The attenuation formula is calculated as follows: Measure initial signal power. Measure power at the receiving end. It's measured in decibels per kilometer (dB/km), and it determines how far a signal can travel before it becomes too weak to read. A standard single-mode fiber operating at 1550 nm loses. Optical Signal Attenuation is the single greatest factor limiting the distance and performance of your network. Whether you're designing a data center, setting up a home network, or deploying long-distance communication systems, understanding how to reduce signal loss is essential for maintaining reliable. Follow these steps to check your cables: Look for sharp bends or kinks in the cable.