Performance analysis of randomized MAC for satellite telemetry systems

The overwhelming success of the Internet provides scientists new tools to understand our mother nature. Argos is a worldwide satellite system dedicated to Earth observation and environmental research. Argos system has an excellent track record for data collection, processing and dissemination to the scientific and international community and gains popularity steadily. However, when the number of Argos users exceeds certain limit, the transmission success rate is reduced significantly, which results in the severe dead-station problem. To solve the problem, a randomized transmission scheme has been proposed: stations transmit in their designated repetition rate but with a random deviation. We quantify and compare the probabilities of successful reception during a satellite pass and the system capacity for deterministic, independent, and randomized transmissions. How the random level affects the system performance is evaluated and verified by simulation. The results provide important guidelines for future growth and success of the satellite telemetry system and other sensor networks.