基于排队模型的无线Mesh网延时分析与优化

Delay analysis and optimization in wireless mesh networks based on queuing model

摘要:

在提供无线接入的网格网中，不同用户因所处地理位置的不同所获得的服务质量(吞吐量、延时)会有较大程度的差异。文中使用排队网络对Mesh网建立模型，从理论上分析了非饱和流量的情况下不同用户获得的延时的差异。分析发现，通过设置多个缓冲区并调度不同数据流在中间节点上的优先级别，可以使不同用户的延时趋于均匀从而保证网络的公平性。把优先级的分配问题归结为一个以公平性为目标的组合优化问题并提供了解法。使用Lorenz曲线来度量公平性，仿真结果表明，使用优化的调度算法可以获得更好的网络公平性。

Abstract:

In Wireless Mesh Networks(WMNs) for Internet access, service quality of different users will vary greatly depending on the locations of users. In this study, WMNs were simulated as queuing networks and the delay variance of different users in unsaturated load case were analyzed. The analytical results indicated that delay fairness could be guaranteed by setting multiple buffers in mid-node and scheduling priorities of all flows. The priority assignment problem was formulated as a combinatorial optimization problem which was targeted to achieve maximal fairness, and a solution was also provided. The fairness was evaluated by using Lorenz curve. Simulation results show that better fairness index can be acquired by using optimal assignment algorithm.