Date Added: Jan 2011
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, the authors 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, they employ an easy use of CDMA codes. The actuators schedule sensors to reduce the total network energy consumption per successful transmission. They identify the advantages of their proposal over existing TDMA-MAC schemes for cluster-based sensor networks. Their 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.