基于平面路由的无线Mesh网切换技术

通过对无线Mesh网络区别于传统无线局域网的特性的分析,以及无线Mesh网的链路层切换机制、网络层切换机制的深入研究,提出了一种基于平面路由和移动IP的无线Mesh网络快速切换机制,并在该机制下给出了2种具体的实现方案。仿真分析表明,上述方案都充分利用了无线Mesh网络的特性,能够有效降低切换时延、减少数据包丢失率,基本可实现无线Mesh网络的无缝切换,并且能够保证与现有的IEEE802.11协议标准兼容。     

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。     

基于地理位置的无线传感器网络IPv6地址配置方式

采用全IP互联方式,提出以数据为中心,按地理位置信息实现无线传感器网络IPv6地址配置的方案。此方案将无线传感器网络栅格化,在每一个网格内头节点采用无状态地址自动配置方法为普通节点分配IPv6地址,各个网格的节点地址配置过程可同时进行。最后通过仿真分析,验证了此方案的有效性。     

基于地理位置的无线传感器网络IPv6地址配置

采用全IP互联方式,提出以数据为中心,按地理位置信息实现无线传感器网络(Wireless Sensor Networt,WSN)IPv6地址配置的方案.此方案将无线传感器网络栅格化,在每一个网格内头节点采用无状态地址自动配置方法为普通节点分配IPv6地址,各个网格的节点地址配置过程可同时进行.最后通过仿真分析,验证了此方案的有效性.     

WLAN的移动IPv6快速切换研究

移 动 IPv6 标准切换包括移动 节点的二层切换、路由发 现、重复地址检测(DAD)、家 乡代理绑定更新(BU)、通信节 点绑定更新这几个环节,在此期 间移动节点不能收发应用的 IP 分 组。在无线链路质量不佳,或者 家乡代理与移动节点距离遥远等 情况下,标准切换过程引起的分 组传输延时和分组丢失无法满足 实时业务的要求。 移动 IPv6 的快速移动切换 研究是当前的一个热点,IETF 对 此提出了移动 IPv6 快速移动切换(FMIPv6)草案。FMIPv6 利用移 动节点或网络的二层链路信息, 对移动切换事件进行预测或快速 响应,通…     

一种新的WLAN环境下移动IPv6的低时延切换方法

提出了一种IEEE 802.11无线局域网环境下移动IPv6的低时延切换方法NDPR.在不依靠链路层触发的条件下,NDPR使用非均匀检测模型来减小切换检测产生的时延,降低了切换检测过程的开销.通过IP地址与MAC地址的映射机制和转交地址的预注册机制,NDPR减小了移动IPv6的移动检测和转交地址配置过程的时延.仿真结果表明,该方法不但能够有效降低节点切换过程的时延,而且其性能优于以往相关的工作.     

IPv6商用部署探讨

1引言全球IPv4地址即将耗尽,应对地址短缺的思路主要有两种：一种是引入IPv6,从根本上解决地址问题,另一种仍然从IPv4层面考虑解决。IPv4地址空间不足是迁移的原动力,但两种协议互不兼容是不能快速切换的最大原因。烽火通信认为,IPv4在向IPv6的演进过程中,网络中所有设备的支持应该循序渐进,逐渐过渡到全IPv6。2IPv6引入的主要过渡技术IPv6的引入涉及网络和业务系统的各个方面,业界主要的演进路线包括双栈、隧道和协议翻译三种。     

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。     

移动IPv6节点切换安全认证的研究与实现

近几十年来,随着互联网络的飞速发展,Internet逐步走近人们的日常生活和工作当中。另一方面,随着移动通信技术突飞猛进的发展,越来越多的移动用户都希望能够以更加灵活的方式接入到因特网中去,而不受时空限制．移动IPv6（Mobile IPv6,MIPv6）协议为用户提供可移动的IP数据服务,让用户可以在世界各地都使用同样的IPv6地址,实现了无线数据网络和电信网络中的跨子网漫游和切换等功能。     

Hierarchical Mobile IPv6 Mobility Management in Heterogeneous 3G/WLAN Networks

The research and development of next generation networks results in continuously growing in heterogeneity of wireless systems. Those systems also offer users the increasing possibility of roaming between different networks, which undoubtedly needs seamless integration. As mobile users continue to expand their requirements for seamless roaming, a good handoff mechanism is necessary especially for cellular networks and wireless local area networks. The most critical problem faced in the handoff mechanism is that users may need immediate data transmission. However, immediate data transmission is always obstructed because handoff latency occurs. In this paper, we propose a Hierarchical Mobile IPv6 handoff scheme using active measurement-foreign mobility agent to measure the residual bandwidth of each access point (AP) for handoff decision. As a result, the proposed scheme prevents whole efficiency from being affected by the registration time and improves immediate data transmission. In addition, a dual-threshold of the received signal strength is used to avoid the ping-pong effect. Simulation results show that the proposed scheme outperforms the traditional Mobile IPv6 and enhanced multilayer Hierarchical Mobile IPv6.     

Research on IPv6 address configuration for wireless sensor networks

The paper proposes an IPv6 address configuration scheme for wireless sensor networks. In the scheme, one wireless sensor network is divided into multiple clusters and the scheme creates the IPv6 address formats for the cluster heads and the cluster members respectively. Based on the proposed IPv6 address format, the scheme proposes to adopt the division method of the hash function to allocate the IPv6 addresses for the cluster heads and cluster members and to utilize linear probing to deal with assigned address collision. From the perspectives of duplicate address detection cost, address configuration cost and address configuration delay time, the paper analyzes and compares the performances of Strong DAD, MANETConf and the proposed scheme. Analytical results demonstrate the effectiveness and efficiency of the proposed scheme. Copyright © 2010 John Wiley & Sons, Ltd.     

一种新的基于移动IPv6的快速切换方案

基本的移动IPv6（MIPv6）切换延迟非常大，不能满足实时业务的要求。本文基于对MIPv6的切换时延的分析，提出了一种IEEE802．11无线局域网环境下MIPv6的低时延切换方法，该方法通过结合使用连接触发器和快速路由器公告，并通过IP地址与MAC地址的映射机制来优化切换过程。仿真结果表明，该方法能够有效降低节点切换过程的时延，同时其性能优于以往相关的工作。     

A framework of handoffs in wireless overlay networks based on mobile IPv6

Although there are various wireless access network technologies with different characteristics and performance level have been developed, no single network that can satisfy the anytime, anywhere, and any service wireless access needs of mobile users. A truly seamless mobile environment can only be realized by considering vertical and horizontal handoffs together. With the advantages of Mobile IPv6, a more comprehensive and integrated framework of heterogeneous networks can be developed. In this paper, we discuss the issues related to handoffs including horizontal and vertical handoffs. We present a scheme for integrating wireless local area network and wide area access networks, and propose a micromobility management method called HiMIPv6+. We also propose a QoS-based (quality-of-service-based) vertical handoff scheme and algorithm that consider wireless network transport capacity and user service requirement. Our prototype evaluations and the simulations show that our framework performs as expected.     

A conflict-insensitive NATed roaming framework using NAToD for proxy mobile IPv4 in WLANs

Providing efficient mobility management in the current Internet is increasingly important due to the quick growth of wireless mobile users. The emerging Proxy Mobile IPv4 (PMIPv4) technique brings a possible solution for that purpose. Since NAT function is widely adopted in IPv4 environment nowadays because of lacking IPv4 addresses, the PMIPv4 interoperating with NAT must be considered. Unfortunately, owing to the possible conflict of private IP address, we encounter a problem in broadcasted point-to-multipoint wireless networks such as IEEE 802.11 networks. To address this issue, we proposed a novel Network Address Translation on Demand (NAToD) scheme, which can well interoperate with the PMIPv4 solution. With our scheme, single public IPv4 addresses can be shared by multiple mobile nodes in both home and foreign networks, low-latency handoff can be achieved, deployment cost can be reduced, and software upgrade can be avoided for mobile nodes in wireless LANs. Our work allows mobile users in WLAN to access Internet based on the advantages of both PMIPv4 and NAT.     

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。     

在CNGIIPv6上建立诚信安全的P2P环境和分布管理系统

文章指出中国为实施中国下一代互联网(CNGI)计划而大规模布设IPv6骨干网,这为发展P2P应用、建立诚信安全具有分布管理能力的P2P网络环境提供了机会:一方面在CNGI的IPv6网上一开始就可以实行实名制,从而发展建立网络新秩序;另外一方面可以在CNGI上以无缝和持续演进的方式建立智能结点重叠网,以支持P2P应用并提供分布式管理.文章认为CNGI发展的IPv6终端和IPv6用户网(如家庭网、传感器网等)可以通过在现有IPv4有线/无线接入网和城域网中建立IPv6隧道连接到IPv6骨干网P2P平台,以获得足够的通达能力,并在此基础上发展基于P2P的各种新应用.     

A cross‐layer partner‐based fast handoff mechanism for IEEE 802.11 wireless networks

In wireless/mobile networks, users freely and frequently change their access points (APs) while they are communicating with other users. To support the mobility of mobile nodes (MNs), Mobile IPv6 (MIPv6) is used to inform the information of MN's home address and current care‐of‐address (CoA) to its home agent. MIPv6 suffers from a long delay latency and high packet losses (PLs) because MIPv6 does not support micromobility. A Hierarchical Mobile IPv6 (HMIPv6) is proposed which provides micromobility and macromobility to reduce handoff latency (HL) by employing a hierarchical network structure. In this paper, we propose a cross‐layer partner‐based fast handoff mechanism based on HMIPv6, called the PHMIPv6 protocol. Our PHMIPv6 protocol is a cross‐layer, layer‐2 + layer‐3, and cooperative approach. A cooperative node, called a partner node (PN), is adopted in the PHMIPv6 protocol. A new layer‐2 trigger scheme used in the PHMIPv6 protocol accurately predicts the next AP and then invites a cooperative PN in the area of the next AP. With the cooperation of the PN, the CoA can be pre‐acquired and duplicate address detection operation can be pre‐executed by the PN before the MN initializes the handoff request. The PHMIPv6 protocol significantly reduces the handoff delay time and PLs. In the mathematical analysis, we verified that our PHMIPv6 protocol offers a better HL than the MIPv6, HMIPv6, and SHMIPv6 protocols. Finally, the experimental results also illustrate that the PHMIPv6 protocol actually achieves performance improvements in the handoff delay time, PL rate, and handoff delay jitter. Copyright © 2009 John Wiley & Sons, Ltd.     

异构网络垂直切换技术

下一代无线网络(Next Generation Wireless Networks,NGWN)将融合多种不同的网络体系结构与无线技术,NGWN的异构性要求向用户提供无缝切换。为此文章引入了异构无线网络垂直切换策略,并深入论述了其中的关键细节——网络发现、切换判决和切换信息交互流程等。