Operational References; Calculating A Carrier-In-Carrier Link Budget; J.5 Operational References - Comtech EF Data CDM-760 Installation And Operation Manual

Appendix J
CDM-760 Advanced High-Speed Trunking Modem
J.5

Operational References

J.5.1

Calculating a Carrier-in-Carrier Link Budget

Do these steps to calculate the link budget for a CnC Link:
Step Task
1 Calculate the link budget for both carriers in the duplex link, with required CnC margin:
2
Verify that the CnC ratio is within spec for the CDM-760.
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 are equal or 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 + PEB
Duplex Link Carrier 1
Leased BW = Greater of (BW
Duplex Link
, BW )
Carrier 1 Carrier 2
Carrier 2
, PEB
Duplex Link Duplex Link
J–15
Revision 4
MN-CDM760
)