Integration of RIS into CloudRT Simulator for Railway Tunnel Scenarios

Radio communication in tunnels presents significant challenges due to the high likelihood of signal obstruction by elements like tunnel walls, ceilings, train carriages, or blocked trains. Reconfigurable Intelligent Surfaces (RIS) offer a promising and cost-effective solution to mitigate signal-blocking issues by transforming the unpredictable radio environment into a controllable one through managed reflections. This paper extends the CloudRT ray-tracing simulator to accommodate RIS technology and assesses its feasibility for railway tunnel scenarios. RIS is integrated into the CloudRT simulator as a phased antenna array acting as a virtual receiver (Rx)/ transmitter (Tx), The study then explores how various key parameters influence received power and compares two scenarios: one where a masking train obstructs the direct Tx-Rx path, and another where there is no obstruction. The results underscore the potential benefits of deploying RIS in obstructed tunnel environments.