Democratizing Direct-to-Cell Low Earth Orbit Satellite Networks

Multi-tenant Low Earth Orbit (LEO) satellites emerge as a cost-effective win-win solution for direct 4G/5G access to our regular phones/IoTs anywhere on Earth. However, the current hop-by-hop stateful cellular session impedes this effort due to its need for tight functional coupling and stable service relationships among satellite operators, mobile operators, and users. Our empirical study with real satellite data shows that, it restricts LEO satellites' serviceable areas, limits the use of available (possibly competitive) satellites, and suffers from signaling storms and dynamic many-to-many relationships in extreme LEO mobility. We thus devise MOSAIC to strive for self-serve multi-tenant LEO satellites. MOSAIC defines policy-embedded one-time tokens for pay-as-you-go local satellite access. These tokens allow satellites to self-serve users anywhere without relying on remote mobile operators, alleviate inter-satellite coordinations to enjoy competitive satellites, and simplify many-to-many service relationships for on-demand multi-tenancy. MOSAIC is attack-resilient and incrementally deployable using our SIM-based solution. Our evaluations with the real satellite data and commodity 3GPP NTN protocol stack validate MOSAIC's viability.