Nortel Networks 10292FA, 10396EA manual Hub and spoke signal loss values

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34Chapter 2 Calculating transmission distance

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 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 shows the calculations used to determine maximum transmission distance for the hub and spoke network in Figure 13.

Table 8 Hub and spoke maximum transmission distance calculations

Result

Calculation

Passthrough nodes	the number of OADMs between add OADM and OMUX

Passive loss	OADM add + OMUX8 demux + (passthrough nodes × OADM passthrough loss)

Implied fiber loss	loss budget – passive loss – system margin

Maximum transmission	implied fiber loss ÷ attenuation per kilometer
distance

Transmission distance calculation for the hub and spoke network example in Figure 13:

•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

212257-B

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Contents Installation and Networking Guidelines for Optical Routing Copyright 2002 Nortel Networks 212257-BInstallation and Networking Guidelines for Optical Routing Canada requirements onlyNortel Networks Inc. software license agreement Installation and Networking Guidelines for Optical Routing 212257-B Contents Chapter Installing the shelf, OADM, and Omux ContentsFigures Figures 212257-B Tables Tables 212257-B Preface Component FunctionHard-copy technical manuals Before you beginPreface How to get help Technical Solutions Center TelephonePreface 212257-B Chapter Describing the optical routing system Wavelength division multiplexingDescribing the optical routing system Parts of the optical routing systemGigabit interface converter description Parts of the optical routing systemOptical add drop multiplexer description Cwdm Gbic transceiver and labelNetwork add/drop ring application Cwdm Oadm network and equipment side connectionsCwdm Oadm ring configuration example Optical multiplexer/demultiplexer descriptionCwdm OMUX-4 Cwdm Omux in a point-to-point application Cwdm OMUX-8 network and equipment side connectionsCwdm Omux point-to-point configuration example Cwdm Omux in a ring applicationCwdm Omux ring configuration example Describing the optical routing system 212257-B Chapter Calculating transmission distance About transmission distance and optical link budgetHow to calculate maximum transmission distance How to calculate expected loss budgetCalculating transmission distance Point-to-point network configuration example Point-to-point transmission distanceMesh ring transmission distance Point-to-point signal loss valuesPoint-to-point maximum transmission distance calculations Mesh ring network configuration Mesh ring signal loss values Mesh ring maximum transmission distance calculationsHub and spoke network configuration Hub and spoke transmission distanceHub and spoke signal loss values Hub and spoke maximum transmission distance calculationsPreparing for installation Chapter Installing the shelf, OADM, and OmuxExceeding class 1 power level warning Environmental and physical requirements Installing the shelf, OADM, and OmuxElectrostatic discharge Installing the shelf Inserting a Cwdm Oadm or a Cwdm Omux Shelf with plug-in module in 19-inch rackCabling a Cwdm Oadm or a Cwdm Omux Cabling a Cwdm OadmCabling a Cwdm Oadm Cabling a four-channel Cwdm Omux Cabling a Cwdm OMUX-4Cabling an eight-channel Cwdm Omux Cabling an Cwdm OMUX-8 Removing a Cwdm Oadm or a Cwdm Omux Appendix a Cwdm Oadm specifications Cwdm Oadm specificationsAppendix a Cwdm Oadm specifications 212257-B Cwdm Omux specifications Cwdm Omux specificationsAppendix B Appendix B Cwdm Omux specifications 212257-B Appendix C Handling and cleaning fiber optic equipment PrecautionsAppendix C Handling and cleaning fiber optic equipment Cleaning Fiber Optic ConnectorsTools and Materials Cleaning Single SC and FC Connectors Cleaning Duplex SC Connectors Cleaning Receptacle or Duplex Devices Page Glossary Glossary Dwdm See optical fiber Group of circuits connected at one point on a network See MMF Ndsf An optical wavelength band for WDM optical communications Device that does not require a source of energy to function See SMF WDM Glossary 212257-B Index Cwdm OmuxIndex OMUX, CwdmIndex Index 212257-B