随机访问网络后退避机制的性能分析  

Performance analysis of random access network with post-backoff

作　　者：步超伦 肖扬[1] 叶通[1] 吴鹏 张小建 吴军民 

机构地区：[1]上海交通大学区域光纤通信网与新型光通信系统国家重点实验室,上海200240 [2]国网智能电网研究院,江苏南京210003

出　　处：《电信科学》2016年第2期34-40,共7页Telecommunications Science

基　　金：全光交换关键技术及电网应用研究项目~~

摘　　要：无线局域网随机访问协议的性能分析是近年来的研究热点,而现有的模型还未能对其后退避机制进行有效刻画。基于一种两阶段的马尔可夫模型,分析非饱和业务状态下随机访问网络的性能。首先,利用嵌入式马尔可夫链描述每个站点队头分组的服务过程,引入虚拟服务时间的概念,即将传输成功之后的后退避也看成队头分组服务时间的一部分,从而得到队头分组的虚拟服务时间分布。然后,将每个用户队列看成一个Geo/G/1系统,求得非饱和业务状态下系统吞吐量、时延等参数的闭合解表达式以及系统的稳定区间。仿真结果验证了模型的准确性。本文所提模型将对今后研究无线局域网的分布式协调功能(DCF)协议打下基础。Performance analysis of random access network protocol in wireless local area network is a research hotspot in recent years, and the existing models have yet to describe post-backoff mechanism effectively. Therefore, the performance of the random access network under the unsaturated condition based on a two stage Markov model was analyzed. First of all, embedded Markov chain was used to describe the service process of the head-of-line （HOL） packet in each node, then the concept of virtual service time was introduced, namely regarding the p ost-backoff process after the successful transmission as a part of the HOL packet service time, then the virtual service time distribution of the HOL packet was attained. Next, the queuing process of each node was considered as a Geo/G/1 system, then the close-form result of system throughput, daisy and the range of the stable region under the unsaturated condition was achieved. The simulation results have verified the accuracy of our model. The modal will shed light on the future research on distributed coordination function （DCF） protocol in wireless local area network.

关 键 词：随机访问网络 后退避 性能分析 马尔可夫链 

分 类 号：TN929.5[电子电信—通信与信息系统]