2.5 GHz mid-band spectrum drives T-Mobile’s 5G speeds in the US

The U.S. 5G experience is in the middle of a period of great change. Soon, the carriers will be able to start using new mid-band spectrum (3.7 GHz, or C-band) in 46 markets from December. Together they have spent a combined $81.11bn in licences to improve the 5G experience with this additional capacity. Already, Opensignal has observed an impressive rise in T-Mobile users’ 5G Download Speed enabled by T-Mobile’s existing mid-band spectrum. Our T-Mobile 5G users saw their average 5G download speeds soar by 66.5%, from 71.3 Mbps in Opensignal’s April 2021 5G Experience report to 118.7 Mbps in the latest report published in October 2021.

This means that in our most recent analysis T-Mobile led by 62.7 Mbps over second placed Verizon and 67.2 Mbps over AT&T — with 5G download speeds more than twice as fast as those achieved by their competitors. In our new analysis we see that T-Mobile’s use of its 2.5 GHz mid-band spectrum enabled this increase and non-standalone access was important here. Furthermore, this change helps explain the different amounts that each carrier spent in the C-band auction: Verizon, $45.45bn; AT&T, $23.41bn; while T-Mobile spent significantly less at $9.34bn.


To explain the change in 5G experience observed by our  T-Mobile users, we analyzed their average 5G download speeds over time looking at the two different spectrum bands that the operator is focusing its 5G deployment efforts on — the 600 MHz (NR band 71) and 2.5 GHz (NR band 41).

Our analysis shows that T-Mobile’s surge in 5G Download Speed was driven by its ongoing deployment of the 2.5 GHz band. We observed that, not only T-Mobile expanded its use of the 2.5 GHz band over time, but the operator has also very likely increased the amount of spectrum capacity allocated for 5G in that band. In fact, we have seen the average 5G download speeds experienced by our T-Mobile users when connected to the 2.5 GHz band increase by more than 40% rising from 170.1 Mbps in March 2021 to 239.3 Mbps in September 2021. By contrast, average 5G speeds on the 600 MHz band had no statistically significant change and remained flat at slightly below 30 Mbps.

Notably, the bulk of the boost on the 2.5GHz band happened between March and July 2021 —an increase of 39.3% — after that average 5G speeds remained stable just above 235 Mbps. For context, in September 2021 T-Mobile said that it had deployed 60-80 MHz of the mid-band, up from the 40-50MHz it had been using in late 2020, and that stated that it is aiming to use 100 MHz on sites by the end of the year. Additional spectrum capacity makes it easier for users to see higher 5G speeds.

We saw much slower speeds that changed little when our T-Mobile users connected to the 600 MHz band. This is not surprising, given the propagation characteristics and amount of spectrum that T-Mobile owns on this band. Low bands like 600 MHz provide mobile coverage to wider areas with fewer cells deployed, but at a cost of more limited capacity. Mid-bands like 2.5 GHz, which T-Mobile acquired after its merger with Sprint, usually offer higher capacity, but need more cells per square mile to achieve similar coverage to the low bands.

T-Mobile refers to its 5G spectrum deployment strategy as a ‘layer cake’ — with low bands used for wide coverage, complemented by mid and higher frequency bands to provide greater capacity for small and dense city areas. The way T-Mobile uses these spectrum bands is consistent with what we observed in our analysis.

We then looked at the proportions of 5G readings that we collected when our users were connected to T-Mobile’s 600 MHz and 2.5 GHz bands. The share of 5G readings observed on the 2.5 GHz band has increased more than three times, from nearly 9% in March 2021 to over 27% in September 2021. This means that T-Mobile 5G users are able to access the 2.5GHz band more easily which further explains the increase in the overall 5G speed seen by T-Mobile users.


We investigated the role of standalone access (SA) and non-standalone access (NSA) 5G in explaining T-Mobile’s experience, building on our previous analysis of standalone 5G on T-Mobile. 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).

Perhaps counterintuitively, the average 5G download speed our users saw on the 600 MHz band with SA was slower than on NSA. In part, this is because of the role of 4G bands in supporting the 5G experience when a smartphone is in NSA mode as we have seen in other markets (for example South Korea or in Europe).

AT&T and Verizon will seek to boost their 5G experience with mid-band soon

Our analysis shows that T-Mobile’s acquisition of Sprint’s mid-band spectrum assets through the merger allowed it to build a substantial lead over its competitors as measured in our recent USA 5G Experience reports. T-Mobile now has a significant competitive advantage over its competitors, which don’t have access to any mid-band spectrum bands just yet. 

However, everything will change soon, as U.S. operators purchased licenses in the C-band spectrum band (3.7 – 3.98 GHz) during Auction 107 earlier this year. In fact, the first tranche of this C-band spectrum will be available for use by December 2021. Plus the second portion will be available by the end of 2023. T-Mobile’s 5G experience highlights the importance for Verizon and AT&T to maximize their use of new mid-band spectrum.