Uplink & Downlink

Up link is radio frequency signal (RF) which relayed from earth station to satellite. On the contrary, down link is radio frequency signal relayed from satellite to earth station.

Mostly, VSAT uses Ku-band or C-band frequency. Ku-band frequency is usually used in North America and Europe by utilizing small VSAT antenna with up link frequency about 14 GHz and down link around 12 GHz, while C-band is intensively used in Asia, Africa and Latin America and operating with much larger antenna, with up link frequency around 6 GHz as for down link frequency around 4 GHz.