(AP) — The U.S. government will hold a massive auction to bolster 5G service , the next generation of mobile networks, and plans to spend $20 billion to expand broadband access in rural areas.

5G will mean faster wireless speeds and has implications for technologies like self-driving cars and augmented reality. The rollout started last week in the U.S. and South Korea but will take years.

The Federal Communications Commission said Friday that it would hold the largest auction in U.S. history to boost wireless companies’ networks.

“Our goal is to maintain American leadership in 5G technology,” said FCC Chairman Ajit Pai Friday on a call with reporters.

The U.S. is jockeying for position with China over 5G. It has effectively banned Chinese telecom equipment maker Huawei from most U.S. networks due to concerns that it might enable Chinese government spying, which the Huawei denies. The U.S. has pushed its allies to do the same, with mixed results . Huawei is the world’s largest maker of such equipment.

FCC Commissioner Jessica Rosenworcel, a Democrat, criticized the agency’s approach to 5G Friday. She said the U.S. has not auctioned off “midband” spectrum that is better suited to serve rural areas because of how far it can carry signals, and that the Trump administration’s actions on 5G have “set us back.” She cited tariffs on telecom equipment that have raised costs and said the administration has been “alienating allies” on the 5G security issue.

The FCC also said Friday that it will be “repurposing” funds from existing subsidy programs to provide $20.4 billion, over a decade, to internet providers, with the goal of connecting up to 4 million rural homes and small businesses to high-speed internet.

The agency spent $34.5 billion on rural-broadband network subsidy programs from 2010 to 2017, according to the Government Accountability Office.

It’s more expensive for telecom companies to serve spread-out rural areas than cities and suburbs, so the government provides grants to incentivize them to build internet networks in rural parts of the country. As of the end of 2016, there are 24 million Americans without access to high-speed internet by the FCC’s count.

Pai said Friday that he hopes to start the auction in December and the fund proceeding later this year.

The agency said he will talk about these 5G initiatives at a White House event with President Donald Trump later Friday.