Optical power budget checklist
An optical power budget compares transmitter launch power minus path losses against the receiver sensitivity window (including margins). For PON, include splitter ratios, connectors, splices and fiber attenuation before activation.
Key facts
- Task-level guide (Level 5)
- Always prefer measured loss over assumed loss
- Document wavelength and coexistence filters when GPON/XGS-PON share plant
Audience
Field engineers and designers validating ODN readiness.
Prerequisites
- Design split plan
- Power meter (and OTDR when fault isolation is needed)
Workflow / checklist
- Record Tx min/max from equipment class documentation you are authorized to use
- Sum fiber attenuation for length and wavelength
- Add connector and splice allowances
- Add splitter loss for each stage
- Subtract total loss from Tx; compare to Rx sensitivity + margin
- Validate with measured receive power at ONT
Decision table
| Observation | Likely action |
|---|---|
| Rx too low | Reduce split, clean connectors, check bends/breaks |
| Rx too high | Add attenuation or redesign short drop/high launch cases |
| Intermittent LOS | Inspect patching and dirty/damaged connectors |
Verification
Measured Rx within window for each activated ONT sample.
Troubleshooting
Rollback
Revert splitter/patch changes to last labeled known-good state; re-measure.
References
Related guides
- XGS-PON design basics — Foundational XGS-PON design inputs, verification, and rollback considerations.
- FTTH access reference architecture — OLT–ODN–ONT access architecture and coexistence considerations.
- PON optical alarm triage — Triage LOS/LOSi/dying-gasp style optical symptoms without vendor-specific CLI dumps.
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.