Digital Twin for Non-Terrestrial Networks: Vision, Challenges, and Enabling Technologies

This paper explores the transformative potential of digital twin (DT) technology in the context of non-terrestrial networks (NTNs). NTNs, encompassing both airborne and space-borne elements, present unique challenges in network control, management, and optimization. DT is a novel approach to design and manage complicated cyber-physical systems with a high degree of automation, intelligence, and resilience. The adoption of DTs within NTNs offers a dynamic and detailed virtual representation of the entire ecosystem, enabling real-time monitoring, simulations, and data-driven decision-making. This paper delves into the envisioned integration of DTs in NTNs, discussing the technical challenges and highlighting key enabling technologies. Emphasis is placed on technologies such as Internet of things (IoT), artificial intelligence (AI), space-based cloud computing, quantum computing, and others, providing a comprehensive overview of their potentials in empowering DT development for NTNs. In closing, we present a case study involving the implementation of a data-driven DT model to facilitate dynamic and service-oriented network slicing within an open radio access network (O-RAN) architecture for NTNs. This work contributes to shaping the future of network control and management in the dynamic and evolving landscape of non-terrestrial communication systems.