Comtech EF Data SLM-5650A Installation And Operation Manual page 480

While the traditional link was based on QPSK, TPC 3/4 and required 3.9 MHz of leased
bandwidth, the Carrier-in-Carrier link was based on QPSK, LDPC 3/4 and QPSK, LDPC 1/2 and
required 2.8 MHz of leased bandwidth.
The savings summary is as follows:
Item
Data Rate (kbps) 3000
Modulation QPSK
FEC TPC 3/4
Occupied BW (MHZ) 2.8
Power Eq. BW (MHz) 3.3
Leased BW (MHz)
Hub HPA (W) 26.0
Remote HPA (W) 10.6
If this link was designed using QPSK, LDPC 3/4 in both directions, it would have required:
•
Occupied BW – 2.8 MHz
•
Power Eq. BW – 3.0 MHz (a 7.2% increase in Power Eq. BW)
•
Leased BW – 3.0 MHz (a 7.2% increase in Leased BW)
•
Hub HPA – 20.3 W
•
Remote HPA – 8.3 W (a 30% increase in Remote power)
Appendix H
Original Link
Hub to Remote to
Remote Hub
1000
QPSK
TPC 3/4
0.9 3.7
0.6 3.9
3.9
With Carrier-in-Carrier and LDPC
Hub to Remote to
Total
Remote
3000 1000
QPSK QPSK
LDPC 3/4 LDPC 1/2
2.8 1.4
2.5 0.3
20.3
6.4
G–14
SLM-5650A Satellite Modem
Revision 10
Savings
Total
Hub
2.8
2.8
2.8 27.5%
22%
40%
MN-SLM-5650A