CAREER: Opportunistic Routing in Multihop and Multirate Wireless Networks

摘要：机会路由是一个强大的新概念，它利用无线介质的广播性和网络拓扑的空间多样性来应对多跳无线网络中的时变无线链路。它在改善网络性能(如网络容量)方面的潜力还没有被很好地了解，也缺乏有效的分布式路由协议来充分利用它的优势在端到端路径级别实现性能优化。本课题主要研究多跳无线网络中OR的原理和协议设计。该成果还将扩展到包括其他新兴的无线技术，如多速率、多通道等。该项目有两个主要推动力。第一个重点是对OR所能达到的网络容量和性能界限进行理论研究。建立了一个新的理论框架来描述无线干扰、多速率能力、时变信道衰落以及它们对OR性能的影响。将设计一种方法来计算给定OR网络中的源和目的地对之间的吞吐量界限。第二个重点是开发分布式和高效的通信协议。现有的OR方案主要集中在链路层的协调机制上，而本课题中的路由协议设计的重点是在路径级更大范围地利用空间分集，以端到端的性能最优为目标。这项研究将推进多跳无线网络中OR基本极限的理论前沿，并将为此类网络中有效的OR协议设计提供更好的理论指导。

Abstract:Opportunistic routing (OR) is a powerful new concept that exploits broadcast nature of wireless medium and spatial diversity of network topology to cope with time-varying wireless links in multihop wireless networks. Its potential to improve the network performance, such as network capacity, has not been well understood and there is also a lack of efficient and distributed routing protocols that fully exploit its advantage to achieve performance optimality at the end-to-end path level. This project focuses on the theory and protocol design of OR in multihop wireless networks. The results will also be extended to incorporate other emerging wireless technologies, such as multi-rate, multi-channel, etc. There are two main thrusts in this project. The first thrust focuses on a theoretic study on the network capacity and performance bounds achievable by OR. A novel theoretical framework will be established to characterize the wireless interference, multirate capability, time-varying channel fading, and their impact on the performance of OR. A method to compute the throughput bounds between a source and destination pair in a given OR network will be devised. The second thrust is to develop distributed and efficient communication protocols. While existing OR schemes mainly focus on the link layer coordination mechanisms, the emphasis of routing protocol design in this project is on the exploit of the spatial diversity in a larger scale at path level and target to end-to-end performance optimality. This research will advance the theoretical frontier in characterizing fundamental limits of OR in multihop wireless networks and will provide a better understanding of theoretical guidelines to the efficient OR protocol design in such networks.