移动IPv6中基于QoS切换策略的研究

在移动IPv6中,切换策略是保证实时业务服务质量的关键问题之一。该文分析和比较了层次MIPv6(HMIPv6)移动管理协议、快速切换MIPv6(FMIPv6)协议和快速层次MIPv6(F-HMIPv6)切换策略。仿真结果表明,快速层次MIPv6切换策略具有更小的延时和更少的丢包,改善实时业务的服务质量。     

基于多播机制的层次型网络实时无缝切换的研究

通过对移动IPv6(MIPv6)及其衍生机制和实际应用中网络部署的学习和研究,提出一种集成了快速分层移动(F-HMIPv6)、缓存方法和多播机制的基于多播机制的层次型网络移动IPv6切换优化方案(MMIPv6)以提高实时传输中的切换性能。运用NS-2分别对MMIPv6、MIPv6、FMIPv6和HMIPv6针对切换时延、丢包率、信令负载进行了模拟,通过对仿真结果的分析证明了MMIPv6在无缝切换速度、平滑性上都优于MIPv6、FMIPv6、HMIPv6,更适合于实时业务中的数据传输。     

相关移动IPv6协议在车辆网络环境中的性能评估

针对IPv6,IETF工作组相继给出MIPv6及其增强协议HMIPv6、FMIPv6和F-HMIPv6的草案。移动IP技术为移动终端提供了Internet服务。但在高速环境下,切换会频繁发生从而造成严重的服务中断。为了评估上述协议在高速环境——车辆网络中的性能,开发了一个两层仿真模型,包括生成车辆移动轨迹的高速公路微观交通模型和配置了上述四类协议的车辆网络模型,然后通过切换时延、丢包数以及吞吐量等性能参数对四类协议进行了评估分析。仿真结果表明,相比于低速环境,高速环境对四类协议性能均有严重的影响,其中,对F-HMIPv6的影响最小,FMIPv6次之,MIPv6最大。     

HMRSVP：层次化移动资源预留协议

本文提出了一种新的资源预留协议--移动资源预留协议（HMRSVP）。此协议建立在层次化移动IPv6（HMIPv6）框架与快速切换技术（FHMIPv6）基础之上。此协议能够让移动节点在进行子网间切换的时候获得更加平滑的切换性能。同时，本文还和现有基于HMIPv6和FHMIPv6的IntServ方案进行了性能比较分析。     

引入信息学习和绑定代理的FMIPv6切换方案

针对FMIPv6和F-HMIPv6存在的切换延迟长和丢包率高的问题,提出了一种引入信息学习和绑定代理的FMIPv6改进方案。该方案通过引入信息学习机制,将新转交地址配置、重复地址检测DAD和隧道建立等工作提前完成;并使用隧道定时器,按需设定路由器之间的隧道生存时间;结合代理机制,使得绑定注册过程在二层切换前由路由器代理执行。NS-2仿真结果表明,改进方案在切换延迟和丢包率方面的性能优于FMIPv6和F-HMIPv6。     

基于IPv6组播的M-FHM IPv6切换技术

由于快速分层切换技术FHMIPv6将FMIPv6和HMIPv6切换技术结合起来,因此,在层次移动管理模型中部署快速切换时具有两种技术所具有的优点,可使切换延时进一步减少。文中通过对FHMIPv6的研究发现,其切换过程中DAD重复地址检测过程严重影响了切换性能,因此提出了基于IPv6组播的M-FHMIPv6切换技术。理论分析证明,M-FHMIPv6能有效减少DAD检测过程和各种信息交互的延迟。通过NS2实验仿真进一步说明:改进的M-FHMIPv6方案能减少切换延迟,平滑切换过程。     

重复地址检测的MIPv6网络切换方法

为减小MIPv6网络切换时延,保证实时性要求高的语音、视频等业务的服务质量,针对MIPv6网络中,DAD操作时延严重影响网络切换性能的问题,提出一种减少DAD操作时延的方法。该方法将PIM和MLD协议用于FHMIPv6,并分别对微移动和宏移动中组播组的创建方法进行改进,利用仿真软件NS-2进行实验。实验结果表明,改进的方法减少了重复地址检测时延,降低了丢包率,提高了MIPv6网络切换性能。     

基本Mobile IPv6及其改进协议切换时延分析和评估

为支持IP移动性及减小切换时延,当前IETF工作组相继提议了基本移动IPv6及其增强协议HMIPv6、FMIPv6和F-HMIPv6。本文详细研究四类协议中造成切换时延的因素,并定性地比较了以上协议在切换时所产生时延大小。然后从用网络仿真器ns-2实现的仿真试验中,得到与分析结果基本一致的实测时延数据。     

MIPv6与FMIPv6切换性能分析与优化

随着移动通信的迅速发展，越来越多的移动设备提出了接入互联网的需求。移动IPv6的切换性能是保证移动互联网服务质量的重要因素之一。该文描述了MIPv6及FMIPv6的切换流程，分析了MIPv6及FMIPv6的切换性能及其切换过程中存在的问题，提出和归纳了一些优化思想和改进方法。     

一种层次型移动IPv6的MAP选择机制的研究

在MIPv6(Mobile IPv6,移动IPv6)的基础上,学者们提出了HMIPv6(Hierarchical MIPv6,层次移动IPv6)。但是HMIPv6的移动锚点MAP(Mobile Anchor Point)选择机制存在MAP负载过于集中、MAP中路径过长等问题。在HMIPv6的基础上,提出一种基于位置区域的MAP选择机制,使MN(Mobile Node)主动选择最适合自己的MAP。仿真结果显示,负载不再集中在某一MAP上,MN选择了最适合的MAP,缩短了MAP到MN的路径。     

移动IPv6协议的切换时延性能比较分析

移动IPv6中的切换时延对于特定网络情景中的性能起着很大的作用,它会导致数据包的丢失和严重的端对端性能下降,文章对移动IPv6中的各种协议的切换时延作了性能分析比较,介绍了移动IPv6的基本知识及快速切换的重要性,阐述了层次化移动IPv6和快速移动IPv6的工作原理,采用网络仿真工具NS-2对三种移动IPv6协议的切换性能进行了比较和仿真,实验结果表明快速移动MIPv6具有良好的性能。     

802.11环境下移动IPv6快速切换性能研究

主要研究下一代移动IP（MIPv6）在WLAN内的快速切换。对IEEE的“Mobile IPv6 Fast Handovers for 802.11 Networks”草案提出的一种快速切换思想进行改进,利用少量的链路触发信号,通过结合分层快速切换技术和快速路由公告,大大降低了网络层切换时延和数据丢失。该切换算法在NS 2仿真环境下进行了模拟实现。     

Mobility-Aware RSVP: A framework for improving the performance of multimedia services over wireless IP-based mobile networks

This paper proposes the Mobility-Aware Resource Reservation Protocol (MARSVP) in which mobility and QoS signaling are performed as a single functional block. The key concept of MARSVP is to convey mobility-specific information (binding updates and their associated acknowledgments) by using newly defined RSVP objects embedded in existing RSVP messages. An appealing feature of MARSVP is that it adheres to the current RSVP standard (RFC 2205) and thus requires minimal changes to end nodes without affecting any of the conventional RSVP routers in between. The proposed mechanism is evaluated using a simulation model for application-level performance and an analytical model for network-level signaling cost. Simulation results indicate a 27.9% improvement in QoS interruption when using Mobile IPv6 (MIPv6), 12.5% when using Hierarchical Mobile IPv6 (HMIPv6), and no improvement when using Fast Handovers for MIPv6 (FMIPv6). On the network-level, signaling cost savings of 9.4% and 11.9% are achieved for MIPv6 and HMIPv6, respectively, while FMIPv6 achieves savings of 17.9% when using Voice-over-IP traffic and 26.7% for Video-over-IP traffic. The results of the conducted studies indicate MARSVP’s superiority to conventional RSVP when deployed over wireless networks.     

Mobility management for IP-based next generation mobile networks: Review, challenge and perspective

IP Mobility management protocols are divided into two kinds of category: host-based and network-based mobility protocol. The former category, such as MIPv6 protocol and its enhancements (e.g., HMIPv6 and FMIPv6), supports the mobility of a Mobile Node (MN) to roam across network domains. This is done through the involvement of MN in the mobility-related signalling, which requires protocol stack modification and IP address changes on the MN. The latter category, such as PMIPv6 protocol, handles mobility management on behalf of the MN thereby enabling it to connect and roam within localized domains, which requires neither protocol stack modification nor IP address change of the MN. PMIPv6 attracts attention in the Internet and telecommunication societies by improving the performance of the MN's communication to fulfil the requirements of QoS for real-time services. In this article, we present IPv6 features to support mobile systems and survey the mobility management services along with their techniques, strategies and protocol categories, and elaborate upon the classification and comparison among various mobility management protocols. Furthermore, it identifies and discusses several issues and challenges facing mobility management along with an evaluation and comparison of several relevant mobility studies.     

基于HMIPv6的RSVP新方案

在移动IPv6环境中,IntServ/RSVP模型很难实现QoS保证。针对该问题提出一种新的资源预留方案,该方案建立在分层移动IPv6协议的基础上。分析移动节点在域内的资源预留机制,与MRSVP, HMRSVP进行性能比较,结果表明该方案具有较高性能。     

基于F-HMIPv6的MAP自适应选择算法

移动IPv6提供了移动节点在不同子网中漫游通信的能力,同时为了缩短切换延迟和减少丢包率,层次化移动IPv6模型、快速切换机制及F-HMIPv6相继被提出.在层次化移动IPv6模型和F-HMIPv6中引入了MAP来缩短绑定更新延迟,但目前还没有较完善的MAP选择算法被提出.提出了一种自适应的MAP选择算法,该算法能根据移动节点的移动特点来选择合适的MAP.     

Optimized fast handover scheme in Mobile IPv6 networks to support mobile users for cloud computing

In the future cloud computing, users will heavily use mobile devices. Mobile networks for cloud computing should be managed efficiently as well as support seamless services to mobile users regardless of their locations and movements. Hence, in mobile networks for cloud computing, it is important to support seamless mobility management to mobile users who request real-time services such as VoIP, streaming, and interactive game playing. To support seamless mobility management for various wireless technologies in cloud computing, Mobile IPv6 (MIPv6) and fast handovers for MIPv6 (FMIPv6) have been studied. FMIPv6 has been emerged to reduce long handover latency and packet loss in MIPv6. FMIPv6 may provide seamless handover by minimizing the handover latency, and prevent packet loss through buffering and tunneling. FMIPv6 uses anticipation based on layer 2 trigger information, and consists of two operation modes such as the predictive mode and the reactive mode. Several works have been done to evaluate the performance of FMIPv6 in different network environments. However, the previous works did not consider the probability of predictive mode failure (PPMF) that distinguishes two operation modes. Even in the most previous work, two operation modes of FMIPv6 are evaluated separately. However, to accurately analyze the overall performance of FMIPv6, two operation modes should be analyzed altogether. In this paper, FMIPv6 combining two operation modes is analyzed considering the PPMF that is affected by the radius of a cell, velocity of mobile nodes, and the layer 2 triggering time. The effect of system parameters, such as the PPMF, the time required to process additional layer 3 signaling, and the layer 2 trigger time, is analytically investigated with respect to the signaling cost and the packet delivery cost. Analytical results show a trade-off between performance and system parameters. Then we show methods to optimize overhead of FMIPv6. Finally, mobile networks for cloud computing can be efficiently managed through the optimized FMIPv6.