Making Sense of Constellations: Methodologies for Understanding Starlink's Scheduling Algorithms

Speaker: Hammas Bin Tanveer, University of Iowa, IA, USA
Date: Monday, November 27, 2023

Abstract: Starlink’s constellation is currently the largest LEO WAN and has seen considerable interest from the research community. In this talk, we use high-frequency and high-fidelity measurements to uncover evidence of hierarchical traffic controllers in Starlink — a global controller which allocates satellites to terminals and an on-satellite controller that schedules transmission of user flows. We then devise a novel approach for identifying how satellites are allocated to user terminals. Using data gathered with this approach, we measure the characteristics of the global controller and identify the factors that influence the allocation of satellites to terminals. Finally, we use this data to build a model which approximates Starlink’s global scheduler. Our model is able to predict the characteristics of the satellite allocated to a terminal at a specific location and time with reasonably high accuracy and at a rate significantly higher than baseline.

Brief Bio: Hammas Bin Tanveer is a 5th year PhD student at The University of Iowa. He is currently also a visiting researcher at Center for Applied Internet Data Analysis (CAIDA) and was previously an Open Technology Fund's Senior Information Controls Fellow at The University of Michigan. His primary research includes better understanding and securing next-generation networking technologies, specifically IPv6 and Starlink.