## 1 Introduction
This can be done using orthophotos, various maps, or modelling programs, or by measuring the areas concerned using an RF EMF meter and identifying and selecting zones with the highest RF EMF values [24]. In order to identify RF EMF propagation limits and adjustment areas in a specific locality, it is necessary to appropriately select the main parameters of antenna spatial distribution: the height of the antenna's geometric centre, the direction of the main radiation (main lobe), and the required downtilting of the directional pattern on the vertical and horizontal planes [25; 26]. However, evaluation of the main components of the physical environment (relief, buildings, etc.) restricting RF EMR propagation is problematic. Furthermore, it is difficult to estimate RF EMF values on building facades and to calculate the total propagation values of several antennas [27; 28]. RF EMR measurements are carried out according to standards, norms, references, and legal rights specific for radiation generated by mobile telephony base station antennas [29]. However, it is difficult to evaluate the specific features of RF EMR according to the description. Accordingly, in order to evaluate which antenna provides a radiation level spread in the environment, detailed RF EMR investigations need to be carried out and measurement points need to be multiplexed [30; 31; 32]. However, field measurements carried out according to the requirements do not always reflect the real dispersion of mobile telephony base station antennas' RF EMR in the environment [33]. When conducting field measurements on RF EMR, it is very important to foresee and evaluate the areas in which field measurements will be conducted. One of the most important parts is to evaluate where the values of RF EMR will be highest, that is, to determine the direction of the main radiation (main lobe) from each antenna [34; 35; 36]. This is done in two steps: by analysing the technical characteristics of mobile telephony base station antennas and by conducting field measurements. In order to evaluate the direction of the main radiation, all of the directional diagrams of the antenna in the vertical and horizontal planes are used. All mobile telephony antenna manufacturers provide antenna radiation diagrams with technical characteristics presented in specialised catalogues [37; 38; 36; 39]. Selecting a model that will enable understanding of the principal qualities, structure, development tendencies, and interaction with the environment of the RF EMF is of particular importance. A properly created pattern not only helps with managing the RF EMFs of the antenna, but also assists in predicting direct and indirect consequences of practical applications (e.g., impacts on other objects or the environment) [40]. Simulation is required for both existing and intended objects and makes it possible to predict the conditions under which RF EMR meets the required value but still does not exceed the permitted limits [41]. RF EMR produced by antennas for mobile telephony can be experimentally measured with the help of different software applications employed to simulate the reference values of RF EMR [42]. The simulation of the RF EMR of mobile telephony includes the analysis of one or several different antennas emitting RF EMR, which would be difficult or impossible to research in normal conditions, using their emission models [43; 44; 45]. The simulation must evaluate parameters such as the radiation diagram (direction) of the antenna for mobile telephony, amplification, polarization, power, frequency, landscape openness, land relief, the height of buildings, the distance between buildings, the angle of the direction of the dispersed signal, the impact of signal diffraction on rooftops and reflections, the operating wavelength, and other factors [46; 47; 48; 49; 50]. In order to analyse the power density of the RF EMF under changing terrain, a number of different environmental factors must be assessed [51].