The careful planning and safe deployment of 5G technologies will bring enormous benefits to society and the economy. Higher frequency, beamforming, and small-cells are key technologies that will provide unmatched throughput and seamless connectivity to 5G users. Superficial knowledge of these technologies has raised concerns among the general public about the harmful effects of radiation. Several standardization bodies are active to put limits on the emissions which are based on a defined set of radiation measurement methodologies. However, due to the peculiarity of 5G such as dynamicity of the beams, network densification, Time Division Duplexing mode of operation, etc, using existing EMF measurement methods may provide inaccurate results. In this context, we discuss our experimental studies aimed towards the measurement of radiation caused by beam-based transmissions from a 5G base station equipped with an Active Antenna System(AAS). We elaborate on the shortcomings of current measurement methodologies and address several open questions. Next, we demonstrate that using user-specific downlink beamforming, not only better performance is achieved compared to non-beamformed downlink, but also the radiation in the vicinity of the intended user is significantly decreased. Further, we show that under weak reception conditions, an uplink transmission can cause significantly high radiation in the vicinity of the user equipment. We believe that our work will help in clearing several misleading concepts about the 5G EMF radiation effects. We conclude the work by providing guidelines to improve the methodology of EMF measurement by considering the spatiotemporal dynamicity of the 5G transmission.

翻译：5G技术的审慎规划与安全部署将为社会与经济带来巨大裨益。高频段、波束赋形及小基站等关键技术将为5G用户提供前所未有的吞吐量与无缝连接。公众对这些技术的片面认知引发了关于辐射危害的普遍担忧。多个标准化组织正积极基于既定辐射测量方法体系设定排放限值。然而，由于5G技术具有波束动态性、网络密集化、时分双工运行模式等特殊性，沿用现有电磁场测量方法可能导致结果失准。在此背景下，我们开展面向配备有源天线系统的5G基站的波束传输辐射测量实验研究，详细阐释当前测量方法的局限性并回应多项待解问题。研究表明，相较于非波束赋形下行链路，用户专属下行波束赋形技术不仅可实现更优性能，还能显著降低目标用户周围的辐射强度。此外，我们发现弱接收条件下上行链路传输会导致用户设备附近产生显著辐射。本研究成果有助于澄清关于5G电磁辐射影响的若干认知误区。最终，我们通过考虑5G传输的时空动态特性，提出改进电磁场测量方法体系的指导建议。