T-Mobile is touting the strength of its 5G network following a record-breaking FCC auction of coveted mid-range spectrum.

Experts expected the FCC auction to fetch as much as $47 billion. Instead, it topped a whopping $81 billion. The spectrum auctioned was mid-range C-band, desperately needed by both Verizon and AT&T to help roll out their 5G networks. Both companies spent appropriately, with Verizon coming in at more than $45 billion and AT&T spending more than $23 billion.

In contrast, T-Mobile only spent a little more than $9 billion, largely thanks to its strong spectrum portfolio. Thanks to its merger with Sprint, T-Mobile aready had a wealth of mid-band spectrum — considered the ideal spectrum for 5G — which it has been rapidly deploying. Providing a good blend of range and building penetration, T-Mobile has already achieved speeds in excess of 1 Gbps using its mid-band spectrum. Thanks to its position, T-Mobile only bought spectrum in top urban and suburban markets to help round out its existing holdings.

In its latest post, however, T-Mobile also highlighted the advantage its mid-band spectrum has over the C-band spectrum the FCC was auctioning. With wireless spectrum, the lower the frequency, the longer the range it provides and the better it penetrates obstacles, such as buildings.

T-Mobile’s current mid-band spectrum is primarily in the 2.5 Ghz range. In contrast, the C-band spectrum just auctioned is in the 3.7 Ghz to 4.2 Ghz range. In other words, the spectrum Verizon and AT&T spent more than $68 billion on is more than a full gigahertz higher than T-Mobile’s primary mid-band, meaning it will offer less range and worse penetration. This will, in turn, result in higher deployment costs for those companies, as T-Mobile points out:

In the mid-band range, C-Band offers a great mix of coverage and speed, but there are some key differences from 2.5 GHz, the mid-band spectrum T-Mobile is primarily using to roll out Ultra Capacity 5G. Most notably, it doesn’t travel as far. T-Mobile engineers estimate it will require 50% more cell sites for meaningful and continuous coverage, and in some areas, for example in-building, the required densification can be 4x higher than 2.5 GHz. That’s why T-Mobile strategically invested in C-Band to supplement its much broader 2.5 GHz footprint in select urban and suburban areas where it already has a dense network. This will allow for the spectrum to quickly be deployed and provide a more meaningful performance boost for customers.

C-Band vs 2.5GHz Comparison

The company promises it will continue with its 5G deployment, covering 200 million with its high-speed Ultra Capacity 5G this year.

“T-Mobile customers are the clear winners in this auction. Our already industry-leading 5G network enabled us to be highly selective and strategic, concentrating our wins in top markets nationwide,” said Mike Sievert, CEO of T-Mobile. “As I predicted last fall, the other guys spent an unbelievable amount — because they had to. And even then, the truth is that C-Band is best for urban areas because it doesn’t propagate as well as T-Mobile’s substantial existing mid-band frequencies. For us, C-Band makes a great story even better, and we are incredibly pleased with our clear success in this auction. Our competitors had no choice but to go all in with a break-the-bank attempt to remain relevant in the 5G era.”