The rapid expansion of Low-Earth-Orbit (LEO) satellite networks is critical for the advancement of beyond-6G (B6G) and IoT systems. However, the highly dynamic nature of LEO networks presents significant challenges for network protocols, including routing, handovers, and delay management. Existing LEO emulation tools struggle to efficiently scale to large constellations. In this paper, we present bLEO, a novel eBPF-based LEO network emulator designed to address these challenges. bLEO can emulate LEO constellations defined through configurable orbital parameters (e.g., number of orbital planes, number of satellites per plane, altitude, and inclination) and with dynamic inter-satellite and ground-satellite connectivity. Unlike traditional tools that rely on tc-netem , bLEO leverages eBPF to dynamically manage propagation delays and link states in real time. bLEO efficiently scales to thousands of satellites and ground stations while maintaining high performance through container-based virtualization and direct virtual Ethernet ( veth ) links. Our evaluation demonstrates that bLEO provides a scalable, accurate, and resource-efficient solution for testing protocols and applications in large-scale LEO networks. • High-performance emulation of large-scale networks. • eBPF applied to overcome Linux network emulator ( netem ) delay restrictions. • Open source development. The emulator can be download and freely redistributed.
Muñoz-Gea et al. (Fri,) studied this question.