Modeling and Throughput Analysis for X-MAC with a Finite Queue Capacity

MAC layer duty-cycling is widely used to reduce idling listening, which is energy-intensive in wireless sensor networks. Among duty-cycling MAC protocols, asynchronous protocols generally have higher energy-efficiency and lower packet latency than synchronized ones. In this paper, we propose a Markov model to analyze the throughput of X-MAC, an asynchronous duty-cycled MAC protocol for wireless sensor networks. Simulations show that our analytical model provides throughput values that closely match the simulation results under various network conditions. Using our model to estimate the throughput of X-MAC is computationally efficient, providing accurate results quickly compared with simulations, which take a long time to run and require many iterations due to the large standard deviations in throughput. More importantly, our model enables designers to obtain a better understanding of the effect of different numbers of nodes and data arrival rates on the performance of X-MAC.