Installation guide

Overview
16 FTTH Application Guide
Planning GPON networks
When deploying GPON networks, you have to think in optical terms, rather
than electrical or copper based terms. With copper based solutions you think
of distance and transport technology (“Will ADSL or VDSL reach from the
CO to the subscribers?” is a significant network design question); with fiber
based networks, and GPON in particular, you have to think in terms of optical
link power loss budgets.
Link loss is the amount of signal attenuation as you proceed farther away
from the OLT toward the subscribers’ ONTs. Each component, including the
fiber cable itself, degrades the signal. Attenuation is the term used for
describing the amount of signal degradation.
Figure 1: Link loss in an GPON Optical Deployment Network
The plan for both a GPON network and Active Ethernet network should
include a link loss budget map that shows how each component, even the
distance of each length of fiber, should affect signal attenuation. Because
GPON lines are split into multiple lines which have a significant power loss,
the link loss budget map is a more important requirement for GPON