Optical cable attenuation (DB) = maximum optical fiber attenuation coefficient (dB/km) × Length (km)
Connector attenuation (DB) = number of connectors × Connector loss (DB)
Fusion attenuation (DB) = number of fusion splice × Fusion splice loss (DB)
The following is a practical example to demonstrate how to calculate the fiber loss. Suppose there is a single mode fiber optic cable is installed between two buildings, with a transmission distance of 10km and a wavelength of 1310nm. At the same time, the optical fiber has 2 ST connectors and 1 fusion joint.
Optical cable attenuation – according to the above standard table, the maximum attenuation value of outdoor single-mode optical cable with wavelength of 1310nm is 0.5dB/km, so the attenuation value of optical cable is 0.5dB/km × 10km=5dB.
Connector attenuation – because 2 ST connectors are used and the maximum loss of each ST connector is 0.75dB, the connector attenuation is 0.75dB × 2=1.5dB. In the actual calculation, the insertion loss of the connector can refer to the specification value provided by the supplier.
Fusion attenuation – the TIA / EIA standard specifies that the maximum loss of fusion is 0.3dB, so the fusion attenuation is 0.3dBx1 = 0.3dB.
It can be concluded that the total loss of the optical fiber link is 5dB + 1.5dB + 0.3dB = 6.8dB.
Because the fiber network has great advantages in meeting people’s demand for high bandwidth, the application range of optical fiber is becoming wider and wider. It is necessary for the selection of high-quality fiber optic cable, fusion splicer machine and other connection components to ensure the accuracy of network performance.