中文摘要：

在改进的马尔可夫模型的基础上引入Z变换，分析了802．11的DCF机制MAC延时性能，研究了从非饱和到饱和信道状态的延时性能。通过MATLAB数值分析和OPENT 10．0网络仿真，基于马尔可夫模型的MAC延时分析能够与网络仿真的MAC延时很好地吻合，验证了分析模型在预测媒介接入延时方面的有效性，为无线分布式系统的进一步设计提供理论依据和数据参考。

英文摘要：

This paper provided an improved Markov model and used Z transform to analyze and compute the MAC delay of 802.11 DCF, which included the non-saturation and saturation delay performance of transmission channel. The numerical analysis of MAC delay in MATLAB matched the network simulation of MAC delay in OPNET 10.0 well, which proved the accuracy of the analysis model in MAC delay predication. The results are beneficial to further designing in theory arguments and data reference.