Evaluation of Microwave Transmission Path Performance for Rural Broadband Connectivity in Kwara State

Point-to-point microwave radio links are a widely deployed technology for extending broadband internet and voice connectivity to rural communities in Nigeria where fiber optic infrastructure is absent. This study evaluates the radio transmission path performance of sixteen licensed microwave links operating in the 7 GHz and 15 GHz frequency bands across rural Kwara State, North Central Nigeria. Link budget analysis was performed using path loss predictions from the ITU-R P.530 propagation model, accounting for terrain diffraction losses derived from 30-meter SRTM digital elevation data, atmospheric refractivity gradient statistics, and rain attenuation estimates based on Nigerian rain rate climatology. Predicted outage probabilities were compared against measured link availability statistics extracted from network management system records over a twelve-month operational period. Results indicate that measured annual availability averaged 99.87 percent across the 7 GHz links but only 99.62 percent at 15 GHz, reflecting higher rain attenuation susceptibility at the higher frequency. Three links experienced sustained outage periods exceeding ITU-T G.826 objectives, correlated with periods of heavy rainfall during the July to September rainy season. The study identifies incorrect antenna height specification at two links as contributing to excess diffraction loss. A practical path planning guide incorporating local climatological corrections is developed for use by telecommunications engineers designing rural microwave networks in the North Central zone. Keywords: microwave transmission, path loss, rural broadband, Kwara State, radio propagation