优化限定性链路层触发在PB-FMIPv6中的应用  

Implementation of the optimized definitive link layer trigger algorithm in PB-FMIPv6

作　　者：马李罡[1] 

机构地区：[1]南京邮电大学自动化学院,南京210003

出　　处：《电子测试》2012年第6期46-53,共8页Electronic Test

摘　　要：PB-FMIPv6是FMIPv6的优化协议,它通过授权PrNAR来代替MN做绑定更新过程,使绑定更新过程和MN链路层切换并行执行,从而缩短了切换时延。限定性链路层触发算法是在FMIPv6基础上提出的链路层触发算法,它通过提供精确的触发时间标准,使MN接收到FBack消息后立即开始链路层切换,即保证FMIPv6工作在预应式工作模式,又最大程度的减小了切换时延。借鉴限定性链路层触发算法的思想,本文针对PB-FMIPv6提出了优化限定性链路层触发算法,理论分析表明,该算法能够动态地根据网络情况,选择合理的触发时间,既保证PB-FMIPv6工作在预应式工作模式,又在合理的范围内缩短切换时延,避免MN在新链路中等待PrNAR完成绑定更新过程情况的发生。利用OMNeT++的仿真结果表明优化限定性链路层触发算法降低了PB-FMIPv6协议的延迟数据包数量和切换时间,提高了PB-FMIPv6协议的整体切换性能。PB-FMIPv6 is an optimized protocol based FMIPv6. The protocol delegates PrNAR to do binding update processes in behalf of MN, while which is switching to a new link. Through the method, the overall handover latency is reduced. Definitive link layer trigger is an algorithm implied in FMIPv6, which provide accurate time criterion to trigger FMIPv6. The algorithm triggers FMIPv6 immediately after MN receives FBack from PAR, thus, it not only makes FMIPv6 to work in proactive mode, but also reduces handover latency as much as possible. Inspired by the great ideas in definitive link layer trigger algorithm, an improved algorithm in PB-FMIPv6 called optimized definitive link layer trigger algorithm is proposed in this paper. Theoretical analysis indicates that the algorithm in the paper can reasonably judge when to generate L2 trigger according to the dynamically changed network conditions. The method makes PB-FMIPv6 to work in proactive mode, at the same time, it shortens handover latency feasibly which avoid the embarrassing condition where MN in a new link has to wait PrNAR to complete binding update processes. The simulation results in OMNeT＋＋ show that the optimized definitive hnk layer trigger algorithm reduces the amount of delayed packets and handover duration of PB-FMIPv6, hence makes PB-FMIPv6 has better handover performance.

关 键 词：MIPv6协议 FMIPv6协议 PB-FMIPv6协议 优化限定性链路层触发算法 

分 类 号：TP393.04[自动化与计算机技术—计算机应用技术]