Avaya 8800 Planning And Engineering, Network Design page 48

Optical routing design
Table 13: Assumptions used in calculating maximum transmission distance
Parameter
Cable
Repair margin
Maximum link budget
System margin
Fiber attenuation
Operating temperature
CWDM OADM expected loss
CWDM OMUX expected loss
To calculate the maximum transmission distance for a proposed network configuration:
• Identify all points where signal strength is lost.
• Calculate, in dB, the expected loss for each point.
• Find the total passive loss by adding the expected losses together.
• Find the remaining signal strength by subtracting the passive loss and system margin from the
total system budget.
• Find the maximum transmission distance by dividing the remaining signal strength by the
expected fiber attenuation in dB/km.
Point-to-point reach example
The following factors affect signal strength and determine the point-to-point link budget and the
maximum transmission distance for the network shown in the following figure.
• OMUX multiplexer (mux) loss
• OMUX demultiplexer (demux) loss
• Fiber attenuation
June 2016
Value
Single mode fiber (SMF)
0 dB
30 dB
3 dB (allowance for miscellaneous network loss)
0.25 dB/km
0 to 40°C (32 to 104°F)
Use OADM specifications
Use OMUX specifications
Planning and Engineering — Network Design
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