Still, it’s just the beginning of the Federal Communications Commission’s 101st spectrum auction, which likely will run for several more weeks and bring increasingly higher bids. The agency is selling more than 3,000 licenses to broadcast in the 28 GHz band, generally best for new 5G wireless networks coming online over the next few years that will be anywhere from 10 to 40 times faster than current 4G LTE networks.

Following earlier auctions, Verizon already owns about half the licenses in the 28 GHz band, including in many prime urban locations, dampening bidding interest. The carrier is already testing a speedy home Internet service using the band in parts of four cities.

For the latest auction, the agency qualified 40 potential bidders, including entities representing all of the four largest carriers, AT&T, Verizon, Sprint (S) and T-Mobile. Some of the licenses covering more rural areas could be bought by much smaller companies or even individuals, as happened at some past FCC auctions. Still, analysts don’t expect that the current auction will raise anywhere close to the $20 billion paid for licenses in last year’s 600 MHz auction.

With so much of the spectrum in the 28 GHz band already taken, many bidders may be more active at the next FCC auction, for licenses in the 24 GHz band, which begins after the current series ends. Then next year, the FCC plans to hold at least three more auctions covering licenses in the 37 GHz, 39 GHz, and 49 GHz bands.

All five bands are considered extremely high wavelength bands compared to those used for mobile phones today, such as the 700 MHz and 2.5 GHz bands. Sometimes called the millimeter wave bands, the high frequency bands have signals that can carry a lot more data but don’t travel as far and have trouble penetrating obstacles like buildings and trees. No mobile phones can yet operate in the bands, but Intel and Qualcomm have announced that compatible modems and 5G phones should start arriving next year, with Apple’s (AAPL) first 5G iPhone rumored for 2020.

The licenses that Verizon now owns were among those auctioned off over the past two decades, mostly for the then-burgeoning startup sector of communications companies that planned to use the airwaves to set up private, microwave-based networks. Most went bankrupt around the time the Internet bubble burst and the licenses have either bounced around among investors or been reclaimed and canceled by the FCC.

Last year, Verizon paid $3 billion to acquire Straight Path Communications, whose former parent, IDT, acquired its licenses from bankrupt wireless pioneer Winstar in 2001. Other licenses Verizon has rights to use were acquired by Carl Icahn from XO’s bankruptcy in 2002. The spectrum was first sold off back in the FCC’s 17th auction in 1998.

But recently, technological advances have allowed carriers to use millimeter wave bands for more typical mobile and home Internet services. Verizon (VZ) and AT&T (T) have been at the forefront of trialing 5G services in the millimeter bands. Verizon’s initial 5G broadband Internet service being offered in parts of four cities so far relies on such high frequency signals, for example. But T-Mobile (TMUS) and carriers in other parts of the world have focused more on using (or reusing) lower frequencies for 5G.

(This story was updated on Nov. 14 with details of the second round of bidding.)