基于M/G/1/K排队理论的IEEE 802.15.4网络吞吐量分析

针对IEEE 802.15.4时隙载波侦听多址接入与碰撞避免（CSMA/CA）算法，利用二维Markov链分析方法提出了一个网络分析模型。该模型特别考虑了IEEE 802.15.4协议的休眠模式以及退避窗口先于退避阶数(NB)达到最大值的情况。在此基础上，结合M/G/1/K排队理论推导得到了吞吐量的表达式，进而分析了网络在非饱和状态下数据包到达率对吞吐量的影响，利用模拟平台NS2进行了仿真。实验结果显示理论分析结果与仿真结果可以较好地拟合，并能准确描述网络吞吐量的变化，验证了分析模型的有效性。

Network throughput analysis of IEEE 802.15.4 based on M/G/1/K queuing theory

According to the IEEE 802.15.4 slotted Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) algorithm, a network analysis model using analysis method of two-dimensional Markov chain was proposed. Not only the sleep mode of IEEE 802.15.4 agreement but also the condition where the backoff window reached the maximum value before the Number of Backoff (NB) were especially considered in the model. On this basis, combined with M/G/1/K queuing theory, the throughput expression was derived, and the packet arrival rate effect on the throughput was analyzed under unsaturated network. Using the simulation platform Network Simulator Version2 (NS2), the experimental results show that the theoretical analysis fits well with the simulation result, and the network throughput is described accurately. Then the effectiveness of the analytical model is validated.