CnG Telecommunication System Engineering

Propagation Losse

•Attenuation due to precipitation

–Rain attenuation is the main contributor in 

the frequency range used by commercial 

radio links

–Rain attenuation increases exponentially 

with rain intensity

–The percentage of time for which a given 

rain intensity is attained or exceeded is 

available for 15 different rain zones 

covering the entire earth’s surface

–The specific attenuation of rain is dependent on 

many parameters such as the form and size of 

distribution of the raindrops, polarization, rain 

intensity and frequency

–Horizontal polarization gives more rain attenuation 

than vertical polarization

–Rain attenuation increases with frequency and 

becomes a major contributor in the frequency bands 

above 10 GHz

–The contribution due to rain attenuation is not 

included in the link budget and is used only in the 

calculation of rain fading