Mobility Tolerant Adaptive Multicast Protocols for Ad Hoc Networks

Ad Hoc 网络的移动容忍自适应组播协议

• 批准号: 0073409
• 负责人: Sandeep Gupta
• 金额: $ 30万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-15 至 2001-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0073409&HistoricalAwards=false
• 关键词: Mobility; Tolerant; Adaptive; Multicast; Protocols

Mobile ad hoc networks consisting of mobile hosts that communicate via wireless radio channels are being increasingly used for local area networks, law enforcement, military operations and myriad of other applications. Most of these applications, if not all, involves sending messages from one host (source) to a specified group of hosts and there can be a large number of such groups in the network for diverse kinds of applications. Multi-cast involves sending messages to a restricted group of processes and forms the basis for efficient implementation of group based applications on a distributed system. Many protocolsfor efficiently performing multi-cast in static networks are available while at this time, a number of critical technical issues in designing such protocols for ad hoc networks remain unresolved, including elegant solutions to issues of power limitations and high speed data, effective methods of assurance for losslessness of the messages during transition period due to host mobility and the ability to contain the effect of any topology change locally. In mobile ad hoc networks the topology of the network changes with node movements, variations in the radio propagation conditions, and depletion of battery power of the nodes. The rate of topological changes can be different at different times, as well as in different regions of the network. The network can experience frequent network partitioning and may require reconfiguration of the partitioned subnetworks. The proposed research will take a combined theoretical and experimental approach and will apply this to emerging distributed applications. In this proposal the researchers with combined expertise in the fields of group based communications in networks and stabilization of protocols in asynchronous distributed computing systems are proposing an innovative integrated research project in fault-tolerant multi-cast protocol design for mobile ad hoc networks. The proposed design intends to demonstrate a variety of impressive benefits including: (1) The protocol will support mixed traffic of variable rates with the ability to adapt fast with ease to sudden changes in traffic via a dynamic link cost estimator (that depends on channel bandwidth, quality-of-service (QoS) to the applications, battery power of the hosts, etc.) (2) The protocol is self-stabilizing in that any topological change due to mobility of nodes will trigger the protocol and the optimal multicast tree will be for the new topology and quickly reconstructed. (3) The self-stabilizing protocols are augmented with features that guarantees that the service remains available while the multi-cast tree is being adapted to the new topology (i.e., multicast messages present in the system during the recovery period are not lost). (4) The self-stabilization features of the protocol are triggered in a controlled manner so as to not overwhelm the system in presence of high mobility by using efficient fault-containment strategies. (5) The research intends to develop a new execution model for the self-stabilizing algorithms in a distributed system based on the real-life conditions of an ad hoc network as opposed to the traditional adversarial oracle model for such algorithms. The researchers expect that this will lead to the use of the concept of self-stabilization to solving other real life problems involving recovery from a transient behavior. Efficient solutions for performing multi-casting in mobile ad hoc networks with the above benefits will rely on what support underlying data link layer can provide and how the network layer multi-cast protocol can exploit these facilities to intelligently control the overheads while providing desirable QoS. This proposal will take a synergistic approach in designing the multi-cast protocols so as to make them compatible with the underlying networking layers. The developed protocols will be extensivaly evaluated through simulation. Further a prototype protocol stack will be implemented on the top of IEEE 802.11 MAC layer to evaluate the improvement in QoS to distributed media distribution and collaboration applications.

由通过无线电信道通信的移动主机组成的移动自组织网络越来越多地用于局域网、执法、军事行动和无数其他应用。 这些应用程序中的大多数（如果不是全部）都涉及从一台主机（源）向指定的一组主机发送消息，并且网络中可能存在大量此类组以用于不同类型的应用程序。 多播涉及将消息发送到受限的进程组，并构成在分布式系统上高效实现基于组的应用程序的基础。 许多用于在静态网络中高效执行多播的协议都可用，但此时，为自组织网络设计此类协议的许多关键技术问题仍未解决，包括功率限制和高速数据问题的优雅解决方案、由于主机移动性而保证过渡期间消息无损的有效方法以及本地包含任何拓扑变化影响的能力。 在移动自组织网络中，网络拓扑随着节点移动、无线电传播条件的变化以及节点电池电量的耗尽而变化。 拓扑变化的速率在不同时间以及网络的不同区域可能不同。 网络可能会经历频繁的网络分区，并且可能需要重新配置分区的子网。 拟议的研究将采用理论和实验相结合的方法，并将其应用于新兴的分布式应用程序。 在本提案中，具有网络中基于组的通信和异步分布式计算系统中的协议稳定性领域的综合专业知识的研究人员提出了一个创新的综合研究项目，用于移动自组织网络的容错多播协议设计。 所提出的设计旨在展示各种令人印象深刻的优势，包括：(1) 该协议将支持可变速率的混合流量，能够通过动态链路成本估计器（取决于信道带宽、应用程序的服务质量 (QoS)、主机的电池电量等）快速轻松地适应流量的突然变化。(2) 该协议具有自稳定功能，因为节点移动性导致的任何拓扑变化都会触发该协议 最优的组播树将针对新的拓扑而快速重建。 (3) 自稳定协议增加了保证在组播树适应新拓扑时服务保持可用的功能（即，在恢复期间系统中存在的组播消息不会丢失）。 (4) 该协议的自稳定功能以受控方式触发，以便通过使用有效的故障遏制策略在高移动性的情况下不会压垮系统。 (5) 该研究旨在基于自组织网络的现实条件，为分布式系统中的自稳定算法开发一种新的执行模型，而不是此类算法的传统对抗性预言模型。 研究人员预计，这将导致使用自稳定的概念来解决涉及从短暂行为中恢复的其他现实生活问题。 在具有上述优点的移动自组织网络中执行多播的高效解决方案将依赖于底层数据链路层可以提供什么支持，以及网络层多播协议如何利用这些设施来智能地控制开销，同时提供所需的 QoS。 该提案将采用协同方法来设计多播协议，以使它们与底层网络层兼容。 开发的协议将通过模拟进行广泛评估。 此外，原型协议栈将在 IEEE 802.11 MAC 层的顶部实施，以评估分布式媒体分发和协作应用程序的 QoS 改进。