PERFORMANCE STUDY OF LOW-EARTH-ORBIT SATELLITE SYSTEMS

Considerable interest has been focusing on the possibility of employin g a large number of low earth orbit (LEO) satellites to provide an ove rall global coverage. However, there has been no performance study of such systems. In this paper we investigate the performance of low eart h orbit-satellite systems in terms of the system capacity, the average number of beam-to-beam handoffs and satellite-to-satellite handoffs, the channel occupancy distribution and the average call drop probabili ty. These performance measures are obtained as a function of: 1) the n etwork constellation, 2) the satellite speed, 3) the cell size, and 4) the average transaction duration. These metrics are exemplified on th e Iridium system. The results derived in this paper provide useful and simple tools for system design as well as for system analysis.