Installation guide

Fiber Solutions

FTTH Application Guide

Installation testing

The theoretical link loss budget map is very important when installing fiber.

Testing should be done before and after each component is added. Matching

the actual signal attenuation with the theoretical link loss budget map helps

identify problems such as

• macro bends in cables (too small a bend radius)

• connector loss from back reflection (the contact between the face ends of

fiber in a connector, or a splice)

• incorrectly matching UPC and APC connectors may also create back

reflections. UPC connectors (Ultra Physical Contact) have a slightly

spherical end face. APC connectors (Angled Physical Contact) use an

industry standard angle on the end face of the fiber. (Though you should

be aware of older, non standard APC connectors which use a different

angle.)

Figure 2: End face of UPC and APC connectors

Component Loss

Optical fiber

-0.3 dB per kilometer

Splitters The link loss for splitters depends on the

number of splits

• 2 splits, -4 dB

• 4 splits, -7.5 dB

• 8 splits, -11 dB

• 16 splits, -14 dB

• 32 splits, -18 dB

• 64 splits, -21.5 dB

Splices

-0.1 dB

Connectors

-0.2 dB

Couplers Couplers are connectorized means for

splicing cable.

-0.4 dB