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Objectives
The project establishes a software-defined 5G NTN base-station designed for regenerative payloads on low Earth orbit (LEO) satellites, with a primary objective of providing a highly flexible and configurable baseband platform adaptable to different non-terrestrial network (NTN) system architectures and operational requirements. The development covers a complete Layer-1 to Layer-3 software stack aligned with Third Generation Partnership Project (3GPP) non-terrestrial network (NTN) features, enhanced with satellite-specific capabilities such as Doppler compensation, long round-trip delay handling, large-cell mobility support, beam-aware control, and adaptive scheduling behaviour.
A key objective is to decouple functionality from hardware through a modular software architecture, enabling portability across different space-grade processing platforms and easing adaptation to varying payload constraints. The project also aims to support multiple deployment configurations, including onboard processing and split satellite–ground architectures, through standardised CU/DU interfaces.
In addition, the project targets end-to-end system validation by integrating the base-station with NTN user equipment developed by Vicinity, enabling realistic system-level testing and performance assessment. Activities progress through design consolidation, integration, and end-to-end validation using NTN channel emulation, resulting in a fully validated, adaptable base-station solution suitable for future commercial deployment.
Benefits
The product delivers a software-defined 5G NTN base-station that provides operators and system integrators with a high degree of flexibility to address different satellite architectures, mission profiles, and regulatory environments. By implementing core functionality in software, the solution allows adaptation to varying waveform configurations, duplexing approaches, traffic profiles, and payload constraints without fundamental hardware redesign. This significantly reduces development risk, shortens system customisation cycles, and lowers overall lifecycle cost.
The base-station supports efficient operation in LEO environments through integrated mobility handling, beam-aware control, and onboard processing, reducing reliance on feeder-link backhaul and improving end-to-end latency. A modular CU/DU architecture with standardised interfaces enables deployment across regenerative and hybrid satellite-ground configurations and simplifies integration with third-party payload components.
When combined with Vicinity’s NTN user equipment, the solution forms a complete end-to-end NTN system, enabling consistent optimisation, validation, and performance tuning across both network and terminal sides. Together, these benefits provide a scalable, adaptable, and future-ready NTN base-station platform suitable for a wide range of satellite constellations and service scenarios.
Features
The product comprises a complete 5G Layer-1 to Layer-3 NTN software stack designed with a modular, software-defined architecture. Core capabilities include satellite-specific Doppler and timing compensation, large-cell mobility handling, beam-aware control, adaptive scheduling, and robust operation under long round-trip delays. The architecture supports flexible configuration of operational parameters to accommodate different NTN system designs and payload constraints.
The Layer-1 subsystem integrates with hardware acceleration using FPGA or DSP technologies to achieve deterministic performance in high-mobility LEO scenarios. Layer-2 functions support delay-tolerant scheduling, enhanced RLC/PDCP behaviour, and efficient multi-cell operation, while Layer-3 provides NTN-aware RRC and core network interfaces.
Standardised external interfaces include O-RAN fronthaul, CU/DU interfaces (F1, N2, N3, Xn, O1), and antenna control interfaces, enabling integration with a wide range of satellite payload processors and radio front ends. The software is portable across space-qualified platforms and supports end-to-end system integration with Vicinity’s NTN user equipment.
Challenges
Key challenges include designing a software-centric base-station architecture capable of adapting to diverse NTN system requirements while operating under long propagation delays, high Doppler dynamics, and rapidly changing satellite geometry. The system must maintain timing stability, efficient resource management, and reliable performance across different deployment configurations and payload constraints. Additional challenges involve validating flexibility and robustness through realistic end-to-end testing, including integration with NTN user equipment, while meeting space-grade limitations on power, processing capacity, and latency.
System Architecture
The system adopts a modular regenerative satellite architecture centred on a software-defined 5G base-station with a CU/DU functional split. The DU hosts Layer-1 and Layer-2 processing and interfaces with hardware acceleration modules for physical-layer computation, while the CU manages Layer-3 control, mobility management, and beam-aware signalling. This separation enables flexible deployment across onboard, split, or hybrid satellite–ground configurations.
The base-station connects to radio units via standardised fronthaul interfaces and to phased-array antenna controllers through dedicated control interfaces. High-speed IP connectivity links the CU/DU with feeder-link gateway systems and onboard routing elements, supporting regenerative payload operation and inter-satellite connectivity.
The architecture emphasises software portability, configurability, and interoperability, allowing adaptation to different constellation designs and mission requirements while remaining aligned with 3GPP NTN standards.
Plan
The project covers design consolidation, software refinement, base-station integration, and preparation for BS-RU interfacing. This is followed by end-to-end functional and performance validation, including integration with NTN user equipment and testing under realistic NTN channel emulation. Formal reviews validate architectural, functional, and system-level objectives, concluding with delivery of the validated software, documentation, and supporting performance evidence.
Current Status
The project is in its early execution stage, with the software architecture and system interfaces consolidated. Layer-1 to Layer-3 software refinement is ongoing, focusing on NTN-specific functionality and configurability. Coordination with hardware partners on acceleration and interface definition is in progress, alongside preparation of laboratory environments for integration and end-to-end testing. Initial activities supporting integration with Vicinity’s NTN user equipment are also underway.
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