Arguments continue to rage between those in favor of a proposal to change 12 GHz spectrum band rules and those who oppose a rule change. At stake is 500 MHz of mid-band spectrum that could be well suited to supporting 5G service, according to rule change advocates.
The latest arguments come from RKF Engineering, which did a study earlier this year that supported the proposed rule change. That study received sharp criticism from SpaceX, a 12 GHz license holder that opposes the proposed change, and on Monday, RKF sent a letter to the FCC in defense of the study.
In the letter, RKF accuses SpaceX of going “well beyond the bounds of zealous advocacy and professional decorum” and using “’hide-the-ball’ tactics” incorporating “half-truth and zero data” in its critique of the study.
The Proposed 12 GHz Spectrum Rule Change
The 12 GHz spectrum band is currently restricted to one-way use. License holders include SpaceX, AT&T/DirecTV, Dish and other satellite providers, as well as companies that use the spectrum for downstream fixed wireless communications.
Some license holders, including Dish and fixed wireless provider RS Access, want the FCC to allow two-way use of the band. To support that view, RS Access submitted the RKF Engineering study that concluded that two-way use of the band would not interfere with incumbent users to the FCC.
In response to the RS Access filing, SpaceX made its own filing with the FCC that criticized numerous aspects of the RKF Engineering study. The 12-page letter that RKF sent to the FCC on Monday offers a rebuttal to SpaceX’s criticisms.
SpaceX argued that the RKF analysis was based on unrealistic deployment scenarios.
But according to the RKF Engineering filing Monday, SpaceX:
- Misread the RKF study to find harmful interference where none may exist. The RKF study states that without coordination between spectrum users, the probability of an “exceedance” of a certain ITU limit would impact less than 1% of users. “The likelihood of a technically defined exceedance event is different from the likelihood of harmful interference,” RKF argues.
- Ignored the study’s detailed siting discussion and falsely claims the study assumes a 12 GHz 5G buildout will only occur in urban areas.
- Claims that SpaceX Starlink satellite broadband service will provide service to tens of millions more customers than analysts’ long-term most aggressive expectations. RKF references a research note from MoffettNathanson financial analysts in support of this view.
- Says RKF should have assumed more Starlink user terminals, even though that would not have changed the results.
- Blames RKF for using the elevation of Starlink’s partially deployed system but has not revealed what elevation should be used.
- Says RKF used the wrong Starlink antenna heights but refuses to provide the “supposedly correct values.”
- Says RKF should not have used the antenna gain values that SpaceX provided the FCC but doesn’t provide the data that RKF should have used.
RKF said it “cannot tolerate brazen misrepresentation about work we have performed, bad-faith explanations of our assumptions, or allegations casting doubt on our integrity.”
The engineering firm said it stands behind its work and looks forward to “engaging with good faith actors who seek to bring the commission’s 12 GHz rulemaking to a successful conclusion.”
The FCC faces a tough decision on the proposed 12 GHz spectrum rule change and hopefully will be doing a detailed engineering analysis of its own to determine where the truth lies with regard to the accusations flying back and forth between rule change advocates and opponents.
