
Nonetheless, LTE-Advanced will offer a speed jump over current LTE and fast 3G networks by implementing some speedy upgrades at the radio access network (RAN) and handset. These include "carrier aggregation" techniques that bond together two or more separate radio channels to get faster data speeds, two-by-two smart antenna arrays (also known as 2x2 multiple input, multiple output (MIMO)) for faster uplink and downlink and relay nodes -- low power basestations that will provide improved coverage and capacity at the cell edge.
The 3GPP has a useful primer on LTE-Advanced, if you want to get more technical.
Where T-Mobile might go first with LTE
The operator hasn't officially said where it will launch LTE first.
As part of its breakup terms from the proposed AT&T Inc. merger, however, T-Mobile received AWS spectrum in 128 cellular markets, including 12 of the top 20 markets. The 12 are Los Angeles, Dallas, Houston, Atlanta, Washington, Boston, San Francisco, Phoenix, San Diego, Denver, Baltimore and Seattle. These cities appear to be the logical starting point for T-Mobile's faster 4G ambitions. (See T-Mobile Gets Spectrum in AT&T Breakup and Where Will T-Mobile Bring LTE First?)
â€” Dan Jones, Site Editor, Light Reading Mobile