The US Federal Communications Commission (FCC) said Friday it had opened bidding in its latest mid-band spectrum auction to boost next generation 5G wireless 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 Chairwoman Jessica Rosenworcel said Friday “we all know there are gaps in 5G coverage, especially in rural America, and this auction is a unique opportunity to fill them in.”

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

The 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 Inc 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 US wireless companies won $78 billion in bids in an FCC C-Band spectrum auction.

Verizon Communications ultimately paid $52 billion for 3,511 licenses and to quickly 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 the 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.

The agencies said they will work cooperatively to resolve spectrum policy issues and are holding formal, regular meetings to conduct joint spectrum planning.