title: Radiofrequency exposure near an attocell as part of an ultra-high density access network.
abstract: 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 (Erms) and peak 10 g-averaged specific absorption rate (SAR10g) values. The Ermsvalues 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 Ermsvalues above the attocell were below 5.9 V/m and lower than reference levels. The SAR10gvalues were measured in a homogeneous phantom, which resulted in an SAR10gof 9.7 mW/kg, and used FDTD simulations, which resulted in an SAR10gof 7.2 mW/kg. FDTD simulations of realistic exposure situations were executed using a heterogeneous phantom, which yielded SAR10gvalues 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.
authors.affiliation: Department of Information Technology, Ghent University, Ghent, Belgium.
authors.forename: Arno
authors.initials: A
authors.lastname: Thielens
authors.affiliation: Department of Information Technology, Ghent University, Ghent, Belgium.
authors.forename: Günter
authors.identifier: http://orcid.org/0000-0002-5309-3808
authors.initials: G
authors.lastname: Vermeeren
authors.affiliation: Department of Information Technology, Ghent University, Ghent, Belgium.
authors.forename: Olivier
authors.initials: O
authors.lastname: Caytan
authors.affiliation: Department of Information Technology, Ghent University, Ghent, Belgium.
authors.forename: Guy
authors.initials: G
authors.lastname: Torfs
authors.affiliation: Department of Information Technology, Ghent University, Ghent, Belgium.
authors.forename: Piet
authors.initials: P
authors.lastname: Demeester
authors.affiliation: Department of Information Technology, Ghent University, Ghent, Belgium.
authors.forename: Johan
authors.initials: J
authors.lastname: Bauwelinck
authors.affiliation: Department of Information Technology, Ghent University, Ghent, Belgium.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Rogier
authors.affiliation: Department of Information Technology, Ghent University, Ghent, Belgium.
authors.forename: Luc
authors.initials: L
authors.lastname: Martens
authors.affiliation: Department of Information Technology, Ghent University, Ghent, Belgium.
authors.forename: Wout
authors.initials: W
authors.lastname: Joseph
mesh_terms: D065638:Absorption, Radiation; D003195:Computer Communication Networks; D006801:Humans; D008962:Models, Theoretical; D019047:Phantoms, Imaging; D000069079:Radiation Exposure / Q000032:analysis*; D011846:Radio Waves; D059015:Wireless Technology
keywords: 5th generation networks; SAR; attocells; compliance; radiofrequency