WOS1 – Satellite Communications
Wednesday, 4 June 2025, 11:00-12:30, room 1.A
Session Chair: Tomaso De Cola (German Aerospace Center (DLR), DE)
Revolutionizing Low-Latency Satellite Networks: Harnessing Optical Hard Limiter Technology for Next-Gen Inter-Satellite Links
Mohammad Taghi Dabiri and Mazen Omar Hasna (Qatar University, Qatar); Khalid A. Qaraqe (Hamad Bin Khalifa University & College of Science and Engineering, Qatar); Saud Althunibat (Texas a and m University at Qatar, Qatar)
This paper investigates the application of Optical Hard Limiter (OHL) technology in inter-satellite communication networks to address the challenges of latency reduction and computational efficiency. By eliminating optical-to-electrical and electrical-to-optical conversions, OHL relays simplify system design while significantly reducing delay, making them a promising candidate for next-generation satellite networks where latency is critical. The study develops analytical models for the end-to-end performance of OHL systems and compares them with Amplify-and-Forward (AF) and Decode-and-Forward (DF) relays. Simulations demonstrate that OHL relays can achieve competitive performance with optimal threshold selection, even outperforming AF relays in certain scenarios. Furthermore, the impact of varying channel conditions, such as link length and tracking system accuracy, on the optimal decision threshold is analyzed. Results highlight the need for dynamic threshold adaptation to improve system robustness in real-world inter-satellite environments. Future directions include developing multi-threshold OHL systems, optimizing key link parameters like beam divergence, and evaluating end-to-end delay in realistic multi-relay LEO constellations. This work establishes a foundation for leveraging OHL technology to enhance the efficiency and reliability of next-generation satellite communication networks.
Satellite Constellation Routing: Trade-off Between Delay- and Power-Based Optimization
Philip Bergmann (Julius-Maximilians-Universität Würzburg, Germany); Tobias Hoßfeld (University of Würzburg, Germany); Oscar Boo Fernández (Julius-Maximilians-Universität Würzburg, Germany); Guido Dietl (University of Würzburg, Germany)
Integrating satellite constellations into cellular communication systems is one of the steps currently pursued on the way to global and reliable coverage. One of the major problems of these emerging communication networks is the choice of the routing strategy, not only due to its dynamics but also due to the energy restrictions given if realized with small CubeSats due to the necessity of cost-efficient implementations. We show that with a combined metric of power and latency, routing with the Dijkstra algorithm allows huge gains in one metric despite introducing only small deficits in the other. With a non-existent one-hop delay, the effects of including a small amount of power cost in the link weight is already significant. However, when such a one-hop delay is present, the relative weight of the power cost must be much larger to see any effect. We conclude this from simulating a multitude of connections between two randomly placed ground stations on earth over a Walker Delta low earth orbit (LEO) constellation. The results for using a combined metric show that the routing strategy can be optimized to be less power-consuming with the trade-off of more hops. However, further research with better models is still needed before deducing guidelines for constellation routing design.
Evaluating 5G Non-Terrestrial Networks: Laboratory and Field Trials with Geostationary Satellites
Amedeo Giuliani (CTTC, Spain); Pol Henarejos (Centre Tecnologic de Telecomunicacions de Catalunya (CTTC), Spain); Erislandy Mozo (Centre Tecnològic de Telecomunicacions de Catalunya, Spain); Marius Caus (CTTC, Spain); Nuria Trujillo Quijada (Hispasat Madrid & HISPASAT CANARIAS SL, Spain); Justin Tallon (Software Radio Systems Ltd., Spain & University of Dublin, Ireland)
This paper presents a comprehensive performance evaluation of 5G Non-Terrestrial Networks (NTNs) as defined by the 3GPP Release 17 standard, with a focus on laboratory emulations and field trials using a geostationary satellite. We show initial laboratory tests, conducted with modems and a channel emulator, emulated various satellite orbits to assess communication latency, random access procedures, and system performance in controlled conditions. These tests provided valuable insights into potential communication challenges before transitioning to field trials. Field tests were performed with a dedicated transponder on a real geostationary satellite, evaluating performance metrics such as latency and throughput in both uplink and downlink channels. Results conducted with connection-less transport protocols indicate that while downlink throughput remains fairly stable across different altitudes, uplink performance degrades with increasing altitude, primarily due to increased latency from scheduling request delays. This trend is accentuated when employing connection-oriented transport protocols without any accelerators. The findings confirm the feasibility of 5G NTN with satisfactory downlink performance, while highlighting the challenges in maintaining consistent uplink throughput at higher altitudes.
Spatially-Aware NFV Orchestration for Dynamic LEO Satellite Management in 6G Networks
Jose Avila Acosta and Hossein Rouzegar (I2CAT Foundation, Spain); Anna Calveras Augé (Universitat Politècnica de Catalunya, Spain); Joan Adria Ruiz-de-Azua (i2CAT Foundation, Spain)
The integration of Low Earth Orbit (LEO) satellite constellations into 6G networks offers unprecedented opportunities for global connectivity, particularly in underserved regions. However, these non-terrestrial networks (NTNs) face significant challenges, including satellite mobility, frequent handovers, and dynamic resource allocation. This paper introduces a novel GIS-enhanced Network Function Virtualization (NFV) Management and Orchestration (MANO) framework tailored for multi-LEO satellite coordination. By embedding Geographical Information Systems (GIS) into the ETSI MANO architecture, the proposed framework enables resource allocation, dynamic scaling of containerized network functions, and seamless handovers across satellites. The system leverages Kubernetes-based orchestration and a Satellite Mobility Manager to optimize service deployment based on real-time geospatial data. Experimental validation using a multi-satellite testbed demonstrates the framework’s ability to maintain service continuity, enhance resource utilization, and ensure seamless communication during satellite transitions. These results highlight the potential of GIS-driven NFV orchestration as a foundational solution for efficient NTN management in 6G networks.
Vertical Handover Scheme Evaluation for GOVSATCOM Systems
Giovanni Giambene, Sara Nasirian and Minh Hoang Nguyen (University of Siena, Italy); Sergio Barrachina-Muñoz (Centre Tecnològic Telecomunicacions Catalunya, Spain); Josep Mangues-Bafalluy (Centre Tecnològic de Telecomunicacions de Catalunya (CTTC), Spain)
The EU GOVSATCOM program aims to federate European satellite operators and integrate their systems with 5G terrestrial networks to improve mission-critical services. This paper investigates the Vertical Handover (VHO) between Terrestrial Networks (TN) and Non-Terrestrial-Networks (NTN) and proposes a scheme suitable for the experimentation of the trial phase of the 5G-GOVSATCOM project. A suitable model has been identified for analyzing the VHO scheme, taking into account the effect of shadowing correlation. Suitable SINR-based VHO triggering conditions have been identified. The VHO performance has been evaluated using key performance indicators (i.e., VHO failure rate and VHO ping-pong rate), identifying the settings that meet the QoS requirements.
