The advent of ubiquitous computing and the proliferation of portable c- puting devices have raised the importance of mobile and wireless networking. Recently, there has been a tremendous interest in broadband wireless access systems, including wireless local area networks (WLANs), broadband wireless access,andwirelesspersonalareanetworks(WPANs). Thisdomainisasubject ofhugeresearchandmanystandardizationactivitiesareundertakenthroughout the world. Based on the most recent developments in the ?eld of wireless techno- gies related to WLAN, WPAN, wireless sensor networks (WSN) and wireless metropolitan area network (WMAN), this book gives a detailed description of the widespread or recently used standards like Wi-Fi, Bluetooth, ZigBee, and WiMAX. Our book aims at regrouping in a single volume up-to-date inf- mation related to these different technologies, which can be used separately or combined to provide speci?c applications. The emergence of these very promising systems is mainly due togreat technological progress in the ?eld of wireless communication protocols; they will also make it possible to offer a broad range of new applications in both civilian and military domains. The inherent characteristics of these systems imply new challenges. Our book deals with several relevant topics related to the evolution of these spontaneous, se- organized, or cellular-based networks. Through its seven chapters, we tackle critical problems such as the design of medium access control (MAC) and ro- ing protocols, the support of the quality of service, the security mechanisms, the mobility/roaming aspects, etc.