................................................................................................................... III ACKNOWLEDGEMENTS............................................................................................IV TABLE OF CONTENTS................................................................................................. V LIST OF FIGURES ....................................

Electronic payment systems for wireless devices need to take into account the limited computational and storage ability of such devices. Micropayment schemes seem well suited to this scenario since they are specifically designed for efficient operation. Most micropayment schemes require a digital signature and therefore users must support public key operations and, furthermore, a public key inf...

Multiple-input multiple-output (MIMO) technology constitutes a breakthrough in the design of wireless communication systems, and is already at the core of several wireless standards. Exploiting multi-path scattering, MIMO techniques deliver significant performance enhancements in terms of data transmission rate and interference reduction. This book is a detailed introduction to the analysis and...

The Subscriber Identity Module (SIM) is conventionally used in wireless communication systems. However, several limitations involving SIM significantly reduce public access in wireless communications. This study examined the feasibility of using public telephone cards in wireless communications. This novel application retains the merits of SIM. Among the relevent issues addressed are location t...

Frequency Hopping Spread Spectrum (FHSS) as a communications technique has also been considered as one of security mechanisms to provide a good level of security against eavesdroppers in wireless sensor networking environment. We claim that the version presently used in wireless sensor communications does not yield a high level of security. In this paper, we develop algorithms to break the FHSS...

Wireless communications have numerous applications in terrestrial and space environments, but for one environment the number of civil wireless applications is small. This is the underwater environment where for wireless communications acoustic waves are used instead of electromagnetic waves. The underwater acoustic channel is a very difficult medium for wireless communications and is subject to...

The ( ) wireless information dispersal scheme (WIDS) is useful for fault-tolerant parallel wireless communications, where it can be used to tolerate up to path (subchannel) failures. This paper constructs a performance model of ( ) WIDS used in wireless communications, and proposes an algorithm to find the optimal set of ( ) with the highest reliability. This algorithm reduces the complexity of...

Wireless communications from air to fresh water are studied here. Our analysis relies on plane wave propagation models. Specifically, the transmission loss and propagation loss of RF waves penetrating into fresh water are calculated for various propagation depths. Even though RF wireless communications are not well suited for seawater due to its high attenuation, our paper illustrates that RF c...