HW081: What to Do About the 6GHz Upper Band Split

In this solo episode of Heavy Wireless, Keith Parsons breaks down the regulatory fragmentation occurring in the 6 GHz spectrum band (5925–7125 MHz), which represents the largest single chunk of spectrum ever allocated to Wi-Fi. The core issue is that while the lower half of the band (roughly 5925–6425 MHz) has been broadly settled for Wi-Fi use across the US, UK, EU, and many other regions, the upper half (6425–7125 MHz) is now the subject of a significant regulatory fight between Wi-Fi proponents and mobile/cellular carriers.

In the United States, the FCC opened the entire 1200 MHz band for unlicensed use in 2020. Low Power Indoor (LPI) mode works across the full band without coordination requirements, while Standard Power mode enables outdoor and higher-power use but requires AFC (Automatic Frequency Coordination), where an AP queries a database to confirm channel availability. Parsons describes the US situation as the most favorable for Wi-Fi designers, with the full band available.

The UK's regulator Ofcom has taken a middle-ground approach for the upper band, splitting it into two priority zones: the bottom 160 MHz of the upper band is designated as Wi-Fi priority, while the top 550 MHz is mobile priority — though Wi-Fi can access it via AFC if mobile is not actively using it. This makes AFC a mandatory requirement for upper-band access in the UK, not an optional feature.

The EU's Radio Spectrum Policy Group (RSPG) has issued opinions recommending mobile priority across most of the upper 6 GHz band, with only limited Wi-Fi access permitted. Parsons attributes this to Europe's mobile carrier lobby carrying more weight in spectrum policy decisions, partly influenced by international (ITU) processes that leaned toward mobile in that frequency range.

Parsons also addresses the practical consequences for hardware and network design. Access points use regulatory domain settings to determine legal channels per country, meaning the same hardware may operate very differently — or be legally restricted — depending on where it's deployed. He warns against assuming vendor data sheets reflect real-world channel availability in all regions. He also cautions against over-relying on 320 MHz channels, noting that even in the US only three non-overlapping 320 MHz channels exist in the full 1200 MHz band, and in the EU or UK such wide channels are essentially impractical. His design guidance: US designers can use the full band with confidence; UK designers should build flexibility into upper-band plans; EU designers should not anchor any designs on the upper 6 GHz band at all.