34
Chapter 2 Calculating transmission distance
212257-B
Table 7
shows typical loss values that can be used to calculate the transmission
distance for the hub and spoke network in
Figure 13
.
Table 8
shows the calculations used to determine maximum transmission distance
for the hub and spoke network in
Figure 13
.
Transmission distance calculation for the hub and spoke network example in
Figure 13
:
•
•
•
•
Table 7 Hub and spoke signal loss values
Signal loss element
value
Loss budget
30 dB
CWDM OADM insertion add loss
1.9 dB
CWDM OADM passthrough loss
2.0 dB
CWDM OMUX8 demux loss
4.5 dB
System margin
3 dB
Fiber attenuation
.25 dB per km
Table 8 Hub and spoke maximum transmission distance calculations
Result
Calculation
Passthrough nodes
Passive loss
Implied fiber loss
Maximum transmission
distance
the number of OADMs between add OADM and OMUX
OADM add
OMUX8 demux
passthrough nodes
OADM passthrough loss
×
(
)
+
+
loss budget
passive loss
system margin
–
–
implied fiber loss
attenuation per kilometer
÷
7 Passthrough nodes
1.9 dB
4.5 dB
+
7
2.0
×
(
)
20.4 dB Passive Loss
=
+
30 dB 20.4 dB
–
3 dB
–
6.6 dB Implied Fiber Loss
=
6.6 dB
.25 dB
26.4 km Maximum Transmission Distance
=
÷
Summary of Contents for 10292FA
Page 10: ...10 Figures 212257 B ...
Page 12: ...12 Tables 212257 B ...
Page 16: ...16 Preface 212257 B ...
Page 26: ...26 Chapter 1 Describing the optical routing system 212257 B ...
Page 46: ...46 Appendix A CWDM OADM specifications 212257 B ...
Page 48: ...48 Appendix B CWDM OMUX specifications 212257 B ...
Page 54: ...54 Appendix C Handling and cleaning fiber optic equipment 212257 B ...
Page 66: ...66 Glossary 212257 B ...
Page 70: ...70 Index 212257 B ...