WLAN中基于OpenFlow的无缝切换机制设计与实现  

Design and Implementation of an OpenFlow-Based Seamless Handover Scheme in WLANs

作　　者：开彩红[1] 胡欣岳 

机构地区：[1]合肥工业大学计算机与信息学院,安徽合肥230009

出　　处：《电子学报》2018年第2期410-417,共8页Acta Electronica Sinica

基　　金：国家自然科学基金(No.61571178;No.61202459);中央高校基本科研业务费专项资金

摘　　要：在传统的WLAN网络中,因为用户使用的移动终端(Station,STA)具有移动性,STA会出现离开当前网络接入点(Access Point,AP)的覆盖范围进入另一AP覆盖范围的情况,此时STA需要在AP间进行切换.传统WLAN中这样的AP间切换会产生网络延迟突然增大、吞吐量损失、以及掉线等服务质量下降的问题.本文提出并实现了一种基于AP虚拟化和Open Flow技术的解决方案,通过搭建基于Open Flow的交换网络对STA的流量进行细粒度的控制从而完成STA在不同AP间的无缝切换.经过实际网络环境测试,本方案具有5ms左右的切换延时、在AP切换时只会造成1秒左右的瞬时吞吐量减少和16ms左右的网络延时.相较于其他方案,本方案由于不需要再次进行认证和重新路由,因而具有更好的无缝切换性能.Intraditional WLANs, when a user with a station （STA） accesses the Internet through AP（ Access Point）, due to the mobility of the user, the STA may move out of the coverage area of current AP and enter the coverage area of anotherAP. Thus, STA needs to handover between APs. In traditional WLANs, such a handover often incurs a sudden increase of the network delay, a sharp decrease of throughputs and even disconnection. This paper presents a new handover scheme based on the AP virtualization and OpenFlow technique. By developing an OpenFlow switch network, we can realize a fine- grained control on the traffic of STAs, and realize the roaming of STA among different APs. Furthermore, we build up a practical WLAN testbed and real experiments show that the proposed scheme will only lead to a handover delay of about 5ms,a throughput reduction of about ls and delay of 16ms when a handover happens. Compared with other existing schemes,the proposed scheme has smoother handover process since it does not need re-authentication and re-routing.

关 键 词：无线局域网 无缝切换 OpenFlow AP虚拟化 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]