T-Mobile debuts new 5G layer cake

T-Mobile execs talked up the carrier's midband 5G network but offered some trash talk on the millimeter wave version of 5G that other executives touted at Qualcomm's summit this week.

Rob Pegoraro, Contributor, Light Reading

December 3, 2021

6 Min Read
T-Mobile debuts new 5G layer cake

WAIMEA, Hawaii – T-Mobile once again brought a layer cake to a smartphone summit, but this year's confectionery creation is shorter.

The dessert prop that the carrier has traditionally used to visualize a three-spectrum-band approach to 5G – a wide bottom layer for lowband spectrum, a narrower one above for midband, and a small top tier for millimeter wave (mmWave) – now features just two layers as displayed in T-Mobile's suite at Qualcomm's Snapdragon Tech Summit here.

In place of that mmWave top: eight candles, one for each city in which T-Mobile has deployed this fast but feeble broadband, which can top 2 Gbit/s but reaches at besta few thousand outdoor feet.

Figure 1: T-Mobile's new 5G layer cake replaces a mmWave top tier with candles. (Source: Rob Pegoraro, for Light Reading) T-Mobile's new 5G layer cake replaces a mmWave top tier with candles.
(Source: Rob Pegoraro, for Light Reading)

(That octet of locales with this outside-only broadband: Atlanta, Cleveland, Dallas, Las Vegas, Los Angeles, Miami, New York and Tampa.)

Millimeter wave? Meh

In a meeting here Wednesday, T-Mobile network-technology SVP Karri Kuoppamaki allowed that mmWave 5G could still help drive localized applications like factory systems but brushed it off as a solution for consumer mobile devices.

"Because of the limited coverage that it provides, it's very hard to support mobility applications," he said. "We're now focusing on continuing to build out on the midband layer."

That clashes with the message from Qualcomm at the summit, at which the San Diego firm introduced its Snapdragon 8 Gen 1 platform for Android phones.

The summit's opening keynote Tuesday featured Qualcomm CEO Cristiano Amon doing a live 8K video call over Verizon mmWave 5G with Verizon CTO Kyle Malady (never mind that Verizon's consumer plans lists a maximum streaming-video resolution of 4K UHD) and declaring that mmWave 5G will "enable next-generation experiences."

In a Q&A session Wednesday, Amon outright labeled mmWave inevitable for bringing sufficient wireless broadband: "Knowing that this needs to happen, it will happen."

Midband might

T-Mobile, however, regards midband 5G – its 2.5 GHz spectrum routinely delivers 400 Mbit/s connections – as not just good enough but great enough to do that job.

And the company also sees the spectrum it inherited from Sprint as a durable competitive advantage over AT&T and Verizon, which won't have their own midband service until they can light up the C-band spectrum they bought at auction.

T-Mobile hit its 2021 goal of covering 200 million Americans with midband 5G in mid-November.

Kuoppamaki predicted that, based on the areas covered in phase one of C-band deployment, AT&T and Verizon will remain behind T-Mobile's current total two years from now.

"By end of 2023, Verizon and AT&T will not be able to get to 200 million," he said.

Another series of cakes in T-Mobile's suite illustrated that: a giant magenta cake to represent T-Mobile's midband, a red one about half as big for Verizon C-band, and a blue one not much bigger than a cupcake for AT&T's.

T-Mobile has expanded its midband capacity along with its coverage and now has 100 MHz in service nationwide.

"In some places it might be a little bit less than that, in some it might be a little bit more than that," Kuoppamaki said, adding that carrier aggregation provides a further boost in capacity.

C-band blues

AT&T and Verizon's C-band ambitions also face the unexpected obstacle of the Federal Aviation Administration's late-breaking request for a safety review of possible interference with radio altimeters. The carriers responded by agreeing to lower their C-band power nationwide for the first six months.

Kuoppamaki, observing that other countries have widely deployed C-band without creating problems for the aviation industry, said "We're optimistic and confident that those issues will be non-issues in the US as well."

T-Mobile, for its part, did purchase C-band spectrum during an FCC auction earlier this year, but its licenses won't be available for commercial use until 2023. Presumably interference concerns will be addressed by then.

Lowband 5G

Lowband continues to offer T-Mobile's widest 5G reach, with 308 million people now covered. Among them: everybody on the Big Island of Hawaii, the summit's location.

The carrier's suite included yet another dig at T-Mobile's competition on that point: a Lite-Brite rendition of its coverage map showed 5G covering all but some interior pockets of the island, standing next to a second Lite-Brite showed Verizon 5G confined to a tiny beachhead on the west coast, presumably the mmWave network it built at the resort for the summit.

Lowband 5G is in no danger of enabling many next-gen experiences – before launching it, T-Mobile advised reviewers to expect only 20% faster downloads – but Kuoppamaki said markets confined to lowband 5G would still be fine if people are sufficiently scarce. "You can get great experiences in lowband layer if you don't have too many users on the same cell," he said.

Next steps

The progress of T-Mobile's 5G rollout depends heavily on its ability to shut down 3G service and refarm that spectrum. It plans to close its own 3G network on July 1, 2022, with an earlier sunset for the 3G network inherited from Sprint – originally January 1, but pushed back to March 31 after Dish Network complained that the move would strand too many customers.

Ryan Sullivan, T-Mobile's VP of device engineering, professed confidence that this schedule will stick, even for Dish.

"There's motivation across the board to get them on the best network that's available," he said, adding that phones represented a smaller obstacle overall: "It's more of an M2M and wholesale issue than anything else."

Like many carriers in other markets, however, T-Mobile has no timetable for retiring its 2G network.

T-Mobile is also taking a slower approach with expanding its lead in standalone 5G beyond its current focus on lowband.

"It's predominantly used today to provide 5G in lowband only areas," Kuoppamaki said of T-Mobile's standalone 5G network. "To be able to move to a full standalone architecture depends on 5G being available everywhere."

One last 5G goal seems likely to come to fruition sooner: voice over 5G.

"We have been conducting extensive testing on it," he said. "The development is in good shape." But he wouldn't offer a timetable beyond "soon," adding that the carrier wanted to avoid any glitches on consumer phones.

Said Kuoppamaki: "We're taking a no-device-left-behind approach."

— Rob Pegoraro, special to Light Reading. Follow him @robpegoraro.

(Disclosure: Qualcomm covered airfare and lodging for most of the journalists and analysts covering this invite-only event, myself included.)

About the Author(s)

Rob Pegoraro

Contributor, Light Reading

Rob Pegoraro covers telecom, computers, gadgets, apps, and other things that beep or blink from the D.C. area since the mid-1990s. In addition to right here, you can find his work at such places as USA Today, Fast Company and Wirecutter, you can e-mail him at [email protected], find him on Twitter as @robpegoraro, and read more at robpegoraro.com.

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