This book provides a novel method based on advantages of mobility model of Low Earth Orbit Mobile Satellite System LEO MSS which allows the evaluation of instant of subsequent handover of a MS even if its location is unknown. This method is then utilized to propose two prioritized handover schemes, Pseudo Last Useful Instant PLUI strategy and Dynamic Channel Reservation DCR-like scheme based respectively on LUI and DCR schemes, previously proposed in literature.  The authors also approach a different aspect of handover problem: calls with short durations dropped due to a handover failure. We propose a decision system based on fuzzy logic Rescuing System that allows the rescue of calls with short durations facing a premature at the expense of those lasting for long durations.