Mobility management for all-IP mobile networks: mobile IPv6 vs. proxy mobile IPv6 [architectures and protocols for mobility management in all-IP mobile networks]

Recently, a network-based mobility management protocol called Proxy Mobile IPv6 (PMIPv6) is being actively standardized by the IETF NETLMM working group, and is starting to attract considerable attention among the telecommunication and Internet communities. Unlike the various existing protocols for IP mobility management such as Mobile IPv6 (MIPv6), which are host-based approaches, a network-based approach such as PMIPv6 has salient features and is expected to expedite the real deployment of IP mobility management. In this article, starting by showing the validity of a network-based approach, we present qualitative and quantitative analyses of the representative host-based and network-based mobility management approaches (i.e., MIPv6 and PMIPv6), which highlight the main desirable features and key strengths of PMIPv6. Furthermore, a comprehensive comparison among the various existing well-known mobility support protocols is investigated. Although the development of PMIPv6 is at an early stage yet, it is strongly expected that PMIPv6 will be a promising candidate solution for realizing the next-generation all-IP mobile networks.     

基于快速DAD的分层移动IPv6切换算法

针对分层移动IPv6(HMIPv6)在重复地址检测(DAD)环节耗时严重的问题,提出一种基于快速DAD的HMIPv6切换算法.该算法通过引入IP地址分配管理(IAAM)模块建立DAD查表和地址主动生成机制,可大大加快DAD进程,且实现简单.仿真结果表明,经过算法优化后的HMIPv6(F-DAD-HMIPv6)可使域内切换延迟减少到202ms,域间切换延迟减少到339ms,优于MIPv6和HMIPv6.     

移动IPv6网络的层次AAA方案研究

针对AAA和移动IPv6的融合问题，从整体结构、基础设施部署及性能问题开展研究，提出了新的解决方案，包括优化的层次AAA结构，引入了新实体RAAAS，合理部署AAA与移动基础设施使两者协同工作，并利用建立短期外地安全关联和上下文转移技术提高系统性能。对比IETF提出的方案，本方案具有高的安全性和好的性能。     

移动IPv6快速切换在MBWA中的应用

目前的无线局域网和3G网络都还无法满足人们对移动多媒体通信的需求。IEEE802．20——移动宽带无线接入(MBWA)工作组的目标是使高速移动的用户也能获得与有线链路相媲美的数据业务体验。为了支持网络层的移动性，MBWA系统中引入了移动IPv6技术。介绍了一种可以应用于MBWA系统的移动IPv6快速切换机制，此机制是对标准IPv6切换的改进，从而能够在最大程度上减小由于IP协议操作引起的切换时延。     

Enhanced fast handover for proxy mobile IPv6 in vehicular networks

To reduce the handover latency in PMIPv6, Fast Handover for PMIPv6 (PFMIPv6) is being standardized in the IETF. On the other hand, vehicle-roadside data access has been envisioned to be useful in many commercial Internet services; however, integrating the current Internet into Vehicular Networks (VNs) presents a new set of challenges. In particular, to provide rapid IP handover in the VNs, simply applying PFMIPv6 to VNs may not improve handover performance since PFMIPv6 handover restricts the previous Mobile Access Gateway (MAG) from forwarding the packets until it receives an HAck/HI from the next MAG, even though the vehicle may have already arrived at the next MAG. We also note that PFMIPv6 does not consider the impact of geographic restriction on vehicular mobility. Therefore, in this paper, we propose an enhanced PFMIPv6 (ePFMIPv6) for VNs in which the serving MAG pre-establishes a tunnel with candidate next MAGs for next MAG so that the packets can be immediately forwarded to the next MAG once the serving MAG is indicated the vehicle’s handover by the serving road side unit. To evaluate the performance of the proposed protocol, we derive analytical expressions for packet loss, latency and signaling overhead caused by ePFMIPv6 and PFMIPv6 handovers. Our analytical study is verified by simulation results.     

Leakage-resilient security architecture for mobile IPv6 in wireless overlay networks

The coupling of mobility and quality-of-service with security is a challenge that should be addressed in future wireless overlay systems. The mobility of a node can disrupt or even intermittently disconnect an ongoing real-time session because a secure handover must be performed to ensure continuous connectivity. The duration of the such interruptions is called disruption time or handover delay and can heavily affect the user satisfaction. The handover procedure needs to protect its integrity and confidentiality-otherwise, the packets may be rerouted to a malicious node and the legitimate handover may not be performed. The security procedure to ensure this should not lengthen significantly the handover delay to provide good quality real-time services. In this paper, we focus on the network-layer mobility, specifically, on Mobile Internet protocol version 6 (MIPv6) since it is the natural candidate for providing such mobility in future systems. To solve the problem of on-path attackers and prevent leakage of secrets, we propose a security architecture for MIPv6 based on leakage resilient-authenticated key establishment (LR-AKE) protocol and its cooperation with public key infrastructure. The proposed architecture prevents against on-path attackers which was not addressed in the specifications of MIPv6, and also provides robustness against leakage of secret values. Using analytical models, we evaluate MIPv6 handover delay for real-time services. We identify the crucial factors affecting the handover delay among transmission delays of MIPv6, security and LR-AKE messages, queueing delays and en/decryption delays.     

层次移动IPv6的增强切换方案

随着互联网技术与移动通信技术飞速发展,移动IPv6技术已经成为下一代移动互联网的研究热点。切换技术是影响移动互联网实时运行质量的重要技术之一。低延迟、低丢包的无缝切换方案对移动IPv6的性能至关重要。层次移动IPv6(HMIPv6)利用移动锚点(MAP)降低了延迟和数据丢失。然而,只有移动节点在同一MAP域的网络上进行切换时,HMIPv6才能有效减少延迟。当移动节点在不同MAP域的网络移动时,其切换性能并不优于标准移动IPv6。文章针对层次移动IPv6提出了一种增强切换方案(EHMIPv6),该方案在HMIPv6的基础上实现并行重复地址检测(PDAD),以减少不同区域网络间切换的延迟。分析表明,该方案比HMIPv6具有更好的性能。     

Transition to IPv6 in GPRS and WCDMA mobile networks

The limited size and structure of the Internet address space of IPv4 has caused difficulties in coping with the explosive increase in the number of Internet users. IPv6 is a feasible solution for the problems identified with IPv4. Efficient interworking between IPv4 and IPv6 is very important, because IPv4 networks and services will exist for quite a long time. The transition period will be lengthy, and network/terminal equipment supporting both IP versions will be needed during the transition period. Thus, IPv4 to IPv6 transition issues need special care and attention. The three main transition methods are dual IPv4/IPv6 stacks in network elements/terminals, tunneling, and translators in the network. Three transition phases from IPv4 to IPv6 can be identified. These phases are described. Different transition scenarios from the 2G/3G mobile network point of view are also analyzed. Finally, some conclusions are drawn, and some recommendations on the use of transition methods are given     

一种新的分层移动IPv6快速切换方案研究

分层移动IPv6快速切换在一定程度上减少了切换延时，但切换过程中由网络层移动检测和使用重复地址检测（DAD）配置一个新转交地址引起的延时对实时业务仍然有很大的影响。为了减轻这些影响，文中提出了一种更加有效的快速邻居发现和DAD机制，减小了切换延时，提高了网络的性能。     

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。     

Inter-domain security for mobile IPv6

Mobile IPv6 is only adapted to the mobile’s movements within its own administrative domain. As Mobile IPv6 is expected to be the basis for beyond 3G networks, a solution for inter-domain security is required allowing the visited domain to authenticate any mobile to grant it access. As such, new concepts known as AAA for Authentication, Authorization, Accounting were defined by the IETF. The IETF is currently defining the Diametr protocol to support those three functions in a Mobile IPv4 environment. Today’s difficulty is to adapt the Diameter protocol to Mobile IPv6. After introducing the Mobile IPv6, IPsec and Diameter protocols, this paper presents our solution (IETF draft of December 2001), and an IETF alternative for adapting Diameter to Mobile IPv6. It gives a comparison and describes our prototype.     

IPv6对移动IP的支持

ＩＰｖ６是下一代的互联网协议,它最终将取代目前使用的ＩＰｖ４成为互联网的主要网络层协议。移动ＩＰｖ６目前是ＩＥＴＦ（Ｉｎｔｅｒｎｅｔ Ｅｎｇｉｎｅｅｒｉｎｇ ＴａｓｋＦｏｒｃｅ）移动ＩＰ工作组议程中的主要课题。移动ＩＰｖ６的文件发展得很快,本文只讨论基于移动ＩＰｖ６文件的第二版本。 ＩＰｖ６和ＩＰｖ４的区别 ＩＰｖ６与ＩＰｖ４有许多重要大的区别,其中最大的两个区别是：（１）地址长度（ＩＰｖ６为１２８比特,而ＩＰｖ４为３２比特）;ＩＰｖ４报头中许多不常用的域被从ＩＰｖ６报头中删除了,放入了可选项和报头…     

基于动态策略的分布式移动IPv6网络安全管理机制

为解决移动IPv6节点与接入网间的安全兼容性问题,提出了一种基于动态策略的分布式移动IPv6网络安全管理机制.将分布式安全防御体系与移动IPv6相结合,构建了基于策略的分布式安全体系结构,在节点移动过程中实现安全策略的动态迁移,使机制对网络结构的变化具有感知能力和自适应防御能力,提高了接入网络的安全性和移动节点的可用性.     

Handover and channel assignment in mobile cellular networks

A taxonomy of channel assignment strategies is provided, and the complexity in each cellular component is discussed. Various handover scenarios and the roles of the base station and the mobile switching center are considered. Prioritization schemes are discussed, and the required intelligence distribution among the network components is defined     

移动Ad Hoc网络基于IPv6的Internet接入技术研究

针对实现移动用户无线上网的需求，通过对移动AdHoc网络的体系结构和路由技术的研究，以及对移动IPv6协议的工作原理及其与IPv4特性的比较分析，提出了AdHoc网络基于IPv6的Intemet接入方法，并对其地址自动配置、路由发现、网关发现、协议转换和分组转换等关键技术进行了分析，同时针对这两种技术相结合存在的广播和多跳问题提出了改进方法，并对今后的工作进行了展望。     

乒乓切换在移动IPv6扩展协议中的性能分析

 综合评价了多种移动IPv6扩展协议在基于端到端的TCP协议L3层的切换性能,模拟仿真了乒乓切换在MIPv6、FMIPv6、HMIPv6和FHMIPv6中的时延、吞吐量和丢包现象,提出了一种优化的FHMIPv6方案.该方案通过定义新的Hop-by－Hop 选项报头TM、 PCoA表和双向隧道表,实现MN的快速、平滑切换,比FHMIPv6进一步减少了时延,提高了吞吐量,降低了丢包率.     

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.     

Reactive Handover Optimization in IPv6-Based Mobile Networks

In recent years, there has been a rapid growth in the need to support moving hosts and moving networks in IPv6-based mobile networks. As the number of such hosts and networks grows, so will the demand for delay sensitive real-time applications, such as voice over IP (VoIP), that require seamless handover. Two well-known approaches to reduce the handover latency have been proposed in the literature: proactive and reactive approaches. While proactive handover is known to generally outperform reactive handover, its reliability and practicality are still questionable since it basically depends on predictive information which may be unreliable in some cases. In this paper, based on the standard specification for IPv6 mobility support, we analyze the existing movement detection and address configuration procedures which are the main components of reactive handover approach. We also propose a novel reactive handover procedure which employs our optimized movement detection and address configuration schemes. The proposal is simple and robust because it does not need any predictive information and it requires a minimum number of signaling messages. The performance evaluation shows that the proposal substantially reduces the signaling load on wireless/wired networks and its handover latency is reduced enough to support seamless services.