Supporting broadband communications needs of the International Space Station using commercial satellites

NASA is interested in using commercial satellites to provide broadband communications support for the International Space Station. We describe a large-scale simulation model that we plan to use for detailed performance studies of critical parameters such as QoS guarantees for specific services, traffic routing schemes, transport protocol support, dynamic bandwidth allocation methods, queuing disciplines, and handoff strategies. In this paper we focus on the unique challenges we face and how we plan to use simulations to investigate: (a) the feasibility of using proposed commercial constellations to carry mission telemetry, command and control, and tele-science traffic between ground terminals and near-earth spacecraft; and (b) the end-to-end performance optimization of this system.