CIF: Small: A New Theory for Second-Order Cross-Layer Design

The rapid evolution of wireless networks has ushered in a new era of connectivity, enabling transformative applications like Virtual Reality/Mixed Reality, Internet of Things, and connected vehicles. Traditional quality of service metrics, such as data rate and latency, fall short of capturing the performance and service requirements of these applications. This gap may be addressed by contemporary performance metrics, including age of information, quality of experience, and timely throughput. Current research, however, often approaches these metrics in isolation, hindering the transfer of insights across different applications. This project aims to bridge this gap by pursuing a comprehensive theory for second-order cross-layer design, unifying the analysis and optimization of diverse performance metrics within a single framework. By doing so, it seeks to advance the fundamental understanding of wireless networks' capabilities in supporting emerging applications and facilitate the development of network algorithms for next-generation networks. The project seeks to tightly integrate research with a significant education and outreach program that includes developing hands-on projects for undergraduate students, creating new course components, and engaging students with diverse backgrounds in research activities. At the core of this project lies the development of a novel theory of second-order cross-layer design for complex and dynamic networks. This theory characterizes all network processes, including information arrivals, channel rates, and goodputs, by their respective means and temporal variances. The consideration of temporal variance enables the proposed theory to provide a simple and yet precise characterization for the network behaviors in the non-asymptotic regime. To realize this theory, this project pursues three complementary research thrusts. The first thrust focuses on centrally scheduled wireless networks, aiming to precisely characterize the second-order capacity region and devise low-complexity resource allocation policies. The second thrust addresses interference among nearby wireless devices, seeking to develop distributed policies that converge to the desirable mean and temporal variance. Lastly, the third thrust applies this theory to a range of emerging network applications, tailoring network policies to accommodate diverse requirements and behaviors. Through these efforts, this project aims to not only advance the theoretical foundations of wireless networking but also to facilitate the practical implementation of novel network algorithms to support the next generation of wireless technologies. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.