一种改进的预先式快速切换技术

介绍了移动IPv6快速切换技术的原理,分析了快速切换技术的切换过程,指出了它的不足,并提出了快速切换技术的优化方案.新的切换技术使用链路层触发器和快速路由器通告来获取接入路由器的IP地址信息,并且使用IP地址与MAC地址映射来加快获得AR的IP地址.在切换过程中提前建立基站之间的隧道进行数据传输,进一步改善了快速切换的切换性能.     

移动IP技术的优化

移动IP技术解决了移动终端在移动时随时随地接入Internet网络的问题。但是现有的移动IP技术解决方案在路由、切换、注册等方面还存在一些缺陷。本文介绍了移动IP注册技术、移动IP路由技术和基于层次和转发链的移动IP切换技术,在此基础上对现有的移动IP注册、路由和切换技术进行了分析研究,并提出了移动IP基于区域的注册优化方案、通信对端保存移动节点地址绑定信息的路由优化方案及基于层次和转发链的移动IP切换优化方案。     

一种基于标地分离的卫星网络移动切换管理技术

移动卫星网络因具有覆盖区域广、通信延时低等优势受到广泛关注,当前有大量研究旨在开发IP协议的组网技术,并将其与地面IP网络融合。融合网络的挑战之一,即为卫星移动性,用户在卫星网络中的接入点频繁切换导致移动管理问题,而现有的移动IP技术不能高效支持卫星网络移动切换。为了高效支持移动切换,在卫星网络中应用标地分离思想,在标地分离的架构下研究切换管理问题;用映射服务系统对终端进行位置管理,在移动切换中由新接入卫星网关和终端的标志为主要信息在原卫星中形成通告转发表。仿真结果表明,相对移动IP技术,该方法有明显优势。将其应用于卫星网络时可以降低切换延时,减少大量的绑定更新开销或是次优路由,提升系统的性能和可扩展性。     

CDMA和WLAN之间的移动IPv6切换

随着IP技术和无线通信技术的发展和融合,移动IPv6成为了全球移动解决方案。针对移动IPv6的大规模应用,该文通过建立Silkroad隧道,实现CDMA和WLAN之间的移动IPv6垂直切换。针对CDMA网络进行切换优化的情况,提供了一种在蜂窝网和WLAN之间运用的移动IPv6切换方案。实验证明了该方案的有效性。     

一种移动IP协议链路层部分的设计与实现

为了解决移动IP协议切换过程中时延过高和丢包问题,论文给出了一个完整的基于双链路的移动IP协议的无线局域网链路层部分的设计和WindowsXP下一个基本的原型实现,利用链路层得到的无线网络信息预测和触发切换。这个原型在NDIS中间层驱动中实现,利用对象标识符(OID)来查询网络信息和控制无线网卡连接。同时论文阐述了设计和实现中的要点,通过与基本的移动IP切换过程进行分析和比较,证明了该系统在实现无缝切换方面的优势。     

一种有效的移动IP自适应主动预测邻居切换机制

现有的移动IP切换机制存在切换时延大,分组易丢失,安全性差等问题。该文从移动IP切换的关键问题移动检测出发,提出并实现了一种有效的自适应主动预测邻居移动IP切换机制,运用主动自适应预测算法,根据网络和移动主机的运动状态动态智能地预测移动主机的切换,实现快速平滑切换。仿真结果表明,该策略与现有机制相比,极大地减少了切换时延和切换次数,保证分组按时到达,提高了系统的切换性能,保证了系统的QoS。      

高速铁路移动通信网移动IPv6应用研究

针对高速铁路的运行特点,提出一种基于预测的高速铁路移动通信切换方法,引入列车路径信息表,移动节点切换到新链路前预先指定下一接入路由,准确判断切换方向,提前完成配置子网前缀和新转交地址过程。通过NS2仿真实验证明,该方法提高了切换效率,解决了网络资源利用率低和切换延迟大的问题。     

MG-HMIP协议模型的实现及应用

由于无线局域网(WLAN)IEEE802.11协议不能解决移动节点的三层漫游问题,介绍了WLAN与移动IP结合的解决方案。由于上述方案存在切换延时长、不支持微移动性等缺陷,研究了分层移动IP技术,并对分层移动IP进行了改进,提出了一个多GFA分层移动IP(MG-HMIP)模型,并详细介绍了MG-HMIP模型的注册机制和MN选择GFA的机制。最后,给出了MG-HMIP与WLAN结合的模型。这个改进的方案不仅解决了WLAN与传统的MobileIP结合所存在的切换延时长、频繁切换等问题,而且增强了分层移动IP的网络健壮性。     

双链路移动IP系统的实现与性能分析

为了解决移动IP中的切换时延和丢包问题,提出了一个基于链路层触发的双链路移动IP系统的实现方案,即利用链路层触发提前发起切换缩短切换延时,利用链路冗余防止丢包达到无缝切换的效果。详细介绍了该系统的设计和结构,以及链路层触发的发现、无线连接控制、移动路由和隧道的实现方法。最后对系统的性能进行了测试与分析,通过与基本的移动IP系统进行比较,验证该系统达到了无缝切换的效果。     

一种移动IP中链路层触发的方法

为了解决移动IP中的切换时延问题,提出了链路层监测触发和预测链路层切换的两种链路层触发方法。链路层监测触发方法省去了切换中移动检测时间,预测链路层切换方法将网络层切换提前于链路层切换进行。这两种方法通过在链路层属性中绑定网络信息或利用外地代理获得当前子网与相邻子网的网络信息的方法,判断发生了网间切换时才进行触发,避免了由链路层触发而导致的网络层的盲目切换。     

安全高效矿井通信系统技术要求

提出了矿用有线调度通信系统、矿井广播通信系统、多基站矿井移动通信系统、矿井漏泄通信系统、矿井感应通信系统、矿用透地通信系统、矿井救灾通信系统的技术要求。矿井广播通信系统应具有音频和视频全播、组播、选播及录音和记录功能;具有调度台与井下终端双向通话功能;具有井下终端呼叫地面调度功能等。多基站矿井移动通信系统应具有移动台与移动台、移动台与固定电话之间通话功能;具有短信和数据传输功能;具有移动台位置登记和越区切换功能;具有优先权设置、用户限时、非法用户禁用、中继汇接、自诊断和故障指示功能。矿井救灾通信系统应具有移动台与移动台、移动台与基站、移动台与地面基地通信终端、基站与地面基地通信终端通话功能;具有发起急呼、全呼和组呼的功能;具有基站和移动台脱网工作功能;具有图像监视功能;具有CH4,CO,O2及温度等监测功能;具有救护队员心跳、体温、姿态监测功能等。     

一种基于P2P的IP网络分层移动性管理方法

针对传统网络技术不适合移动通信且移动IP和SIP有单失效点固有缺陷的问题,文章提出了一种基于对等网络的IP网络分层移动性管理方法.该方法首先将问题结构定义为本地接入域网络和Internet全局网络两层模型,使用本地和全局两级覆盖网来处理该模型中接入网内的水平切换和跨接入网的垂直切换,并使用HIP协议来解耦静态主机标识和实际的网络位置.文章通过仿真实验指明将对等网络与移动性管理相结合的方法可以有效改善网络的可扩展性,并且信令开销和时延增加较少,此外HIP协议还为应用提供了透明的移动性和安全性的支持.     

蜂窝中继网络中协作切换策略研究

传统蜂窝网络架构存在着不少缺陷,小区边缘用户的服务质量远差于靠近基站中心的用户。通过部署中继,并完善其切换算法,提出了在该蜂窝中继网络中基于中继协作的切换策略,且对小区内及小区间切换策略进行细化,这样可以更精确的选择接入站点。比较了传统切换与协作切换中的切换阻塞率以及切换次数,通过仿真证明基于中继协作的协作切换的切换阻塞率小于传统切换,且基站间切换次数也得到降低,减轻了基站的负担,使系统性能得到提升。     

A novel re-authentication scheme based on tickets in wireless local area networks

Fast re-authentication schemes during handover of a mobile station are essential to seamless services for real-time multimedia applications in wireless local area networks. Although much research has been done to reduce re-authentication latency, the schemes developed so far either suffer from heavy burden problems or degrade the security level. In this paper, a novel ticket-based approach is proposed for re-authentication during handover. The mobile station receives handover tickets from the authentication server as a proof of authorization, and it presents the corresponding ticket when associating with a new access point. Our scheme reduces re-authentication delay to the delay of 2-way handshake between a mobile station and an access point. Furthermore, this scheme imposes less burden over the entities compared with other proactive key pre-distribution schemes, while satisfying 802.11i security requirements.     

移动IPv6快速切换在无线局域网中的实现

基本的移动IPv6切换延迟太大，不能满足实时业务的要求．因此IETF提出了基于隧道的移动IPv6快速切换协议．对移动IPv6的切换性能进行了分析，在无线局域网环境下提出了一种实现基于隧道的移动IPv6快速切换的方法．这种方法通过结合使用链路连接触发器和快速路由器公告，实现了将无线接入点链路地址快速映射成其连接的接入路由器信息，并且使用接入路由器信息缓存机制来优化切换过程．实验结果表明，该方法实现了移动IPv6快速切换，达到了很好的切换性能．     

Design,implementation and experimental evaluation of an end-to-end vertical handover scheme on NCTUns simulator

This paper presents the simulation study of “Host based autonomous Mobile Address Translation” using NCTUns simulator. It is a network layer, end-to-end vertical handover solution, based upon modification of “Mobile IP with address Translation”. Vertical handover approaches generally require new network elements, a new layer in TCP/IP stack, or fixing a protocol at a particular layer. To enhance handover experience, recent approaches focus on reducing signalling, localizing the registration, creating hierarchies, using proxy, preparing handover in advance, predicting target network, or exploiting multicasting and path extension techniques. These approaches, however, demand change in the network infrastructure to support mobility and limit the scope of mobility. Despite end-to-end signalling, the Host based autonomous Mobile Address Translation scheme ensures minimum service disruption and distinctly allows global mobility of the mobile node without requiring any modification in the network. We have simulated the mobility of a multi-interface mobile node in a heterogeneous network environment composed of WiFi (IEEE802.11a, IEEE802.11b) and WiMAX (IEEE802.16e) access networks. Performance of the scheme is evaluated taking into account wide range of end-to-end delays between mobile node and the correspondent node, various speeds of the mobile node and different packet loss rates of the network. Based on our detailed simulation study, it has been observed that this scheme offers reduced service disruption time, packet loss and packet latency. The service disruption time is found to be significantly low (typically in the range of 10 ms) compared to that of Mobile IP (which is in the order of 100 ms); this makes this new scheme perfectly suitable for real time applications. Low service disruption time consequently reduces the packet loss by manyfold and the packet latency remains unaffected during and after handover due to translation of address at the source. The results suggest that this protocol is a viable vertical handover solution due to its simplicity, scalability, low overhead and ready deployability.     

Call Admission and Handover in Heterogeneous Wireless Networks

Today's mobile communication networks support not just simple mobile voice and data services but also access to mobile Internet-based services with varying bandwidth and quality-of-service requirements. The work presented in this article addresses this issue by proposing a management architecture for mobile user roaming based on efficient call admission and handover control in heterogeneous wireless access networks. Our proposed architecture consists of databases that hold profile and policy information, a roaming controller with two main elements (namely, call admission control for new and handover traffic), and intersystem handover control     

An IMS-based integration architecture for WiMax/LTE handover

To enable seamless handovers for broadband networks, many researchers have addressed the integration of heterogeneous access technologies to provide users with always-on connectivity. Currently, there are several researches reported in the literature that discuss the integration of beyond 3G networks such as 3GPP Long Term Evolution LTE and mobile WiMax networks. They mainly focused on providing mobile users with seamless mobility when switching between heterogeneous access networks. In this context, many solutions for integration architecture have been proposed with mobility management considerations such as loose and tight coupling, IP Multimedia Subsystem IMS-based architecture and Evolved Packet Core EPC-based solutions for the purpose of providing mobile users with seamless handovers. In this paper, we present the different integration solutions and propose an integration architecture for WiMax and LTE access technologies with EPC as core network and IMS for service provisioning. A vertical handover VHO scheme is presented based on cross-layer approach that enables vertical handover with less handover latency and signaling cost.     

引入预处理转交地址池的HMIPv6切换技术研究

提出一种HMIPv6的改进协议PA-HMIPv6.PA-HMIPv6提供接入路由预选择机制,并在接入路由器和移动锚点引入转交地址池.接入路由器利用多重连接特性预先获取切换信息,提前为移动节点进行转交地址配置和重复地址检测操作,在移动节点切换之前完成地址池的初始化和信息更新工作,力求最大程度地减少切换时延.仿真实验表明,PA-HMIPv6协议能够有效缩短切换时延,减少切换过程中的数据包丢失率.