Some of the world's largest tech companies this week urged the Federal Communications Commission to promptly adopt rules that would allow unlicensed users to take advantage of additional spectrum in the 6 GHz band.

A group of 29 companies — including Apple, Google, Microsoft, Facebook, Intel and Qualcomm — submitted comments to the agency Monday in conjunction with the Wireless Internet Service Provider Association.

The FCC this summer announced plans to look into freeing up additional mid-band spectrum to meet increasing demands for wireless connectivity. The agency sought to investigate three mid-range bands in particular — 3.7-4.2 GHz, 5.925-6.425 GHz and 6.425-7.125 GHz — but also asked for additional comments about potential bands between 3.7 and 24 GHz.

The tech companies this week argued that unlicensed access to the 6 GHz band would be essential to easing current wireless congestion and meeting future demands as both public and private entities bolster their use of WiFi in coming years.

The companies added that additional spectrum would be crucial to transitioning to 5G networks and, under new standards, would enable device manufacturers to "deliver orders of magnitude more capacity and efficiency than prior generations of WiFi."

"This will enable a significant market opportunity in the U.S. and Europe, with U.S. industries poised to lead the evolution to 6 GHz on a worldwide basis," the companies wrote.

The testimony also noted that unlicensed bands are crucial for rural broadband access as well as Bluetooth and Internet of Things applications.

"By opening this entire band to unlicensed radio local access network operations, the commission will allow us to bring consumers faster service, lower latency, and more pervasive coverage, and allow the nation to reap the economic and public safety benefits that are associated with unlicensed technologies," the group wrote.

The companies also cautioned the FCC to adopt new spectrum regulations that promote maximum utilization and rapid adoption of the new bands while protecting the current users of those frequencies from interference. They suggested "different combinations of coexistence techniques in different 6 GHz sub-bands."

"Rules that vary across well-defined contiguous portions of the 6 GHz range would be far preferable to imposing strict least-common-denominator limitations across the entire band," they wrote.