Now, 5G can really begin. On Tuesday Qualcomm announced the X55 modem, the first 5G modem that will support AT&T's and T-Mobile's low-band networks, which will cover far more area than the fast, but limited-coverage millimeter-wave networks we've been mostly hearing about.

The X55 is too late for Samsung's expected Galaxy S10 announcement, though; the first round of 5G phones will rely on Qualcomm's existing X50 modem, which doesn't support the FDD style of low-band networking that the US carriers will be using. In a recent survey, we found that Americans want broad coverage from their 5G—that's what low-band 5G is going to deliver.

The first US 5G phones, including the Galaxy S10, will work on millimeter-wave and TDD networks. That means they'll get very high speeds in limited urban areas where AT&T, T-Mobile, and Verizon install high-frequency networks; they'll also work on Sprint's nationwide 5G network, which is on a lower frequency but is TDD.

But for nationwide 5G coverage, we need FDD, which uses narrower bandwidths of older cellular spectrum. All four US carriers plan to eventually convert some of their FDD 3G and 4G spectrum to 5G.

"The leading operators launching 5G in the US were Verizon and AT&T, pushing millimeter-wave deployments," Nitin Dhiman, Qualcomm's senior manager of product marketing said. "The X50 was created to support that with the early 5G launches."

This One Has the Missing Features

The new modem has all the features I thought were missing from the X50—the features that phones will need to light up on different kinds of 5G networks worldwide. It supports low-band FDD spectrum. It supports standalone networks, like the ones that the three Chinese carriers will be launching later this year. It supports spectrum sharing between 4G and 5G, which will let carriers start to shift their older 4G bands over to 5G without damaging 4G coverage.

"It's dynamic and simultaneous, and it can simultaneously support LTE and 5G on the same band," Dhiman said.

Unlike the X50, which requires a separate 4G modem to operate, the X55 runs from 2G to 5G in one chip. On the 4G side, it's the first Category 22 modem we've seen, supporting 24 data streams over seven carriers for speeds up to 2.5Gbps. By combining 4G and 5G, the modem can achieve 7Gbps speeds, Qualcomm says.

Qualcomm's modem will probably be the only one that will appear in US phones in 2019. Samsung and Huawei also currently have 5G modems, but they don't put them into phones sold in the US. (Samsung's modems are used for Verizon's 5G home rollout, however.) Intel and Mediatek are both working on 5G modems that will probably appear in US phones in 2020—Intel's in iPhones, and Mediatek's in lower-cost devices.

By being a single-chip, multi-mode modem, the X55 is also easier to build non-phone devices with. Hotspots will get smaller than the Netgear Nighthawk 5G on AT&T, which is about the size of a paperback book. D-Link's home broadband unit for T-Mobile, which we saw at CES, will use the X55.

"The features put together in the X55 accelerate the 5G rollout and footprint," Dhiman said.

Improving 5G Battery Life

Along with the X55, Qualcomm announced three components that will make 5G phones slimmer and more power efficient. The QTM525 millimeter-wave antenna module will fit into smartphones less than 8mm thick and will simultaneously support 26GHz, 28GHz and 39GHz networks. Phones with the X55 and this module will therefore be able to support all four US carriers' 5G networks with the same hardware. If carriers want to release exclusive models, that's on them, Qualcomm said.

The QET6100 envelope tracker and QAT3555 antenna tuner improve coverage and efficiency by making phones handle connections more precisely. These components are key to having much longer battery life in this year's phones, especially with power-hogging 5G connections.

All together, these components make a very strong argument for waiting for the 5G phones that will appear in the back half of this year. (AT&T has promised one from Samsung.) Those phones could potentially be sleeker, more widely compatible, and have better battery life than the initial round of X50-based phones, and they'd start appearing only about six months later.

The X55 will appear in phones in the second half of this year, Qualcomm said.

Further Reading