Transmission Distance; Reach And Optical Link Budget; Reach Calculation Examples - Avaya 8800 Planning And Engineering

Transmission distance

To ensure proper network operation, given your link characteristics, calculate the maximum
transmission distance for your fiber link.
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Reach and optical link budget

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Reach calculation examples

Reach and optical link budget
The absorption and scattering of light by molecules in an optical fiber causes the signal to lose
intensity. Expect attenuation when you plan an optical network.
Factors that typically affect optical signal strength include the following:
• optical fiber attenuation (wavelength dependent: typically 0.20 to 0.35 dB/km)
• network devices the signal passes through
• connectors
• repair margin (user-determined)
The loss budget, or optical link budget, is the amount of optical power launched into a system
that you can expect to lose through various system mechanisms. By calculating the optical link
budget, you can determine the transmission distance (reach) of the link (that is, the amount of
usable signal strength for a connection between the point where it originates and the point
where it terminates).
Important:
Insertion loss budget values for the optical routing system CWDM OADM and OMUX include
connector loss.
Reach calculation examples
The examples in this chapter use the following assumptions and procedure for calculating the
maximum transmission distances for networks with CWDM components.
The examples assume the use of the values and information listed in the following table. Use
the expected repair margin specified by your organization. For GBIC, SFP, XFP, and
multiplexer specifications, see Avaya Ethernet Routing Switch 8800/8600 Installation — SFP,
Planning and Engineering — Network Design
on page 45
on page 45
Transmission distance
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