US operators appeared set to get an infusion of much-needed mid-band spectrum, as Federal Communications Commission (FCC) chairman Ajit Pai teed up a vote on a plan to auction unused portions of the 2.5GHz band.

If approved at the FCC’s next regular meeting on 10 July, the stage would be set for an auction in 2020.

Pai’s proposal would rewrite existing rules to allow commercial 5G deployments and other flexible uses in a 140MHz portion of the band, which was previously allocated for educational broadband services. Unused spectrum in the band would be offered first to tribal nations before being put up for auction.

Senior FCC officials told journalists fallow portions of the band cover approximately half of the geographic US, particularly in rural areas west of the Mississippi River. Licences would be offered in 100MHz and 16.5MHz blocks.

Existing licensees would be granted more flexibility, but FCC officials said the move would not directly impact lease arrangements, for example those held by Sprint.

In a blog post, Pai noted previously envisioned uses for the band largely failed to materialise, adding an auction offers a “prime opportunity” to bring mid-band spectrum to market.

The move could mark the FCC’s first auction of mid-band spectrum for 5G, if other efforts to bring 3.5GHz and C-Band spectrum to the block are delayed.

Mid-band spectrum delivers slower speeds than the mmWave spectrum hitherto favoured by the FCC, but offers broader coverage and better in-building penetration. Operators in the country flagged it as a key part of their plans for widespread 5G coverage, but warned a lack of available airwaves could hamper their efforts.