This book investigates the performance of point-to-point wireless ad hoc networks. Approaching the design of these networks through the medium access control (MAC) layer, analytical expressions are derived for the outage probability, which is defined as the probability of receiving messages erroneously. Moreover, the impact of various ad hoc network characteristics (such as fading and bounded region) is investigated. Having established an understanding of the behavior of ad hoc networks, we propose MAC layer techniques to improve the performance. Three schemes are proposed: 1) optimization of the sensing threshold in CSMA, 2) enhanced decision making ability of CSMA, and 3) introduction of bandwidth partitioning. Finally, we step into the domain of multiple input multiple output (MIMO) communications. The performance of MIMO networks with no transmitter channel state information (CSIT) is analyzed, and different transmission schemes are proposed to achieve the best usage of transmit antennas. With the addition of CSIT, we consider various interference management schemes, and propose a distributed binary power control scheme that ensures an increase in the sum rate of MIMO networks.