Predicting Rain Attenuation at D Band for 6G Backhaul Link Design: a Frequency Scaling Approach

A frequency scaling (FS) model is presented for the prediction of rain-induced attenuation affecting a short terrestrial link operating at D band, to be potentially used as backhaul link in future sixth generation (6G) networks. The methodology, which aims at estimating rain attenuation at a target higher frequency from measurements collected at a lower band, requires as input local time series of the rain rate and defines a scaling ratio as a function of the specific attenuations at the two frequencies. Data from a long-term propagation study, conducted in collaboration between Politecnico di Milano and the Huawei Microwave Centre in Milan, are employed to assess the accuracy of the proposed model in scaling rain attenuation from E band (83 GHz) to D band (156 GHz). Results indicate high prediction accuracy. This corroborates the use of the proposed FS model as a tool to fill the current lack of tropospheric impairment data at carrier frequencies not currently licensed but to be potentially employed in the near future in 6G networks.