The Security of Wireless Communications Networks has become a fundamental concern to both the developing and the developed nations. Because the communication mediums- the airwaves - of wireless networks are openly exposed to intruders, the risks and threats associated with wireless networks nowadays have taken a new dimension. This new text for introductory courses in wireless comms challenges addresses the various vulnerability issues associated with wireless comms networks from a top-down approach. The book is organized into four sections: the first section provides the big picture - the introductory background of wireless comms; the second section develops the fundamental concepts and gives an overview of wireless comms which includes the wireless age, wireless comms goals, advancements in wireless comms and the impacts on telecommunications industries. The third section presents the diversity techniques employed in wireless comms while the fourth sections elaborately discusses the various security threats with wireless comms & their control-mechanisms. The book is a must-read for teachers, scholars and network managers as it comprehensively addresses network vulnerabilities.