Radiofrequency exposure near an attocell as part of an ultra-high density access network.

In the future, wireless radiofrequency (RF) telecommunications networks will provide users with gigabit-per-second data rates. Therefore, these networks are evolving toward hybrid networks, which will include commonly used macro- and microcells in combination with local ultra-high density access networks consisting of so-called attocells. The use of attocells requires a proper compliance assessment of exposure to RF electromagnetic radiation. This paper presents, for the first time, such a compliance assessment of an attocell operating at 3.5 GHz with an input power of 1 mW, based on both root-mean-squared electric field strength (E ) and peak 10 g-averaged specific absorption rate (SAR ) values. The E values near the attocell were determined using finite-difference time-domain (FDTD) simulations and measurements by a tri-axial probe. They were compared to the International Commission on Non-Ionizing Radiation Protection's (ICNIRP) reference levels. All measured and simulated E values above the attocell were below 5.9 V/m and lower than reference levels. The SAR values were measured in a homogeneous phantom, which resulted in an SAR of 9.7 mW/kg, and used FDTD simulations, which resulted in an SAR of 7.2 mW/kg. FDTD simulations of realistic exposure situations were executed using a heterogeneous phantom, which yielded SAR values lower than 2.8 mW/kg. The studied dosimetric quantities were in compliance with ICNIRP guidelines when the attocell was fed an input power <1 mW. The deployment of attocells is thus a feasible solution for providing broadband data transmission without drastically increasing personal RF exposure. Bioelectromagnetics. 38:295-306, 2017. © 2017 Wiley Periodicals, Inc.