Once touted as the key building block of 5G networks, high band millimeter wave spectrum has taken a back seat to longer-distance low and mid band frequencies in most carriers’ early rollouts. But the FCC hasn’t had problems auctioning increasingly large millimeter wave blocks: Today, the Commission announced that it netted $4,474,530,303 in sales of upper 37GHz, 39GHz, and 47GHz spectrum for 5G use, in addition to $3,084,172,898 in incentive payments to hasten the removal of existing licensees from the bands.

Touted as the largest auction of spectrum (by quantity) in U.S. history, Auction 103 effectively adds three additional millimeter wave bands to previously auctioned 24GHz and 28GHz frequencies, giving carriers the ability to offer exceptionally high-bandwidth wireless services on a national basis. The 24GHz and 28GHz auctions raised $2.7 billion, led by top bidders AT&T, T-Mobile, and Verizon, with large cable companies and smaller regional carriers participating to lesser extents.

Verizon led the latest bids, winning 4,940 licenses, followed by AT&T (3,267 licenses), Dish Network (2,651) and T-Mobile (2,384). Collectively, the recent auctions have opened nearly 5GHz of additional millimeter wave spectrum for 5G use, with the latest round adding 3.4GHz in total across three bands. FCC chairman Ajit Pai notes that the quantity of auctioned spectrum now eclipses that “used for terrestrial mobile broadband by all wireless service providers in the United States combined.”

Spectrum has been described as the “mother’s milk of wireless technology,” with each new block of spectrum similar to adding another set of tuning frequencies to a car radio’s dial. Since cellular devices can transmit and receive data across multiple frequencies — think radio stations — at once, download and upload speeds can get dramatically faster if big blocks are made available. U.S. carriers have made multi-billion-dollar bets on these newly available millimeter wave frequencies as the next big pipes for wireless data transmission.

The FCC plans to start bids later this year in two separate mid band auctions, with a block of 3.5GHz spectrum beginning the process on June 25 and 3.7GHz C-band spectrum on December 8. While the raw quantity of spectrum being offered in these frequencies won’t match the millimeter wave allocations, they’ll enable U.S. carriers to extend the combined distance and speed of their 5G networks and aid in harmonizing with Asian and European 5G deployments that have focused on similar frequencies.