一种基于时间阈值和协作分集的切换优化机制

针对基于协作节点的分层移动IPV6协议(PHMIPv6)在域间切换时,因未充分考虑非合作节点而可能导致的预切换操作失败问题,该文通过计算移动节点与协作节点的链路终止时间(LET)并引入时间阈值,保证所选择的协作节点能够及时执行预切换过程并返回新的转交地址,有效缩短切换准备时长;另外,在切换完成后,以协作节点为中继,移动节点与新的接入点在上下行建立包括蜂窝网络和Ad hoc网络的异构协作信道,充分利用协作分集技术来提高小区边缘的通信质量.应用NS2搭建了仿真环境,并分别从预切换成率、丢包数、切换时延等三个方面验证了该切换机制在性能上的优越性.

Optimal Handover Mechanism Based on Time-threshold and Cooperative Diversity

Partner based hierarchy mobile IPv6 protocol don’t consider the non-cooperative partner in inter-domain handover,and perhaps fail to perform pre-handover operation,this paper define a time-threshold based on Link Expiration Time(LET) between mobile node and cooperative partner,ensure the partner to complete pre-handover and return new care-of address timely,shorten the handover prepare time efficiently;on the other hand,this mechanism build heterogeneous cooperative channel between MN and new access point using cellular network and ad hoc after complete the handover,make full use of cooperative diversity to improve communication quality in cell edge.Application of NS2 build simulation environment,prove the advantage of performance on handover success rate,packet loss,and latency.