Fiber Max Length for a Loss Budget

The inverse of the fiber-loss-budget tile: the longest fiber run that still passes the channel loss budget, len_max = 1000 x (max_channel_loss - connector_loss - splice_loss) / attenuation (TIA-568 / IEEE 802.3). A 2.6 dB budget on OM4 (3.0 dB/km) with two connectors reaches about 367 m; single-mode (0.4 dB/km) reaches 2,750 m. Every connector or splice eats budget that would buy distance. Answers 'how far can I run it' instead of the loss of one length. A planning estimate; the OTDR/power-meter field test certifies the link.

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Formula and source

len_max_m = 1000 x (max_channel_loss - connectors x loss_per_connector - splices x loss_per_splice) / attenuation_dB_km. The inverse of loss = attenuation x length_km + connectors + splices.

Optical link loss budget solved for length, per the TIA-568 / TIA-526 fiber-test methods and the IEEE 802.3 channel-loss limits, by name; first-principles.

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