FTTH access reference architecture
An FTTH access architecture connects an OLT through a passive optical distribution network (ODN) to ONTs/ONUs at subscriber or building demarcation points. Design quality is dominated by optical budget, split plan and coexistence — not by marketing capacity claims.
Key facts
- Core elements: OLT, splitter plant, drop fiber, ONT/ONU
- XGS-PON may coexist with GPON when wavelength plans and filters are correct
- Site survey and measured losses beat spreadsheet assumptions
Audience
Access network planners and implementation leads.
Prerequisites
- Building/address list and expected take rates
- Existing GPON inventory if migration/coexistence is required
- Test equipment plan (power meter/OTDR as applicable)
Architecture
- Central office / POP: OLT and uplinks
- ODN: feeder, distribution, drop with documented split ratios
- Premises: ONT/ONT placement and power
Verification
- End-to-end power levels within ONT receive window
- Splitter labeling matches design records
- Service profile smoke tests after activation
Troubleshooting
Rollback
Preserve GPON paths during coexistence cutovers; keep patching records for rapid restore.
References
Related guides
- XGS-PON technology — 10G symmetrical PON technology domain summary with design rules and limits.
- XGS-PON design basics — Foundational XGS-PON design inputs, verification, and rollback considerations.
- Optical power budget checklist — Task checklist for calculating and validating end-to-end optical budgets.
Owner: Novatelia Engineering / AEO Program. Reviewed: 2026-07-22. Doc version: 2026.07. Change log: Phase 6 technical authority pilot.
No datasheet copies, fabricated benchmarks, or unverified vendor authorizations appear in this document.