无线多跳网络中802.11 DCF广播信道接入性能分析  

Performance analysis of 802. 11 DCF broadcast channel access in wireless multi-hop networks

作　　者：张三峰[1] 刘铮[1] 吉逸[1] 

机构地区：[1]东南大学计算机科学与工程学院,南京210096

出　　处：《东南大学学报（自然科学版）》2014年第1期34-38,共5页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(61300200);江苏省自然科学基金资助项目(BK2011335)

摘　　要：分析了采用网络编码和机会路由方法的无线多跳网络中存在的信道接入问题,建模描述了802.11 DCF广播信道接入过程,并对影响无线多跳网络的吞吐率、延迟、信道资源分配等性能指标的因素进行了定量分析.利用M/M/1/K队列和离散时间的二维Markov链,建模描述具有相异报文到达速率的多个节点竞争信道时各个节点上的报文到达、排队、信道接入和发送过程.通过求解该模型,得到各节点的实际发送速率、报文平均服务时间和系统总吞吐率等指标的计算公式.将模型计算结果和基于NS-2网络模拟平台得到的实验结果进行对比.结果表明,该模型能够有效地预测各种传输负载组合情况下的报文平均服务时间和信道资源分配的公平性等网络性能指标.Channel access problems in wireless multi-hop networks adopting network coding and op- portunistic forwarding technologies are analyzed. A model for an 802. 11 distributed coordination function （DCF） broadcast channel access process is built to quantitatively analyze the factors that af- fect the performance including the throughput, delay and fairness in wireless multi-hop networks. Behaviors of nodes such as packet arriving, queuing, channel access and sending are modeled based on an M/M/1/K queue and a two-dimensional discrete-time Markov chain when these nodes have different packet arriving rates. By solving the model, equations are obtained to calculate several per- formance indices such as the actual transmission rate and packet service time on each node and the total throughput of the system. Results generated by the model are compared with experimental re- suits from a simulation based on the NS-2 platform. It is shown that the model can effectively predict transmission performance indices including average packet service time and fairness of channel re- source allocation under various traffic load combinations.

关 键 词：无线MESH网络 MARKOV链 广播信道接入 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]