SpaceX SCS Power Levels Under Fire

Critics of aspects of SpaceX's direct-to-device service continue pressing the FCC. In a docket 23-135 filing Tuesday, AT&T said it supports prompt approval of SpaceX secondary supplemental coverage from space (SCS) service that meets FCC power limits, but opposes the elective power boost that would increase its throughput at the expense of AT&T's primary incumbent terrestrial PCS C-block network. "Secondary service cannot degrade primary service, especially a primary service with the myriad established public interest benefits of terrestrial mobile," AT&T said. An AT&T analysis of how the elective power boost would affect its Tucson, Arizona, PCS C-block network predicts "a devastating" 18% degradation in average downlink throughput due to SpaceX's elective power increase, and in some areas on the network's edge coverage might be out altogether. Verizon challenged T-Mobile's throughput calculations that back granting a waiver of FCC out-of-bound emissions (OOBE) limits (see 2408230013), saying they weren't applicable to SCS service. Omnispace said the 1990-1995 MHz block is allocated for mobile satellite service uplink use both in the U.S. and internationally, and SpaceX has yet to meaningfully address concerns about it using that band for downlinks. It said SpaceX's rebuttal "is more ad hominem than rigorous." The FCC's aggregate OOBE limits in its Part 25 rules don't need relaxing for SCS service, AST SpaceMobile CEO Abel Avellan told Commissioners Geoffrey Starks, Anna Gomez and Nathan Simington, said a filing posted Tuesday in docket 20-32. Avellan said AST and numerous mobile network operators (MNO) believe that OOBE levels need to be maintained to protect incumbents' use of spectrum. He said AST will meet aggregate OOBE limits in low- and mid-band spectrum. AST said it has agreements and understandings with more than 45 MNOs with roughly 2.8 billion subscribers. It said its SCS service has a 120 Mbps peak data rate.