限制TTL的PREQ广播风暴抑制方案  

A TTL limited scheme to reduce PREQs broadcast storm

作　　者：游波[1] 牟荣增[1] 阎跃鹏[1] 

机构地区：[1]中国科学院微电子研究所电子系统总体技术研究室,北京100029

出　　处：《重庆大学学报（自然科学版）》2014年第8期119-126,共8页Journal of Chongqing University

基　　金：国家高技术研究发展计划("863"计划)资助项目(2011AA040102);国家科技重大专项(2010ZX03006-003-02)

摘　　要：在使用混合无线网状网协议(hybrid wireless mesh protocol,HWMP)的IEEE802.11s树状网络中,子节点之间通过洪泛PREQ(path request)来维护路由,会带来严重的PREQ广播风暴问题。为了解决这个问题提出了一种限制TTL(time to live)的PREQ广播风暴抑制方案。该方案设计了一种子节点分级策略:利用HWMP的表驱动路由,根据子节点到根节点的路由跳数将子节点分级,并在网络中同步等级信息。源节点在发送PREQ时不再使用HWMP默认的TTL,而是将PREQ的TTL设置为源节点与目的节点的等级和。理论分析和实验结果表明,该方案限制了PREQ的传输距离,在节点位置固定的静态树状网络中,当源节点与目的节点的等级和不大时该方案在路由开销、回路时延、丢包率和吞吐量上的性能表现都优于HWMP。In the tree network of IEEE802.11 susing HWMP（hybrid wireless mesh protocol）as its routing protocol,PREQs（path requests）are simply flooded for maintaining the routes between leaf nodes,which causes PREQs broadcast storm problem.This paper proposes a TTL limited scheme to solve the problem.The scheme designs a method to grade the leaf nodes.With the help of table-driven routing in HWMP,the leaf nodes are divided into different grades according to their hop counts to the root node and the grade information is synchronized in the network.The source node no longer uses the default TTL in HWMP when sending PREQ,instead,it sets the TTL of the PREQ to the sum of its own grade and the destination node＇s grade.Theoretical analysis and experimental results show that the scheme limits the delivery distance of PREQs and outperforms HWMP at overhead,loop delay,package loss rate and throughput in static tree network if the sum of the source node＇s grade and the destination node＇s grade is not large.

关 键 词：路由协议 树状网络 广播风暴 混合无线网状网协议 生存时间 路由请求 

分 类 号：TP393.02[自动化与计算机技术—计算机应用技术]