Apple, Google-led group responds to critics of RKF study

A group of companies, including Apple, Facebook and Google, is responding to critics who poked holes in a study by RKF Engineering that showed the 6 GHz band can support sharing without risking harmful interference to incumbents.

Specifically, satellite and fixed wireless companies operating in the 6 GHz band are concerned about potential inference with their own operations, while the parties who enlisted the RKF study (PDF) say there’s a growing unlicensed spectrum crisis that could be alleviated by sharing in the band.

Representatives from Apple, Broadcom, Cisco Systems, Facebook, Google, Hewlett Packard Enterprise, Intel, Microsoft and Qualcomm met with FCC staff members, as well as separately with Commissioner Michael O’Rielly and Commissioner Brendan Carr, to address the comments of the incumbents. The companies are collectively lobbying for more unlicensed spectrum.

In their presentation (PDF) to the FCC, the technology companies pointed to the incumbents’ focus on situations where unlicensed devices will operate in the main beam of a Fixed Services (FS) link, but they say the RKF report demonstrates that such a situation will be extremely rare.

“FS incumbents’ recent complaints about RKF’s report are misplaced,” the group said, insisting that the report’s conclusions remain correct and that commenters mischaracterized it.

RELATED: Fixed wireless coalition takes on Facebook, Google and more over 6 GHz sharing proposal

The Fixed Wireless Communications Coalition (FWCC) filed comments (PDF) last month saying the study was badly flawed and should not be relied upon to allow for an array of unlicensed devices in the 6 GHz band. It argued that the uncontrolled distribution of unlicensed devices, referred to as RLANs, in the numbers and at the power levels RKF studied, will cause widespread harmful interference to fixed microwave receivers. 

The tech companies also responded to concerns raised by Fixed Satellite Service (FSS) incumbents, saying Intelsat/SES failed to address the most important point of the RKF analysis: that unlicensed would not add in a meaningful way to the interference FSS already receives from FS deployments. It also said that Intelsat/SES’s specific criticisms of RKF are incorrect in terms of gain-to-noise temperature value, propagation models and other factors.

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One of the big reasons for the high-tech interest in 6 GHz is proximity. The 5.925-7.125 GHz band is adjacent to current unlicensed U-NII bands, meaning existing technologies designed for the 5 GHz band can be rapidly deployed. The technology manufacturers signing onto the 6 GHz sharing proposal said they are committed to delivering 6 GHz-capable products and services to the market in a timely manner.