Stochastic-Deterministic Thermal Dosimetry Below 6 GHz for 5G Mobile Communication Systems

The article deals with stochastic-deterministic thermal dosimetry in lower portion of GHz frequency range for human exposure to radiation from 5G communication systems. Deterministic assessment of a temperature distribution in multilayered head model is based on the finite element solution of Pennes equation while the stochastic analysis uses the stochastic collocation approach. Thermal conductivity and volumetric blood perfusion rate of scalp, skull, and brain tissues are modeled as uniformly distributed random parameters, while values of other thermal input parameters are fixed to their respective average values. The stochastic mean and variance of the heating factor at 3.5 GHz are computed and confidence interval is estimated for some observation points of interest. By using “one-at-a-time” and analysis of variance principles, sensitivity analysis of input parameter set is carried out. Some illustrative numerical results stemming from deterministic and stochastic model, respectively, are presented. When observing the impact of input parameters on heating factor values in the direction of incidence, blood perfusion of scalp is dominant with exception in the interior head parts, where the impact of the brain blood perfusion prevails. For the exposure scenario of interest, the temperature elevation is within the limits given by basic restrictions.