Spatial Performance Analysis and Design Principles of Random Access-Based Wireless Mutual Broadcast in Various Spectral Environments

Proximity-aware services are expected to grow further in the B5G and 6G era, often leveraging random access based wireless mutual broadcast (RA-WMB) operations among nearby nodes. This letter establishes a tractable framework for RA-WMB performance across sub-6GHz, mmWave, and THz bands, incorporating LoS/NLoS channels, beamforming, and molecular absorption. It analytically examines the impact of beamforming on the number of successful messages and broadcast coverage, derives an explicit suboptimal transmission probability for performance maximization, and highlights the critical role of sidelobe gain through both analytical and numerical results.