## 3 Results and Discussion
### Multi-Location On-Body RF EMF Exposure Evaluation (Physical Measurements)  
The results of recordings in LTE800, LTE900, LTE1800, LTE2100, LTE2600 and LTE3600 (5G) frequency bands, collected by a three wearable PEMs following the two test measurements exposure scenarios described in Section 2.2, were compared with the unperturbed E-field value, which was measured in the location of the test measurements in each of the mentioned frequency bands without presence of anyone there. The discrepancy in the sensitivity of the equipment used was taken into account by applying a relevant correction factor--C\({}_{\mathrm{f}}\) (covering discrepancy in the sensitivity of particular PEM and deviation of sensitivity from the omnidirectional one)--determined by the calibration of the PEMs in the laboratory reference RF EMF. The recordings from each PEM were normalized to the sensitivity unified across all the PEMs. Finally, the recordings were normalized to the level of the unperturbed E-field in the environment under study. The following KSL ratio is a measure of the influence from the proximity of the human body on the distribution of the evaluated E-field during test measurements:  
\[\mathrm{KSL}=(\mathrm{C_{fb}}\times\mathrm{E_{x}(fb)})/\mathrm{E_{up}(fb)}, \tag{4}\]  
where: C\({}_{\mathrm{fb}}\)--individual correction factors determined for each used PEM to compensate for discrepancies in sensitivity between devices, performed separately in each analysed frequency band (fb); E\({}_{\mathrm{x}}\)(fb)--the E-field value recorded in the analysed frequency band by an on-body PEM; E\({}_{\mathrm{up}}\)(fb)--the unperturbed E-field value measured at particular fb during test measurements using omnidirectional spot ball-probe. Figure 10 presents the statistical analysis (mean and MMR values) of this KSL ratio for each PEM, considered to be three on-body single-point measurements (E-field sensor locations: H--head, CF--chest front, CB--chest back). The smaller dispersion of results  
recordings was obtained in second exposure scenario with quasi-vertical RF EMF propagation (more typical in the urban out-door environment). The reduction in the uncertainty of the measurement results caused by the impact from the proximity of the body (on the distribution of the evaluated E-field during the test measurements), when to the on-body distributed (multi-location) PEM recordings is applied, was analysed using the following KDM ratio:  
\[\text{KDM}=\text{E}_{\text{dx}}(\text{fb})/\text{E}_{\text{up}}(\text{fb}), \tag{5}\]  
where: (E\({}_{\text{dx}}(\text{fb})\)--the arithmetic mean of the E-field value recorded in the analysed frequency bands by the on-body PEMs used, which constitute the modelled distributed measurement system, where each individual recording is normalized to compensate for any discrepancy in the sensitivity between devices following the formula: (C\({}_{\text{fb}}\times\text{E}_{\text{x}}(\text{fb})\)) (see Equation (4)), for each PEM used, performed separately for each analysed frequency band (fb); E\({}_{\text{up}}(\text{fb})\)--the unperturbed E-field value measured at particular fb during the test measurements. Figure 11 presents the statistical analysis (MMR--mean and range between minimum and maximum values) of this KDM ratio for considering the particular combination of PEM locations (H--head and CF--chest front and CB--chest back), obtained during physical tests (note RF EMF from 100 and 400 MHz frequency bands was not present in the location of tests--what is very common in an urban environment).