Interference protection of radio astronomy services using cognitive radio spectrum sharing models

Radio astronomical services (RASs) use the radio spectrum to observe cosmic sources (Srcs). They are protected from interference by establishing national radio quiet zones (NRQZs). However, NRQZs do not prevent interference from satellite networks with intersatellite links. This causes impairment in directly observing cosmic sources. Therefore, current knowledge of the universe is inaccurate being obtained from filtered signals. However, accurate knowledge can be obtained in RASs via a pristine observation of Srcs using cognitive radio (CR) technology. This paper, examines the suitability of CR spectrum sharing models for interference protection of RASs. It proposes an interference protection framework and investigates the satellite´s transmit opportunities using visibility duration data of RASs. It then examines the end to end delay of the satellite network when the framework is used. Simulation is conducted for a constellation of low earth orbit satellites and the obtained results show that transmit opportunities exist for intersatellite links when the interweave spectrum sharing model is used without causing any interference to RASs or significantly increasing the end to end delay.