Comtech EF Data SLM-5650A - Manual (Page 154)

SLM-5650A Satellite Modem Revision 8
Base Modem HTTP Interface MN-SLM5650A
7–14
7.3.3.5 Config Mdm | AUPC (Automatic Uplink Power Control)
Use this page to enable the Automatic Uplink Power Control (AUPC) feature.
Figure 7-10. Config Mdm | Automatic Uplink Power Control page
AUPC enables the modem to automatically adjust its output power to maintain as constant the
Eb/No of the remote end of the satellite link. This provides protection against rain fading, a
particularly severe problem with Ku-Band links.
You must use the AUPC mode of operation to accomplish this protective adjustment. With
AUPC mode enabled, the distant end modem constantly sends back information about the
demodulator Eb/No, using reserved bytes in the overhead structure. The local modem uses Eb/No
to adjust its output power, and a closed-loop feedback system is created over the satellite link.