基于移动IPv6的平滑切换算法研究

切换时延和数据包丢失一直是制约移动IPv6发展的关键因素.文章针对现有切换算法及存在的问题进行了分析,然后在现有算法的基础上提出了一种改进算法.仿真实验结果表明,该算法能有效地抑制因移动节点的网络切换而导致的通信节点拥塞控制机制的启动,提高了移动网络数据流的正确率和吞吐量,进而提高了移动网络的通信质量.     

基于动态分布结构的一种微观移动切换方法

提出了一种在动态分布结构下微观移动的切换方法,它可根据移动主机进入微观局网收到的首次注册信息,动态地选择微观移动的网关,调整微观局网结构,分布了网络负载。通过用比较分析的方法和仿真实验对切换时间进行了计算和验证,表明此方法减少了微观移动网关的切换时延。     

大型CDMA网络中移动IP技术应用和部署策略研究

近年来随着互联网和移动通信的高速发展,人们对移动业务如语音、视频、互联网访问、游戏、定位等提出了更高的要求.在新的市场竞争环境、新业务发展和新技术促进下,运营商将高带宽移动接入和基于互联网的服务结合起来.在提高无线频率利用效率的同时,为用户提供更经济、内容更丰富的无线数据业务和移动增值业务.本文对CDMA分组域组网的网络参考模型进行研究.提出了部署移动IP的策略.     

移动IP中的移动检测方法

本文介绍了移动IP的基本概念和工作原理,并着重探讨了移动检测方法。按链路上有无代理广播消息,移动检测通常分为两种情况进行。移动节点收到代理广播消息后,可用生存时间域和网络前缀做移动检测;如果收不到代理广播消息,在本地链路上,移动节点设法按固定节点通信的方式进行通信尝试,在外地链路上移动节点将通过DHCP协议或手工配置进行通信,或对TCP进程进行监测并检查链路的数据包以确定自己在移动网络中的位置。     

基于移动代理的MANET网络管理任务切换

由于自组网(Mobile Ad Hoc Network,MANET)网络的动态移动性,节点从一个网管域移动到新的网管域时,使用移动IP的网管任务切换可以解决异域网络的管理问题,但是由于在网管中,管理者和被管设备都在一个区域中,使用基于移动IP的网管任务切换就具有严重的三角路由问题。将移动代理与网络管理结合起来,提出一种新的网络管理任务切换方案,该方案节省了网络资源,减少了切换时延并降低了管理任务的丢失,同时增加了网络管理的灵活性。     

移动IP中的移动检测方法

本介绍了移动IP的基本概念和工作原理，并着重探讨了移动检测方法。按链路上有无代理广播消息，移动检测通常分为两种情况进行。移动节点收到代理广播消息后，可用生存时间域和网络前缀做移动检测；如果收不到代理广播消息，在本地链路上，移动节点设法按固定节点通信的方式进行通信尝试，在外地链路上移动节点将通过DHCP协议或手工配置进行通信，或对TCP进程进行监测并检查链路的数据包以确定自己在移动网络中的位置。     

移动IP中切换方法的探讨

文章提出了一种关于移动IP中同一个外地代理下和不同外地代理下切换的新方法，并通过比较说明新方法的优点。     

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。     

头标压缩算法在移动IPv6中的应用

无线网络的带宽相对较窄,为了解决移动IPv6分组头标开销过大问题,本文提出了移动IPv6头标压缩算法。在无线链路上仅在数据流开始的时候发送完整的分组和选项头标,后续的IPv6分组只传送头标域中的变化部分和相对同一个流的关键标识符,在无线链路的两端压缩/解压缩分组头标。该算法有较好的容错功能,有效利用了无线带宽,应用前景广阔。     

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。     

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.     

基于多智能体的CGF建模研究

为了解决某分布式虚拟训练系统中计算机生成兵力建模问题,对计算机生成兵力建模需求进行了全面分析。在此基础上,研究了基于多智能体的CGF模型。设计了由任务规划层和路径规划层组成的混合型智能体。根据智能体任务规划特点,提出了基于ANFIS的智能体任务务规划算法。通过仿真实验对智能体模型和算法的正确性进行验证,结果表明提出的智能体模型满足了建模需求,任务规划算法具有较好的精度。     

基于移动代理的应用层主动网络框架研究

将移动agent技术和主动网络思想融入下一代网络体系结构的研究中，提出了基于移动Agent的应用层主动网络的概念和框架模型。该模型主要从两个方面利用移动代理技术：一是主动包的封装；二是构造可迁移的移动代理环境MAE。并提供了对主动节点和网络服务动态定制的能力。     

移动协议网络层切换时延分析

对移动协议网络层切换时延进行了研究。提出合适的网络模型,从理论上分析了各移动协议的路径更新时间,并采用数值仿真的方法对采用微观移动协议和只使用移动IP协议以及采用不同的微观移动协议的情形进行了比较。研究结果表明路径更新时间与所采用的移动协议的路径更新方法相关;采用微观移动协议时的路径更新时间远小于只使用移动IP协议时的情形;在所有的微观移动协议中,MIP-RR协议中使用的路径更新方法性能最佳。     

A Proactive mobile‐initiated fast handoff scheme using the multihomed approach

Mobile IP (MIP) defines a mobility management for mobile users to continuously access data when the currently attachment is changed to another network. However, when mobile node (MN) roams between network segments, the handoff latency results in packet losses and transmission delay. In this paper, we propose a multihomed fast handoff scheme (MFH‐MIP) to decrease the handoff cost. In the proposed MFH‐MIP scheme, each MN is implemeted with the link layer trigger and multihomed techniques. Based on the link layer trigger, MN can collect signal strengths of nearby access points (APs) and switch to a new link automatically when the old link becomes unsuitable to connect. Using the multihomed technique, MN can prepare for handoff using two (or more) interfaces, in which (i) one is connected with the old link to receive packets and (ii) the other one is used to access nearby APs and select the most suitable one as the new link, in parellel. In this way, MN can continuously transmit and receive packets during handoff. Based on the proposed method, MN can roam smoothly among different networks in the wireless environment. Copyright © 2008 John Wiley & Sons, Ltd.     

分层多跳无线网中结合负载均衡的切换管理

该文主要研究分层多跳无线网络中的切换管理,提出一种新的用户切换管理算法和移动基站路由切换策略.在网络动态变化时,用户切换管理算法可以减少用户的切换次数,使用户负载分布均匀.移动基站路由切换策略则尽可能地从基站本地找出替代路由,可以在较小的开销下达到快速和无缝切换的目的.     

Route optimization in mobile ATM networks

This paper presents an algorithm for optimizing the route of a connection that becomes suboptimal due to operations such as handoffs and location-based reroutes, and applies this algorithm to the handoff management problem in mobile ATM (Asynchronous Transfer Mode) networks based on the PNNI (Private Network-to-Network Interface) standard. The route optimization algorithm uses hierarchical route information of the connection and summarized topology and loading information of the network to determine a “crossover node” such that adjusting the connection from that crossover node results in an optimally routed connection. Handoff management schemes that perform local rerouting of connections have been proposed in order to support fast handoffs. These methods result in suboptimally routed connections. In this paper, we demonstrate how this route optimization algorithm can be used to optimize the route of a connection after such a handoff is executed, as the second phase of a two-phase handoff scheme. This route optimization procedure can also be executed as part of the handoff procedure resulting in a one-phase handoff scheme. Applying this route optimization algorithm, we propose two one-phase schemes, the one-phase optimal scheme and the one-phase minimal scheme. A comparative performance analysis of one- and two-phase handoff schemes is presented. Measures of comparison are handoff latency and the amount of network resources used by a connection. Handoff latency in the one-phase optimal scheme is greater than that in the two-phase schemes, and handoff latency in the one-phase minimal scheme is smaller than that in the two-phase schemes. The one-phase methods show a significant increase in efficiency of the connection compared to the two-phase methods. This revised version was published online in June 2006 with corrections to the Cover Date.     

LEO卫星网络动态混合卫星切换策略

LEO卫星网络切换协议中的路由选择策略应当综合考虑路由本身优化性,路由计算复杂性,路由更新的信令代价。提出适合LEO网络卫星切换要求的动态混合路由选择策略(DHRS:DynamicHybridRouteSelection),即发生卫星切换时,由卫星节点根据移动终端用户切换前所处位置和切换前路由表等信息,为移动终端选择合适的路由。     

A wireless access network based on WDM-PON for HMIPv6 mobility support

In this paper, an IP-based wireless access network is proposed, which is designed to support the hierarchical MIPv6 standard on the wavelength division multiplexed passive optical network access network in order to provide a fast and seamless handoff support. Two schemes for enhancing the mobility management are included in the proposed network’s infrastructure support. Firstly, the local-link channels between sub-networks are provided to improve the mobility management efficiency for the mobile nodes roaming between neighboring sub-networks. Secondly, the early route optimization scheme has been applied, which optimizes the mobility management process between the corresponding node and the home agent (HA), resulting in reduced bandwidth waste and long end-to-end packet delays, as well as lowering the heavy burden on the HA. The performance of the proposed mobility management scheme has been evaluated in terms of handoff delays, packet losses and transmission costs. The superior performance of the proposed scheme has been verified and compared to other schemes.