On site-specific propagation models for the evaluation of V2X applications

In this paper, we investigate the use case of an approaching emergency vehicle warning, considering site-specific propagation characteristics. Especially in urban environments, the presence of buildings leads to shadowing properties of the radio signal. In traditional propagation models, these properties are described with stochastic processes. However, for the evaluation of warning use cases where every individual message is important, stochastic models may be too simplistic. Therefore, we implemented efficient ray tracing techniques to identify the specific locations of buildings in the surrounding of the transmitter. Then, we employed adopted models that consider the effects of shadowing, penetration and diffraction to achieve a more accurate result. The comparison of the stochastic and the site-specific models showed that the stochastic models lead to overoptimistic propagation conditions in our scenario. In turn we can rely on a more credible result for the performance of the approaching emergency vehicle warning, when the site-specific models are applied.