A Real-Traffic-Driven Emulator for LEO Satellite Mega Constellations

Abstract

The low Earth orbit (LEO) satellite mega constellation assumes an indispensable role in upcoming 6G networks. Aiming to evaluate real-system protocol stacks in LEO networks, we propose a real-traffic-driven emulator (REr). To enable the integration of real systems, we design a distributed architecture consisting of three primary components: Emulation core, traffic injection host, and traffic reception host. The emulation core integrates a topology engine, a runtime routing engine, and a custom real-traffic-driven NS-3 (RNS3) module that extends the NS-3 framework to support real application traffic. Utilizing ZeroMQ as a messaging middleware, the containerized traffic injection host, equipped with full Linux stacks, streams realworld traffic into the emulation core, from which the data is ultimately transmitted to the traffic reception host. Furthermore, we design a parallel path calculation (PPC) mechanism to mitigate the computational overhead caused by the highly dynamism of constellation topologies. Experimental results demonstrate that our REr achieves higher fidelity in reflecting real-world application performance compared to dummy-payload simulations, and the PPC mechanism realizes significant speed improvements for the emulation process, such as a 279% speedup with 8 threads for a 1024-satellite constellation.