T-Mobile's low-band LTE network has extended the carrier's reach across the northern and central US, according to our exclusive crowdsourced coverage map. The 600MHz or "band 71" network, which has only been live since August 2017, now covers 340 rural cities and towns T-Mobile never covered before, according to the carrier.
T-Mobile won its nationwide Band 71 licenses in a 2017 auction, but it still hasn't been able to roll all of it out. The spectrum used to be TV channels 38-51, and while TV stations have been moving their signals to lower channels, some still have until mid-2020 to make the switch.
We worked with Ookla Speedtest to identify all the ZIP codes since April 2018 where T-Mobile customers with Android phones had run speed tests on the low-band network. While T-Mobile would not give us its official 600MHz map, we were able to consult with the carrier to remove false positives from our map.
Our resulting map doesn't show quite all of T-Mobile's low-band network—it only shows where we were able to identify the tests. Many areas of the US are also covered by T-Mobile's 700MHz Band 12 network, which we aren't focusing on here. For a full-scale T-Mobile coverage map, check out the carrier's own website.
(Click to expand the map)
The network also covers pretty much all of Puerto Rico.
Compare that 600MHz map to T-Mobile's full, current LTE coverage map, which the carrier provided us and you can see below:
As you can see, T-Mobile has made great strides over the northern part of the US. If you live in southern Maine, northern Michigan, Wisconsin, Minnesota, the Dakotas, Montana, Missouri, Kansas, southern Illinois, or New Mexico, you're going to see much better T-Mobile coverage now than a year ago.
"When I had to get my tires changed in Wenatchee (Washington), I was able to tether my laptop and have speeds of 20-25Mbps comfortably in places where I couldn't get coverage for voice before," said Mark McDiarmid, T-Mobile's SVP of Radio Network Engineering & Technology Development.
The network now covers 43 states and Puerto Rico, T-Mobile said. But while the company now owns 600MHz spectrum covering the whole US, it hasn't been able to cover the nation yet because it's been waiting for TV stations currently occupying their airwaves to "clear" the spectrum, a process that's still continuing. By the end of this year, T-Mobile expects to clear areas covering 272 million people, the company said.
Many existing subscribers aren't getting that coverage, though, because their phones are not Band 71-compatible. Currently, 29 devices support 600MHz, including both high-end phones like the Samsung Galaxy S9, Apple iPhone XS, and OnePlus 6T, and low-end devices like the T-Mobile Revvl 2 and Motorola E5 Plus. But all 600MHz phones have been released after August 2017, which means that if you're carrying an older phone, you won't be able to see or hear this network.
Rural wireless coverage has been a hot topic recently in part because T-Mobile is pledging that it will cover rural areas even better if allowed to merge with Sprint. The Vermont Department of Public Service also did an unprecedented coverage drive test showing poor cellular coverage on all the networks in more rural parts of Vermont.
According to the Vermont state drive test, the carrier's coverage—especially in west-central Vermont—is weaker than Verizon's or AT&T's. But in northwest Vermont, near St. Albans where T-Mobile now has 600MHz, the drive test showed T-Mobile coverage is much stronger. Currently, two of the TV stations holding 600MHz spectrum in Vermont are scheduled to move out of their frequencies by March 3 and July 3, 2020, according to Spectrum Gateway.
What This Means for 5G
T-Mobile will be using the same 600MHz spectrum to set up its "nationwide" 5G network, but you can't use this map to predict where T-Mobile will install 5G. That's because T-Mobile is splitting its 600MHz allocation between 4G and 5G, depending on what other frequencies the carrier has in play and how many 5G handsets are available.
Remember, T-Mobile has nationwide licenses for 600MHz, but it hasn't installed it everywhere for various reasons. In some places, the TV stations haven't cleared out. In others, the carrier may think it has enough 4G spectrum between 700MHz, 1700MHz, and 1900MHz, and so may be holding back its whole 600MHz allocation for 5G.
In existing 600MHz LTE zones, T-Mobile will probably be using a cool feature of the Qualcomm X55 modem to dynamically mix 4G and 5G in the same spectrum. On 600MHz, 5G will be 25-50 percent faster than 4G, T-Mobile exec Karri Kuoppamaki said last year. The carrier will slide more 600MHz over to 5G as more devices become available and more traffic moves over to the 5G network.
In any case, T-Mobile will keep some 600MHz for 4G in areas where it didn't have coverage before, which means that if you don't have a 600MHz-capable phone and you're considering T-Mobile, you should get one immediately.