Wireless networks are facing growing demand for high capacity, better coverage, support of new applications and broad range of services. In this book, the authors first present an overview of beamforming antennas and millimeter wave communications followed by a discussion on the challenges and issues facing MAC and multi-hop routing in the wireless networks with beamforming antennas. Then, they discuss various MAC and routing prools that are specifically designed to address those issues and exploit the benefits of millimeter wave and beamforming antennas. Authors also present a framework to provide Quality of Service (QoS) in contention-based wireless networks with beamforming antennas. Finally, the book is concluded with a discussion on open research topics for future generation WLAN systems.