Report Urges Wide Spectrum Sharing for 5G Below 6-GHz

U.S. 5G spectrum has to focus on the sub-6-GHz ranges if U.S. mobile carriers are to take advantage of global supply chains organized around products for the sub-6-GHz spectrum, an advisory committee to the U.S. Secretary of Defense says.

The report, co-written by vice president of wireless at Google, Milo Medin, and tech venture capitalist Gilman Louie, makes the point that such a development hinges on use of spectrum sharing, as has been pioneered by Citizens Broadband Radio Service.  

The recommendations are sweeping, arguing that the Federal Communications Commission and Department of Defense “must flip their prioritization from mmWave to sub-6 GHz spectrum for 5G.”

That inevitably means “DoD must prepare itself for that future operating environment by focusing on co-existing, if not explicitly sharing, with civil 5G operations in those bands of spectrum.” That includes all assets in the spectrum ranges below 6 GHz, including about 500 MHz of spectrum used by DoD in the 4-GHz range already.

Focus should be on the 3.2-3.6 GHz and 4.8-5.0 GHz ranges.

The report also recommends the “NTIA, FCC and Department of State should advocate the reallocation of the C-band satellite spectrum to IMT-2000 5G use at the World Radio Conference later this year (WRC-19), and take measures to adopt sharing in all 500 MHz of the band in the United States on an accelerated basis for fixed operations.”

Such spectrum sharing would allow U.S. defense interests to take advantage of global supply chains expected to be most robust for equipment and infrastructure in spectrum below 6 GHz.

A shift of former C-band satellite spectrum in the 4-GHz region might also be more important than some believe, if global 5G supply chains and service providers build product volume in the 3-GHz to 4-GHz frequency ranges.

“In the near term, 3 and 4 GHz spectrum will likely serve as the dominant global bands that drive volume in infrastructure and device deployments,” the authors argue.

And that provides some idea of the importance of how the Federal Communications Commission sets policy for refarming as much as 500 MHz of C-band spectrum in the United States, which is in the crucial band the authors say will be an area of robust supply chain focus.

The U.S. military, the authors note, will have to operate globally in sub-6-GHz spectrum internationally. So “DoD must prepare to operate in a sub-6 5G ecosystem, which will require a shift in strategy and a consideration of where DoD is willing to share bandwidth in the sub-6 realm.”