The integration of terrestrial and non-terrestrial networks (NTN) is becoming essential for developing a unified system architecture that caters to various vertical sectors. This includes public safety and disaster recovery (PPDR), mobile transportation, societal needs, and Industry 4.0. Traditionally, the industry has relied on extending existing air and network interfaces to integrate these diverse technologies. However, such an approach is no longer sufficient in addressing the complexities of today’s telecommunications landscape.

Modern telecommunications demands have evolved significantly, driven by the convergence of multiple network technologies, each with unique characteristics. The recent service categorization established within the IMT-2030 framework highlights the necessity for service ubiquity, supported by distributed intelligence. As we approach the rollout of 6G systems, incorporating a native NTN component into the design is crucial to enhancing service delivery and performance.

While the promise of a unified network system is promising, it also introduces significant challenges. The dynamic nature of NTN network topologies, alongside fluctuations in data traffic and user service needs, necessitates a versatile and adaptable architecture. The complexity of this unification emphasizes the need for a polymorphic network design that can efficiently respond to varying service requirements.

Here, the concept of self-organizing networking becomes particularly relevant. This paradigm can effectively support trends such as direct-to-satellite connectivity and utilize advancements in network softwarization and automation. A key player in this transition is the 5G-STARDUST project, which aims to demonstrate the convergence of terrestrial and non-terrestrial networks in the near term.

5G-STARDUST, which stands for Satellite and Terrestrial Access for Distributed, Ubiquitous, and Smart Telecommunications, is a European initiative funded by the Smart Network Service Joint Undertaking (JU) within the Horizon Europe program. Launched in January 2023 and set to conclude by December 2025, the project seeks to create and validate laboratory testbeds that illustrate this convergence effectively.

At the heart of the project is the objective of illustrating the feasibility of deploying gNB (Next Generation NodeB) in space, utilizing a self-organized networking architecture and a unified radio interface. This endeavor includes developing key functionalities aimed at optimizing system performance and enhancing network automation through innovative AI-driven strategies. Specific focus areas include Radio Resource Management (RRM), multi-link connectivity, and the principles of network slicing.

The ultimate goal of the 5G-STARDUST initiative is to establish a fully integrated proof-of-concept, expected to be executed at a laboratory facility run by project partner Thales Alenia Space France in Toulouse. What sets this project apart is its aspiration to develop a flexible system architecture that can adapt its functionalities in response to specific user demands and varying network conditions.

One of the primary challenges in integrating NTN with 5G/6G systems is the mobility of non-geostationary orbit (NGSO) satellites, which often leads to handover events. Additionally, the deployment of gNB in space is limited by the current capabilities of satellite systems concerning size, power, and storage. To address these issues, 5G-STARDUST explores a flexible architecture that distributes gNB functionalities, allowing them to be activated based on real-time service and traffic conditions.

In addition to enhancing network performance, the project emphasizes the importance of coordination between terrestrial and non-terrestrial subnetworks. Effective communication operations are vital, particularly in multi-connection scenarios where traffic must be managed between different networks. This requires seamless data distribution across the space segment, facilitated by fully interconnected space nodes and robust control plane mechanisms.

The ability to deploy inter-satellite links and routing solutions in space has been deemed crucial for operational success. The 5G-STARDUST project goes beyond existing systems, innovating a semantic routing approach grounded in experiences from other research initiatives. By prioritizing the softwarization of space segments, the project aims to facilitate service-oriented data communication, setting the groundwork for a new generation of 6G-enabled satellite systems.

In summary, the 5G-STARDUST project is making significant strides toward achieving the ambitious goal of a unified telecommunications infrastructure that merges regenerative satellites with terrestrial networks. Through this effort, the project is actively contributing to the standardization processes within the 3GPP framework, advancing specifications that are part of the next wave of 5G-Advanced technologies and laying the foundational elements for a 6G network system.

5G-STARDUST stands as a testament to the innovative spirit driving the telecommunications industry. It encapsulates the urgent need for a converged network architecture that not only meets today’s demands but also anticipates the future of communication technology. As we look ahead, the integration of terrestrial and non-terrestrial networks represents a pivotal shift toward a more cohesive and effective telecommunications ecosystem.