Implication of RF EMF Exposure Limitations on 5G Data Rates Above 6 GHz

For future 5G devices operating above 6 GHz, a consequence of existing electromagnetic field (EMF) exposure limits is that the maximum transmit power may have to be reduced several dB compared with what is used for the current cellular bands. To understand the consequences of such limitations on the system capacity, an indoor geometry is used to assess the achievable data rates for low power indoor nodes and UEs. The evaluation is performed as a function of the carrier frequency, the Tx power, and the amount of Tx and Rx beamforming. Ray tracing in combination with physical and experimental models or reasonable assumptions of diffraction-, reflection-and penetration-losses are used for modeling. The paper shows that the current exposure limitations might reduce the achievable data rates in non-line-of-sight regions to levels that may be inconsistent with 5G performance expectations. For the currently given maximum transmit power, high order beamforming seems necessary to achieve a good coverage already for carrier frequencies well below 15 GHz.