Operational References; Carrier-In-Carrier Link Budget Calculation - Comtech EF Data CDM-625 Installation And Operation Manual

CDM-625 Advanced Satellite Modem
DoubleTalk Carrier-in-Carrier Option

10.5 Operational References

10.5.1

Carrier-in-Carrier Link Budget Calculation

The following steps are required for calculating the link budget for a Carrier-in-Carrier Link:
Step Task
1
Calculate the link budget for both carriers in the duplex link, with required CnC margin:
2 Verify that the PDS ration is within spec for the CDM-625.
3
Calculate the Allocated Bandwidth (BW) and Power Equivalent Bandwidth (PEB) for the duplex
link:
4
For an optimal link, the Leased Bandwidth and the Power Equivalent Bandwidth should be
equal / nearly equal.
5
Repeat the link budget process by selecting different Modulation and FEC, until the BW and
PEB is nearly balanced.
• BW = Greater of (BW
Duplex Link
• PEB = PEB
Duplex Link Carrier 1
• Leased BW = Greater of (BW
Duplex Link
, BW )
Carrier 1 Carrier 2
+ PEB
Carrier 2
, PEB
Duplex Link Duplex Link
10–17
Revision 13
MN-CDM625
)