基于线路信息和QoS上下文转移的无缝切换方案  

Seamless Handover Scheme Based on Line & QoS Context Transfer

作　　者：彭军[1] 严旭影[1] 原小六[1] 张伟[1] 

机构地区：[1]中南大学信息科学与工程学院,湖南长沙410075

出　　处：《铁道学报》2009年第3期100-106,共7页Journal of the China Railway Society

基　　金：中国北车集团公司科技研究开发计划(2006NX109)

摘　　要：在高速客运专线环境中,信息传输的实时性和可靠性是保障铁路系统运营安全和提高客运系统无线接入服务的前提和基础。本文将分层移动IPv6网络拓扑结构应用于高速客运专线移动通信网。为减少其中实时业务的切换延迟和资源预留信息重建延迟,提出基于线路信息和QoS上下文转移的分层移动IPv6切换方案。首先,利用客运专线固定的线路信息和接入路由信息,事先建立顺序接入路由表;综合接收到的信号强度及位置信息和时间信息预知列车移动通信网的切换,从顺序接入路由表中主动选择合适的切换目的路由器,在此基础上有目的地进行提前切换。其次,利用上下文机制实现在切换之前将QoS信息传递给目标接入路由器,对新接入路由器扩展移动代理功能,提前为移动主机建立资源预留信息。仿真结果分析表明此方案减少了切换延迟,降低了数据丢包率。In the high-speed passenger-dedicated railway lines environment, the real-time capacity and reliability of information transmission are the premise and foundation for guaranteeing the railway security and improving the quality of wireless access services. In this paper, the hierarchical mobile IPv6 （HMIPv6） network topology is introduced into the high-speed passenger dedicated lines mobile communication network. In order to reduce the latency caused by handover and the resource reservation protocol （RSVP） information re-establishment, a HMIPv6 seamless handover scheme based on line and context transfer （L＆CT-based HMIPv6） is proposed. Firstly, an ordered access router table is established based on the fixed line and access touters information. When the handover of the train is predicted according to the signal strength, locations and the time information, the scheme can select the appropriate new access router from the ordered access router table and perform handover in advance. Secondly, the Context Transfer Protocol is used to transfer QoS information to the new access router before handover. The new access router is extended to be a mobility agent to reserve resource before the arrival of Mobile Nodes. The simulation results show that L＆CT-based HMIPv6 can decrease the latency and packet losses to provide seamless handover.

关 键 词：分层移动IPV6 上下文转移 QOS 移动切换 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]