In the fight for the best wireless networks, U.S. carriers often tout their fastest connections. But T-Mobile (NASDAQ:TMUS) is taking a new approach that will both boost speeds for its existing LTE network and make it more reliable at the same time. While T-Mobile's new signal technology will be a big improvement over its current system, Sprint (NYSE:S) is about to release some new network capabilities of its own, which could easily outpace T-Mobile's current efforts.

Upgrading existing signals
T-Mobile is implementing new technology called 4x2 MIMO to its existing 4G LTE network, which increases the number of antennas on the company's cellular towers. Most LTE networks use two antennas that send signals to two corresponding antennas in smartphone, called 2x2 multiple-input and multiple-output (MIMO). But as the name suggests, 4x2 MIMO tech increases the tower's antennas to four.

As GigaOM reports, those extra antennas will allow T-Mobile to increase the consistency of its 4G LTE signals, bringing faster upload and download speeds at the outer edges of its networks. While the top LTE speed won't change, customers will find their signals much stronger and reliable as they move through the carrier's network.

A big game of catch-up
Carriers are always trying to lure new customers to their networks with high-speed offerings, and as the No. 4 carrier by customer base T-Mobile has been playing catch-up with the competition for a while. But it's going to face some additional pressure in the coming months as Sprint starts integrating its new Spark technology.

Sprint Spark is a tri-band signal that will boost the carrier's network up to 50 to 60 megabits per second, or Mbps. That's extremely fast, considering the average data speed in the U.S. is just 6.5 Mbps, according to OpenSignal. Sprint will deploy Spark in 100 cities in the U.S. over the next three years, but's starting in just five markets.

While T-Mobile has already started adding 4x2 MIMO in Chicago, Dallas, and San Antonio, it may not be enough to keep up when Sprint's Spark debuts later this year.

Foolish thoughts
T-Mobile has been focused on gaining more customers by building out its LTE network, dropping yearly contracts and offering lower monthly plan prices than its competitors -- and much of it has worked. The company is no longer hemorrhaging customers like it used to, but the carrier's problems are nowhere near solved.

As Sprint rolls out Spark over the next few years, T-Mobile will have to do more than just make its network more consistent -- it'll have to beef up peak speeds as well. While T-Mobile's 4x2 MIMO initiative may be one of the first of its kind among the nation's top four wireless carriers, it's clear that the company may not get the change to celebrate once Sprint Spark launches.

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