Designing Efficient Communication Subsystems for ۳U CubeSat Satellites: Utilizing UHF and VHF Frequency Bands and Optimal Communication Links and Protocols

This article deals with the design of communication subsystems for ۳U CubeSat satellites. The mission of these satellites includes receiving commands, transmitting data to ground stations, and providing information to users via the Internet of Things (IoT) protocol. The satellite operates in a Low Earth Orbit (LEO) and during operational mission phases, data transfer processes, user terminal communication, and data management are carried out in the satellite's memory. Due to different physical conditions in the communication environment, UHF and VHF frequency bands are used for communications. Suitable communication links are examined based on the mission type, and three main links have been selected. Different antennas are used for each link based on frequency range and environmental conditions. Directional antennas with high efficiency in the UHF frequency band are chosen for the control and command link. Additionally, omnidirectional antennas with high performance in the VHF band are used for data transmission links. Antennas with high scattering characteristics and suitable penetration power in the UHF band are selected for service links. Communication protocols for the Internet of Things have also been studied, and LoRaWAN has been chosen as the best protocol. LoRaWAN has been widely used in the satellite and IoT industries with similar missions and has demonstrated reliability. This appropriate combination of components and technologies allows the satellite to perform its missions with high efficiency and suitable flexibility, using up-to-date and reliable capabilities.

Keywords:

Telecommunication satellites , CubeSats , Communication subsystem , Internet of Things protocol , UHF and VHF bands , S-band