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。     

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.     

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。     

移动IPv6切换技术

基本的移动IPv6切换时延太大,无法满足实时业务的要求。文章在分析了现有移动IPv6网络切换技术的基础上,提出了一种基于分层移动IPv6网络模型的快速切换方案F-HMIPv6。该方案实现了移动节点在不同移动锚点域移动的快速切换操作。从理论分析得出结论,该方案可以弥补现有移动IPv6网络切换技术中的一些缺陷。     

一种移动IPv6的切换优化方案

移动节点在两个不同子网之间移动时产生切换。移动节点的切换技术是保证实时业务服务质量的关键问题之一。目前比较经典的三种切换机制是快速移动IPv6、层次型移动IPv6和快速层次移动IPv6。在简单介绍了三种机制原理并分析了它们的不足后,提出了一种自适应移动IPv6切换时延优化方案。     

基于2层、3层信息交互的移动IPv6切换延迟优化

移动IPv6作为下一代互联网的移动性管理的协议标准,能否很好的适应未来网络的需求,切换延迟是其中亟待解决的重要问题。移动IPv6的切换延迟主要由移动检测、地址自动配置和绑定更新三个阶段构成,本文通过分析移动IPv6的切换过程,设计并部署了一个模块,能够提取链路层的信息与移动IPv6进行交互,从而有效缩短移动IPv6切换过程中产生的延迟。     

移动IPv6切换技术的研究

切换技术是移动IPv6技术的关键技术之一,其优劣在很大程度上决定了MN在移动通信过程中的通信质量。本文介绍了移动IPv6的工作原理,阐述了移动IPv6切换的关键技术,以及三种切换的实现方式。     

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。     

一种改进快速移动IPv6性能的方法

快速移动IPv6(FMIPv6)协议是改进移动IPv6(MIPv6)协议性能的增强型协议之一,但是由于链路层触发原语的限制,性能提升十分有限。文章在介绍802.21媒介独立性切换的基础上,通过增加新的原语和参量,提出了一种基于媒介无关切换(MIH)方法来改进快速移动IPv6性能的方案。     

基于树状MAP的移动IPv6无缝实时切换策略研究

提出了一种移动IPv6切换策略,基于分级移动IPv6和快速移动IPv6构造树状MAP框架,设计逐跳绑定更新机制对快速移动IPv6进行改进,实现移动节点的无缝(快速平滑)切换。同时,根据资源预留协议扩展策略功能,提出提前预留方式,增强对实时数据流的支持能力。     

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.     

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。     

Study and enhancement on buffer management for smooth handover in MIPv6

For improving Transfer Control Protocol (TCP) performance in mobile environment,smooth handover with buffer management has been proposed to realize seamless handovers. However in our simulation, even if smooth handover in Mobile IPv6 (MIPv6) is implemented, TCP can not always achieve better performance due to packets forwarding burst. Based on the study of buffer management for smooth handover, this paper proposes an enhanced buffer management scheme for smooth handover to improve TCP performance. In this scheme, a packet-pair probing technology is adopted to estimate the available bandwidth of the new path from Previous router (Prtr) to Mobile Node (MN), which will be used by Prtr to control the buffered packets forwarding. The simulation results demonstrate that smooth handover with this scheme can achieve better TCP performance than the original scheme.     

A Robust Seamless Handover Scheme for the Support of Multimedia Services in Heterogeneous Emerging Wireless Networks

With the rapid development of wireless technologies and numerous types of mobile devices, the need to support seamless multimedia services in Mobile and Ubiquitous Computing (MUC) is growing. To support the seamless handover, several mobility protocols such as Mobile IPv6 (MIPv6) (Johnson et al., Mobility Support in IPv6, IETF, RFC 3775, 2004) and fast handover for the MIPv6 (FMIPv6) (Koodli et al. Past handovers for mobile IPv6 (FMIPv6), IETF, RFC 4068, 2005) were developed. However, MIPv6 depreciates the Quality-of-Service (QoS) especially in multimedia service applications because of the long handover latency and packet loss problem. To solve these problems in the MIPv6, FMIPv6 is proposed in the Internet Engineering Task Force (IETF). However, FMIPv6 is not robust for the multimedia services in heterogeneous emerging wireless networks when the MN may move to another visited network in contrast with its anticipation. In MUC, the possibility of service failure is more increased because mobile users can frequently change the access networks according to their mobility in heterogeneous wireless access networks such as 3Generation (3G), Wireless Fidelity (Wi-Fi), Worldwide Interoperability for Microwave Access (WiMax) and Bluetooth co-existed. In this paper, we propose a robust seamless handover scheme for the multimedia services in heterogeneous emerging wireless networks. The proposed scheme reduces the handover latency and handover initiation time when handover may fail through the management of tentative Care-of Addresses (CoAs) that does not require Duplicate Address Detection (DAD). Through performance evaluation, we show that our scheme provides more robust handover mechanism than other scheme such as FMIPv6 for the multimedia services in heterogeneous emerging wireless networks.     

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.     

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.     

Handover management for mobile nodes in IPv6 networks

We analyze IPv6 handover over wireless LAN. Mobile IPv6 is designed to manage mobile nodes' movements between wireless IPv6 networks. Nevertheless, the active communications of a mobile node are interrupted until the handover completes. Therefore, several extensions to Mobile IPv6 have been proposed to reduce the handover latency and the number of lost packets. We describe two of them, hierarchical Mobile IPv6, which manages local movements into a domain, and fast handover protocol, which allows the use of layer 2 triggers to anticipate the handover. We expose the specific handover algorithms proposed by all these methods. We also evaluate the handover latency over IEEE 802.11b wireless LAN. We compare the layer 2 and layer 3 handover latency in the Mobile IPv6 case in order to show the saving of time expected by using anticipation. We conclude by showing how to adapt the IEEE 802.11b control frames to set up such anticipation.     

一种减少移动IPv6切换延时的新方法

切换问题是移动计算环境中最基本的问题。理想的切换是指同时具备快速切换和平滑切换能力的无缝切换;快速切换就是要求系统具有最小的切换时延,平滑切换则要求系统具备最低的丢包率。现提出一种基于组播的平滑切换框架模型,该模型的基本思想是让移动节点本身携带途经的接入路由器绑定更新队列,每当移动节点到达一个新的链路并获得该链路的转交地址,就向家乡代理和队列成员进行组播。该模型有效地减少了数据包的丢失率,减少了延时,并与现有的快速切换/IPv6路由优化技术能很好地结合起来。     

Fast RSVP: Efficient RSVP Mobility Support for Mobile IPv6

In recent years, with the development of mobile communication technologies and the increase of available wireless transmission bandwidth, deploying multimedia services in next generation mobile IPv6 networks has become an inevitable trend. RSVP (resource reservation protocol) proposed by the IETF is designed for hardwired and fixed networks and can not be used in mobile environments. This paper proposes a protocol, called Fast RSVP, to reserve resources for mobile IPv6. The protocol adopts a cross-layer design approach where two modules (RSVP module and Mobile IPv6 module) at different layers cooperate with each other. Fast RSVP divides a handover process with QoS guarantees into two stages: (1) setup of the resource reservation neighbor tunnel and (2) resource reservation on the optimized route. It can help a mobile node realize fast handover with QoS guarantees as well as avoid resource wasting by triangular routes, advanced reservations and duplicate reservations. In addition, fast RSVP reserves “guard channels” for handover sessions, thus greatly reducing the handover session forced termination rate while maintaining high performance of the network. Based on extensive performance analysis and simulations, Fast RSVP, compared with existing methods of resource reservation in mobile environments, performs better in terms of packet delay and throughput during handover, QoS recovery time after handover, resource reservation cost, handover session forced termination rate and overall session completion rate.