T-Mobile Walks a Fine Line on 5G Spectrum

T-Mobile is taking both the high and low roads to deliver 5G mobile broadband, starting in 2019.

On its earnings call Thursday, T-Mobile US Inc. said it will use its 600MHz spectrum holdings to initially deliver 5G -- using the 3rd Generation Partnership Project (3GPP) 5G New Radio specification -- and is deploying "5G-capable" equipment now. The commercial service will start in 2019, via a software update, and will go nationwide in 2020, the carrier says. (See Qualcomm Rejects Latest Broadcom Bid.)

"We’ll launch... as soon as... smartphones are available, which will be the first half of 2019," CTO Neville Ray said on the call.

This initial low-band 600MHz deployment puts T-Mobile in contrast to its 2 largest rivals, AT&T and Verizon. Both have been testing very-high band millimeter wave spectrum -- 28GHz and 39GHz -- for 5G mobile broadband. Verizon is launching fixed wireless on 28GHz using its own 5GTF spectrum in several markets in the 2nd half of 2018. AT&T, meanwhile, says it will have mobile 5G available late in 2018 in 12 markets. (See 5G in the USA: Where We At?)

Ray noted that AT&T will launch "probably on 39GHz" with a "mobile puck," not a smartphone. (See AT&T's 'Mobile' 5G: What the Puck?)

Ray saved most of his snark, however, for what he described as the "dead-end street" of Verizon's "outside-in" fixed wireless 5G strategy. Verizon is planning to deploy this using a 5GHz small cell that connects to a 28GHz window-mounted antenna, which then distributes 5G signal in a user's home.

"It's a pre-standard system, they'll have to rip and replace almost everything they have put in the ground between now and the end of the year," Ray claimed. Verizon's CEO has previously claimed that the carrier will update to the 3GPP standard as soon as possible, however.

Like Sprint's CEO, however, Ray highlighted the propagation issues of millimeter wave, as high-band frequencies can have problems penetrating certain types of glass, walls, and dense greenery. Verizon has shown in tests that mmWave works at a range of up to 2000 feet, but the gigabit data speeds get less consistent beyond 1000 feet. (See Sprint Promises Mobile 5G in H1 2019, Signals More Job Cuts and Nokia Bell Labs & Verizon Stretch Fixed 5G to the Home.)

Now the CTO had to walk a fine line here, as T-Mobile itself plans to use millimeter wave itself in 2019.

"Don't get me wrong, I love millimeter wave spectrum,” Ray said. "We have a nice big, hefty chunk of it available, we will start to use that as smartphones become available."

This will happen early in 2019, he said.

The difference, aside from the fact that Verizon has many more 28GHz licenses available than T-Mobile, is going to be in the way the "Un-carrier" uses the spectrum. It will be "deployed smartly in urban [outdoor] environments where the propagation is less of an issue," Ray suggested, rather than trying to deliver broadband to the home.

”You need low-band as your mobility anchor,” Ray says.

This suggests that T-Mobile will use 28GHz to create "hot zones" in open city areas, at least where it has 28GHz licenses, which were acquired when it bought MetroPCS. The FCC is planning to hold its first millimeter wave auctions releatively soon, but Ray doesn’t expect that to get underway until 2019.

5G "will be in every spectrum band" eventually, T-Mobile CEO John Legere claimed. "It sure as hell isn't a 2018 arms race," he noted earlier on the call.

— Dan Jones, Mobile Editor, Light Reading