Comtech EF Data CDM-570A Installation And Operation Manual page 582

To continue, consider this example:
Satellite & Transponder
Earth Station 1
Earth Station 2
Data Rate
Whereas the original link used 8-PSK TPC 3/4, the Carrier-in-Carrier link used QPSK VersaFEC
0.803.
The savings summary is as follows:
Item
Data Rate (kbps)
Modulation
FEC
Occupied BW (MHZ)
Power Eq. BW (MHz)
Leased BW (MHz)
Hub BUC (W)
Remote BUC (W)
Using Carrier-in-Carrier and VersaFEC reduced the leased bandwidth by almost 44% and the
BUC size by 60% at the Hub and 75% at the Remote.
DoubleTalk Carrier-in-Carrier Option
CDM-570A/570AL Satellite Modem with Optional Packet Processor
Original Link
Hub to Remote
Total
Remote to Hub
2048 2048
8-PSK 8-PSK
TPC 3/4 TPC 3/4
1.3 1.3 2.6
2.2 1.0 3.2
3.2
5
20
G–16
IS-901 @ 342º W, 22/22 (EH/EH)
Africa – 9.2 m
Africa – 4.5 m
2.048 Mbps / 2.048 Mbps
With Carrier-in-Carrier and VersaFEC
Hub to Remote to
Remote Hub
2048 2048
QPSK QPSK
VersaFEC VersaFEC
0.803 0.803
1.8 1.8
1.1 0.5
2
5
Revision 5
Savings
Total
1.8
1.6
1.8 44%
60%
75%
MN-CDM570A