Exploiting the Wireless Broadcast Advantage in Coded Wireless Mesh Networks

本研究计画旨在探讨无线网状网路中无线广播优势的潜力。最近的理论和实验研究表明，无线广播的优势提供了显着的收益在无线网状网络。利用无线广播的一个关键技术是可管理的开销是网络编码，它侧重于转发包含在数据包中的信息到目的地，而不是未经修改的数据包本身。我们建议研究网状网络中的无线广播优势与网络编码和实验证明网络编码在真实的世界环境中的适用性。为此，我们最近开发的polymatroid广播功能模型的无线广播的优势，以国家的最先进的WiFi网络和研究媒体访问机制和物理层技术与此模型的相互作用。基于此模型，我们设计了一个无线网状协议，利用网络编码，有效地利用无线广播的优势，以提高各种性能指标。尽管用于无线网络的现有技术的网络编码协议是科普和MORE，两者都是在MIT开发的，并且由于无线介质的广播性质而都显示出基本的增益，但是它们都为关于介质访问方案的优化、双向和多播业务、与更高层协议的互操作性、以及关于自适应物理层模型。此外，我们提出的协议是无线网格演示和实验设置的核心，基于IEEE 802.11消费设备的节点多达25个。实验的目的是证明网络编码的好处，在无线网状网络与不同的流量情况下，并分析网络编码的性能，以利用无线广播的优势，在真实的世界的情况下的吞吐量，可靠性，延迟，协议和协调开销，与常见的网络和传输层协议的相互作用，以及进一步的指标。我们还旨在比较所提出的方法，最先进的无线网状网络解决方案，如IEEE 802.11s。

This research project aims at exploring the potential of the wireless broadcast advantage in wireless mesh networks. Recent theoretical and experimental research has shown that the wireless broadcast advantage offers significant gains in wireless mesh networks. A key technique to exploit the wireless broadcast with manageable overhead is network coding, which focuses on forwarding the information contained in packets to the destinations instead of the unaltered packets themselves. We propose to study the wireless broadcast advantage with network coding in mesh networks and experimentally demonstrate the applicability of network coding in real world environments. To this end we extend the recently developed polymatroid broadcast function model for the wireless broadcast advantage to state of the art WiFi networks and study the interaction of medium access mechanisms and physical layer techniques with this model. Based on this model, we design a wireless mesh protocol that utilizes network coding to efficiently exploit the wireless broadcast advantage to improve various performance metrics. Although the state of the art network coding protocols for wireless networks are COPE and MORE, both developed at the MIT and both showing fundamental gains due to the broadcast nature of the wireless medium, they both leave room for major contributions with respect to the optimization of the medium access scheme, the bidirectional and multicast traffic, the interoperability with higher layer protocols, and with respect to adaptive physical layer models. In addition our proposed protocol is the core of a wireless mesh demonstrator and experiment setup with up to 25 nodes based on IEEE 802.11 consumer devices. The experiment is designed to demonstrate the benefit of network coding in wireless mesh networks with different traffic scenarios and to analyze the performance of network coding to exploit the wireless broadcast advantage in a real world scenario in terms of throughput, reliability, delay, protocol and coordination overhead, interaction with common network and transport layer protocols, and further metrics. We also aim at comparing the proposed approach to state of the art wireless mesh network solutions like IEEE 802.11s.