Appendix M. Dpc (Vms Dynamic Power Control; Overview - Comtec CDM-840 Installation And Operation Manual

Appendix M. DPC (VMS DYNAMIC
M.1

Overview

VMS v3.x.x VIPERSAT Management System User Guide (CEFD P/N MN/22156)
This appendix provides information on Dynamic Power Control in reference to the
return path only – CDM-840 Remote Router to CDD-880 Multi Receiver Router
control.
The DPC (Dynamic Power Control) feature provided in Comtech EF Data's Advanced VSAT
products provides a mechanism whereby remote satellite uplinks have their transmit power
levels adjusted in order to optimize the receive signal quality as measured by the corresponding
demodulator E
acts to either increase or decrease transmitted signal levels in order to:
•
Achieve a minimum level of received E
margin.
•
Reduce transmit power where sufficient link margin exists in order to optimize group station
uplink saturation and/or satellite transponder power usage reducing costs.
•
Increase link availability when margins apply (typically Ku-Band or Ka-Band).
•
Maintain proper power backoff to eliminate high power amplifier saturation and carrier
distortion.
DPC is a selectable software feature operating independently on CDM-840s exchanging a UDP
message between the receiving unit (where the signal quality is being measured) and the
transmitting unit (where the power level is to be adjusted). This message contains link quality
status, which is directed to the transmit site on timed intervals, updating the link state.
This appendix explains the design details, mechanisms, and functional operation of Dynamic
Power Control.
/N (the ratio of energy per symbol to noise density). This optimization process
S 0
POWER CONTROL)
/N consistent with providing an error free link or set
S 0
M–1