Midband spectrum is often referred to as having the right mix of performance capability and coverage for mobile networks, particularly 5G, when compared to low-band or millimeter-wave spectrum. As midband spectrum is being deployed, what impact is it having on network performance?
–T-Mobile US’ jump-start on midband has improved its performance over the past 18-24 months. For evidence of the impact of midband spectrum on performance, one need look no further than T-Mobile US’ network performance improvements in the past couple of years. Up until about 2021, network speed and data performance awards from the likes of Rootmetrics were a competition between AT&T and Verizon, with Verizon the frequent winner. (T-Mobile US tended to do better at the metropolitan level in terms of performance.) In the second half of 2020 (when T-Mobile US closed on the Sprint merger), Rootmetrics recorded the three national carriers’ aggregate median download speeds on a U.S.-wide basis as Verizon at 40 Mbps, AT&T at 33.8 Mbps and T-Mobile US at 20.1 Mbps. Verizon was outcompeting both AT&T and T-Mobile US, by Rootmetrics’ reckoning, in a majority of metropolitan markets across the country as well.
But that began to shift the following year, as T-Mobile US began its multi-year effort to integrate the Sprint network and put its new midband spectrum holdings at 2.5 GHz to work. In the first quarter of 2021, Ookla reported that based on its crowd-sourced Speedtest data, T-Mobile US had overtaken AT&T as the fastest U.S. operator, with Verizon in third place. By the second quarter of 2021, that translated to median network speeds of 54.13 Mbps for T-Mo, 47.96 Mbps for AT&T and 40.02 Mbps for Verizon. In the second quarter of this year, even though the deployment of new C-Band spectrum had boosted Verizon’s median speed to 59.67 Mbps and put the carrier in second place, T-Mobile US was registering 116.54 Mbps as a median network speed—largely because of the 2.5 GHz that T-Mobile US had deployed, as well as the increased adoption of 5G.
In terms of 5G-only tests, Ookla said that T-Mobile US had the fastest median 5G download speed during the second quarter of this year: 187.33 Mbps. Verizon was in second with 113.52 Mbps, an increase over the 107.25 Mbps that it registered in the first quarter of 2022. AT&T, meanwhile, which has yet to deploy most of the C-Band spectrum that it acquired because it gets cleared later, was at 5G speeds of 71.54 Mbps in the second quarter of 2022. Availability comes into play as well; Ookla reported that 5G availability was highest for T-Mobile US users, with 68.5% of them on 5G for the majority of the time; AT&T was second at 55.8% and Verizon was third at 31.2%.
–C-Band is enabling Verizon and AT&T to pursue T-Mobile US’ 5G lead. In analysis from Opensignal published last week, both AT&T and Verizon are turning up more C-Band spectrum across the country and seeing their network speeds increase as a result.
Opensign said that the percent of AT&T’s sub-6 GHz 5G tests that came via C-Band rose from 5.9% in April 2022 to nearly 10% in May; by September, more than 30% of 5G readings on AT&T’s network took place in 3.7 GHz, reflecting expanded deployment of the spectrum. On speeds, Opensignal reported that AT&T users’ download speeds on 5G were up by 34.6% since March of this year. These improvements come even though AT&T won’t get access to a substantial amount of the spectrum it purchased until late next year—leaving substantial runway left for turning up additional 5G midband spectrum over the coming years.
In terms of impacts on Verizon’s network, Opensignal found that 5G readings coming from C-Band spectrum have increased from 16.2% in March 2022 to nearly 50% in September. Average 5G download speeds increased 15.8% during that same timeframe. Read more details here.
–CBRS boosts performance significantly as well. Despite lower power levels and a tiered spectrum-sharing system for use, the Citizens Broadband Radio Service (CBRS) spectrum is also providing a boost to mobile networks. In terms of deployment, multiple testing and analysis reports from Rootmetrics (prior to its acquisition by Ookla) and Opensignal have reported that Verizon’s deployment of CBRS has been on the rise even before the company acquired PALs. Rootmetrics said that as of late 2020, it observed CBRS spectrum in use on Verizon’s network in 70 metropolitan areas, up from 41 cities in the first half of 2020. In CBRS-specific testing in Philadelphia, the benchmarking company found median download speeds in CBRS versus non-CBRS spectrum of 135.1 Mbps and 64.2 Mbps, respectively. Peak speeds were even more impressive: 692.1 Mbps in CBRS spectrum and 404.9 Mbps in non-CBRS spectrum. Adam Koeppe, Verizon’s SVP of network technology and planning, told RCR Wireless News at the time that the power limits were still a good fit for small cells and urban rooftop sites, and that the clear path to 5G NR in CBRS was another bonus of the spectrum.
Opensignal analysis from late 2021, meanwhile, found that (under conditions of 40 megahertz of spectrum being used) Verizon’s CBRS LTE provided faster speeds than other LTE midband spectrum (AT&T’s 2.3 GHz and T-Mobile US’ 2.5 GHz). “On the connections with the CBRS band involved, 4G download speeds experienced by Opensignal users were 78.8% faster than those without the CBRS band — clocking in with an impressive score of 74.4 Mbps. This was faster than what AT&T and T-Mobile achieved with the support of their mid-band spectrum in the cities — 47.3 and 61.6 Mbps, respectively.” However, predictably, the power levels in CBRS dropped off much faster than other midband airwaves; while LTE users within about 770 feet of a CBRS site saw average download speeds of more than 136 Mbps, that dropped to around 76 Mbps at a distance between 770-1540 feet and when they were more than 2,300 feet away, the average speed dropped to around 23 Mbps. All the analyzed spectrum bands saw a fall-off in performance, Opensignal noted, but both CBRS’ peak performance, and its drop-off with distance, was the greatest.
Looking for more information on 5G spectrum and RF issues in 4G/5G networks? Check out our recent webinar featuring Anritsu and LitePoint, and download the free accompanying editorial special report.
