karmano hy api boddhavyam boddhavyam ca vikarmanah akarmanas ca boddhavyam gahana karmano gatih The intricacies of action are very hard to understand. Therefore one should know properly what action is, what forbidden action is, and what inaction is. The Bhagvad Gita (4.17) This book is the outcome of the research contribution of Hanane Fathi towards her Ph.D. studies jointly with Shyam S. Chakraborty and Ramjee Prasad as - pervisors. To the best of the authors' knowledge, this is a ?rst book on voice over Internet protocol (VoIP) covering such a broad perspective as illustrated in Figure P.1. This book is a new, forward-looking resource that explores the present and future trends of VoIP in the wireless heterogeneous networks. This book also provides the discovery path that these network infrastructures are following from a perspective of synergies with the present systems and how they will pave the way for future systems. This book is intended for everyone in the ?eld of wireless information and multimedia communications. It provides different levels of material suitable for managers, researchers, network providers, and graduate students.
We hope that all readers will experience the bene?ts and power of this knowledge. We have tried our best to make each chapter comprehensive and we cannot claim that this book is without errors. Any remarks to improve the text and correct the errors would be highly appreciated.

This book reveals the state-of-the-art in wireless ad-hoc networking. It addresses many complex and open problems for researchers in the field of ad hoc networks. It further discusses some of the key research topics that are expected to promote and accelerate the commercial application of these networks (e.g., MAC, routing, QoS, optimization issues, service discovery, traffic models, mobility, handovers, security). It also presents "killer applications".


asakta-buddhih sarvatra . jitatma vigata-sprhah . . . . naiskarmya-siddhim paramam . sannyasenadhigacchati Detached by spiritual intelligence from everything controlling the mind, without material desires, one attains the paramount perfection in cessation of re- tions by renunciation. The Bhagvad Gita (18.49) Compared to traditional carrier-based, Ultra-Wide Band (UWB), or carrier-less, systems implement new paradigms in terms of signal generation and reception. Thus, designing an UWB communication system requires the understanding of how excess bandwidth and very low transmitted powers can be used jointly to provide a reliable radio link. UWB offers systems transceiver potential for very simple implementations. Comparison between UWB and traditional narrow-band systems highlights the following features: Large bandwidth enables very fine time-space resolution for accurate lo- tion of the UWB nodes and for distributing network time stamps. Very short pulses are effectively counter-fighting the channel effect in very dense multipath environments. Data rate (number of pulses transmitted per bit) can be traded with power emission control and distance coverage. Very low power density leads to low probability of signal detection and adds security for all the layers of the communication stack. Very low power density is obtained through radio regulation emission masks; UWB systems are suitable for coexistence with already deployed narrow-band systems.