软件定义无线Mesh网络路由的设计与实现

Design and implementation of software-defined wireless mesh network routing

传统无线Mesh网络的分布式架构,转发设备软硬件的紧耦合状态,给网络的资源管理、运维及业务创新带来了一系列挑战.为应对传统无线Mesh网络存在的问题,本文将软件定义网络(software-defined network,SDN)引入无线Mesh网络中,其主要思想是将控制平面和数据平面分离,提高网络的灵活性.在无线Mesh网络中,建立稳定有效的控制平面是软件定义无线Mesh网络正常运行的基础,本文在AODV协议的基础上,基于邻居筛选机制使网络设备建立到控制器的稳定路径,并使网络设备主动将邻居信息发送到控制器.与传统的OpenFlow发现协议(OpenFlow discovery protocol,OFDP)方法相比,该方法使控制器获得的网络拓扑更加长效、稳定.在建立稳定的控制平面后,控制器获得了全网拓扑.本文基于该网络拓扑,研究了在控制器集中控制下,结合链路实时丢包率、时延以及跳数的软件定义无线Mesh网络路由算法.与AODV协议相比,该算法在链路带宽、平均往返时延、丢包率和时延抖动上均有所改善.

The distributed architecture of traditional wireless mesh network and the tightly coupled state of the software and hardware of the forwarding equipment have brought a series of challenges to the network resource management,operation and maintenance,and business innovation.In order to cope with the problems of the traditional wireless mesh networks,software-defined networks(SDNs)are introduced into the wireless mesh networks.The main idea of the software-defined wireless mesh networks is to separate the control plane and data plane to improve the flexibility of the network.In the wireless mesh network,the establishment of a stable and effective control plane is the basis for the normal operation of the software-defined wireless mesh network.On the basis of AODV protocol,the network equipment establishes a stable path to the controller based on neighbor screening mechanism and actively sends neighbor information to the controller.Compared with the traditional OpenFlow discovery protocol(OFDP)method,this method makes the network topology obtained by the controller more long-lasting and stable.After establishing a stable control plane,the controller obtains the entire network topology.Based on the network topology,the software-defined wireless mesh network routing algorithm that combines the real-time packet loss rate,delay and hop count of the link under the centralized control of the controller is studied.Compared with the AODV protocol,the algorithm has improved the link bandwidth,average round-trip delay,packet loss rate and delay jitter.