Coexistence of Terrestrial and Satellite Networks in the 28-GHz Band

We present a practical framework for maximizing the average data rates of terrestrial networks operating in the 28-GHz band while considering their coexistence with satellite networks. The 28-GHz mmWave band is licensed to fixed satellite services for Earth-to-space uplink transmissions, which are also used by the terrestrial cellular and backhaul networks for downlink operation. Our approach focuses on finding the optimal radii for exclusion zones, which are the areas where certain network elements are restricted from operating in the 28-GHz band. Through stochastic geometry, we derive the average data rate expressions for the terrestrial networks as functions of the exclusion zone radii of the Earth stations and the backhaul points. We then convert the discrete problem of frequency allocation into a continuous problem through Poisson point process approximation of the transmitters' locations. We perform logistic regression on the integral-form coverage probability expression to obtain closed-form approximation of the data rate expressions. This facilitates faster optimization, making our framework viable for deployment in frequency allocation systems, offering near-optimal results with lower complexity compared with combinatorial techniques. We improve the data rate of cellular users by up to $\sim \!30\%$ at the expense of the data rate of the backhaul points degrading by $\sim \!2\%$.