Wireless sensor networks (WSNs) have attracted a great deal of research interest during the last few years, with potential applications making them ideal for the development of the envisioned world of ubiquitous and pervasive computing. Energy and computational efficiency constraints are the main key issues when dealing with this type of network. The main research effort has been channeled towards routing and distributed processing, in order to achieve better quality of service (QoS) provisions, lower interference, and a lower power-consumption rate while data dissemination is carried out. The embedment of smart antennas on wireless-sensor nodes is proposed herein as an alternative and novel approach at the physical layer, with the potential for relieving traditional challenges faced by current wireless-sensor-network architectures. Studying the behavior of wireless sensor networks consisting of different types of antennas (omnidirectional or adaptive directional) yielded unexpectedly favorable results that improved the operation of networking systems of this type. In the test cases presented herein, the incorporation of smart antennas resulted in approximate improvements in the quality of service by 20%, the efficiency by 50%, the percentage of active nodes by 20%, and the energy consumption by 50%, depending on the simulation setup.