T-Mobile’s deployment of standalone 5G (SA 5G) in the 600 MHz band has improved both latency and coverage, according to a new report from Opensignal. T-Mobile is the only carrier that currently claims nationwide U.S. coverage, but others are expected to hit the gas on SA 5G this year.
Latency on T-Mobile’s SA 5G network was 23.8% better than on the company’s non-standalone (NSA) network in urban areas and was 21.6% better in rural areas.
Five months after T-Mobile’s nationwide SA 5G announcement, the company’s 5G availability had increased from 26.9% to 31.5% in urban areas. In rural areas, availability improved even more — from 24.5% to 33.3% in rural areas. Opensignal measured availability by the amount of time users with 5G devices spend on T-Mobile’s 5G network, rather than falling back on LTE.
It’s important to note, though, that the increased availability wasn’t the direct result of the shift to SA 5G but instead was related to how T-Mobile initially deployed 5G and how it implemented the shift to standalone 5G.
T-Mobile Standalone 5G
Initially all U.S. carriers deployed 5G in non-standalone mode, meaning that the service used the same core network as earlier-generation service. Standalone 5G uses a dedicated network core that is designed to provide lower latency and to support capabilities such as network slicing, which enables carriers to offer a range of services with different performance characteristics over the same network.
T-Mobile initially deployed 5G in non-standalone mode in the 600 MHz band, which supports lower speeds but broader coverage in comparison with the non-standalone 5G service that the company subsequently deployed in the 2.5 GHz band.
In August 2020, T-Mobile shifted the traffic on its 600 MHz 5G network to a dedicated standalone core, essentially flipping the switch on standalone 5G. As T-Mobile explained, that gave the company an immediate boost of about 30% in 5G coverage –the reason being that sharing the non-standalone core with service deployed in the 2.5 GHz band had limited the range of the company’s 5G service deployed in the 600 MHz band.
At the time, the company noted that the extended range would make 5G available to rural areas that previously couldn’t get 5G, and the company celebrated this with a drone light show over rural Lisbon, N.D.
OpenSignal’s research confirms T-Mobile’s rural standalone 5G expectations. While urban 5G availability increased 4.6 percentage in the first five months after the SA 5G launch, rural 5G availability increased 8.8 percentage points.
Speeds, on the Other Hand . . .
The downside to the way that T-Mobile implemented standalone 5G is that customers are seeing slower speeds on the company’s SA 5G network than on the NSA 5G network. In urban areas, the average 5G download speed was 64.4 Mbps on the NSA network and 28.6 Mbps on the SA network. In rural areas, those numbers were 53.4 Mbps and 30 Mbps, respectively.
According to Opensignal, the reason for this is that SA 5G was implemented in the 600 MHz band, where speeds are lower. Opensignal expects that to change when newer smartphones hit the market that are able to connect simultaneously to T-Mobile’s 600 MHz network and the company’s 2.5 GHz network.
The Opensignal research suggests that, as other carriers get serious about deploying standalone 5G, they’re also likely to see improved latency. But the coverage and speed impact that SA 5G had on T-Mobile may be unique to that company.