Motivation and Technical Background
The AUPC (Automatic Uplink Power Control) mechanism controls the modem output power in order to compensate uplink attenuation and keep a constant power level at the satellite transponder. Using AUPC allows the satellite link to be planned with less system margin which is translated to more available capacity. AUPC estimates uplink fading conditions and changes the output power according to changes in uplink attenuation. Uplink attenuation is estimated based on information such as beacon signal from the satellite, CeC measurements, SNR readings, remote side readings and user configuration.
AUPC System Behavior with NovelSat DUET CeC
When using AUPC, uplink attenuation estimation is based on internal modem information using NovelSat DUET CeC echo cancelation measurements and user configuration. No information from remote peers is used. When uplink fading increases, AUPC increases modem output power and decreases power when fading decreases. This feature makes it possible to maintain a much smaller link margin since AUPC compensates for any uplink fading, leaving the link margin to absorb only downlink fading. This yields additional capacity increase.