Hybrid Antenna Measurement and Post-Processing for 5G Small Cell Exposure Assessment With Site-Specific Mounting Conditions

Ongoing mobile radio small cell deployment requires detailed analysis of the electromagnetic exposure which is dependent on the installation environment. To facilitate site-specific small cell exposure analysis, a hybrid exposure assessment approach is utilized which combines antenna nearfield measurement and post-processing. An equivalent current antenna model is investigated under virtually varying installation conditions, considering three real applications of small cell installation. The equivalent current antenna model's results are in good agreement with reference measurements and geometry-based simulations. Antenna pattern deviations vary between 0.9 dB and 2.9 dB, depending on the installation environment selected. This highlights the advantages of using the hybrid exposure assessment approach which adequately captures and reflects changes in the installation surroundings. Additionally, it yields comparable results to established methods and provides extensive flexibility for virtual exposure estimations by taking into account varying installation environments.

I. Introduction

To meet mobile network capacity requirements of an increasingly connected world, some network operators are relying on the installation of small cell base stations, which can contribute to a local improvement in network coverage and capacity. In contrast to macro cell base stations, small cells are characterized by their compact size, small coverage area (up to a few hundred meters), and low radiated power [1] which is often close to 10 W EIRP. This is why, cellular small cell base stations tend to be installed indoors, in public spaces or within road infrastructure e.g. traffic lights, billboards, or street lights [2].