Interference-to-Noise (I/N) Compliance Validation of Telesat, OneWeb and SpaceX’s 2020 Ka-Band NGSO FCC Processing Round Applications
In March 2020, the Federal Communications Commission (FCC) initiated a processing round calling for additional applications for non-geostationary satellite orbit (NGSO) fixed-satellite service (FSS) operations in Ka-band. Satellite operators submitted descriptions of their planned constellations and provided proof that their systems would comply with interference limits set by the FCC and the International Telecommunications Union (ITU). All ten companies in this processing round provided power flux density (PFD) compliance calculations. Three companies optionally submitted interference-to-noise (I/N) compliance calculations: Telesat, SpaceX, and OneWeb. This paper documents a standardized process to calculate I/N and analyzes I/N compliance for these three companies. I/N analyses consist of static analyses, which considers the worst-case interference scenario, and dynamic analyses, which computes the interference over time. In ITU-R F.1495, the long-term I/N limits are defined to not exceed -10 dB for greater than 20% of the year, requiring dynamic analyses to prove compliance. Static I/N analysis is calculated in this paper, which allows for verification of compliance with the long-term dynamic -10 dB limit in the worst-case scenario. Dynamic I/N analyses are required to verify compliance fully and will be addressed in future work. This study shows that Telesat, OneWeb, and all SpaceX operations at a minimum elevation angle of 25° complied with I/N long-term dynamic limits of -10 dB, but SpaceX operations at altitudes of 360 km and 373 km with a minimum elevation angle of 5° exceeded I/N limits in the worst-case scenario.