Narrowband frequency-selective up-link and down-link evaluation of daily personal-exposure induced by wireless operating networks

Abstract

The aim of the study is to present a frequency-selective evaluation of personal exposure induced by wireless operating networks in typical daily environments, derived by analysis of 1,905,162 samples of electric field strength, taken at a 5-s sampling interval. Measurements were collected with calibrated isotropic three-axial electric field probe personal exposure meters operating in the frequency range 88---5850 MHz. `' To estimate the electric field distribution below the measurement equipment detection limit, the robust regression on order statistics method was applied, enabling determination of mean values of electric field strength per wireless technology for: home, office, transport, outdoor, and leisure environments. The highest value of total electric field strength exposure is obtained on public transport (buses) followed by coffee shops and outdoor environments, whereas the lowest values are captured in home and office environments. Most of the mean values of the electric field were less than 0.06 V/m. Furthermore, the analyses between the contribution of uplink and downlink exposures for operating wireless cellular networks are given, including a comparison of uplink and downlink electric field levels from other countries. Readings of the 24-h personal-exposure pattern, reveal the GSM + UMTS downlink and Wi-Fi as dominant exposure contributors. The results of this study show that spatial and temporal exposure levels in Kosovo are comparable to those reported for other European countries and far below the international safety guidelines and exposure limits.