Modeling the S-MAC protocol in single-hop wireless sensor networks

In this paper, we present a new analytical model to accurately evaluate the throughput, service delay and the energy consumption of S-MAC protocol. Our model takes into account the impact of several factors together, including periodic listen and sleep cycle, various incoming traffic loads, the backoff mechanism in S-MAC, the queuing behavior at the MAC layer, and the dependency of service delay distributions among the nodes. Simulations show that our analytical results are highly accurate. Based on our model, we study how the listen and sleep cycle effects the trade-off between energy consumption and quality of service (QoS) requirement, and further derive the optimal value for duty cycle under different traffic conditions. Keywords-Wireless sensor networks (WSN), performance analysis, S-MAC, duty cycle, energy efficiency.