Measurement of Ambient Millimeter Wave Exposure Levels around Small Base Stations

This study investigated the implementation and impact of fifth-generation (5G) wireless millimeter wave (mmW) technology. 5G offers significant advancements over previous generations and supports additional frequency bands, including mmW, to enhance mobile broadband with ultra-reliable, low-latency communications, supporting a high volume of diverse communications. This technology is expected to enable billions of new connections in the Internet of Things (IoT), fostering innovations in various sectors including healthcare, manufacturing, and education. This research contributes to the understanding and safe implementation of this transformative technology. Global adoption of 5G is rapidly increasing, with over 1.5 billion subscriptions as of 2024, projected to reach 58% of all wireless subscriptions by 2029. Despite its benefits, 5G mmW installations have raised concerns regarding exposure to electromagnetic fields. This study was conducted using a dual-polarized horn antenna and relatively inexpensive spectrum analyzers to measure typical ambient mmW radiofrequency field power densities near operational radio base stations (RBS) in urban and suburban environments. The measurements were taken at various times of the day and in different weather conditions to ensure a comprehensive understanding of the ambient mmW exposure. The study's results provide reassuring evidence that the ambient mmW exposure from RBSs is significantly lower than the safety limits set by the Federal Communications Commission (FCC) and other international standards. The exposure levels ranged from 0.0003% to 0.0082% of the public maximum permissible exposure (MPE), with the highest levels being more than 25,000 times lower than the allowed continuous public exposure. This study concludes that typical mmW exposure from 5G RBSs is minimal and substantially below established safety limits.