SDN-Enabled Use Cases and Architectures for DDoS-Resilient 5G Non-Terrestrial Networks

Abstract

The integration of 5G systems with satellite megaconstellations is a cornerstone of forthcoming Non-Terrestrial Networks (NTN), but it also turns the space segment into a distributed critical infrastructure exposed to Distributed Denial of Service (DDoS) threats. The SDN4NTN project (Software Defined Networking-based solutions for efficient DDoS protection of 5G Non-Terrestrial Networks), carried out under the ESA ARTES 4.0 Space Systems for Safety and Security (4S) programme, investigates how Software Defined Networking (SDN) can simultaneously act as a functional enabler and as a security instrument in 5G NTN scenarios. This paper presents the main outcome of the project's system definition phase. During this stage, four reference use cases were defined by combining 5G, LEO/MEO satellite systems and SDN. These range from emergency communications supported by on-board gNBs to hybrid terrestrial-satellite backhauling, and further extend to opportunistic IoT store-and-forward services as well as a fully space-borne autonomous private 5G network. For each use case, the paper details the reference architecture, the SDN controller placement strategy, the associated DDoS attack surface and the SDN-based mitigation approach. The technical specification of the emulation platform that will demonstrate the scenarios is then summarized. Structured as a cyber range, the platform integrates orbital simulation, container-based emulation, 5G software stacks and an SDN closed-loop mitigation framework, and is presented together with the validation methodology and target KPIs.