Full optical power budget calculation for PON/FTTH networks. Enter your OLT transmit power, ONT sensitivity, fiber lengths, splitter configuration, and connectors for an instant pass/fail result.
In a Passive Optical Network (PON), the power budget is the total optical loss allowance between the OLT (Optical Line Terminal) at the central office and the ONT/ONU (Optical Network Terminal) at the subscriber premises.
The budget is defined as:
Budget = OLT Tx power − ONT Rx sensitivity
All losses from fiber, splitters, connectors, and splices must fit within the budget minus the safety margin. If total loss exceeds budget − margin, the link fails.
| Split Ratio | Typical Loss | Max Subscribers |
|---|---|---|
| 1:2 | 3.5 dB | 2 |
| 1:4 | 7.0 dB | 4 |
| 1:8 | 10.5 dB | 8 |
| 1:16 | 13.5 dB | 16 |
| 1:32 | 16.5 dB | 32 |
| 1:64 | 20.0 dB | 64 |
| 1:128 (2-stage) | 27.5 dB | 128 |
The three major PON standards differ in downstream/upstream speed and power budget class:
All three standards operate on single-mode fiber at 1310 nm upstream and 1490 nm or 1577 nm downstream, using WDM to carry both directions on the same fiber.