【作者】 刘亮；

【导师】 张钢；

【作者基本信息】 天津大学 ， 计算机应用技术， 2004， 硕士

【摘要】 无线局域网（WLAN）应用的迅速增长表明无线网络正在成长为现代通信的一个重要方式。随着对移动设备的熟悉和应用，人们越来越希望能充分利用这些设备的优势。为了保证移动设备从原来的域运动到另一个域后仍然可以保持与其他主机的通信，人们设计了移动 IPv6 协议，解决了移动设备在多个域间漫游所带来的诸多问题。但是，由于无线信号存在的衰减和干扰造成了 WLAN 中基站的覆盖范围有限，这就使得移动 IPv6 部署成本十分昂贵。为了在减少接入点的同时保证接入网络的服务覆盖范围，可以将 Ad hoc 网络和移动 IPv6 相结合，利用 Ad hoc 网络内移动节点到接入点的多跳路由来实现 Internet 无线接入。 本论文给出了移动 IPv6 和 Ad hoc网络路由协议相结合的 Internet 无线接入方案。使得那些不在接入点直接覆盖范围之内的移动节点，可以通过多跳 Ad hoc路由与接入点相连，进而获得 Internet接入服务。首先，论文扩展了移动 IPv6 机制，确保它可以同 Ad hoc 网络协同工作。新的移动 IPv6 机制可以很好地解决移动节点的宏观移动问题，规定了移动节点从一个域移动到另一个域后的一系列操作，保证了移动节点与 Internet通信的连续性。其次，在 AODV 路由协议的基础上给出网关发现算法，实现了移动节点在 Ad hoc 网络内部的网关自动发现和配置功能。最后，在 NS2 仿真平台上实现了三种类型的网关发现算法，并对它们的性能进行了比较。从仿真结果来看，基于 AODV 协议上的网关发现算法是可行的。 此外，还搭建了一个基于 Linux 系统的试验床，完成了 AODV 路由协议的IPv6 实现，并测试了实现代码的时延性能和网络应用支持情况。作为本文 Internet接入方案实现的第一步，AODV 的 IPv6 实现为后面的工作奠定了基础。更多还原

【Abstract】 The booming trend of Wireless LANs indicates that wireless networking israpidly becoming a prevalent form of communication. As users become moreaccustomed to the use of mobile devices, they increasingly require the additionalbenefit of roaming. The Mobile IPv6 protocol has been developed as a solution forallowing users to roam outside of their home networks, while still retaining networkconnectivity. However, the deployment of Mobile IPv6 with WLAN is expensivebecause coverage areas of WLANs are limited due to fading and interference. Toreduce the number of required Access Pointes while still maintaining the samecoverage, Ad hoc network functionality can cooperate with Mobile IPv6 such thatmulti-hop routes between mobile nodes and APs can be utilized. In this thesis, we present a method for enabling the cooperation of Mobile IPv6and the Ad hoc routing protocol, such that mobile nodes that are not within directtransmission range of an access point can still obtain Internet connectivity. Firstly, wehave modified the Mobile IPv6 protocol, in order that the protocol can cooperate withmobile Ad hoc networks. Secondly, we have made an extension to AODV protocol,using our algorithm to discover gateways. Finally, a lot of simulation experimentshave been carried out under NS2, and three approaches for gateway discovery areimplemented and for performance camparison. The result of the simulationsdemonstrates that the proposed gateway discovery mechanism added to AODV worksproperly. In addition, we have built up a test-bed based on Linux system. An AODVimplementation for IPv6 has been completed, which provides foundation for thefurther work.更多还原