The canonical chain
CO/POP → feeder → FDH (fiber distribution hub with splitters) → distribution → NAP/drop terminals → drops → homes. Serving-area boundaries are drawn so each FDH covers a natural cluster (typically 200–600 homes) within drop-length limits.
Centralized vs cascaded splitting
Centralized (1:32 at the FDH): every customer fiber appears at one cabinet — clean testing, flexible port assignment, efficient OLT fill; costs more distribution fiber. Cascaded (1:4 FDH × 1:8 terminal): saves fiber and suits low take-rate rural spans; testing beyond the first splitter is harder and port stranding rises. Many operators standardize centralized in dense areas, cascaded on long rural runs.
Terminals and drops
Pre-connectorized (plug-and-play) terminals cut drop install time from hours to minutes and de-skill the last hop — at higher hardware cost and ~0.5 dB extra per connection that the budget must carry. Drop rules: G.657, max lengths per budget, one spare port per terminal minimum.
Civil reality
CAPEX is 60–80% civil works. Design shares trenches, uses existing ducts and pole lines, chooses microtrenching or aerial where soil and rules allow, and sequences builds to open revenue-generating areas first. A beautiful optical design over an unbuildable civil plan is a slide deck, not a network.