无线Mesh网络中基于跳数的TCP不公平性研究

摘要

在无线Mesh网络中,不同跳数的TCP流会引发严重的不公平性.搭建一个无线Mesh网络的实验床,并在该实验床上测试了基于跳数的TCP不公平性现象,从MAC层、队列管理机制、TCP拥塞控制机制等3个方面对产生这种基于跳数不公平性现象的原因进行了分析.同时对提出的几种典型的解决方案进行了仿真分析,仿真结果表明,这些方案提升了跳数不同的数据流之间的公平性,并从部署的代价、总的吞吐量影响、公平性改善情况、参数的设置等方面分析比较了这几种方案的优势和劣势.%In Mesh network, the TCP flows with different hops can cause severe unfairness. A test bed of wireless Mesh Network was built and the unfairness phenomenon was verified in that test bed. The reasons of the phenomenon which is the unfairness of TCP flows with different hops from the aspects of MAC layer, queue management and TCP congestion control were analyzed, some typical solutions were simulated, the results show that those solutions can improve the fairness based on different hops, and from the cost of deployment, the impact of network throughput and the set of parameters, the advantages and disadvantages of those solutions were compared.