Use Cases, System-Level Approaches, and Achievable Performance of Fused PNT with NTN in FR2 and FR3

Ivan Lapin, Samuele Larese, Tommaso Panicciari, Rui Sarnadas, Václav Valenta, Florin-Catalin Grec, Felix Abel, Jose Antonio Garcia Molina, Lionel Ries, Roberto Prieto-Cerdeira

Peer Reviewed

Abstract:	The future of positioning, navigation, and timing (PNT) services lies in the seamless integration of multiple technologies into a cohesive system-of-systems that enhances PNT resilience, accuracy, and availability. This paper further develops the vision of integrating traditional Global Navigation Satellite System (GNSS) with low Earth orbit PNT (LEO-PNT) solutions to address the limitations of GNSS in challenging environments and enhance the PNT resilience and performance. The emergence of broadband Satcom constellations in LEO, operating in the Ku and Ka bands, presents opportunities for integrating communication services with PNT through a concept known as Fused PNT. The 3GPP standards for 5G and emerging 6G non-terrestrial networks (NTNs) are evolving as potential key enablers for future LEO Satcom systems, with growing consideration for tightly integrated Fused PNT capabilities, where Satcom and PNT share the frequency band, payload, physical layer, protocol, and signaling structure. This paper investigates the use cases, system-level approaches, and achievable performance of LEO-based Fused PNT systems implemented within the NTN framework. To estimate the expected PNT performance of a prospective Fused PNT system, the minimum user elevation angle for signal reception and corresponding carrier-to-noise density ratio (C/N0) are first evaluated by monitoring satellites from an existing Satcom constellation in Ku-band using a monitoring setup deployed at the Navigation Laboratory (NavLab) of the European Space Agency (ESA) European Space Research and Technology Centre (ESTEC). The collected results are then scaled in terms of a representative NTN user terminal and four prospective PNT waveforms to derive the expected user equivalent range error (UERE) of a theoretical NTN system. The analysis assumes that the NTN constellation adopts an appropriate cell orchestration strategy, allowing to provide PNT signals to ground users via multiple, potentially overlapping satellite beams, without causing significant degradation to communication services. The analysis reveals that, under the scaled conditions, three out of four evaluated NTN waveforms achieve positive link budget margins for PNT. However, additional impairments, such as a lower gain-to-noise temperature ratio (G/T) of the user terminal, severe rain attenuation, or moving to lower latitudes with larger tropospheric attenuation, may render ranging with NTN under the given conditions unfeasible. Based on the formulated PNT use cases, it is concluded that, alongside finding a suitable solution to ensure signal coverage from at least four satellites, the number of satellites and geometric configuration of the Satcom constellation are key enablers of the Fused PNT concept. While the results presented in this paper focus on Ku-band systems, the findings are also applicable to Ka-band.
Published in:	Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025) September 8 - 12, 2025 Hilton Baltimore Inner Harbor Baltimore, Maryland
Pages:	3450 - 3464
Cite this article:	Lapin, Ivan, Larese, Samuele, Panicciari, Tommaso, Sarnadas, Rui, Valenta, Václav, Grec, Florin-Catalin, Abel, Felix, Molina, Jose Antonio Garcia, Ries, Lionel, Prieto-Cerdeira, Roberto, "Use Cases, System-Level Approaches, and Achievable Performance of Fused PNT with NTN in FR2 and FR3," Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025), Baltimore, Maryland, September 2025, pp. 3450-3464. https://doi.org/10.33012/2025.20463
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