GEO–LEO Hybrid Networks Using Laser Communication Terminals: A Scalable Architecture for High-Throughput and Sovereign Space Connectivity

The growing demand for high throughput, resilient and sovereign space communication is accelerating the convergence of LEO and GEO systems into hybrid network architectures. LEO satellites provides low latency and flexible regional coverage, while GEO platform offer continuous visibility, centralized routing and stable long term operations. Combining these complementary capabilities enables a unified communication backbone that overcomes the limitations of single orbit systems.
The paper presents a GEO-LEO hybrid network architecture based on Laser Communication Terminals (LCT) and Optical Communication Terminal (OCT). The goal is to demonstrate how laser based inter orbit connectivity can support multi-Gbps data rates, low probability of interception and spectrum independent operation when compared to traditional RF communication systems. In the architecture the GEO satellite is positioned as a high capacity relay and routing node that aggregates data from multiple LEO satellites and enables global data distribution with reduced dependence on dense and geographically constrained ground station network.
The research combines link level analysis with system level network design. At link level, we evaluate pointing acquisition and tracking requirements, orbital geometry constraints and link availability for GEO-LEO connections, together with atmospheric impacts on GEO to ground links. At system level, routing strategies, latency trade-offs, fault tolerance mechanisms and hybrid RF integration are asses to characterize the overall operational robustness of the network.
The expected outcome is a scalable and strong network concept that demonstrates how GEO-LEO optical interconnection can form a high capacity space backbone. The architecture will support sovereign connectivity and is highly relevant for Europe initiatives such as IRIS2.