ndoor positioning remains one of the main challenges for location-based services in mobile networks, including 5G and beyond, due to multipath propagation and severe signal attenuation in complex environments. This paper investigates multilateration-based positioning methods, namely Time of Flight (ToF), Time of Arrival (ToA), and Time Difference of Arrival (TDoA). The algorithms were implemented and validated through MATLAB simulations and experimental measurements obtained using a Vector Network Analyser (VNA) with wideband antennas. The results demonstrate centimetre-level accuracy, with ToF and TDoA showing strong robustness in multipath conditions. Three-dimensional (3D) experiments further reveal the impact of anchor geometry and noise, quantified using Geometric Dilution of Precision (GDOP) metrics. The findings confirm the validity of the developed algorithms and their potential integration into private 5G networks, paving the way for advanced Industry 5.0 applications such as indoor navigation, asset tracking, and autonomous robotics.