Democratizing Direct-to-Cell Low Earth Orbit Satellite Networks

The emergent Direct-to-cell Low Earth Orbit (LEO) satellites promise to eliminate cellular coverage dead zones by enabling direct network access to our regular phones and IoTs everywhere on Earth via 4G, 5G, and beyond. However, their large-scale deployment can be impeded by scarce orbital slots in space, a lack of licensed cellular spectrums, and prohibitive capital costs for satellite deployment and operation. This article explores how to enable multi-tenant direct-to-cell LEO satellites as a cost-effective win-win solution for satellite operators, mobile operators, and users. We demonstrate that the state-of-the-art cellular networks' stateful hop-by-hop session-based architecture restricts the LEO satellite multi-tenancy. To remove this technical barrier, we propose MOSAIC [1], an alternative scheme to shift from the hop-by-hop session-based cellular service to pay-as-you-go satellite self-service. MOSAIC lets mobile operators supply their users with one-time digitally signed tokens as "coins" to pay for local satellite access on demand. Any satellite operator's authentic satellite can accept these tokens to serve this user without pre-establishing sessions or contacting mobile operators. Akin to cloud computing, this paradigm lets satellite operators flexibly lease their satellites to more mobile operators or higher revenues and return on investment, and allows mobile operators and users to enjoy competitive satellites for complementary coverage and cost optimizations. Our evaluations with the real satellite data and commodity 3GPP NTN protocol stack validate MOSAIC's scalability and performance advantages compared to the state-of-the-art.