移动IP中的切换策略

移动切换是移动IP中的关键技术之一，对于移动IP的性能有着重要的意义。对移动IPvl6基本切换策略、分级移动IPvl6切换策略和快速切换协议切换策略进行了分析，阐述了各种策略的流程，并重点探讨了它们的优缺点。最后给出了关于移动IP切换策略的一些结论和建议。     

移动IP中切换方法的探讨

文章提出了一种关于移动IP中同一个外地代理下和不同外地代理下切换的新方法，并通过比较说明新方法的优点。     

IP微移动的切换管理

IP微移动是一种能够在移动过程中有效改善移动节点通信质量的移动性管理方式,其核心部分为切换管理。该文首先分析了IP微移动的切换过程,并从网络层切换和链路层切换的关系及其交互性的新视角提出了切换管理的分类方法,详细分析和研究了目前典型的IP微移动协议的特点和存在的问题,并给出对这些协议的性能比较,最后讨论了IP微移动切换管理的未来研究方向。     

移动IP无缝切换技术研究

移动IP协议是宏移动管理方案,但它不支持无缝切换.针对移动I P的不足,人们提出了许多改进方案来增强其性能.根据切换过程的技术特征,文章从基于缓存和转发机制的切换、基于减少组件延时的切换、基于上下文转移的切换和基于候选访问路由器发现策略的切换等角度,对增强移动IP性能的各种无缝切换技术进行了研究.     

一种移动IP快速平滑切换方案

无线IP网络中将采用移动IP实现移动性管理,但该方案应用在高频度切换环境,存在不可接受的切换时延和数据包丢失,很难保证通信业务的服务质量.提出了一种移动IP快速平滑切换方案,该方案利用后注册切换的概念,在切换过程中不存在数据包的丢失,并可以获得很小的切换时延,在实际系统中运行能够达到良好的效果.     

无线网络中移动IP切换方法的探讨

介绍了一种与无线网络相结合的一种解决移动节点切换中预先注册的方法,并说明了这种方法的缺陷和局限性.     

基于层次管理结构的移动IP切换

在介绍了移动IP及其切换原理的基础上．针对移动环境下移动节点的频繁切换造成的切换延迟大的情况,提出了基于层次管理结构的移动IP切换方案,能够有效地实现快速切换。     

一种基于SIP与移动IP技术的无缝切换机制

随着移动通信技术的发展,能够在各种异质接入网络之间无缝切换已经成为对下一代无线网络的一个基本要求。介绍了一种新的无缝切换机制,通过这种机制,运营商能够提供相应的增值服务,带给用户一种＂随时、随地＂的资讯体验。首先分别介绍了SIP技术与移动IPv4技术的原理,然后结合SIP与移动IPv4技术提出一种全新的无缝切换机制,最后总结并提出了有待进一步研究的相关问题。     

移动IP及基于IPv6的切换

本文首先对移动IP的工作原理作了简单的介绍，进而提出作为未来移动网络首选的移动IPv6协议的特点。在此基础上，对基于IPv6的各种切换方案作了深入的探讨，引入了类比于3G移动通信切换的思路，提出了基于IPv6切换的下一步研究方向。     

下一代无线IP移动通信网中的IP微移动性协议

与Internet无缝连接和IP基的移动性是下一代移动通信网的重要特点。为了减少移动IP中的时延和信令开销，减少包丢失，提出了支持快速、 可靠切换和IP寻呼（IP paging)的IP微移动性（micro-mobility)协议。本文研究了提交到IETF移动IP工作组（MIP WG)的几种关键IP微移动性协议，分析了协议的动机、特点，比较了性能、信令复杂度和实用性，给出了可能的优化途径。     

基于服务质量的下一代移动IP架构

在下一代互联网中，服务质量（QoS)的提高已经变得非常重要，而在下一代移动互联网中，由于移动用户的频繁移动使得基于服务质量的移动切换管理变得更加复杂，提出了一种新的基于服务质量和扁平化管理思想的下一代移动IP架构——移动代理扁平架构（MAFS），该架构可以在移动用户频繁移动时提供良好的服务质量保证和移动切换管理。     

通过优化Mobile IP的平滑切换改善TCP性能

Mobile IP中的切换将会导致数据包的丢失。平滑切换避免了数据包的丢失，却可能导致数据包的失序。文章分析了已有的减少失序数据包的方案的不足，提出了新的改进方案，并进行了评估，证明了其优越性。     

A Robust Analytical Model of Mobile IP Handoff with Multiple Traffic Profiles

Mobile IP has been developed to provide the continuous information network access to mobile users. The performance of Mobile IP mobility management scheme is dependent on traffic characteristics and user mobility. Consequently, it is important to assess this performance in-depth through these factors. This paper introduces a novel analytical model of handoff management in mobile IP networks. The proposed model focuses on the effect the traffic types and their frame error rates on the handoff latency. It is derived based on general distribution of both successful transmission attempts and the residence time to be applicable in all cases of traffic characteristics and user mobility. The impact of the behavior of wireless connection, cell residence time, probability distribution of transmission time and the handoff time is investigated. Numerical results are obtained and presented for both TCP and UDP traffics. As expected, the reliability of TCP leads to higher handoff latency than UDP traffic. It is shown that, higher values of FER increase the probability of erroneous packet transfer across the link layer. A short retransmission time leads to end the connection most likely in the existing FA; however a long retransmission time leads to a large delivery time. The proposed model is robust in the sense that it covers the impact of all the effective parameters and can be easily extended to any distribution.     

An Empirical Analysis of Handoff Performance for SIP,Mobile IP,and SCTP Protocols

Over the last decade, we have witnessed a growing interest in the design and deployment of various network architectures and protocols aimed at supporting mobile users as they move across different types of networks. One of the goals of these emerging network solutions is to provide uninterrupted, seamless connectivity to mobile users giving them the ability to access information anywhere, anytime. Handoff management, an important component of mobility management, is crucial in enabling such seamless mobility across heterogeneous network infrastructures. In this work, we investigate the handoff performance of three of the most widely used mobility protocols namely, Mobile IP, Session Initiation Protocol (SIP), and Stream Control Transmission Protocol (SCTP). Our empirical handoff tests were executed on an actual heterogeneous network testbed consisting of wired, wireless local area, and cellular networks using performance metrics such as handoff delay and handoff signaling time. Our empirical results reveal that Mobile IP yields the highest handoff delay among the three mobility protocols. In addition, we also found that SIP and SCTP yield 33 and 55% lower handoff delays respectively compared to Mobile IP.     

基于MPLS的移动IP网络的移动性支持：平滑切换与路由优化

为了减小基于MPLS的移动IP网络的信令开销、切换时延和切换丢包,人们提出了一种称为LSP扩展的移动性管理机制。LSP扩展存在两个问题：一是扩展的LSP可能存在环路;二是需要定义中止LSP扩展的准则。针对上述问题,该文首先给出了LSP扩展的环路消除技术,然后定义了中止扩展LSP的准则,即用户信息和信令信息代价函数;并理论分析了用户信息和信令信息代价函数的计算过程,讨论了如何通过该代价函数中止扩展LSP。性能分析结果表明,根据该准则中止扩展LSP能在较大程度上减小LSP扩展机制的开销。     

Intelligent Handoff for Mobile Wireless Internet

This paper presents an intelligent mobility management scheme for Mobile Wireless InterNet – MWIN. MWIN is a wireless service networks wherein its core network consisting of Internet routers and its access network can be built from any Internet-capable radio network. Two major standards are currently available for MWIN, i.e., the mobile IP and wireless LAN. Mobile IP solves address mobility problem with the Internet protocol while wireless LAN provides a wireless Internet access in the local area. However, both schemes solve problems independently at different layers, thereby some additional problems occur, e.g., delayed handoff, packet loss, and inefficient routing. This paper identifies these new problems and performs analyses and some real measurements on the handoff within MWIN. Then, a new handoff architecture that extends the features of both mobile IP and wireless LAN handoff mechanism was proposed. This new architecture consists of mobile IP extensions and a modified wireless LAN handoff algorithm. The effect of this enhancement provides a linkage between different layers for preventing packet loss and reducing handoff latency. Finally, some optimization issues regarding network planning and routing are addressed.     

移动通信系统中的切换和切换算法

切换是蜂窝系统所独有的功能,也是移动通信系统的一个关键特征,它直接影响整个系统的性能。本文对移动通信系统中切换和切换算法进行了深入细致的研究,包括切换的分类和功能、性能指标、各种切换方式及算法的优缺点,提出了自己的建议及需要继续研究的问题。     

Performance Analysis of Handoff Techniques Based on Mobile IP, TCP-Migrate, and SIP

Mobility management protocols operating from different layers of the classical protocol stack (e.g., link, network, transport, and application layers) have been proposed in the last several years. These protocols achieve different handoff performance for different types of applications. In this paper, mobile applications are grouped into five different classes, class A through class E, based on their mobility management requirements. Analytical models are developed to investigate the handoff performance of the existing mobility management protocols for these application classes. The analysis shows that applications of a particular class experience different handoff performance when different mobility management protocols are used. Handoff performance comparisons of different mobility management protocols are carried out to decide on the suitable mobility management protocol for a particular application class. The results of mathematical analysis advocate the use of transport layer mobility management for class B and class C applications, mobile IP for non-real-time class D and class E applications, and session initiation protocol-based mobility management for real-time class D and class E applications. Moreover, through analytical modeling, the parameters that influence the handoff performance of mobility management protocols are identified. These parameters can be used to design new application-adaptive techniques to enhance the handoff performance of the existing mobility management protocols.