A Comparison of Empirical and Ray-Tracing Models for Indoor Radio-Wave Propagation [Wireless Corner]

Both empirical and ray-tracing models are powerful tools for studying propagation in indoor environments. Although the empirical models perform well in many cases, their physical significance is not clearly understood. Ray tracing is based on physics fundamentals, and its application as well as the interpretation of its results is more general. We compare the performance of both models for indoor environments. We found that the path-loss (PL) prediction error of the ray-tracing model is comparable to the error of the linear regression fit of the PL in a site-specific empirical model. Those empirical models provide some advantages when making estimations in the same environment in which they were trained, but their performance degrades in other environments. Ray-tracing models obtain better results when a wider range of application environments is sought. Ray tracing also provides a good insight into the specific propagation phenomena that take place in the wideband radio channel, so the relevant contributions can be identified.