Representatives from Apple, Broadcom, Cisco Systems, Hewlett Packard Enterprise, Facebook, Google, Intel, MediaTek, Microsoft and Qualcomm met with FCC staff last Thursday to make a case for quickly opening up the 6 GHz band for shared unlicensed services to coexist with existing users of the band.
While a group of entities previously lobbied for wider usage of the 6 GHz band, these latest efforts include a study by RKF Engineering Solutions that analyzed sharing between unlicensed operations in the band and existing services. The study, which was submitted to the FCC, found that unlicensed services can coexist with the primary services present in the band, which include satellite, microwave and mobile.
The companies said they believe the need for new unlicensed spectrum is urgent, and they hope that providing a detailed engineering analysis this early in the process—before the FCC issues a Notice of Proposed Rulemaking—will aid in moving the whole process along.
Last August, the FCC released a Notice of Inquiry to study midband frequencies for wireless broadband use. The RKF study notes that in the U.S., the 5.925 to 7.125 GHz band (aka the 6 GHz band) is shared primarily by two services: Fixed Satellite Service (FSS) uplinks and fixed microwave (Fixed Service or FS) links. Portions of the band are also used by Mobile Service (MS) designated for public safety and electronic news gathering applications such as TV Broadcast Auxiliary and Cable Relay Services.
RKF analyzed the potential impact of what it calls unlicensed Radio Local Area Network (RLAN) devices on existing 6 GHz FSS, FS and MS operations in the 48 contiguous states and said the results show that a national deployment of RLAN devices in the 6 GHz band, using established RLAN mitigation techniques and regulatory constraints similar to those applied in the neighboring 5 GHz band, will be complementary in spectrum utilization to these primary services and will not cause harmful interference.
Demand for unlicensed spectrum has been growing and that's expected to continue. The group points out that the Wi-Fi Alliance has concluded that between 500 MHz and 1 GHz of additional unlicensed spectrum may be needed by 2020 to support the growth of Wi-Fi.
Of course, the full commission has yet to weigh in on what it will do with the 6 GHz band, but at a Spectrum Management Conference last year, FCC Commissioner Michael O’Rielly noted that there is recognition by proponents that this large swath of spectrum—5925 to 7125 MHz—is not homogenous and different sub-bands may need different sharing mechanisms.
“Commenters seem confident that the Part 15 rules, along with additional co-existence mechanisms, should allow for sharing, but similar to the [mid] bands above, it is necessary to determine exactly what is needed to protect incumbent uses,” he said at the time. “Hopefully, further analysis will ease the minds of those entities that have expressed concerns about the ability to protect existing operations.”