CAREER: Opportunistic Routing in Multihop and Multirate Wireless Networks

摘要机会路由（OR）是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时变的无线链路的一个强大的新概念。它改善网络性能（如网络容量）的潜力尚未得到很好的理解，而且还缺乏有效的分布式路由协议，无法充分利用其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。研究结果还将扩展到其他新兴无线技术，如多速率、多信道等。这个项目有两个重点。第一部分的重点是理论研究的网络容量和性能边界可达到的OR。本文将建立一个新的理论框架来描述无线干扰、多速率性能、时变信道衰落及其对OR性能的影响。设计了一种计算给定OR网络中源对和目的对之间吞吐量边界的方法。第二个重点是开发分布式和高效的通信协议。现有的OR方案主要关注链路层协调机制，而本项目路由协议设计的重点是在更大范围内利用路径级的空间多样性，并以端到端性能最优为目标。本研究将推进多跳无线网络中OR基本限制特征的理论前沿，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.