Nortel Communication Server 1000 Series Manual page 34

34 Product description
Assume a 5 km length of fiber link made from five 1 km lengths of
fiber-optic cable with four splices in the cable (one splice every 1 km).
Calculations:
Example 2 - High quality multi-mode fiber-optic cable and splices
High quality multi-mode fiber-optic cable provides a loss of 1.0 dB per km.
High quality splices provide 0.1 dB loss per splice.
Assumptions:
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Assume a 9 km length of fiber made from nine 1 km lengths of cable with
eight splices in the cable (one splice every 1 km).
Calculations:
Example 3 - Medium quality single-mode cable and splices
Medium quality single-mode cable provides a loss of 1.0 dB per km.
Medium quality splices provide 0.2 dB loss per splice.
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dB loss = (5km) x (1.5 dB per km) + (4 splices) x (0.5 dB per splice)
dB loss = 7.5 dB + 2.0 dB = 9.5 dB
Safety margin = 10 dB - 9.5 dB = 0.5 dB
dB loss allowed over multi-mode fiber by the Fiber Remote Multi-IPE
Interface: 10 dB
dB loss per km of fiber: 1.0 dB
dB loss per splice: 0.1 dB
dB loss = (9km) x (1.0 dB per km) + (8 splices) x (0.1 dB per splice)
dB loss = 9.0dB + 0.8 dB = 9.8 dB
Safety margin = 10 dB - 9.8 dB = 0.2 dB
Assumptions:
dB loss allowed over single-mode fiber by the Fiber Remote Multi-IPE
Interface: 15 dB
dB loss per km of fiber: 1.0 dB
dB loss per splice: 0.2 dB
Nortel Communication Server 1000
Fiber Remote Multi-IPE Interface Fundamentals
NN43021-556 03.01
11 May 2009