快速层次移动IPv6的乒乓切换研究

针对现有的预测式FMIPv6(快速移动IPv6)没有提供域内乒乓切换机制,因而可能导致大量远程注册开销和系统通信开销的问题,在FMIPv6的基础上引入HMIPv6(分层移动IPv6)层次结构,提出了一种基于FHMIPv6(快速层次移动IPv6)的乒乓切换优化方案。分析结果表明,与FHMIPv6相比,所提方案在乒乓切换模式下能够有效减少时延和丢包率,进一步提高吞吐量。     

快速分级MIPv6协议栈优化研究与设计

文章介绍了MIPv6的研究现状和快速分级管理FHMIPv6协议栈设计机制,研究提出了一种能够更加准确预测移动节点下一小区位置的切换机制FHMIPv6＋。该方案具有更加准确的位置预测及降低切换时延、减少数据丢失率的功能。     

快速分层切换移动IPv6协议的分析及仿真

随着互联网和无线移动通信技术的快速发展,越来越多的用户使用移动终端接入互联网,无线移动接入技术与IPv6结合起来成为目前的研究热点。当移动主机在一个子网内移动时,对数据分组的接收几乎没有影响。但是当移动主机在两个不同的子网之间移动时,就会发生切换过程,这时己有的连接就会出现中断。切换延时过长对一些实时性的应用来说是无法接受的。为此,分析了移动IPv6三种增强协议,得出FHMIPv6在切换延时、吞吐量和丢包这几个方面表现为最优。     

基于IPv6的快速切换改进方案

在移动IP网络中,当前的移动性管理方案由于其基本协议的切换时延较大、丢包率较高而不能适应实时业务和移动通信的要求,所以需要改善移动性管理策略的切换性能,尽量实现无缝切换和零丢包率。提出了一种基于移动IPv6的快速切换的改进方案,采用一种新的地址分配方式使得移动节点能够在移动至新的网络后迅速获取新的转交地址,有效地减少了切换所产生的时延和丢包率,具有较好的切换性能。     

基于移动节点在PAR和NAR间频繁切换的预测式快速移动IPv6新方案

针对移动节点频繁地在PAR和NAR间频繁切换时,现有的预测式FMIPv6存在着时延大、丢包率高、信令冗余大等问题,本文提出了一种新的解决方案.该方案定义了新的Hop-by－Hop 选项报头TM (Tunneling Message)、 PCoA表和双向隧道表,并将TM捎带在NAR向PAR发送的最后一分组数据包的确认中,告知PAR,MN不久将会移回PAR域,以便PAR提前准备好其与NAR之间以前建立好的双向隧道,从而达到MN的快速和平滑切换.理论分析表明,该方案能有效地减少切换时延、丢包率及信令冗余等问题,提高移动用户的QoS.     

移动IPV6在改进数据包发送路径模型下性能分析

针对现有移动IPV6中数据包发送代价较高的问题,对现有移动IPV6协议性能分析模型中数据包发送路径进行了改进,将访问路由发送至移动节点的数据包由代价很大的隧道发送改进为直接发送,避免了隧道代价因子对数据包发送代价的影响。同时分析对比了移动IPv6协议MIPV6、FMIPV6、HMIPV6和PMIPV6在现有模型下和改进数据包发送路径模型下的数据包发送代价和切换时延、吞吐量。理论分析与实验仿真表明:现有移动IPv6协议在改进数据包发送路径模型下的数据包发送代价和切换时延比在现有模型下低,吞吐量有所提高。该改进数据包发送路径模型适合应用于数据包传输速率较高的场合。     

一种实时信头压缩上下文转移方法

文章综合F—HMIPv6（次移移动IPv6的快速切换技术）、鲁棒性信头压缩和上下文转移三种机制,提出一种实时上下文转移方和ROHC（鲁棒性信头压缩协议）压缩状态迁移协调策略。在切换的同时将信头压缩上下文转移到新接入路由器中。避免了切换后在新接入路由器上重新运行压缩协议重建上下文的开销。分析表明,该方案能有效解决因切换导致的丢包和时延造成的压缩端与解压端上下文不同步问题。     

WiMAX网络快速切换技术研究

如何快速切换，降低切换时延和丢包率一直是移动WiMAX网络大规模部署所面临的关键问题。本文在研究802．16e标准的MAC切换机制和移动IPV6基础上提出了一种新的基于F—HMIPv6（快速分级移动IPv6）的WiMAx网络快速切换方案，它具有时延低、链路开销小等特点。     

一种基于移动IPv6协议的软切换实现方案

移动IPv6协议解决了IPv6网络中移动节点的位置更新和路由可达问题,使移动节点能够在不同IPv6子网间进行切换而不中断当前连接。但是这种切换的时延较长,影响移动IPv6网络的性能。为了减少切换时延,文章在移动IPv6协议中引入软切换技术,提出一种采用绑定更新计时器和路由优先级变换机制的软切换工程实现方案,实验结果表明,该软切换方案可以有效提高移动IPv6网络的性能。     

WiMAX与WLAN跨层优化切换的研究

通过结合IETF提议的快速移动IPv6（FMIPv6）协议与IEEE802.21工作组提出MIH（Media Independent Handover）草案,引入了一种WiMAX与WLAN垂直切换的跨层优化方案。此外,移动节点引入信息映射表,在存储链路质量下降之前以MIH消息检索介质独立信息服务器MIIS获取邻居网络信息,减少了IP层切换初始化获取邻居网络信息的时间,增强了FMIPv6预测切换成功概率,减少了切换时延和丢包率。     

快速层次移动IPv6切换性能分析及优化

移动IPv6技术中切换延时对实时应用影响很大。介绍了目前移动IPv6常用的快速移动和层次移动切换技术,描述其切换原理和过程。结合2种技术的优缺点,给出了一种新的快速层次移动IPv6的切换方案。利用NS-2对这3种切换方法进行仿真得到的结果表明,快速层次移动IPv6切换延时要小于快速移动IPv6和层次移动IPv6的切换延时,且降低了数据包丢失率,提高了网络的性能。     

Analysis and Evaluation of Mobile IPv6 Handovers over Wireless LAN

In this paper, we analyze the IPv6 handover over wireless LANs. Mobile IPv6 is designed to manage mobile nodes movements between wireless IPv6 networks. Nevertheless, a mobile node cannot receive IP packets on its new point of attachment until the handover completes. Therefore, a number of extensions to Mobile IPv6 have been proposed to reduce the handover latency and the number of lost packets. We focus on Fast Mobile IPv6 which is an extension of Mobile IPv6 that allows the use of L2 triggers to anticipate the handover. We compare the handover latency in four specific cases: basic Mobile IPv6, the forwarding method of Mobile IPv6, the Anticipated method, and the Tunnel-Based Handover. The results of the handover latency are calculated with the L2 properties of IEEE 802.11b. In particular, we take into account the L2 handover for different configurations of the wireless network.     

移动IPv6切换时延优化新方法

移动IPv6中,移动节点(MN)在不同子网间移动时,既不中断与通信对端(CN)的通信,也不用改变其本身的IP地址.但是当MN与其家乡代理(HA)之间相距较远时,移动IPv6切换时延较大,对于实时性要求较高的业务无法适用.本文分析比较了目前移动IPv6常用的切换时延优化方法,提出了一种自适应快速层次移动IPv6切换时延优化方法,减小了移动IPv6切换时延,提高了网络的性能.     

Performance Analysis of Hierarchical Mobile IPv6: Does it Improve Mobile IPv6 in Terms of Handover Speed?

There has been a rapid growth in the need to support mobile nodes in IPv6-based networks. IETF has completed to standardize Mobile IPv6 (MIPv6) and Hierarchical Mobile IPv6 (HMIPv6) for supporting IPv6 mobility. Even though existing literatures have asserted that HMIPv6 generally improves MIPv6 in terms of handover speed, they do not carefully consider the details of the whole handover procedures. In this paper, based on the current IETF standards of both MIPv6 and HMIPv6, we conduct a comprehensive study of all IP-level handover procedures: movement detection, duplicate address detection, and location registration. Based on this study, we provide a mathematical analysis on MIPv6 and HMIPv6 performance in terms of handover speed. From the analysis, we reveal that the average HMIPv6 handover latency is not always lower than the average MIPv6 handover latency. Furthermore, even the intra-domain handover latency of HMIPv6 is not reduced much compared with MIPv6 handover latency. A finding of our analysis is that optimization techniques for movement detection and duplicate address detection are essential to shortening HMIPv6 handover latency and increasing the benefit of HMIPv6.

基于重叠网络的移动IPv6快速切换

基本的移动IPv6切换延迟太大，不能满足实时业务的要求。本文提出了一种基于重叠网络的移动IPv6快速切换算法，这种算法通过在两个不同的IPv6子网间设置重叠网络来实现IP层的无缝(零延迟)切换。文中给出了算法实现的网络结构及其切换过程，并且对其性能进行了分析。算法实现了移动IPv6快速切换，在大部分情况下都可以达到最佳性能。     

基于特征投影的移动IPv6快速切换方法

研究了移动IPv6协议中的越区切换问题,提出了一种基于特征投影的移动IPv6快速切换方法。该方法通过构造先验切换经验与小区覆盖范围的映射关系来协助移动接入网关对切换目的地进行预测。仿真结果表明,文中方法能够获得比FPMIPv6更小的切换延迟,并具有较好的鲁棒性。     

A Scheme for Supporting Fast Handover in Hierarchical Mobile IPv6 Networks

This Letter proposes a scheme that supports a fast handover effectively in hierarchical mobile IPv6 networks (F‐HMIPv6) by optimizing the associated data and control flows during the handover. By NS‐2 simulation, we show that the proposed scheme can give better handover performance than a simple combination of existing schemes.     

Hierarchical mobility management for fast handoff and load distribution in IPv6 networks

Hierarchical Mobile IPv6 (HMIPv6) has been proposed by the Internet engineering task force (IETF) to compensate for such problems as handover latency and signalling overhead when employing Mobile IPv6 (MIPv6). HMIPv6 supports micro‐mobility within a domain and introduces a new entity, namely mobility anchor point (MAP) as a local home agent (HA). However, HMIPv6 has caused load concentration at a particular MAP and longer handover latency when an inter‐domain handover occurs. In order to solve such problems, this paper establishes a virtual domain (VD) of a higher layer MAP and proposes a MAP changing scheme. The MAP changing scheme enables complete handover by using binding‐update of the on‐link care of address (LCoA) only when inter‐domain handover occurs. In addition, the concentrated load of a particular MAP is distributed as well. Copyright © 2008 John Wiley & Sons, Ltd.     

Fast Handover in Hierarchical Mobile IPv6 Based on Motion Pattern Detection of Mobile Node

To meet the increasing communication requirement for people in ubiquitous environments, some handover schemes and improvements were proposed by the IETF in order to support mobility effectively. FHMIPv6 combines the advantages of FMIPv6 and HMIPv6. This paper proposes an improved scheme based on FHMIPv6 which mainly implements a combined-detection function between Mobile Node (MN) and Mobility Anchor Point (MAP) and calculates the Normalized Edit Distance to analyze the motion trail and estimate the motion pattern of MN. According to the estimating result, MAP determines the way MN attaches to the new access point so as to reuse some previous handover information and intellectualize the handover process to avoid redundant binding updating. Simulation results based on Network Simulation 2 (NS2) show that this improved scheme can reduce the packet’s loss rate and handover latency, enhance the throughput and improve the network performance as a whole, especially for MN with the Ping-Pong motion pattern.     

移动IPv6在无线局域网中的实现

介绍了移动IPv6的工作机制,提出一个移动IPv6和无线局域网(WLAN)集成的设计方案,以实现移动终端在无线局域网之间无缝切换,并建立实际的实验环境对移动IPv6进行测试.