T-Mobile US completed a 5G network test using its millimeter-wave (mmWave) spectrum that could allow the carrier to boost the speed and capacity of its rapidly expanding fixed-wireless access (FWA) service.

The test, which was conducted with partners Ericsson and Qualcomm, used the carrier’s 5G standalone (SA) network to aggregate eight channels of mmWave spectrum that produced peak download speeds in excess of 4.3 Gb/s. It also tied together four channels of mmWave spectrum on the uplink that produced speeds of more than 420 Mb/s.

Uplink speeds in wireless networks often trail that of downlink speeds. This is most often due to the power requirements needed to beam a spectrum-heavy connection between a device and base station. Most end-user devices have a smaller form factor than a cell tower so they need more creative antenna technology to support the signal. The devices also often rely on an embedded battery, which can quickly heat up and drain while trying to power that connection.

The latest speed marks surpass recent tests T-Mobile US has conducted using its mid- and low-band spectrum holdings. This included a test this summer where it used four-carrier channel aggregation to combine spectrum from its 2.5 GHz, 1.9 GHz and 600 MHz portfolio to produce downlink speeds in excess of 3 Gb/s.

T-Mobile US noted that the 5G mmWave testing is geared toward deployments in “crowded areas like stadiums and, potentially, for fixed-wireless service.” This last part would be T-Mobile US’ High-Speed Internet (HSI) fixed-wireless access (FWA) service.

“We’ve always said we’ll use millimeter wave where it makes sense and this test allows us to see how the spectrum can be put to use in different situations like crowded venues or to power things like fixed-wireless access when combined with 5G standalone,” Ulf Ewaldsson, president of technology at T-Mobile US, said in a statement.

That FWA use case could become an important mmWave avenue for T-Mobile US.

CEO Mike Sievert told an investor conference this week that the carrier has designed its network to support up to 80 gigabytes of usage per month by each customer. However, T-Mobile US EVP and CTO John Saw said during a keynote speech at the recent MWC Las Vegas event that its FWA customers were using around 450 gigabytes of data per month.

The carrier has managed this disparity by parsing out FWA connections to its network. This includes monitoring of network capacity per cell site, which can impact on a day-to-day basis the ability for new customers to sign up for the service.

“If three people in your neighborhood sign up, or four or five people depending on the sector, the whole neighborhood comes off our list until such time as we’ve got that excess capacity again,” Sievert had previously stated.

T-Mobile US ended the third quarter with 4.2 million FWA connections on its network, which was more than half-way toward its stated goal of being able to support around 8 million total FWA customers using its current network architecture and spectrum holdings. Those FWA customers have basically been gravy for the carrier as they provide an ongoing revenue stream without needing the carrier to invest any more capex into its network.

Ewaldsson said during the carrier’s second-quarter earnings call that it has deployed mmWave spectrum in some markets, citing specifically Manhattan and Los Angeles, “where we really have that extraordinary capacity need.” He added that while the carrier is more focused on a macro-spectrum strategy based on its mid-band and low-band assets, “millimeter-wave could also be potentially an interesting play for us when it comes to enhancing capacities that could be used, for example, for HSI.”

“And we are working with our vendors, and we are working through our OEMs to figure out if we can make a viable economic and technical performance case out of that with them,” Ewaldsson added.

The use of mmWave spectrum could allow the carrier to increase its FWA capacity potential, including a greater push into the enterprise space.

Mishka Dehgan, SVP for strategy, product and solutions engineering at T-Mobile’s Business Group, told SDxCentral during an interview at the MWC Las Vegas event that the carrier is seeing enterprise FWA growth opportunities, highlighting a specific business need.

“Usually what you see with fixed wireless is a nationwide, distributed footprint that the customer wants to light up,” Dehgan said.

Dehgan also pointed to T-Mobile US’ recent deepening of its enterprise-focused FWA equipment through partnerships with Cisco and Cradlepoint.

Sievert this week said the carrier was looking at various options to boost its FWA capabilities “both kind of the millimeter wave and small cell as well as kind of maybe mid-band, but with standards or non-standards based technologies, all that stuff we're looking at. They're different from each other, and we haven't drawn any conclusions yet.”

While the latest mmWave test included work with vendor partner Ericsson, T-Mobile US remains a strong supporter of its other main 5G infrastructure provider Nokia. That support is significant as Nokia this week lost a significant amount of market share at AT&T as part of that operator’s push toward open radio access network (RAN) infrastructure.

“We really deeply value our partnerships with both Nokia and Ericsson and see it as an advantage that we can buy up and down the stack from multiple partners,” Sievert told the investor conference. “We also think it's very good that the Western world has two global leaders in this space. So we're very comfortable with our relationships and highly value those deep partnerships that we have with both Ericsson and Nokia.”