Synopsis: Millimeter-wave is a core technology for next-generation wireless and cellular networks (5G and beyond). Networks using millimeter-wave technologies are expected to satiate the rapidly growing customer appetite for mobile data and to meet the stringent throughput, latency, and reliability requirements of emerging applications, such as immersive virtual and mixed reality, tactile internet, vehicular communications, and autonomous vehicles safety. However, high directionality, high channel dynamics, and sensitivity to blockages render state-of-the-art millimeter-wave technologies unsuitable for low-latency, high performance, and ultra-reliable applications. This research project focuses on designing software-hardware reconfigurable systems to address the key challenges and improve the performance, availability, and reliability of mobile millimeter-wave networks. This project will impact the broader population positively because it yields near-term benefits in 5G infrastructure and paves the way for long-term millimeter-wave research. Furthermore, this project will engage in outreach activities and involve a diverse set of students, particularly, women and minorities, leveraging the experimental nature of the research on next-generation wireless and cellular networks.
The project addresses the key challenges by executing three thrusts: (1) MilliNet: To overcome high signal attenuation, millimeter-wave radios must focus their power via highly directional, electronically steerable beams. But, aligning the beams and maintaining the link between devices during obstruction and mobility are the fundamental barriers toward reliable connection. MilliNet, a faster beam alignment protocol, draws on ideas from the sparse channel recovery, allowing the radios to quickly discern the best physical millimeter-wave paths even under thousands of beams and picocell choices. (2) ReconMilli: To achieve spectrum flexibility, next-generation radios must be able to operate over a wide range of the spectrum, from micro-wave to millimeter-wave. But the fundamental challenge is that physical space on mobile devices is limited. ReconMilli, a reconfigurable antenna design, joins multiple millimeter-wave antennas physically into a micro-wave antenna, but splits it, when needed, into multiple millimeter-wave antennas; thus, achieving spectrum flexibility and saving physical space. (3) LiMesh: To make the deployment and maintenance of a 5G picocell mesh easy, mobile operators will use multi-Gbps fixed millimeter-wave links. Yet, disruptions in the wireless mesh are common; but, more importantly, such disruptions are catastrophic for ultra-reliable connectivity. LiMesh, an ultra-reliable picocell mesh design, leverages the fixed geometrical arrangement of the directional links to infer disruptions using a space-time failure correlation metric proactively. The research project will design, build, and empirically validate the proposed systems in millimeter-wave wireless test-beds.