基于IPV6时延的路由优化机制研究

随着便携计算机的普及和无线局域网技术的不断成熟,网络对移动性的支持显得越来越重要。移动IPv6技术正是为适应这种需求而产生的一种新的支持移动用户和因特网连接的互连技术。它是为支持移动用户和主机通信而产生的新型IP协议,使移动用户在移动自己位置的同时无需中断正在进行的网络通信。移动IPv6协议是重要的IP层协议,但移动IP会带来三角路由问题,引起网络开销增加和性能下降。路由优化技术是解决三角路由的关键技术,已成为当前业界研究的热点问题。本文通过对移动IPv6路由优化技术进行深入的研究,针对进行路由优化需要注意的安全问题、代价问题、数据包失序问题以及路由优化时机的选择等问题,提出了一种基于时延的路由优化机制。     

移动IP中的路由优化技术

本文介绍了针对移动因特网中移动IP存在的三角路由问题的三种解决方案：移动IPv4中的路由优化、反向路由和移动IPv6，阐述了每种方案实现的关键技术，并分析了协议的技术性能和可行性。最后，对这三种协议进行了比较，提出了现有协议存在的问题以及今后可能的研究方向。     

下一代全IP移动通信网中的微移动性管理

移动IP是IETF支持因特网上主机透明移动性的一种参考协议，在向全IP蜂窝网络演进的过程中，移动IP提供了域之间移动的解决方案，即宏移动性管理，但它不能解决在蜂窝网内移动时所遇到的问题。移动IP的种种缺陷导致了近年来各种微移动性管理协议的出现，分析了几种典型的IP层微移动性协议，在此基础上提出了对设计新的微移动性协议的几点考虑。     

移动IP及其改进技术

为了在移动通信网络中运用IP协议，因特网工程任务组(Internet Engineering Task Force,IETF)制定了Mobile IP协议。Mobile IP是一种简单可扩展的全球Internet移动解决方案，使节点在切换链路时仍可保持正在进行的通信。传统的Mobile IP中要求移动节点移动到异地网络时获得转交地址，数据通过隧道经由家乡代理转发给移动节点。然而当移动节点在微移动条件下频繁移动时，传统的Mobile IP存在着许多不足。本详细介绍了移动IP的工作原理以及移动IP机制中的路由优化策略，并且针对微移动问题，从切换质量、路由更新、位置更新等方面比较了Mobile和Cellular IP、HAWAⅡ、TeleMIP等几种改进方法的性能。     

暂时性家乡代理移动IP解决方案研究

IETF制定的基本移动IP协议不仅存在所谓的“三角路由”问题，而且当移动节点频繁的在网络间移动时，给家乡代理和网络造成了很大的负担。本文在现有的各种切换解决技术的基础上，提出了一种分层次的暂时性家乡代理切换技术，以解决切换过程存在的问题。这种技术不仅缩短了路由路径，避免了三角路由问题，减少了额外的信令开销，而且在解决微移动的同时提高了移动IP的可靠性。     

基于卫星移动通信的网络移动研究

文中研究了利用卫星移动通信支持网络移动的必要性,提出了利用卫星移动通信网扩展地面IP网覆盖范围的设想和实现方案,分析了该方案的特点及需要解决的关键技术问题,重点分析了卫星移动信道对TCP/IP协议的影响及网络移动过程中的连接和路由选择问题,卫星移动信道误码率、往返时延、变化率、信道不对称性及信道频繁通断对TCP/IP协议工作效率的影响,以及提供网络移动应解决的双重隧道问题。     

移动IP中的路由优化技术

本文介绍了针对移动因特网中移动IP存在的三角路由问题的三种解决方案:移动IPv4中的路由优化、反向路由和移动IPv6,阐述了每种方案实现的关键技术,并分析了协议的技术性能和可行性。最后,对这三种协议进行了比较,提出了现有协议存在的问题以及今后可能的研究方向。     

基于AARP协议的移动IP算法及其性能分析

基于RFC2002的移动因特网协议(Mobile Internet Protocol,MIP),解决了因特网协议(Internet Protocol,IP)不支持节点跨子网漫游的问题,但要求移动节点必须具备动态修改路由表的功能;而在实际中广泛应用的操作系统,特别是Windows9x/Me等系统不支持对路由表的动态改变,这严重制约了移动IP的应用与推广.本文提出了主动ARP(Active ARP,AARP)协议,并在此基础上设计了一种新的移动IP算法.实验和分析表明,该算法在不引起性能下降的同时,克服了以往移动IP算法难以在Windows等系统上实现的缺点,极大扩展了移动IP的应用范围,并且易于实现、兼容性强、便于用户使用.同时,虽然该协议主要是针对Windows系统设计的,但也适用于其他许多操作系统.     

移动互联网的发展呼唤IPv6

在移动因特网提供新服务、新功能的同时，必然增加对IP地址的大量需求，现行的IP协议版本4（Ipv4）不能满足这么巨大的地址需求，为了解决这个问题，业界设计出了IP协议版本6（Ipv6）。这篇文章简要介绍了Ipv6的寻址和路由方法，并且对Ipv4与Ipv6进行了比较。     

一种基于移动代理的Ad hoc无线网络路由方法

Ad hoc无线网络是一组具有路由和转发功能的移动节点组成的一个多跳的临时性自治系统，是一种无中心的无线网络。现有的主动路由协议或者按需路由协议都不能很好的满足Ad hoc网络的需要。文中首先介绍了Ad hoc无线移动网络和移动代理技术，接着在分析两种按需路由协议中加入移动代理的技术的基础上，作者提出了综合两种技术的新方法，即基于移动代理的路由方案，以达到既节省网络路由建立所耗费的资源，又缩短路由建立时间的目的。最后给出了仿真的结果和下一步的工作。     

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.     

Integrated Mobility Management Methods for Mobile IP and SIP in IP based Wireless Data Networks

With developments in voice over IP (VoIP), IP-based wireless data networks and their application services have received increased attention. While multimedia applications of mobile nodes are served by Session Initiation Protocol (SIP) as a signaling protocol, the mobility of mobile nodes may be supported via Mobile IP protocol. For a mobile node that uses both Mobile IP and SIP, there is a severe redundant registration overhead because the mobile node has to make location registration separately to a home agent for Mobile IP and to a home registrar for SIP, respectively. Therefore, we propose two new schemes that integrate mobility management functionality in Mobile IP and SIP. We show performance comparisons among the previous method, which makes separate registration for Mobile IP and SIP without integration, and our two integrated methods. Numerical results show that the proposed methods efficiently reduce the amount of signaling messages and delay time related to the idle handoff and the active handoff.     

移动IP的移动性协议及管理机制

本主要从移动网络协议结构开始，讨论移动IP有关现行的和将来的Inernet移动性协议极其管理机制。     

Seamless Support for Mobile Internet Protocol Based Cellular Environments

Cellular is the inevitable architecture for the Personal Communication Service system (PCS) in the coming future. Access to the Internet via cellular networks is expected to become an essential portion of future wireless service offerings. Providing seamless support for IP based packet switched services has become an important issue.The Internet Engineering Task Force's (IETF's) mobile IP protocol offers a standard solution for wide-area mobility at the IP layer. However, Mobile IP does not solve all of the problems involved in providing mobile Internet access to cellular users, especially during handoff period. Thus, IPv6 might be a good candidate to solve this problem.IPv6 is a new version of the Internet Protocol that was standardized by the IETF. It supports mobility and is presently being standardized by the IETF Mobile IP Working Group. At the same time, cellular is an inevitable architecture for the Personal Communication Service system (PCS).This paper introduces the current cellular support based on the Mobile Internet Protocol version 6. We will point out the short-falls using Mobile IP and try to emphasize protocols especially for mobile management schemes that can optimize a high speed mobile station moving among small wireless cells. A comparison between those schemes and future work will be presented.     

Mobility management for VoIP service: Mobile IP vs. SIP

Wireless Internet access has gained significant attention as wireless/mobile communications and networking become widespread. The voice over IP service is likely to play a key role in the convergence of IP-based Internet and mobile cellular networks. We explore different mobility management schemes from the perspective of VoIP services, with a focus on Mobile IP and session initiation protocol. After illustrating the signaling message flows in these two protocols for diverse cases of mobility management, we propose a shadow registration concept to reduce the interdomain handoff (macro-mobility) delay in the VoIP service in mobile environments. We also analytically compute and compare the delay and disruption time for exchanging signaling messages associated with the Mobile IP and SIP-based solutions.     

A Domain-Based Routing Protocol for SSM Source Mobility in Mobile IPv6 Networks

In Mobile IP, the signaling traffic overhead will be too high since the new Care-of-Address (CoA) of the mobile node (MN) is registered all the way with the home agent (HA) whenever the MN has moved into a new foreign network. To complement Mobile IP in better handling local movement, several IP micro protocols have been proposed. These protocols introduce a hierarchical mobility management scheme, which divides the mobility into micro mobility and macro mobility according to whether the host's movement is intra-domain or inter-domain. Thus, the requirements on performance and flexibility are achieved, especially for frequently moving hosts. This paper introduces a routing protocol for multicast source mobility on the basis of the hierarchical mobile management scheme, which provides a unified global architecture for both uni- and multicast routing in mobile networks. The implementation of multicast services adopts an improved SSM (Source Specific Multicast) model, which combines the advantages of the existing protocols in scalability and mobility transparency. Simulation results show that the proposed protocol has better performance than the existing routing protocols for SSM source mobility.     

Using group mobility and multihomed mobile gateways to connect mobile ad hoc networks to the global IP Internet

Connecting multihop mobile ad hoc wireless networks (MANETs) to the Internet would enable MANET nodes to share wireless Internet access with mobile hosts that are one‐hop away from their foreign networks. The integration of MANETs and the global Internet, however, faces an obstacle due to their network architectural mismatches regarding their infrastructure, topology, and mobility management mechanisms. Solutions to the integration problem should introduce an intermediate facility with hybrid mechanism, enabling it to connect to both networks. The quality of the multihop wireless Internet access service provided to MANET nodes depends on the design quality of this facility in order for MANET nodes to enjoy their Internet connectivity anywhere and anytime without much disconnections. In this paper, we propose hierarchical architecture that uses group mobility and multihomed mobile gateways, and present and analyse different simulations results. A multihomed mobile gateway can simultaneously connect to multiple Mobile IP foreign agents, provided it is located within their overlapping coverage area. It runs updated versions of the destination‐sequenced distance vector (DSDV) and Mobile IP protocols, and is responsible for providing MANET nodes with wireless Internet access though they are multiple wireless hops away from the edge of the Internet. The rationale behind using multihoming is to increase reliability of the Internet access service and enhance performance of the integrated network. Copyright © 2006 John Wiley & Sons, Ltd.     

P-MIP: Paging Extensions for Mobile IP

As the number of Mobile IP users grows, so will the signalling overhead associated with Internet mobility management in the core IP network. This presents a significant challenge to Mobile IP as the number of mobile devices scale-up. In cellular networks, registration and paging techniques are used to minimize the signalling overhead and optimize the mobility management performance. Currently, Mobile IP supports registration but not paging. In this paper, we argue that Mobile IP should be extended to support paging to improve the scalability of the protocol to handle large populations of mobile devices. To address this, we introduce P-MIP, a set of simple paging extensions for Mobile IP, and discuss the construction of paging areas, movement detection, registration, paging and data handling. We present analysis and simulation results for Mobile IP with and without paging extensions, and show that P-MIP can scale well supporting large numbers of mobile devices with reduced signalling under a wide variety of system conditions.     

一种代理移动IPv6认证协议

代理移动IPv6为移动节点提供了基于网络的移动性管理方法,移动节点不参与管理移动性信令.为了在移动互联网络中应用代理移动IPv6协议,需要定义安全有效的认证协议.目前还没有见到关于代理移动IPv6认证协议方面的研究,本文提出了一种代理移动IPv6的认证协议,该认证协议可以提供接入认证功能,并可防止重放攻击和密钥暴露.为了分析该认证协议的性能,本文给出了认证费用和认证延迟分析的解析模型,分析了移动性和流量参数对认证费用和认证延迟的影响.研究结果表明提出的代理移动IPv6认证协议安全有效.     

Internet Connectivity for Ad Hoc Mobile Networks

The growing deployment rate of wireless LANs indicates that wireless networking is rapidly becoming a prevalent form of communication. As users become more accustomed to the use of mobile devices, they increasingly want the additional benefit of roaming. The Mobile IP protocol has been developed as a solution for allowing users to roam outside of their home networks while still retaining network connectivity. The problem with this solution, however, is that the deployment of foreign agents is expensive because their coverage areas are limited due to fading and interference. To reduce the number of foreign agents needed while still maintaining the same coverage, ad hoc network functionality can cooperate with Mobile IP such that multihop routes between mobile nodes and foreign agents can be utilized. In this work, we present a method for enabling the cooperation of Mobile IP and the Ad hoc On-Demand Distance Vector (AODV) routing protocol, such that mobile nodes that are not within direct transmission range of a foreign agent can still obtain Internet connectivity. In addition, we describe how duplicate address detection can be used in these networks to obtain a unique co-located care-of address when a foreign agent is not available.