基于SIP的移动性管理

几个无线技术论坛,比如3GPP2,已经决定采用SIP作为移动因特网会话管理的信令协议,很显然SIP将成为移动因特网协议结构中不可分割的一部分。详细描述了怎样使用SIP对终端和个人移动性的支持。移动IP虽然使得移动性对更高层是透明的,但是它也带来了三角路由和隧道管理等问题,而SIP在应用层对移动性进行管理,对于实时通信来说,这种方案更加有效。     

基于SIP的无线网络移动性管理研究

为了使移动设备能在无线IP网络中无缝漫游,无线IP网络必须要能提供有效的移动性管理来支持终端的移动性。基于SIP提出了一种新的应用层移动性管理方案,和已有的移动性管理方案相比,它既支持实时业务的快速切换,减少了切换时的延迟和丢包,也支持非实时业务,而且实现和部署起来比较简单方便。     

基于SIP的无线网络移动性管理研究

为了使移动设备能在无线IP网络中无缝漫游，无线IP网络必须要能提供有效的移动性管理来支持终端的移动性。基于SIP提出了一种新的应用层移动性管理方案，和已有的移动性管理方案相比，它既支持实时业务的快速切换，减少了切换时的延迟和丢包．也支持非实时业务，而且实现和部署起来比较简单方便。     

基于SIP协议的移动Internet解决方案

移动Internet是移动通信与计算机网络技术迅猛发展的产物。介绍了基于应用层的适用于多媒体实时通信的实现方案——基于SIP协议的移动性方案。首先对SIP协议以及移动性支持进行了介绍。在此基础上,与移动IP方案进行对比,分析了SIP所具有的优越性。最后提出以SIP协议为统一信令的移动Internet的设想。     

基于多层小区结构的移动IP移动性管理

1.引言为了支持全球的IP网络互通和设备的漫游,IETF提出了IP移动性支持协议——移动IP。其中规定:只要MN移动到另外一个IP子网,它就会获得另外的转交地址,从而启动注册过程,该过程要求MN必须通过FA向HA进行注册,MN的任何移动都必须报告给HA,由HA来维护MN的移动绑定。这种简单的移动性支持方案可以与现有网络兼容,并且只需要在移动代理(包括HA、FA)和MN上根据终端的移动性要求进行改进即可实现移动IP功能。当应用于“宏移动”(macro mobility)时,这是必要的和充分的,而当应用于“微移动”(micro mobility)和“快速移动”(high mobility)的环境时,则存在许多不足,突出表现在以下三点:1.在网络中将引发大量的注册报文的传输从而严重影响网络性能;2.造成较大的     

一种基于GPRS的IP网管系统移动性扩展方式

IP网管系统因其能有效提高IP网络管理效率而被广泛采用,但仍尚未实现其随时随地接入与访问。通过分析IP网管系统的架构和对其进行移动性扩展的影响因素,提出了一种利用GPRS无线网络为承载,以PocketPCSmartphone为移动网管终端的移动性扩展方案。方案中不仅考虑GPRS数据传输速率的限制因素,也要针对PocketPCSmartphone的操控特点进行分析和设计。试验系统测试结果表明,IP网管系统在进行移动性扩展后,实现了用户通过移动智能终端在GPRS网络覆盖下的IP网管系统接入与访问,使用移动智能     

基于多协议层联合优化的移动性管理技术

针对下一代网络的通用移动性,从多协议层联合优化的角度提出一种可以有效融合多业务的通用移动性管理方案。该方案以网络层移动性支持协议（Mobile IP）及其微移动管理协议为基础,并在此基础上融合会话初始协议（SIP）,将网络层移动性管理与应用层移动性管理进行联合优化设计,同时考虑链路层的切换,减少功能性和信令数据信息的重复。     

Mobile IP指引无线网络

计算机产业的两个趋势越来越明显,一是Internet的发展,二是移动式计算机的运用越来越广泛,人们需要访问基于IP的网络,包括Internet和Intranet。Internet的新标准Mobile IP(移动IP)将用来提供移动计算机的无缝连接,支持任何有线及无线的基础媒介层。 Internet路由器使用分布路由表,可以发送基于IP地址的IP数据包,其中一部分指定目标计算机的子网。这种传统方案妨碍了具有固定IP地址的计算机同其它子网的连接。简单的解决方法是不使用固定IP地址,而通过     

IP是怎样长脚的——移动IP的实现机理

传统 IP 技术的主机使用固定的 IP 地址和 TCP 端口进行通信。在通信期间,它们的 IP 地址和 TCP 端口号必须保持不变,否则 IP 主机之间的通信将无法继续。移动通信的兴起,催生了移动 IP 技术。移动 IP 能够保证计算机在移动过程中,在不改变现有 IP 地址、不中断正在进行的网络通信以及不中断正在执行的网络应用的情况下,实现对网络的不间断访问。一个移动 IP 终端需要两个 IP 代理服务器,第一个称为“家”代理,第二个称为“外”代理。移动 IP 技术的工作机理分为以下几部分。A.移动终端在其归属网中,以普通的 TCP/IP 方式进行通信,不使用移动 IP。B.移动终端漫游到其他网络,仍使用原来的 IP 地址进行通信。为了收到别人发给它的 IP 包,它需要向家代理注册当前位置的地址——转交地址。它可以     

基于SIP协议的应用层个人移动性的分析

移动IP技术对于移动性的支持在网络层,需要对网络协议进行修改,而SIP协议在应用层提供了对移动性的支持,无需底层网络协议的改变.文中深入探讨了SIP协议在应用层支持个人移动性的工作原理,设计了两个典型的个人移动性应用场景,进行了试验验证并对试验结果进行了分析讨论.试验充分证明了SIP协议在应用层对于个人移动性的良好支持,为解决底层移动协议对移动性支持所带来的种种问题以及移动IP缺失的环境提供了有益的补充.     

A flexible graphical user interface for performance modeling

We identify three goals for the graphical user interface (GUI) of a network simulation environment: user friendliness, model re-usability, and application extensibility. We address the user-friendliness issue by proposing a simple yet efficient approach to setup parameters for the simulation models. We address the application extensibility issue with a two-layer GUI architecture. The two layers are loosely coupled, and the first layer can be easily replaced without affecting the other components of the simulation environment. The concept of subnetwork is used to address the model reusability issue. Unlike most existing simulation packages, where a subnetwork is simply a method to group the nodes, the subnetwork construct in our approach is a first-class citizen in the simulation environment (i.e., all operations for a basic node also apply to a subnetwork). The port concept is used to define the I/O relationship between a subnetwork and the outside world. Parameter dialog boxes are used to set up the parameters for a subnetwork conveniently. Finally, a simple stack mechanism is used to measure subnetwork-wide output statistics.     

移动计算机网络协议结构

本文研究了移动计算机网络的动态寻址和移动透明性问题，提出了基于归属名字服务器和拜访名字服务器的移动管理方案。归属名字服务器存在移动台的归属地址和当前地址等信息，拜访名字服务器存有进入其所在子网移动台的寻址信息，并在移动台离开后延缓两倍分组寿命的时间再删除其寻址信息，即避免频繁地交互移动管理信息，又不用担心寻址信息过时。本文给出了移动计算机网络的协议结构，可支持有连接和无连接通信。     

Mobility label based network: Mobility support in label switched networks with multi-protocol BGP

To support mobility the network control plane is required to detect changes in the mobile node’s location and distribute the new location information throughout the network thus enabling the forwarding plane to deliver traffic in an optimal manner. The network responsiveness to the mobile node movements can be generally thought of as the time elapsed between the moment the node’s location in the network has changed and the moment the reception of packets in the new location has resumed. This paper outlines an approach to handling the user mobility at the network layer in the context of multi-protocol label switched networks (MPLS). This new approach does not rely on the existing IP mobility management protocols such as Mobile IP and is instead based on the combination of multi-protocol BGP (MP-BGP) and MPLS. This paper proposes to introduce new protocol elements to MP-BGP to achieve mobility label distribution at the network control plane and the optimal packet delivery to the mobile node by the network forwarding plane using MPLS regardless of the IP protocol addressing and the associated logical network topology.     

Intra domain route optimization for ubiquitous network

The main advantage of a wireless network is user mobility, which calls for efficient routing support at the network layer. An architecture combines hierarchical mobile IPv6 and network mobility for a network mobile and mobile nodes move in tandem and make a hierarchy in the wireless network to management of micro-mobility and seamless handoff. But the capability of the architecture for intra domain route optimization is impaired. So we propose functionality in domain nodes to enable intra domain path optimization for ubiquitous network. It is shown that intra domain cost effect is beneficial in every hierarchical domain that spans mesh network topology. We address the key function for our proposed scheme and analyze the usefulness of our proposed method using mathematically. We show that our proposed scheme performs much better than Network Mobility protocol, especially when the number of mobile nodes or mobile routers or correspondent nodes increases in hierarchically nested in ubiquitous networks.     

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.     

基于IPv6的移动自组网移动切换方案*

提出了一种基于IPv6的移动自组网移动切换方案IMHM.在没有基础设施的MANET中,IMHM实现了移动节点家乡地址的永久性,即用户采用移动节点的家乡地址与移动节点保持通信,无须参与移动切换过程,移动节点的移动过程及转交地址变更过程对用户透明.对AODV和IMHM的移动切换代价和移动切换延迟等性能参数进行了分析比较,分析结果表明IMHM的移动切换代价更小、移动切换延迟更短.     

A mobile knowledge carrier with personalized knowledge provision

In the e-commerce era, the organization knowledge within a centralized knowledge management server can be easily accessed over the Internet by the client PCs at distinct locations. Currently, the personal digital assistant (PDA) has been widely used as the carrier for personal memos and daily records for its high mobility. Taking advantage of the personal information, the user requirements for knowledge can be determined. This research presents an intelligent KM scheme by integrating the PDA information (including notes, schedules and address book) mining model and mobile knowledge management mechanism. Based on the user profile mining technique, the PDA-ready knowledge that fits user requirements can be imported from the knowledge server to the client PDA. Demonstration cases are also provided to illustrate the applications of the proposed model in the content services and healthcare industry. By application of the mobile KM technique, the organization knowledge can be seamlessly provided to the PDA user via the data synchronization process. The attempt of this paper is to present an applicable and intelligent mobile knowledge carrier for realization of the mobile office.     

Context-aware adaptive IP mobility anchoring

The novel distributed mobility management trend is a promising direction to cope with the increasing mobile data traffic and flatten network architectures. Most of the novel mobility approaches distribute the mobility anchors through the access level, as opposed to the centralized mobility anchoring model. Other recent approaches argue that mobility anchors closer to the content servers may be the solution to optimize the mobility performance. However, none of the mobility anchoring models is ideal for all scenarios, since it depends on the user, the session and the network. Hence, we propose an IP mobility approach driven by the context of the user, sessions and the network, where the mobility anchors for IP address allocation and for routing/forwarding are distributed through the network nodes, while the mobility context is managed by the mobile devices. Although each session is properly anchored in the establishment phase, the routing/forwarding is adapted over time, according to the user, the session and the network context: the proposed approach is able to signal different mobility anchors to optimize the routing path to new and ongoing sessions of the user. The outcome of the evaluation shows that the proposed approach overall reduces the data cost, the data delay, the tunneled packets and the tunnel length, when compared with other anchoring models.