Sogand Karbalaei Zadeh - Islamic Azad University, Science and Research Branch
Seyed Mohsen Sajadi - Shahid Beheshti University

The developed communication system is equipped with dual-frequency bands, namely UHFand VHF, enabling seamless communication links with ground stations for the transmissionand reception of data. This system is structured as a constellation of satellites, where eachsatellite independently shares information with others within the network. In instances where asatellite loses connection with the ground station and is outside its direct line of sight, thesatellites within the constellation collaborate by transferring data amongst themselves using theS-band frequency until one of them establishes a connection with the intended ground stations.The selected communication protocol for this system is AX.۲۵, a widely utilized standard innano-satellite communications. AX.۲۵ offers four distinct modes, ensuring robust datatransmission and minimizing the risk of data loss.To facilitate communication for each satellite, dedicated transmitters and receivers areimplemented, tailored to the specific protocol requirements. The AX۲۱۵۰ model is employedfor S-band communication, whereas the AX۱۰۰ model is utilized for UHF and VHF bandcommunications, thereby ensuring a comprehensive and versatile communication infrastructurefor the entire satellite constellation.

CubeSat, Satellite, S-band Antenna, UHF & VHF Band, Communication Protocol