## 1 Introduction  
Measurements and evaluation of radiofrequency (RF) electromagnetic radiation (EMR) levels, the RF EMR exposure guidelines recommended for the general public, and the establishment of other regulations are issues of worldwide importance [1; 2]. At the moment, the most important concern is the contradictory information about mobile telephony base station antennas and their declared effects on human health [3; 4]. After reviewing the scientific literature, in 1998 the International Commission for Non-Ionizing Radiation Protection (ICNIRP) formulated guidelines on exposure guidelines for RF EMFs in the frequency range from 0 Hz to 300 GHz. These guidelines are based on acute health effects such as elevation of tissue temperatures resulting from absorption of energy during exposure to RF EMFs between 100 kHz and 300 GHz [5]. The results of studies on possible long-term effects such as cancer were not considered to be adequate for setting limits on a scientific basis. In 1999, the European Union published recommendations on the exposure guidelines of the general public to RF EMFs. These recommendations rely on the international exposure guidelines (ICNIRP) of 1998 and are therefore based on scientific appraisal of risk-related data. Some countries have established similar national laws, regulations, guidelines, or standards for exposure to radio frequency fields, while others have adopted or are in the process of adopting the ICNIRP guidelines in Europe in response to the EU recommendations. Accordingly, most national and international documents are based on the concept of avoiding the established short-term health effects of exposure [5; 6; 7]. The European Commission recommendation adopted on 12 July 1999 requires that a maximum field strength of RF EMR (0-300 GHz) be established and that information about the population's exposure to RF electromagnetic fields (EMFs) and the measures taken to reduce them be provided [7]. RF EMF intensity parameters are measured for a variety of reasons:  
1. Radio engineering installations are measured in order to evaluate RF EMFs produced by them. Such measurements are done in accordance with safety hygiene norms, standards, or other regulatory documents;
2. RF EMF measurements are carried out according to requests by the general public, authorities, or suppliers. The measurements are conducted in a particular place (for example, in a room, balcony, playground, etc.) by identifying RF EMF sources;
3. Comparative measurements of RF EMFs, produced by a radio engineering facility in one location, are compared against those in another one;
4. Scientific RF EMF studies are based on long-term monitoring measurements covering measurement locations that are most frequented by people, and the obtained data are used for epidemiological studies [8; 9]. The precise experimental determination of the power density of antennas in complex environments is a difficult task. This is mainly due to the existence of three fundamental physical properties of electromagnetic waves: reflection, absorption, and interference [10; 11; 12]. Under uncontrolled conditions, for instance in a complicated environment, different measurements can lead to quite different results due to changing conditions [13; 14; 15]. Moreover, the settings of the measurement equipment may affect the accuracy of the measured values. Special attention should be paid to the exposure assessment methodology [16]. Reducing the highest allowed level of RF EMR, and the establishment of other legislation on High Frequency Electromagnetic Dosimetry, are issues of worldwide importance, taking into consideration the contradictory information about mobile phones, mobile telephony base stations, and their possible dangerous effects on human health [17; 18; 19; 20; 21]. In performing field measurements of RF EMFs, the key task is to appropriately identify measurement locations [22]. An important stage is to evaluate where the values of RF EMF intensity parameters will be the highest [23].