FieldengNetworking & Communications
Fiber Link Budget
Modeled optical receive power and margin from fiber, connector, and splice losses.
Networking & CommunicationsRF, Radio & Wireless
Modeled optical receive power and margin from fiber, connector, and splice losses.
App id: NET-12. Reference version 1.0.
How to fill it
Fill the inputs. The tool shows the outputs.
On the tool screen, Calc is the working sheet. Presets stores values you reuse. Reference is the formula, assumptions, and provenance below.
Formula
Pr = Ptx − fiber − connectors − splices − other; margin = Pr − sensitivityInputs
| Name | Unit |
|---|---|
| TX optical power | dBm |
| Fiber length | km |
| Fiber attenuation | dB/km |
| Connector count (optional) | 1 |
| Loss per connector (optional) | dB |
| Splice count (optional) | 1 |
| Loss per splice (optional) | dB |
| Other losses (optional) | dB |
| Receiver sensitivity | dBm |
Outputs
| Name | Unit |
|---|---|
| Received power (hero result) | dBm |
| Fiber loss | dB |
| Total loss | dB |
| Link margin | dB |
Diagnose
Observations are context. They do not pass or fail a structure. See Diagnose.
Screening bands in the app: Negative · Near zero · Small · Large.
| When | Observation | Severity |
|---|---|---|
not margin ratio > 0 or not Number.is finite(margin ratio) | Insufficient optical budget | warning |
fade margin (dB) < 0 | Insufficient optical budget | warning |
fade margin (dB) < 3 | Little optical tolerance | caution |
fade margin (dB) < 10 | Limited optical margin | info |
fade margin (dB) ≥ 10 | Substantial optical headroom | info |
Assumptions
- Leave connector or splice count blank for none.
- Margin bands are engineering context, not a pass/fail optical specification.
Provenance
- Simple optical power budget. Uses the same dBm/dB unit engine as RF tools.