In the context of Work Package 2, and specifically Task 2.1 the project focused on a comprehensive analysis of user-driven use cases. Close collaboration with end-users—such as CRI and OARMS—allowed the project team to identify and characterize scenarios involving both on-the-move and on-the-pause operations. These efforts highlighted the limitations of current communication technologies and underscored the operational challenges faced by users in the field.
A gap analysis revealed how a hybrid 5G terrestrial and non-terrestrial infrastructure could address these shortcomings. Service requirements were defined based on user expectations for data rates and service reliability, distinguishing between enhancements to existing applications and entirely new use cases. The analysis also assessed the technical feasibility of achieving maximum service levels within both terrestrial and satellite coverage areas, drawing on insights from other EU projects like ENTRUSTED.
Finally, the project identified the most technically challenging aspects of the system architecture, infrastructure integration, and terminal device development, setting the stage for subsequent technical work packages and guiding the overall design and validation strategy for the hybrid 5G-GOVSATCOM system.
The architectural analysis carried out within the 5G-GOVSATCOM project laid the foundation for developing a seamless and secure integration between terrestrial (TN) and non-terrestrial (NTN) networks. Multiple architecture models were evaluated to support the hybrid nature of the system, with a focus on meeting the demanding requirements of mission-critical services. This analysis was aligned with existing 3GPP mobility management standards to ensure compliance and interoperability within the broader 5G ecosystem.
To support mission-critical services such as MCX (Mission Critical Push-to-Talk, Video, and Data), specific enhancements were proposed to ensure service continuity during emergencies and in coverage-limited scenarios. Architectural adaptations were recommended to maintain reliability and performance in hybrid TN-NTN operations.
In terms of resource efficiency, the project proposed dynamic strategies for pooling and allocating network resources, improving handover processes, and optimizing traffic flows through the SGW. These mechanisms are essential for supporting high-quality, uninterrupted services across diverse environments.
Overall, the architectural recommendations developed in this phase contribute to reinforcing the EU’s leadership in secure satellite communications. By defining a robust, flexible, and scalable hybrid communication framework, the 5G-GOVSATCOM project strengthens the strategic foundation for resilient governmental communications and supports Europe’s broader objectives of technological sovereignty and standardization leadership.
A core focus was placed on enabling seamless vertical handovers (VHO) between terrestrial (TN) and non-terrestrial (NTN) networks—an essential capability for ensuring uninterrupted service in mission-critical scenarios. A sophisticated handover algorithm was developed and evaluated, incorporating signal quality metrics such as SINR (Signal-to-Interference-plus-Noise Ratio) to guide transition decisions. To improve handover stability and reduce disruptions such as ping-pong effects, parameters like Time-to-Trigger (TTT) and Handover Margins (HOM) were carefully introduced and tuned.
The results demonstrated substantial improvements in handover reliability, with fine-tuned HOM and TTT parameters significantly reducing both failure rates and unnecessary transitions. Key performance indicators such as VHO failure rate, ping-pong rate, and end-to-end latency confirmed that the solution could support the stringent requirements of real-time mission-critical applications.
This work represents a critical advancement in hybrid network mobility management, ensuring that 5G-GOVSATCOM can deliver secure, stable, and continuous communications across diverse operational environments.
The 5G-GOVSATCOM project also addressed key radio access network (RAN) challenges critical to the success of integrating satellite systems into mission-critical 5G services. A detailed review was conducted on advanced modulation and coding techniques tailored for satellite communication, with a particular focus on adapting them to support the strict performance and reliability requirements of MCx (Mission Critical) applications over non-terrestrial networks (NTN).
To support reliable connectivity with satellite links, initial development work began on an antenna control unit, including hardware component selection and procurement. This phase also involved analyzing the interface between the antenna system and the NTN-enabled user equipment, laying the groundwork for dynamic and responsive communication in varying operational conditions.
As part of system validation, early performance testing of MCx services over satellite was carried out, focusing on service continuity, latency, and throughput under satellite-specific constraints. In parallel, the team reviewed and updated the current mission-critical communication techniques applied over GEO satellite systems, aiming to align them with evolving 5G standards and better accommodate the demands of hybrid TN-NTN environments.
These efforts represent essential steps toward ensuring that MCx services can operate seamlessly and reliably over satellite networks, ultimately reinforcing the robustness and resilience of the 5G-GOVSATCOM platform.
