While AT&T and Verizon started to build out their 5G networks using the fastest mmWave spectrum, they failed to take into consideration that mmWave signals, while speedy indeedy, do not travel far and are easily blocked by trees and structures. However, the characteristics of high-band mean that finding and connecting to a 5G mmWave signal is extremely rare. Low-band, on the other hand, travels great distances and the signals can penetrate buildings and trees. However, low-band airwaves are not the fastest and the downlink data speed is just 20% faster than 4G LTE.

T-Mobile’s 5G layer cake shows the importance of mid-band spectrum in the carrier’s 5G service
Dish complained to the FCC about T-Mobile‘s pending purchase of Comcast’s 600MHz spectrum and said, “This transaction threatens wireless competition and implicates material questions for FCC public policy. The Commission should suspend review of this transaction, or at least condition the transaction, to offset the harms to competition and consumers.”
AT&T wasn’t happy when T-Mobile scarfed up more 2.5GHz mid-band spectrum from a 2022 FCC auction. The carrier spent more than $304 million to win 7,156 2.5GHz mid-band licenses in 2,724 counties. This led AT&T to say, “T-Mobile controls a grossly outsized portion of the mid-band spectrum needed to fuel the 5G revolution.”