Integrated Multicast for Ad Hoc Networks (IMAHN-NSF)

本提案将研究、设计和部署一套主要针对自组织网络的新型多播协议。研究人员认为，由于固有的广播能力，无线网络非常适合多播通信。所提出的组播分组路由和转发协议套件（IMAHN）的贡献可以概括如下：(1)为ad hoc网络设计，评估，原型设计和部署一套组播路由和分组转发协议；(2)为未来混合媒体互联网开发集成多路路由解决方案；这包括调查、评估、原型设计和部署提供无缝多播服务的机制。IMAHN将强调以下几点：(1)鲁棒性与效率：许多现有的组播路由方法依赖于路由器的状态来跟踪组播组成员。这一点，再加上大量的路由信息交换和缓慢的收敛，使得传统的多播方法在由弱（低功耗，低存储容量）主机组成的高动态自组织网络（AHNs）中站不住脚跟。我们提出了一种新的技术，适应性洪水，强调快速和稳健的输送。IMAHN将由一套自适应协议组成，解决一系列ahn和移动模式。在不断变化的ahn中，冗余广播可能是合适的，而在不太动态的ahn中，将考虑一系列带宽效率更高的组播协议；(2)适应性：主机应该能够（并且愿意）在自组网、固定基础设施、移动网络和传统有线网络之间自由迁移。当面对底层基础设施的变化时，为了适当地发挥作用，主机需要在多个多播机制之间动态切换；(3)无限移动：现有的一些解决方案倾向于离散移动，即运动期间穿插着休息期间。另一些则对同时移动的主机的方向、速度和数量有一定的限制。相反，我们强调所有网络组件的通用、无限移动性；(4)集成组播：ahn的组播解决方案很可能与固定网络的组播解决方案有很大不同（主要原因之一是传输速率的显著差异）。为了为未来的混合媒体互联网提供无缝和集成的多播服务，IMAHN将开发新的固定和无线多播解决方案互操作机制。

This proposal will investigate, design and deploy a suite of novelmulticast protocols aimed primarily at ad hoc networks. The investigatorsmaintain that, due to the inherent broadcast capability, wireless networksare well suited for multicast communication. The contributions of theproposed suite of multicast packet routing and forwarding protocols (IMAHN)can be summarized as follows: (1) design, evaluation, prototyping anddeployment of a suite of multicast routing and packet forwarding protocolsfor ad hoc networks, and (2) development of an integrated multicastrouting solution for the mixed-media internetwork of the future; thisincludes investigation, evaluation, prototyping, and deployment ofmechanisms providing seamless multicast service.IMAHN will emphasize the following: (1) robustness vs efficiency: manyexisting multicast routing approaches rely on state in routers to keeptrack of multicast group members. This, coupled with the high volume ofrouting information exchanges and slow convergence, makes traditionalmulticast approaches untenable in highly dynamic ad hoc networks (AHNs)composed of anemic (low-power, low storage capacity) hosts. We propose anew technique, adaptive flooding, that stresses rapid and robust delivery.IMAHN will consist of a suite of adaptive protocols addressing a range ofAHNs and mobility patterns. In constantly changing AHNs, redundantbroadcasting may be appropriate, while, in less dynamic AHNs, a range ofmore bandwidth-efficient multicast protocols will be considered; (2)adaptability: hosts should be able to (and will) migrate freely among adhoc, fixed-infrastructure mobile, and traditional wired networks. In orderto function appropriately -- when faced with changes in the underlyinginfrastructure -- hosts need switch on-the-fly among multiple multicastmechanisms; (3) unlimited mobility: some existing solutions are gearedtowards discrete mobility where periods of movement are interspersed withperiods of rest. Others assume certain limits on direction, speed andnumber of simultaneously moving hosts. In contrast, we stress universal,unlimited mobility of all network components; (4) integrated multicast:multicast solutions for AHNs will most likely differ substantially fromthose for fixed networks (one of the main reasons is the marked differencein transmission rates). In order to offer seamless and integrated multicastservice for the mixed-media internetwork of the future, IMAHN will developnovel mechanisms for inter-operation of fixed and wireless multicastsolutions.