Like it or not, 2019 is the year of 5G. All the major US carriers plan to have some sort of 5G presence by year’s end, but T-Mobile’s plans won’t come to fruition as quickly as we’d hoped. After initially saying the carrier would have 5G operating in the first half of 2019, T-Mobile’s CTO Neville Ray now admits it won’t be until the second half of 2019. If I were to guess, I’d say it will be very late 2019.
The delay (although T-Mobile would prefer not to use that word) is thanks to the carrier’s somewhat unusual approach to 5G. Most of the 5G networks you’re going to use in the coming year or two will have backbones of millimeter wave spectrum. Millimeter wave frequencies reach up into the tens of gigahertz, which offers a ton of bandwidth. On the flip side, it’s also bad at passing through obstacles. T-Mobile’s solution is to make low-frequencies an integral part of its 5G network.
T-Mobile plans to use millimeter wave in the 29-30GHz range, but it also has a heap of 600MHz spectrum for 5G. That block of the airwaves will pass through obstacles like buildings and your hand more efficiently, but it won’t be as fast as millimeter wave. T-Mobile hopes that by combining the two, it can offer a more robust 5G experience.
Qualcomm started hinting at problems with this approach late last year, and now T-Mobile has laid its cards on the table. All the first-gen 5G hardware uses the Qualcomm X50 modem, which doesn’t support sub-6GHz networks on the FDD (frequency-division duplex) standard. FDD simply means that means the up and down channels are separated by frequency. Millimeter wave uses TDD (time-division duplex), which is fully supported by the X50. T-Mobile’s sub-6GHz network just doesn’t work with existing 5G modems.
T-Mobile says it’s waiting for devices that can take advantage of its 5G network, and it’ll be waiting a rather long time. The Qualcomm X55 modem will be part of Qualcomm’s next flagship ARM chip in late 2019, but it won’t even show up in any phones until 2020. T-Mobile is being as vague as possible to look like it’s not lagging, but these timelines are out of its control.
The best case scenario is that T-Mobile gets a hotspot device on its network by the end of 2019. That’s not the end of the world — the first round of 5G phones will be bad, so T-Mobile is sparing its customers from first-gen headaches. It will lose face being the last major network to launch 5G, though.