𝗟𝗶𝗻𝗸 𝗟𝗼𝘀𝘀 𝗕𝘂𝗱𝗴𝗲𝘁, 𝗣𝗮𝘀𝘀𝗶𝘃𝗲 𝗖𝗮𝗯𝗹𝗲 𝗦𝘆𝘀𝘁𝗲𝗺 𝗔𝘁𝘁𝗲𝗻𝘂𝗮𝘁𝗶𝗼𝗻, 𝗮𝗻𝗱 𝗦𝘆𝘀𝘁𝗲𝗺 𝗣𝗲𝗿𝗳𝗼𝗿𝗺𝗮𝗻𝗰𝗲 𝗠𝗮𝗿𝗴𝗶𝗻

Understanding these calculations is crucial to ensure reliable connectivity and optimal performance in Telecommunication infrastructure. Here’s a step-by-step guide on how to approach each one:

𝗟𝗶𝗻𝗸 𝗟𝗼𝘀𝘀 𝗕𝘂𝗱𝗴𝗲𝘁 (𝗟𝗟𝗕)

𝗦𝘁𝗲𝗽 𝟭 : Calculate System Gain
System Gain is the difference between the transmitter average power and the receiver sensitivity

𝗦𝘁𝗲𝗽 𝟮 : Determine Power Penalties
Power penalties add up the loss values from Operating Margin, Receiver Power Penalty and Repair Margin :

✴ Operatin Margin :  Loss due to variation in transmitter center wavelength, changes in the transmitter average power/receiver sensitivity due to age, and temperature changes within the operating range. If unspecified, use 2dB for LEDs and 3dB for Lasers.

✴ Receiver Power Penalty : Some manufacturers specify other penalties like dispersion, jitter, bandwidth, or clock recovery.

✴ Repair Margin : If the cable is vulnerable to accidental damage, allow for at least two splices. More splices may be needed if reroutings are anticipated.

𝗦𝘁𝗲𝗽 𝟯 : Link Loss Budget
Subtract the total value for all power penalties from the system gain. The result is Link Loss Budget.

𝗣𝗮𝘀𝘀𝗶𝘃𝗲 𝗖𝗮𝗯𝗹𝗲 𝗦𝘆𝘀𝘁𝗲𝗺 𝗔𝘁𝘁𝗲𝗻𝘂𝗮𝘁𝗶𝗼𝗻

𝗦𝘁𝗲𝗽 𝟰 : Calculate Optical Fiber Loss
Multiply the length of the proposed link by the cable attenuation (dB/km) for the optical fiber at the operating system wavelength.

𝗦𝘁𝗲𝗽 𝟱 : Calculate Connector Loss
Add the individual attenuation values (dB) for every connector pair along the optical fiber route (excluding transmitter and receiver connectors).

𝗦𝘁𝗲𝗽 𝟲 : Calculate Splice Loss
Add the individual attenuation values (dB) for every splice along the optical fiber route.

𝗦𝘁𝗲𝗽 𝟳 : Calculate Other Component loss
Add the attenuation values (dB) for any other components (Passive Optical Devices like Splitters) contributing to losses in the optical fiber route.

𝗦𝘁𝗲𝗽 𝟴 : Calculate Total Passive Cable System Attenuation
Add all values from Optical Fiber Loss, Connector Loss, Splice Loss, and Other Component Loss to get the Total Passive Cable System Attenuation.

𝗩𝗲𝗿𝗶𝗳𝘆 𝗣𝗲𝗿𝗳𝗼𝗿𝗺𝗮𝗻𝗰𝗲 : 𝗦𝘆𝘀𝘁𝗲𝗺 𝗣𝗲𝗿𝗳𝗼𝗿𝗺𝗮𝗻𝗰𝗲 𝗠𝗮𝗿𝗴𝗶𝗻 (𝗦𝗣𝗠)

𝗦𝘁𝗲𝗽 𝟵 : Calaculate System Performance Margin
The System Performance Margin is the difference between the calculated Link Loss Budget and the actual Passive Cable System Attenuation.

SPM = Link Loss Budget – Passive Cable System Attenuation