Random SALOHA and CSMA protocols that are used to access MAC in ad hoc networks are very small compared to the multiple and spontaneous use of the transmission channel. So they have low immunity to the problems of packet collisions. Indeed, the transmission time is the critical factor in the operation of such networks.

The simulations demonstrate the positive impact of erasure codes on the throughput of the transmission in ad hoc networks. However, the network still suffers from the intermittency and volatility of its efficiency throughout its operation, and it switches quickly to...

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....

This book addresses quantum communications in the light of new technological developments on photonic crystals and their potential applications in systems. Mathematical and physical aspects of quantum optical fibers and photonic crystals are considered in order to optimize the quantum transmissions. Two fundamentals elements are treated, reconfigurable optical add-drop multiplexer and WDM.