Baseline Analysis of Threshold-Based Cooperative Relay Schemes for Enhanced 5G-Enabled Rural EMS Connectivity

The lack of reliable 5G coverage and robust connectivity in rural areas severely constrains Emergency Medical Services (EMS), causing frequent communication dropouts during critical operations. To address this challenge, this study conducts a Phase-I baseline evaluation of threshold-based relay selection schemes—namely Single Threshold (STRS), Double Threshold (DTRS), and Multi-Threshold (MTRS)—using Monte Carlo simulations over Rayleigh fading channels. Experimental results demonstrate that MTRS significantly improves signal reliability, achieving a 6 dB reduction in Symbol Error Rate (SER) compared to STRS and maintaining a coverage probability above 95% at an SNR of 8 dB or higher. Although MTRS incurs a minor 7% increase in relay selection latency under heavy network loads, it ultimately reduces the overall end-to-end Emergency Response Time (ERT) by 25%. These baseline findings establish critical reference metrics that will inform the future development of AI-enhanced, real-time adaptive relay selection frameworks for rural EMS networks.