T-Mobile already has one of the most robust 5G networks in the United States, depending on where you live, but it's not slowing down. With growing competition from both Verizon and AT&T, the carrier needs to step up its development in order to consolidate itself and keep its spot. It's no easy work, by all means, but T-Mobile just scored a notable win as it agreed to buy some wireless spectrum currently owned by Comcast.