Basic Splitter Formula
Theoretical Splitter Loss = 10 × log₁₀(N) dB
Yahan N = total output ports.
| Splitter | Approx. Theoretical Loss |
|---|---|
| 1:2 | 3.01 dB |
| 1:4 | 6.02 dB |
| 1:8 | 9.03 dB |
| 1:16 | 12.04 dB |
| 1:32 | 15.05 dB |
| 1:64 | 18.06 dB |
1. Main Formula
Total Optical Loss = Fiber Loss + Connector Loss + Splice Loss + Splitter Loss + Other Loss
ONT Receive Power = OLT Transmit Power − Total Optical Loss
2. Example: 1:8 Splitter
- OLT TX Power = +4 dBm
- Fiber length = 5 km
- Fiber loss = 0.35 dB/km
- Connectors = 4 × 0.5 dB = 2 dB
- Splices = 4 × 0.1 dB = 0.4 dB
- 1:8 splitter loss = ≈10.5 dB
- Engineering margin = 3 dB
Fiber Loss:
5 × 0.35 = 1.75 dB
Total Loss:
1.75 + 2 + 0.4 + 10.5 + 3 = 17.65 dB
ONT Receive Power:
+4 − 17.65 = −13.65 dBm
➡️ ONT par expected power ≈ −13.65 dBm
3. Agar ONT ki minimum sensitivity −27 dBm hai
Available margin:
−13.65 − (−27) = 13.35 dB
➡️ 13.35 dB ka power margin available hai.
Quick Formula
Power Budget = OLT TX − ONT Minimum RX
Required Link Loss ≤ Power Budget
For example:
+4 − (−27) = 31 dB
