A large portion of the network capacity of an ad hoc network can be wasted by the medium access mechanisms of omni-directional antennas. To overcome this problem, researchers propose the use of directional or adaptive antennas that largely reduce radio interference, improving the utilization of wireless medium and the resulting network throughput. Enhancing the Performance of Ad Hoc Wireless Networks with Smart Antennas discusses these issues and challenges. Following an introduction to ad hoc networks, it presents an overview of basic Media Access Control (MAC) and routing protocols in ad hoc networks with omni-directional antennas. The book then focuses on the use of smart antennas in ad hoc networks and reviews the strategies used in designing MAC and routing protocols for improved medium utilization and improved routing performance with effective load balancing. Finally, it analyzes the design issues related to priority based quality-of-service (QoS) routing protocols, illustrating the potential of these antennas in comparison to omni directional antennas. The book concludes with an examination of open problems and challenges for ad hoc networks.