Low-energy, adaptive, and distributed MAC protocol for wireless sensor-actuator networks

Sensor-actuator networks are often limited in battery capacity and processing power. Therefore, it is exigent to develop solutions that are both energy and delay efficient. In this paper, we propose a low-energy and delay-sensitive TDMA based MAC for wireless sensor-actuator networks (WSANs). These networks are organized into clusters and each cluster is managed by a single actuator. To avoid inter-cluster downlink interference, we employ an easy use of CDMA codes. The actuators schedule sensors to reduce the total network energy consumption per successful transmission. We identify the advantages of our proposal over existing TDMA-MAC schemes for cluster-based sensor networks. Our simulation results demonstrate that the proposed MAC greatly improves the WSAN lifetime and achieves a good trade-off between the packet delay and sensor energy consumption