Verizon appears to be the only US operator with plans to significantly expand its 5G network in millimeter wave (mmWave) spectrum.

And though analysts continue to paint a bright future for 5G in highband, mmWave spectrum globally, the situation nonetheless underscores the challenges of building a network in spectrum that can't transmit signals more than a few thousand feet.

"That lowband [spectrum] layer is critically important," argued T-Mobile's network chief Neville Ray during a recent investor event, noting that T-Mobile's lowband 600MHz network provides a nationwide 5G experience (albeit one much slower than Verizon's).

Continued Ray: "It's the complete reversal of the Verizon challenge with millimeter wave. You've got a concentrated 5G experience with very, very limited coverage. What happens when you leave the hotspot bubble? Nothing really. You drop straight back down to a 4G experience. That's not a sustainable model."

When questioned about T-Mobile's own mmWave plans, Ray didn't offer much in the way of specificity. "We'll continue to evaluate mmWave options," he said, noting the spectrum can provide a good "capacity layer" and could also be used for fixed wireless Internet services or backhaul.

T-Mobile's relative disinterest in mmWave can be clearly seen in Dallas, where the company has installed mmWave transmitters only on its existing macro cell towers. According to data from Aurora Insight, a startup that operates mobile sensors that can geolocate transmitters in a specific area, T-Mobile has deployed 41 mmWave transmitters across Dallas. Verizon, on the other hand, has deployed 76 mmWave transmitters using new sites specifically intended for its mmWave network.

Figure 1: Verizon's mmWave network in Dallas uses new small cell sites, shown on the left, while T-Mobile's mmWave network uses its existing macro sites, as shown on the right. Click here for a larger version of this image.
(Source: Aurora Insight)

An AT&T official offered a similarly tepid response to questions this week from Light Reading about whether the carrier plans to expand its own mmWave network to additional sites or additional cities. "We are continuing our build for mmWave technology (what we call 5G+) in cities across the country," the company said in a statement. "We have been strategic with the locations where we launch 5G+ mmWave and are turning it up in densely populated, high-traffic areas in addition to business locations. We are building it in areas such as convention centers, hospitals, school campuses, sporting venues, shopping areas and targeted business locations – where extra capacity is needed and where higher speeds and low latency can support innovation and provide a better overall experience."

Verizon stands alone
Neither AT&T nor T-Mobile has committed to the kind of mmWave expansion that Verizon has. Verizon, which has been investing in mmWave repeaters to expand its coverage areas, earlier this year said it would roughly double the number of cities where it offers mmWave 5G, from around 30 in January to around 60 by the end of this year.

Indeed, based on data from Aurora Insight, Verizon appears poised to light up an extensive mmWave network in Baltimore.

AT&T, meantime, offers mmWave 5G in parts of around 35 cities. T-Mobile's mmWave network runs in parts of just a half dozen cities. Neither company has offered any firm expansion plans. But both companies have been loudly touting their 5G buildouts in their lowband and midband spectrum holdings.

Further, Opensignal analyst Ian Fogg pointed out that Verizon's entire mmWave 5G strategy has been upended by the COVID-19 pandemic. The places where Verizon has deployed mmWave 5G – stadiums, downtown areas and other high-traffic locations – are exactly the kinds of places that Americans are avoiding due to the coronavirus.

Although Opensignal named Verizon as the fastest 5G provider in the world, there are precious few Verizon customers who can actually enjoy the experience.

Long-term mmWave momentum
Despite the fact that Verizon appears to be the only operator in the world currently operating a commercial mmWave network and working to significantly expand it, most analysts still expect growth in the mmWave space globally.

"We are evaluating if we need to adjust the millimeter wave forecast to reflect not only the improved momentum in 2020 but also the more favorable outlook in the APAC [Asia-Pacific] region," wrote Dell'Oro analyst Stefan Pongratz recently. "More specifically, we are seeking to understand if the uptick in the mmW interest from China is more driven by hotspot deployments for the Beijing Olympics or if there is a broader change to the overall MBB [mobile broadband] strategy in China and the role that mmW will play beyond the Olympics. For now we are operating under the assumption that it is more of the former."

Pongratz explained that interest in mmWave 5G will grow over the next 10 years across the world – starting in Russia, Japan, South Korea and possibly China – as operators run out of lowband and midband spectrum capacity, and as the number of possible mmWave transmission sites increase. Just this week the European Commission adopted rules designed to speed up the deployment of mmWave-friendly small cells.

In fact, the Global mobile Suppliers Association (GSA) reports that 22 operators are known to be building 5G networks using mmWave spectrum

And as for AT&T and T-Mobile, they have plenty of reasons to put mmWave 5G on the backburner during this year of COVID-19. AT&T is enmeshed in the launch of a byzantine number of AT&T- and HBO-branded streaming video services. And T-Mobile, fresh off the close of its merger with Sprint, is working feverishly to build out its 2.5GHz spectrum holdings.

Verizon, meanwhile, has every reason to focus on mmWave during 2020. That's because it will probably start building a massive 5G network with midband C-band spectrum starting next year.

— Mike Dano, Editorial Director, 5G & Mobile Strategies, Light Reading | @mikeddano