T-Mobile Has Started Building A More Resilient LTE Network

As reported by GigaOm: T-Mobile has begun upgrading its LTE network with a new kind of antenna technology that will help fix one of the biggest problems in mobile: the inconsistent signals and connection speeds our phones see as we move through the mobile network.

Anyone who has ever had five bars and a rocking data link to the tower, only to lose it 20 yards later, can attest to this. But starting in Chicago, Dallas and San Antonio, T-Mobile users will soon see those peaks and valleys become plateaus.

The technology is called 4-by-2 multiple input-multiple output, or 4×2 MIMO. You may already be familiar with MIMO if you’re familiar with how LTE or Wi-Fi works: multiple antennas send multiple parallel transmissions from the transmitter to the device. While nearly all LTE systems today use 2×2 MIMO — two antennas at the tower connecting to two antennas in the phone — T-Mobile is doubling up on spatial streams being transmitted over the network.

What that means is that there will be a lot more signals flying at your T-Mobile 4G phone, tablet or mobile hotspot, ensuring you can get a better downlink connection even if you’re at the fringes of the network or their obstacles between you and the tower. The biggest benefits will be on the return trip, though. With more antennas at the tower to pick up your phone’s generally weaker signals, you’ll get a big boost in your uplink connection.

Gigaom first got the scoop on T-Mobile’s plans last June, when one of its vendors Nokia Solutions and Networks confirmed to me T-Mobile planned on deploying the antenna array technology. At the time, T-Mobile wouldn’t even acknowledge that it was using 4×2 MIMO, but this week T-Mo VP of Technology Mark McDiarmid confirmed to me that T-Mobile is in the process of rolling it out in multiple cities across its network this year as part of a larger LTE upgrade.

“We do see the benefits 4×2 MIMO offers and will be deploying this in many cities in 2014 as part of our Wideband LTE rollout,” McDiarmid said in a statement to Gigaom. “All of T-Mobile’s available devices currently support 4×2 MIMO and we’ll ensure that new devices will as well. We believe this will be one of the first deployments by a top carrier network in the US.”

Source: Flickr / swruler9284

Sprint is performing trials of a similar technology called 8T8R, which actually creates eight transmit paths as opposed to T-Mobile’s four, and will incorporate it into future upgrades to its new tri-band Spark network.

Historically T-Mobile has always trailed its competitors when it comes to launching new generations of network technologies. It was the last to get 3G and the last to start rolling out LTE, but once it had gotten started it took advantage of its newer network equipment to surpass its rivals. It built the fastest 3G network in the U.S. in 2011, and with 4×2 MIMO its now among the pioneers in one of the latest advancements in 4G networking.

T-Mobile wouldn’t offer any details as to where the network is now live, but Gigaom’s favorite network tracker Milan Milanovic found evidence of 4×2 in the wild in Chicago, Dallas and San Antonio by polling fellow network testers on Howard Forums. This screenshot supplied by forums user besweeet shows iPhone in engineering mode in San Antonio with the arrow indicating four transmit signals from the tower.

Source: Howard Forums user besweeet

What does this mean to me?

So if you’re a T-Mobile subscriber with an LTE handset, 4×2 MIMO basically means you’re going to get a more resilient connection as you move throughout the network. You won’t actually see your peak speeds improve, but you’ll be able to maintain a fast, consistent connection far more often, even when the network starts getting crowded.

According to Nokia networks’ Head of Technology for North America Petri Hautakangas, at the cell edge – those fringe areas of the network where your connection often suffers the most — you could see a 50 percent to 60 percent boost in download speeds and as much as 100 percent increase in upload speeds.

That boost provides a lot of advantages to T-Mobile as well as its customers. By connecting more customers throughout its network with faster speeds it increases its overall data capacity considerably, meaning it will take a lot more traffic to make its network congested.

As for where the network heads next, the location of the three sightings we've had so far provides a hint. They’re all Nokia-built networks. Nokia’s systems are concentrated in the interior of the U.S. Ericsson holds T-Mobile’s contract for most east and west coast cities. If Nokia has the jump on Ericsson for this new technology, then it might take a while before it arrives in New York or San Francisco.

In any case, this technology is an important step for mobile networking, demonstrating the subtle shift away from building faster networks, to building better networks. The 5-10 Mbps speeds we typically see on a smartphone today is plenty fast. But providing a consistent 5-10 Mbps connection no matter where you go in the network? That’s where the mobile industry should be heading.