Operational References; Calculate Carrier-In-Carrier Link Budget - Comtech EF Data CDM-425 Installation And Operation Manual

F.3

Operational References

F.3.1

Calculate Carrier-in-Carrier Link Budget

Comtech EF Data recommends that you do these steps to calculate the link budget for a CnC
Link:
Step
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-425 Advanced Satellite Modem.
3 Calculate the Allocated Bandwidth (BW) and Power Equivalent Bandwidth (PEB) for the duplex link:
For an optimal link, the Leased Bandwidth and the Power Equivalent Bandwidth should be equal / nearly
4
equal.
Repeat the link budget process by selecting different Modulation and FEC, until the BW and PEB is
5
nearly balanced.
Appendix F
BW = Greater of (BW
•
Duplex Link
PEB = PEB
•
Duplex Link Carrier 1
Leased BW = Greater of (BW
•
Duplex Link
Task
, BW )
Carrier 1 Carrier 2
+ PEB
Carrier 2
, PEB
Duplex Link Duplex Link
F–19
CDM-425 Advanced Satellite Modem
)
MN-CDM-425
Revision 0