Power Flux Density (PFD) Compliance Validation of FCC's Ka-band NGSO Processing Round Participants

In March 2020, the Federal Communications Commission (FCC) initiated a processing round for additional applications and petitions for non-geostationary orbit (NGSO) fixed-satellite services (FSS) operations in the 10.7 – 12.7 GHz, 12.75–13.25 GHz, 13.8–14.5 GHz, 17.7–18.6 GHz, 18.8–20.2 GHz, and 27.5–30 GHz bands. As part of the application process, the FCC assesses each system's compliance with the current FCC and International Telecommunications Union (ITU) rules which include, but are not limited to, power flux density (PFD) limits. These specific limits ensure that the power emitted from an FSS system does not cause harmful interference into terrestrial fixed service (FS) systems. This study analyzes the PFD of the ten communication systems (EOS Defense Systems, Kepler Communications, Kuiper, Mangata, New Spectrum Satellite, O3b, OneWeb, SpaceX, Telesat, and Viasat) that participated in the FCC's March 2020 Processing Round, in order to validate the applicant's PFD compliance. The methodology consists of obtaining the relevant data provided in each application, analyzing the anticipated PFD and the specific PFD limits according to Article 21 of the ITU's Radio Regulations, and then comparing the results to the submitted PFD values. Of the ten applications, four of the satellite operators' compliance calculations were verified to within 0.1 dB over all operational angles and two were verified within 0.1 dB for a subset of all operational angles. Of the remaining four applications, discrepancies were identified between the values presented in the applications and the values computed in this work. Discrepancies for two of the systems can be explained by the different operational strategies that the applicants propose to employ. For the remaining three systems, discrepancies seem to stem from the use of parameters that differ from required ITU and/or FCC inputs for PFD assessment. The validation results and discrepancies are discussed in detail with the goal of providing the industry with insight into the potential harmful interference from the proposed new or modified NGSO communications constellations into FS systems and assisting the FCC in evaluating the permissibility of these recent applications.