Evolution of Sharing in 6 GHz

It has been more than three years since the U.S. Federal Communications Commission (FCC) issued the Report and Order (R&O) and Further Notice of Proposed Rulemaking (FNPRM) for the 6 GHz (5.925-7.125 GHz) band on April 24, 2020, permitting unlicensed use on a shared basis [1]. Since then, many countries have followed the U.S. lead in allowing unlicensed use over the entire 1.2 GHz band, while others have permitted unlicensed use in the lower half, 5.925-6.425 GHz, while evaluating options for the upper 6 GHz, 6.425-7.125 GHz [2]. Agenda item 1.2 on the International Telecommunication Union's (ITU) World Radio-communication Conference (WRC-23), to be held in November 2023, will discuss allocating the upper 6 GHz for International Mobile Telecommunications (IMT) applications, with a possibility of a primary allocation for mobile [3]. Nations, such as the U.S., who have already allocated the entire band for unlicensed use will recommend “No change” [4], since there is an expanding ecosystem of Wi-Fi 6E devices that operate in the full band. Furthermore, on September 28, 2023, the FCC announced a Second R&O and FNPRM permitting the use of a new class of devices, Very Lower Power (VLP), in 6 GHz [5] and the U.K.'s regulatory agency Of com's consultation exploring a new, hybrid-sharing mechanism, closed on September 15, 2023 [6], indicating that sharing in the band could be extended beyond current rules. However, there continue to be concerns from incumbents that expanding unlicensed use in the 6 GHz band will lead to harmful interference. All of these recent developments lead to new research problems related to spectrum sharing in 6 GHz.