M7/M7L/M7LT Modular Satellite Modem
Maintenance
M7/M7L/M7LT - Rev. 0.05
3-101
3.10. Automatic Uplink Power Control (AUPC) Operation
The modem has built-in logic for Automatic Uplink Power Control (AUPC). There are three (3)
operating modes available: Point-to-Point, Local, and Point-to-Multipoint.
NOTE: The examples following will assume the modems at all ends of the satellite links are
configured with the M7 Express Ethernet Interface (E7).
The Point-to-Point mode is used to maintain constant Eb/No performance in a duplex Point-to-
Point (PtP) link by adjusting the transmit power at both ends of the links during changes in link
performance. This is especially useful when operating over a satellite at Ku-Band or Ka-Band
frequencies in locations with high rainfall periods.
The Local mode is used in a broadcast or Point-to-Multipoint (PtMP) network where feedback
from remote ends of the link is not possible. In this mode, the transmit power of the broadcast
carrier is adjusted based on the Eb/No performance of the local receiver that is monitoring the
broadcast carrier.
A third mode is used in Point-to-Multipoint (PtMP) when information from the hub demod is routed
through the outbound hub carrier to each of the remote sites in order to maintain a defined Eb/No
performance on each of the return links independently.
There must be safeguards built into any AUPC system to limit the automatic maximum and minimum
power output level changes. Other safeguard controls are built into the operating control software to
limit response times and detect adverse operating conditions.
The AUPC selection parameters and their descriptions are shown in Table 3-14.
Table 3-14 - AUPC Functions
Function
Selection Criteria
Description
Mod: IF AUPC Mode
0 = Disable,
1 = Enable,
Automatic Uplink Power Control.
Mod: IF AUPC Eb/No
3.0 to 20.0 dB
AUPC remote receive Eb/No level
set point.
Mod: IF AUPC Max Level
+5.0 dBm to Minimum
level
Max. Transmit level under AUPC
control
Mod: IF AUPC Min Level
Maximum level to
–35 dBm
Min. Transmit Level under AUPC
control
Demod: IF AUPC Send Path
0 = Disable,
1 = Local,
2 = Out MCC Port,
3 = Out IP Control Port
Sets the output path for the AUPC
data
“Out MCC Port” setting at both
ends of a duplex PtP link is the
standard for bi-directional AUPC on
a duplex link. “Local” is the setting
for AUPC of the transmit carrier in a
broadcast network.
Demod: IF AUPC Remote MCC Address 1 to 254.
255 = Global
Set the address of the target MCC
port
Intf: MCC Mode
0 = Disable
1 = Read Only
2 = Full Access
Sets the rights of the MCC channel.
Intf: MCC Send Rate Limit
Entered in kbps up to
the maximum rate of
the satellite data rate.
Sets the maximum rate the MCC
channel will use from the satellite
channel. AUPC will require at least
0.5 kbps
