If the propagation of electromagnetic waves in ‘free-space' is taken as a standard reference, the corresponding wave propagation through precipitation filled media can experience several physical effects: wave attenuation, phase shifts exceeding the ones due to free-space propagation delay, change of polarisation state (so-called wave depolarisation), dispersion over the signal bandwidth, scintillations, and the addition of radiometric noise. These effects, in turn, are capable of significantly impairing the quality, strength, and even the character of information carrying radio signals. As one might expect, the named propagation effects are strongly dependent on the frequency of the EM-waves and the nature (hydrometeor type, particle size distribution) of the precipitation medium.