Propagation measurements allow us to better understand the different propagation mechanisms (reflection, transmission, diffraction, scattering, guiding) and to characterize the propagation channel in the considered environments (urban, suburban, rural, mountainous, inside buildings, etc.) for better models and predictions. This modeling is necessary for the conception of telecommunication systems and, once they have been designed, for their actual field deployment.
In the first case propagation models are implemented in software in order to simulate the transmission chain. These models are based on the consideration of the impulse response and its evolution in space and time and rely on generic or typical environments rather than on geographical databases.
In the second case propagation models are implemented in engineering tools for the prediction of different parameters useful for the field deployment of systems, for the study of radio coverage (selection of emission sites, frequency allocation, powers evaluation, antenna gains, polarization, etc.) and for the definition of the interference occurring between distant transmitters.
So, different measurements methods are managed as a function of analysis and model requirements: narrowband measurements (field strength measurements), broadband even ultra wide band measurements (impulse response measurements), direction of arrival measurements and transmission rates. ...