Enabling 6G and Beyond Network Functions From Space: Challenges and Opportunities

Cellular networks from space, powered by recent technological advances in satellite megaconstellations, promise to expand operators' service areas to anywhere on Earth for commercial revenues and social goods. While the existing 5G has attempted to support satellites via its nonterrestrial network enhancements, its hop-by-hop stateful session-based network architecture impedes this progress due to various functionality, scalability, reliability, and security concerns under the megaconstellation's extreme mobility in harsh outer space. This article investigates these issues and explores how to remove this architectural barrier for 6G and beyond from space. We propose a usercentric design that shifts from the hop-by-hop session-based to stateless on-demand cellular service. We discuss how this paradigm shift can stabilize the cellular function internetworking under extreme satellite mobility, refactor in-orbit cellular functions to be stateless with the assistance of local user equipment, and foster the efficient use of satellites for low capital costs and large-scale deployments.