Introduction to radiowave propagation effects in wireless communications systems. Propagation effects on terrestrial point-to-point (line of sight), satellite (fixed service, mobile, and direct broadcast), and cellular services are evaluated. Clear air, multipath (atmospheric and terrestrial), diffraction, refraction, tropospheric and ionospheric scintillation, rain attenuation, ice crystal and rain depolarization, and low angle fading effects are covered. Impact of climate and path geometries on fade margin assessed, and mechanisms for reducing potentially adverse effect of propagation conditions discussed.