by TAMPA, Fla. — Plans to use part of the Ku band for 5G networks in the United States could disrupt Starlink broadband services even more than SpaceX previously estimated, the company said Oct. 4 as it released interference analysis from third party.
SpaceX said the analysis validates its internal study in June, when it warned that Starlink would be useless to most Americans if a high-power 5G mobile service was allowed to operate on 12 GHz band frequencies across the United States.
The analysis by engineering consulting firm Savid also shows that “SpaceX may have underestimated the potential for interference and potential damage to Starlink services,” SpaceX’s senior director of satellite policy, David Goldman, wrote to the Federal Communications Commission.
Starlink uses 12 GHz spectrum to connect its non-geostationary orbit (NGSO) satellites to user terminals.
Satellite broadcaster Dish Network uses frequencies in the band to provide linear television programming and is seeking permission from the FCC to upgrade its license to provide 5G terrestrial services.
According to Dish and RS Access, a spectrum holding company that is also seeking to adapt its license in the band to operate a terrestrial network, their plans can coexist with other users of the band.
RS Access, backed by billionaire Michael Dell, commissioned studies from engineering firm RKF Engineering Solutions to show how such a network would affect less than 1% of terminals connected to non-geostationary orbit (NGSO) satellites.
Dish and RS Access point to mitigation techniques they say are readily available for affected terminals, though it’s unclear how quickly they could deploy their proposed networks after FCC approval.
“SpaceX’s latest submission follows the company’s familiar pattern: making exaggerated claims about snagging 500 MHz of 5G-ready spectrum,” Dish executive vice president of external and legislative affairs Jeff Blum said via email.
“Unsurprisingly, yesterday’s filing by SpaceX includes a flawed technical analysis that purports – unsuccessfully – to contradict the multiple studies submitted to the FCC by the best experts in the field concluding that coexistence is eminently possible.”
SpaceX says the interference studies drawn from Dish and RS Access are inaccurate and based on incorrect assumptions about its network.
In the letter to the FCC, Goldman said its latest analysis also addresses a claim by RS Access that “only a third party could really analyze” how the proposed network would interfere with NGSO satellites.
Broadband service provider NGSO OneWeb also uses the band to connect end users. OneWeb submitted his own study to the FCC in July to show how spectrum use for terrestrial 5G will seriously disrupt NGSO broadband across the United States.
DirecTV, a rival satellite broadcaster majority-owned by US telecoms giant AT&T, said its TV customers they also face great disruption if the FCC approves the plan. A study DirecTV filed with the FCC in July that supported its warning was also conducted by Savid.
“The record is conclusive that unavoidable interference caused by high-powered transmitters in the 12 GHz band would be devastating to millions of American consumers who depend on satellite service in the band,” Goldman wrote to the FCC.
“SAVID’s technical conclusions validate the SpaceX study and reveal how RKF is seriously underestimating interference with Starlink customers.”
Third party findings
While Savid found SpaceX’s power assumption in the June study to be conservative in Dish’s favor by a factor of four, SpaceX’s outside analyst said the report commissioned by RS Access underestimated by a factor of 40.
Plate had also criticized how SpaceX’s earlier study extrapolated data from the Las Vegas area to simulate a nationwide interference effect;
According to Savid, the Las Vegas market is representative of other major areas in the US where Starlink services are deployed.
SpaceX’s Goldman said Dish had also argued that SpaceX should not assume that Dish “will actually deploy enough base stations to meet its manufacturing requirements.”
But he said Savid found that even Dish’s own base station assumptions would result in “degraded service suggesting little difference in results” and “many multiples that would still make the band unusable for existing satellite services”.
He said RKF’s assumptions that Dish’s network would only operate at low power levels were also found to be inconsistent with status report Plate issued in Julyshowing its progress in deploying 5G in other spectrum bands.
In the interference analysis released by SpaceX on Oct. 4, Savid said Dish’s 5G deployment practice to date “clearly indicates” that Dish’s land mobile systems “will tend to maximize” base station transmission power.
Savid also noted that the use of statistical methods in any of the analyzes submitted to the FCC “washes out the actual interference that a Starlink user will see from high-power mobile ground base stations operating nearby,” Goldman added.
He called on the FCC to quickly reject terrestrial 5G plans.
