Empirical Channel Characterization of Multi-Band V2X: A Comparative Analysis from DSRC to mmWave

Autonomous transportation demands a paradigm shift in Vehicle-to-Everything (V2X) communications beyond single-band architectures. This paper presents a hardware-based measurement campaign characterizing radio frequency propagation across three bands: 5.9 GHz DSRC and emerging mmWave bands at 29 and 40 GHz. The comparative analysis reveals fundamental trade-offs between sub-6 GHz reliability and mmWave throughput, quantifying significant mmWave challenges, including a path loss increase of over 20 dB and heightened susceptibility to jamming and spoofing. The findings provide critical empirical data for designing next-generation, multi-band V2X systems that balance coverage, capacity, and security.