T-Mobile has made remarkable strides in the last three years. Back in 2014, its network languished almost depressingly far behind Verizon and AT&T, and consumers had to choose between cheap and bad, or expensive and good.
Jump forwards to late 2017, and it’s a very different picture. T-Mobile has built out conventional towers across the country, bought and deployed new low-band spectrum from Verizon, and is in the midst of rolling out a brand-new LTE network that should enhance coverage in buildings and rural areas.
But network coverage isn’t the be-all end-all it once was. An increasing number of devices on networks, coupled with new trends in mobile video streaming, are putting a new kind of stress on mobile networks. Congestion became a big problem for networks this year: All networks now employ some kind of traffic-management (usually a restriction in the quality of video they’ll allow to be streamed), and global LTE speeds are down.
Combating this problem isn’t a matter of building more cell towers. Networks are employing new LTE technologies that make better use of existing spectrum and hyper-local “small-cell” sites, and T-Mobile is taking that mission to heart.
At an event in San Jose today, Qualcomm and T-Mobile demonstrated new gigabit LTE technologies in the wild. Gigabit LTE is a catch-all for a series of new LTE technologies that, on paper, can mean gigabit download speeds over LTE. More significantly, they can also increase capacity on a network, helping mitigate congestion and meaning that everyone can still enjoy a workable LTE connection.
There are three technologies which, when combined, deliver impressive speed and capacity upgrades. Carrier aggregation is the first, a technology that’s not really new to the scene. All four carriers have been using some form of CA for years; it combines multiple chunks of LTE spectrum across different frequencies to allow handsets to download data from multiple LTE bands simultaneously. 2CA, aggregating two carriers together, is already in widespread use, but modern phones (especially Android flagships using Qualcomm’s X16 modem) are capable of using four carriers at the same time.
Carrier aggregation will be taken to the next level with the help of another new tech being rolled out. LTE-Licensed Assisted Access (LAA) combines the usual LTE frequencies with unlicenses 5GHz spectrum, the same frequency that your Wi-Fi network uses. 5GHz signals are subject to more intereference and travel shorter distances, but are capable of much higher transfer speeds.
Multiple input multiple output (MIMO) is another new-but-rare technology T-Mobile is pushing out at speed. It increases the overall bitrate available by combining data streams from multiple antennas, and partners well with carrier aggregation. If carrier aggregation is like adding extra lanes to a highway, MIMO is like stacking a whole new highway on top.
The final piece of the puzzle is 256 QAM. Quadrature Amplitude Modulation is the means by which a carrier signal can transfer data, and the 256 means 256 distinct symbols that can be used to encode data. In this instance, more is better.
T-Mobile’s big announcement today was that these technologies are now available in 430 markets nationwide, with LAA support to be rolled out within the next two months. T-Mobile isn’t the first network to use these technologies, but the speed at which it’s deploying is remarkable. AT&T, by comparison, has said that 20 sites will be live by the end of this year.
Verizon has also been working feverishly to deploy LTE-Advanced across its network, with significant success. It has carrier aggregation deployed across 2,000 markets, and all three LTE-A technologies across 560 markets.
