一种基于MobiCast的移动IP组播方案

本文提出一种改进的MobiCast方案来实现移动IP组播通信,主要解决MobiCast方案中进行区域间切换时组播数据包丢失问题。与MobiCast方案相比,在区域外地代理(DomainForeignAgent,DFA)处引入一种缓存的机制。当移动节点发生区域间切换时,移动节点的旧区域外地代理采用隧道技术,将移动节点的信息和缓存的组播数据包发送给移动节点的新区域外地代理处,减少移动节点进行区域间切换时丢失的组播数据包。     

基于IPv4的可靠移动组播技术

移动组播技术是近几年来无线互联网领域的一个研究热点,其相当一部分应用要求移动环境下也能提供相当于有线链路的可靠性。但是移动环境下的突出特点就是链路差错率高,组播成员位置动态变化,这给移动组播尤其是可靠移动组播提出了很大的挑战。基于IPv4的可靠移动组播算法具有两种不同的设计思想,其中一部分算法是针对现有的移动组播算法存在的问题,进行可靠性方面的改进,另一部分算法是专门用于实现可靠移动组播的,它们大都引入了新的功能实体来保证可靠性。     

基于移动IP的组播协议

总结了目前在移动IP网络中组播领域的主要算法,分析比较了它们的特点和性能,概括了其中的主要研究问题,并对该领域未来的研究进行了展望.     

基于移动接收节点的IP组播技术研究

本文分析和研究了当接收节点处在移动环境中时进行IP组播的各种方案,以移动特有的问题为背景,着重讨论了如何综合考虑在组播应用中支持移动接收节点;并对支持组播接收节点移动的各种方案进行了归纳和总结。     

移动IP支持组播的技术

组播（Multicast）是指源一次发送的数据报被送到多个目的地，用来支持点到多点和多点到多点的通信。移动IP作为未来Internet的一支主力军，需要支持组播。本文回顾了移动IP和IP组播技术，分析了几种移动IP支持组播的机制，并对这几种机制进行了比较。     

一种改进的层次型移动组播协议

论文介绍了现有层次性移动组播协议——Mobi Cast协议,分析了该协议的优缺点。在Mobi Cast协议的基础上通过加入隧道技术,并减轻基站开销等方面进行了改进。仿真与分析表明,改进后的Mobi Cast协议具有组播数据丢包率低、网络维护开销小、切换延迟短等特点。     

移动IP组播方案

目前的移动IP方案没有较好解决对组播的支持。文中分析了当前移动IP组播的几种方案以及存在的问题，比较了各自的优缺点，提出了一种改进的基于移动IP的移动主机组播技术方案，并与其他方案做了比较。     

基于组播代理的移动组播实现机制研究

首先介绍了移动组播面临的问题,并对现有的移动组播算法和协议进行了介绍,对其实现的机制、特点进行了详细分析。针对移动组播面临的问题,提出了一个基于组播代理的移动组播协议ABMoM,并对ABMoM的实现原理、组成员管理机制以及移动切换问题的处理方法进行了详细的论述。     

移动因特网及移动IP中的组播技术

移动因特网是因特网和移动通信网未来发展的一个重要方向。本文从因特网协议的层次出发,分析了移动因特网的无线物理和数据链路层、移动IP层等的特点,分析了几种移动IP支特组播的机制。比较了它们与有线因特网层次之间的区别。     

一种适用于动态/移动环境的新的组播协议

组播协议由于能够有效的利用网络带宽并降低服务器的负担因而受到广泛的关注.其中的共享树组播协议由于具有良好的扩展性而得到更多的支持,然而目前的共享树组播协议在动态移动环境中的性能很差,一些改进协议(单核移动协议)虽然可以很好的提高原有协议的性能但是所需要的额外开销很大.针对这种情况,本文提出了一种新的共享树组播协议-动态多核协议,该协议能够根据组播成员的分布动态的渐进的调整组播树的形状,从而能够在低开销的情况下为移动用户提供良好的性能.计算机仿真和数学分析都表明动态多核协议要明显优于共享树组播协议和单核移动协议.     

Wireless Ad Hoc Multicast Routing with Mobility Prediction

An ad hoc wireless network is an infrastructureless network composed of mobile hosts. The primary concerns in ad hoc networks are bandwidth limitations and unpredictable topology changes. Thus, efficient utilization of routing packets and immediate recovery of route breaks are critical in routing and multicasting protocols. A multicast scheme, On-Demand Multicast Routing Protocol (ODMRP), has been recently proposed for mobile ad hoc networks. ODMRP is a reactive (on-demand) protocol that delivers packets to destination(s) on a mesh topology using scoped flooding of data. We can apply a number of enhancements to improve the performance of ODMRP. In this paper, we propose a mobility prediction scheme to help select stable routes and to perform rerouting in anticipation of topology changes. We also introduce techniques to improve transmission reliability and eliminate route acquisition latency. The impact of our improvements is evaluated via simulation.     

A Domain-Based Routing Protocol for SSM Source Mobility in Mobile IPv6 Networks

In Mobile IP, the signaling traffic overhead will be too high since the new Care-of-Address (CoA) of the mobile node (MN) is registered all the way with the home agent (HA) whenever the MN has moved into a new foreign network. To complement Mobile IP in better handling local movement, several IP micro protocols have been proposed. These protocols introduce a hierarchical mobility management scheme, which divides the mobility into micro mobility and macro mobility according to whether the host's movement is intra-domain or inter-domain. Thus, the requirements on performance and flexibility are achieved, especially for frequently moving hosts. This paper introduces a routing protocol for multicast source mobility on the basis of the hierarchical mobile management scheme, which provides a unified global architecture for both uni- and multicast routing in mobile networks. The implementation of multicast services adopts an improved SSM (Source Specific Multicast) model, which combines the advantages of the existing protocols in scalability and mobility transparency. Simulation results show that the proposed protocol has better performance than the existing routing protocols for SSM source mobility.     

Multicast Handoff Agent Mechanism for All-IP Mobile Network

This paper proposes a mechanism called a Multicast Handoff Agent (MHA) to reduce handoff latency for IP multicast. The MHA acts as a proxy for the Internet Group Management Protocol (IGMP) of mobile nodes and keeps information for members of multicast groups in a cell. When a mobile node moves to other cell, the MHA immediately sends unsolicited reports without waiting for the IGMP query. In addition, our mechanism may conserve battery power since it does not need to reply to a query.The mechanism is evaluated through simulation and analysis and compared with the IGMPv2 for mobility and IGMP traffic. Simulation results show that handoff latency can be largely reduced and the IGMP control traffic can be eliminated on the wireless links during the duration of membership.     

Broadband-Facilitated Inter-WLAN Mobility Architecture

The existing WLAN architecture does not have the capabilities to leverage the wired and wireless broadband-accessed network control for the Inter-WLAN mobility. This paper presents a broadband-facilitated inter-WLAN mobility system architecture including its realization with the wired and wireless broadband-accessed network control for the WLAN mobility management. The proposed broadband-based inter-WLAN mobility management concept has changed the notion of the traditional WLAN mobility. Secondly, an implementation of the distribution system with broadband-accessed central network control for the IEEE 802.11 inter-WLAN mobility along with its management protocol is presented. In addition, this paper provides the modification to the enhanced IAPP protocol signaling messaging required for the broadband-facilitated WLAN mobility management. Finally, simulation experimental results for the proposed inter-WLAN communications architecture’s performance vs. WLAN mobility management performance employing standard and optimized MIP are presented. We believe that the proposed architecture would greatly enhance the Inter-WLAN IP mobility performance. This paper serves as a foundation work for future research in inter-WLAN mobility management using broadband, wired and wireless that integrates high-speed wide area network and WLANs.     

一种移动IP快速平滑切换方案

无线IP网络中将采用移动IP实现移动性管理,但该方案应用在高频度切换环境,存在不可接受的切换时延和数据包丢失,很难保证通信业务的服务质量.提出了一种移动IP快速平滑切换方案,该方案利用后注册切换的概念,在切换过程中不存在数据包的丢失,并可以获得很小的切换时延,在实际系统中运行能够达到良好的效果.