Previous research done in wireless mesh networks, typically assumes omni-directional antennas are used, which has the implication of when two nodes are communicating, all nodes in the vicinity must stay silent. With the use of directional antennas, two nodes can communicate without affecting communications of other nodes in the vicinity. One of the primary objectives of this book is to exploit these opportunities that directional antennas can provide, and translate that into improvements of the performance of the mesh network.