Investigation of Rain Attenuation Effect on 5G Millimeter Wave Short-Range Fixed Links

The evolution of wireless communication has been driven by the limitations of spectrum availability below 6 GHz. As a solution, Fifth Generation (5G) networks have embraced Millimeter Wave (mmWave) frequency bands to meet the demand for higher data through- put across diverse applications. Implementing mmWave frequencies for short-range fixed links, specifically in 5G Fixed Wireless Access (FWA), holds the potential for better user experiences through high data rates, low latency, and cost-effective deployment. However, the promising potential of mmWave frequencies is accompanied by a significant challenge – rain attenuation. Rain-induced signal degradation poses a substantial threat to signal quality in mmWave short-range fixed links. In response, this thesis undertakes an extensive measurement campaign utilizing experimental fixed link setups operating at distinct frequencies: 25.84 GHz, 77.54 GHz, and 77.125 GHz. These setups span two short-range fixed links, measuring 36 m and 200 m. Augmented by a sophisticated weather station, which facilitates a comprehensive assessment of rain-induced attenuation and scattering effects. The incorporation of various weather parameters, such as rain intensity, drop size distribution, temperature, and refractive index, enhances the accuracy of attenuation measurement and prediction models. The thesis delves into the investigation of the obtained measurement results, meticulously analyzing rain attenuation across the two short-range links and mmWave frequencies. Key parameters influencing attenuation behaviour, including drop diameter, velocity, and antenna wetness, are examined. A pivotal contribution of this research is the establishment of correlations between measured radio links and weather data. This correlation enhances ITU-R guidelines and guides optimization for FWA 5G networks, particularly impactful in weather-variable regions.