AT&T says SpaceX, T-Mobile satellite-Earth connectivity plans could cause ‘harmful interference’

AT&T believes SpaceX and T-Mobile US have not sufficiently tested their “supplemental coverage from space” broadband system and that the system proposed presents a “risk of harmful interference” to terrestrial mobile services. “SpaceX and T-Mobile’s applications fall far short of meeting the threshold for waiver and cannot be granted in their current state,” AT&T said in a filing to the FCC.  

The comment was sent in response to a consultation about a request by SpaceX to modify its licence so that it could add direct-to-mobile communications capabilities on up to 7,500 Gen Starlink Leo satellites. Specifically, SpaceX wants to operate in the mobile-satellite service using the 1910-1915 MHz (Earth to space) and 1990-1995 MHz (space to Earth) bands. It also wants to support these operations with feeder links using frequencies in the Ka and E bands, for gateway operations. This would include using Ka-band frequencies for gateway stations used to support the company’s Ku-band fixed satellite service links (to end-users). 

SpaceX and T-Mobile US signed a deal in August 2022 to unroll a system that would bring near complete broadband coverage to the US, supplementing satellite connectivity in areas out of reach from traditional mobile signals. The system would harness SpaceX’s Starlink service and its constellation of Leo, and T-Mobile’s LTE and 5G networks. 

AT&T has inked its own long-term spectrum leasing agreement with AST SpaceMobile, also with the aim of providing space-based broadband coverage. To achieve coverage, AST will lease some of AT&T’s 850 MHz A and B block spectrum as well as certain lower 700 MHz B and C block spectrum. AT&T said in the filing that it will provide the necessary documentation, lacking in the application by SpaceX, to demonstrate that its plans with AAST will not cause interference to any authorized terrestrial system. 

The Space Bureau and Wireless Telecommunications Bureau opened about SpaceX’s request on 18 April 2023. AT&T noted it is a licensee of adjacent spectrum and that it therefore “has an interest in this proceeding.”