Propagation models in radio environment map design

Radio Environment Map is a very important element of Dynamic Spectrum Management. It is used by spectrum regulators, wireless networks planners, operators, and Cognitive Radio users. REM is an information system, in which the electromagnetic field strength in every space location for whole usable spectrum is a main data to evaluate spectrum occupancy, and then for quality of signal reception. This data can be obtaining from expensive measurement campaigns, or/and as a prediction of signal sent by known radio transmitters. For such prediction, various propagation models can be used. Two main questions are discussed in this paper. The first one is an impact of used propagation models, and the second one is a digital map accuracy.