A Hybrid Routing and Domain-Boundary Authentication Framework for Heterogeneous Multi-Operator GEO-LEO Satellite Networks

Heterogeneous multi-operator GEO-LEO satellite networks serve as key infrastructure for next-generation global broadband communications. However, existing routing and security frameworks fail to resolve two fundamental challenges. First, orbital layers display inherent topological asymmetry: LEO intra-domain topologies suit fixed routing, while GEO-LEO links change dynamically. This dynamism makes pre-planned SR paths across the GEO layer unfeasible. Second, multi-operator networks introduce cross-domain trust boundaries without pre-established PKI. Centralized packet authentication is impractical for large constellations with intermittent ground contact. Existing solutions either use uniform SR or ground-assisted authentication, neither maintaining correctness in unstable polar regions. This paper proposes H-SID, a hybrid routing and authentication framework for multi-operator GEO-LEO networks. H-SID adopts a dual-layer architecture: SRv6 uSID enables deterministic routing in LEO domains, and a lightweight dynamic protocol handles real-time GEO forwarding. We design uSec, a 16-bit uSID instruction with VER and AuthType fields, allowing GEO nodes to adjust forwarding independently in polar instability. BG nodes perform SR-to-IP conversion and IBC-based authentication for cross-domain flows. GEO satellites act as offline IBE PKGs, issuing long-lived keys to BG nodes without data-plane operations. H-SID concentrates overhead at boundaries and works without cross-operator PKI, ensuring deployability.