Scalable Routing and Multicast in Mobile Ad Hoc Wireless Networks

在这项研究中，研究人员考虑了大量的移动的站，这些站通过多跳无线网络互连。这种无线基础设施的应用范围从自组织网络（例如，协作、分布式计算）到灾难恢复（火灾、洪水、地震）、执法（例如，人群控制）、搜索和救援以及战场。 这一系统的主要特点是用户数量大、移动性强以及能够在没有固定（有线或无线）基础设施支持的情况下运作。 最后一个功能设置这个系统除了现有的蜂窝系统，实际上使其设计更具挑战性。在这种环境中，研究人员建议开发路由和多播策略，以及可扩展到大量的节点，可以处理的流动性。 大量的数字和流动性的结合使这个问题变得非常困难。 事实上，如果节点是固定的，则可以使用分层路由来有效地处理大型网络。 当节点移动时，层次划分必须动态地改变-这是一个重大的挑战。 当存在支持固定“归属代理”概念的固定基础设施时，移动的IP解决方案工作良好。 当所有节点都移动时，归属代理策略就不那么明显了。除了大量和移动性，我们还需要支持多媒体通信，与低延迟的要求为交互式业务和QoS支持的真实的时间流（语音/视频）。在无线路由领域，已经提出并实现了几种方案（例如，分层路由，按需路由等）。研究人员将讨论现有方案的优点和缺点，并将介绍两种新的方案-分层，移动的路由和鱼眼路由-克服了现有方案的一些局限性。 在无线多播领域，我们回顾了有线网络中使用的传统方案（例如，源树，基于核心的树等），并显示它们在高度移动的网络中表现不佳。然后，我们引入了一个新的概念，转发组组播，其中的树被替换为一个网状的转发节点-后者是更容易维护比树在面对的流动性。研究人员建议将按需路由策略扩展到这种结构，以处理大规模。

In this study the researchers consider a large population of mobile stations which are interconnected by a multihop wireless net. The applications of this wireless infrastructure range from ad hoc networking (eg, collaborative, distributed computing) to disaster recovery (fire, flood, earthquake), law enforcement (eg, crowd control), search and rescue and battlefield. Key characteristics of this system are the large number of users, their mobility and the ability to operate without the support of a fixed (wired or wireless) infrastructure. The last feature sets this system apart from existing cellular systems and in fact makes its design much more challenging.In this environment, the researchers propose to develop routing and multicast strategies which scale well to a large number of nodes and which can handle mobility. The combination of large number and mobility makes the problem very hard. In fact, large networks can be effectively handled with hierarchical routing, if nodes are stationary. When nodes move, the hierarchical partitioning must be dynamically changed - a significant challenge. Mobile IP solutions work well when there is a fixed infrastructure supporting the concept of fixed "Home Agent". When all nodes move, the Home Agent strategy is less obvious. In addition to large number and mobility, we address also the need to support multimedia communications, with low latency requirements forinteractive traffic and QoS support for real time streams (voice/video).In the wireless routing area, several schemes have already been proposed and implemented (eg, hierarchical routing, on-demand routing etc). The researchers will discuss the pro's and con's of the existing schemes, and will introduce two new schemes - hierarchical, mobile routing and Fisheye routing - which overcome some of the limitations of the existing schemes. In the wireless multicast area, we review the traditional schemes used in wireline networks (eg, Source Trees, Core Based Tree, etc) and show how they perform poorly in highly mobile networks. We then introduce a new concept, Forwarding Group Multicast, in which the Tree is replaced by a mesh of Forwarding Nodes - the latter being much easier to maintain than the tree in the face of mobility. The researchers propose to extend the on-demand routing strategy to such structure to handle large scale.