Development of Space-based IOT terminal for Nanosatellite UiTMSAT-1

Abstract

This paper presents the development of space-based IOT terminal for Store and Forward (S&F) mission of nanosatellite UiTMSAT-1. The function of this ground terminal is to collect data from the sensor and send the data to the satellites over VHF amateur radio frequency band. In this case, the satellite is replaced by dummy S&F payload. To send the data from the terminal to satellite, a concept of communication in an amateur radio network is adapted. In an amateur radio network, the communication is done by a special microprocessor system called Terminal Node Controller (TNC) which implement a special protocol called AX.25 protocol. The hardware involves the development of the terminal are Control and Communication Unit (CCU) and Very High Frequency (VHF) Transceiver. CCU function as a device that collects the data from the sensor and sends the data to the VHF Transceiver, while VHF Transceiver function as a device that does the data processing before sending them to the satellites. The VHF Transceiver is built-in with TNC, AFSK Modulator, and FM transmitter. With the current setting, the total bytes allowed for sending the data packet to the satellite are 175 bytes with speed of 1200 bits per second. The data packet that was successfully received by the dummy S&F payload can be validated by using terminal emulator communication program such as real-term, here the data packet that is received by the dummy S&F payload will display on the real-term display terminal. The transmitting data from the proposed ground terminal that are successfully received by the dummy S&F payload can be seen at terminal emulator program (Real-Term).