Sang, Cung LianCung LianSangDrawe, MarcoMarcoDraweSiekmann, TimoTimoSiekmannHesse, MarcMarcHesseRückert, UlrichUlrichRückert2026-01-152026-01-152025https://publica.fraunhofer.de/handle/publica/50326010.1109/FNWF66845.2025.11317753In this paper, we present a robust smartphone GNSS localization method aided by publicly accessible 5G signal metrics from existing infrastructure (i.e., public 5G networks). The approach requires only a typical smartphone and needs no external hardware, or operator-supplied information. It is implemented using standard Android APIs, and the signal extraction process is described in detail. We evaluated the method in a real-world test environment at a train station, which included indoor areas, train platforms, and an underground tunnel where GNSS signals were weak or obstructed. The proposed system demonstrates significant improvements in position estimation accuracy in such challenging environments. Notably, the approach is agnostic to mobile network operator, smartphone model, and 5G deployment mode (ie., non-standalone (NSA) and standalone (SA)), underscoring its broad applicability.enLocation awarenessMeasurementGlobal navigation satellite systemAccuracy5G mobile communicationEstimationHardwareRobustnessStandardsOptimization5G positioning5G-aided localizationsmartphone-based 5Gpositioningpublic 5Gnon-private 5Gconference paper