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Opway teaches you how to calculate the link budget

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Many customers may be confused about the calculation of the optical link budget. Here is how to calculate it.
Optical link budget refers to the effective distance of optical signal transmission. There are three main factors;
1、Transmitting optical power of the transmitting end;
2、Receiving sensitivity of the receiving end;
3、Optical fiber attenuation coefficient;
Calculation formula: link budget L=(Ps-Pr-Me-Ac)/(Af+As+Mc)(km)
Ps:Transmitting light power, unit dBm, Ps=(Pmax+Pmin)/2,Pmax,Pmin  is the maximum and minimum of the average transmitting optical power
Pr:receiving sensitivity, unit dBm,
Me:equipment redundancy, generally 3~4dB,
Ac:attenuation of other connectors between transmitting and receiving, such as patch cords, adapters, etc. patch cords are generally 0.1dB per port and 0.2dB per adapter.
Af:optical fiber attenuation coefficient, 1310nm @0.36dB/km,1550nm@0.22dB/km,
As:average welding attenuation of fixed joints, 0.04~0.05dB,
Mc:optical fiber cable redundancy: 0.05~0.1dB
Take our product OP3980D as an example: 10G SFP+ ZR 1550nm 80km


Theoretical value
Ps:Average Optical Power, Pmax=5dBm,Pmin=0dBm, Ps=2.5dBm
Pr:  Receiver Sensitivity,Pr=-23dBm
Me: 0
Ac:  0.2dB(Take a patch cord as an example)
Af:  0.22dB/km
As:  0
Mc: 0
L=(Ps-Pr-Ac)/ Af=(2.5-(-23)-0.2)/0.22=114.5km

Reference value of a customer's actual link (equipment redundancy 3dB, optical fiber cable redundancy 0.05dB)
Ps:Average Optical Power, Pmax=5dBm,Pmin=0dBm, Ps=2.5dBm
Pr:  Receiver Sensitivity,Pr=-23dBm
Me: 3dB
Ac:  0.4dB(One patch cord, one adapter)Af:  0.22dB/km
As:  0.05dB
Mc: 0.05dB
L=(Ps-Pr-Me-Ac)/(Af+As+Mc)=(2.5-(-23)-3-0.4)/(0.22+0.05+0.05)=69.1km
*Different actual link parameter values are different and need to be calculated based on actual conditions.