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Small satellite TT&C allocations below 1 GHz: outcome of ITU WRC-19

von der Ohe, Martin

FG Raumfahrttechnik

As hundreds of new small satellites are being launched each year, the RF spectrum for satellite communication becomes increasingly occupied. The International Telecommunication Union recognized this problem at World Radiocommunication Conference 2015 (WRC-15) and invited study groups to investigate the utilization of frequency allocations. The studies followed a three-step approach: first, the TT&C spectrum requirements of small satellites, being a new class of satellites, were assessed. Second, the utilization of existing TT&C frequency allocations and their potential to incorporate the future number of satellites was studied. Third, the study groups investigated new potential TT&C frequency allocations in the frequency ranges 150.05–174 MHz and 400.15–420 MHz. The studies were completed for WRC-19. This paper presents the results of the study groups. A study of the spectrum requirements of small satellites has been completed. The required spectrum for TT&C was estimated to be less than 2.5 MHz for downlink and less than 1 MHz for uplink. Consequently, the study groups conducted sharing studies in various bands which yield that no new allocations are suitable for small satellite TT&C on a co-channel sharing basis. However, regulatory measures are proposed that in the study groups’ view will satisfy the small satellite developers’ needs. The paper will summarize the regulatory measures taken after WRC-19 along with a personal appraisal of the author.