T-Mobile is claiming a new first for standalone 5G. The operator used a combo of 2.5 GHz and mmWave spectrum to reach nearly 5 Gbps on its commercial SA 5G network.
T-Mobile said it’s the world’s first New Radio Dual Connectivity (NR DC) data call on a commercial standalone 5G network, which resulted in download speeds of 4.95 Gbps. The data session took place in the September-October timeframe on a single site in Southern California, utilizing 100 MHz of 2.5 GHz spectrum and 800 MHz of mmWave, according to a T-Mobile spokesperson. Ericsson provided the network gear, and the call was conducted on a test device, the spokesperson said.
The mmWave portion used spectrum in the 39 GHz band. T-Mobile has long touted a layer cake strategy for 5G but put far less emphasis on mmWave than competitors like Verizon in early days – instead focusing on low-band 600 MHz for coverage and now 2.5 GHz since it later amassed a trove of mid-band spectrum from Sprint that provides a mix of coverage and capacity.
At the FCC’s third millimeter wave auction T-Mobile spent around $931 million to buy licenses in the 47 GHz and 39 GHz bands. Limited deployments, for example to boost capacity before big events like the Super Bowl LV in Tampa earlier this year or in the major market of Las Vegas, have used 39 GHz. Other locations like New York and Los Angeles have used 28 GHz.
While T-Mobile holds the bragging rights of first operator to deploy a nationwide 5G SA network at scale (and still the only U.S. carrier to do so) it hasn’t made much noise about impacts since the rollout.
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During third quarter earnings results this week, T-Mobile CEO Mike Sievert made a short mention of 5G SA efforts and called out enterprise interest in advanced capabilities.
“We've already seen an increase in our win share for traditional postpaid services and we're well positioned to capture advanced 5G services with the most widely built out 5G network and the only stand-alone 5G core, which is exactly why many large enterprises are in active trials with T-Mobile for advanced capabilities like mobile edge compute and private networks,” Sievert said. “And let me remind you that these advanced 5G services represent upside to our plan.”
The recent test focused on throughput although advanced capabilities like network slicing or ultra-low latency tend to be a focus of standalone 5G benefits, rather than straight speed gains. For 5G speeds, like in T-Mobile’s recent data call, spectrum resources and technologies like carrier aggregation or dual connectivity seem to get more attention. That was illustrated in recent Opensignal testing that showed T-Mobile’s 5G service using additional 2.5 GHz spectrum boosted user speeds significantly – but standalone 5G wasn’t the main driver.
T-Mobile until this point has largely focused on 600 MHz for users connected to the SA 5G network, who actually saw slower speeds than those on non-standalone (NSA) 5G which also incorporate 4G LTE mid-band frequencies to support 5G, according to Opensignal.
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T-Mobile and U.S. carriers AT&T and Verizon all started initial 5G deployments in NSA mode, which helps get 5G up and running faster by having the option to still lean on 4G.
“Now, we can see that the 2.5 GHz band is predominantly used with NSA and so SA is not the key reason for the improvement in 5G speeds (although it likely does continue to have other benefits),” wrote Opensignal in an October 27 analysis.
Still, 5G experience improved as latencies dropped with help from the SA core and network reach expanded with the rollout, according to an earlier report.
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“T-Mobile appears to have initially targeted its use of SA 5G to boost the reach of its 5G network, and therefore used its 600 MHz band for SA 5G — a low band that generally propagates further compared to higher bands like its 2.5 GHz band, but doesn’t allow for the same speeds,” Opensignal concluded in a February report on the operator’s 5G SA performance.
However, as T-Mobile’s most recent test shows, a mix of 2.5 GHz and mmWave with SA 5G dual connectivity can deliver ultra-fast results.