Measuring the Effects of AoA on Vehicle Penetration Loss in Cellular Networks

Overcoming the Vehicle Penetration Loss (VPL), introduced by the thermal insulation of windows, is a critical factor for providing seamless connectivity in high-speed mobility scenarios. Several frequency-selective surface solutions for VPL reduction exist on the market. In this paper, we introduce a framework for analyzing the VPL and its dependency on the Angle of Arrival (AoA) utilizing cellular network measurements within real-world vehicular scenarios. Through the fusion of interpolated outdoor and indoor Received Signal Reference Power (RSRP) measurements collected along the track, the high-resolution VPL profile is derived. Exploiting the knowledge of the network and environment layout, the AoA at each measurement location is determined, enabling us to analyze the VPL's AoA dependency. Built solely upon mobile network measurements and geospatial data, the suggested framework is well-suited for extensive crowd-sourced data utilization. It also seamlessly applies to various vehicular contexts, encompassing trains and cars alike. Operating across all frequencies, the framework's scope expands beyond our LTE focus to encompass future generations such as 5G, 6G, and beyond. The presented approach is validated through a comprehensive real-world measurement campaign conducted on a moving train. The evaluation on a per-band basis offers additional insights into the frequency dependency. These findings provide valuable guidance for optimizing the positioning of BSs for track-side deployment, as well as comparing different VPL reduction solutions.