A vast array of broadcasting protocols has been developed to alleviate the Broadcast Storm Problem for single-radio single-channel and single-rate wireless networks. The emergence of Multi-radio Multi-channel and Multi-rate Mesh (M4) networks, however, brings a lot of new challenges, such as channel assignment, adjacent-channel interference, and network capacity. This project focuses on the design, analysis, and implementation of distributed broadcasting protocols for M4 networks. Challenges such as channel assessment and assignment, interference-aware metric design, transmission rate control, broadcasting tree construction, etc., are to be considered. In-depth theoretical analysis, simulations, and real-world network experiments are also conducted to evaluate the broadcasting protocols. This project also explores several educational innovations. These include the development of a novel three-layer teaching structure, efficient pedagogical approaches, and effective means of incorporating research into learning and education. As one important component of this project, outreach activities are developed for underrepresented minorities from local high schools with the aim of improving their academic performance.
This research advances knowledge and understanding in the areas of wireless mesh networks, network optimization, and information dissemination. The problems studied are pragmatically and intellectually important and their solutions are critical to several areas such as the modeling of wireless communication links, networking traffic theory, and network performance analysis. The techniques developed in this project will benefit a broad spectrum of applications, including homeland security and military network deployment. Research results will be disseminated through a number of channels including international conferences, academic journals, seminars, workshops, and websites.
The problem of network wide broadcasting is an important fundamental operation in wireless mesh networks. Many broadcasting protocols have been developed for wireless ad hoc networks assuming a single-radio single-channel and single-rate network model and a generalized physical model, which does not take into account the impact of interference. This project developed high-performance broadcasting protocols for multi-radio multi-channel and multi-rate ad hoc mesh networks to simultaneously achieve 100% reliability, minimum broadcasting latency, and minimum redundant transmissions. The project distinguishes itself in a number of ways. First, a multi-radio multi-channel and multi-rate network model is used. Second, three performance metrics that include reliability, latency, and redundancy are simultaneously considered. Third, a comprehensive link quality metric that includes packet loss rate and date rate among others is used. Finally, the broadcasting tree is constructed by using local information without the global network topological information. The performance improvement of the developed protocols is verified through theoretical and simulation studies. Research results have been disseminated broadly through a number of channels including international conferences such as IEEE INFOCOM, academic journals, seminars, and websites. This project conducted several educational activities, including developing a new course, incorporating research activities into undergraduate senior projects, curricula revision of two wireless networking courses, implementing the three-layer teaching structure, and reaching out to high-school students from undergraduate minorities. The project helped students from underrepresented minorities to improve their academic performance, and train highly skilled graduate students and post-doc. This project also helped the participating graduate and undergraduate students to better understand how to identify and formulate the research problems, find the solutions, and evaluate the results. The problems studied in this project are pragmatically and intellectually important and their solutions are critical to several areas such as modeling of wireless communication links, system performance analysis, and algorithms. A deep understanding of interference and broadcasting will foster the deploying more efficient and robust wireless communication networks, and the development of better network protocols and network architectures. The techniques developed in this project will have a broad impact on a broad spectrum of applications, including homeland security, military network deployment, information dissemination, and daily life.
