US Federal Communications Commission (FCC) said it opened bidding in its latest mid-band spectrum auction to boost 5G services.

The new round will auction about 8,000 county-based licenses in the 2.5 GHz spectrum band in mostly rural parts of the United States, FCC said in a news statement.

FCC Chairwoman Jessica Rosenworcel said: “we know there are gaps in 5G coverage, especially in rural America, and this auction is a unique opportunity to fill them in.”

Auction 108 makes available 8,017 county-based overlay licenses in the 2.5 GHz band, FCC said.

Congress last year approved $42.5 billion for Commerce Department grants to expand broadband deployment in places like rural areas without access to high-speed service.

FCC has been auctioning spectrum in recent years to help address the rising demand for wireless connectivity as the number of internet-connected devices rises sharply.

In January, AT&T led bidders in the 3.45 GHz mid-band spectrum auction, winning $9.1 billion, while T-Mobile won $2.9 billion and Dish won $7.3 billion.

Last year, the three largest U.S. wireless companies won $78 billion in bids in an FCC C-Band spectrum auction.

Verizon Communications paid $52 billion for 3,511 licenses and to clear its use, while AT&T won $23.4 billion in licenses and T-Mobile won $9.3 billion.

FCC Commissioner Brendan Carr in March said FCC should move to expand spectrum use and consider auctioning other spectrum including looking at the lower 3 GHz band and several additional spectrum bands.

In February, the FCC and National Telecommunications and Information Administration (NTIA) vowed to improve coordination on spectrum management after a 5G aviation dispute threatened flights earlier this year.