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 3.5GHz with an input power of 1mW, based on both root-mean-squared electric field strength (E-rms) and peak 10g-averaged specific absorption rate (SAR(10g)) values. The E-rms 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-rms values above the attocell were below 5.9V/m and lower than reference levels. The SAR(10g) values were measured in a homogeneous phantom, which resulted in an SAR(10g) of 9.7mW/kg, and used FDTD simulations, which resulted in an SAR(10g) of 7.2mW/kg. FDTD simulations of realistic exposure situations were executed using a heterogeneous phantom, which yielded SAR(10g) values lower than 2.8mW/kg. The studied dosimetric quantities were in compliance with ICNIRP guidelines when the attocell was fed an input power <1mW. The deployment of attocells is thus a feasible solution for providing broadband data transmission without drastically increasing personal RF exposure. (C) 2017 Wiley Periodicals, Inc.

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