Definition of signal loss in The Network Encyclopedia.
A number of mechanisms can cause signal loss in a wire or cable:
- Attenuation:Caused by resistive losses in the cable and affects only copper cabling
- Absorption:Causes signal loss in fiber cabling because the glass core material is not perfectly transparent
- Fractures:Can result in both attenuation and absorption of signal strength
- Splices, connectors, and couplings:Involve dissimilar materials joined together and generally produce some loss
Signal loss is generally expressed in units of decibels (dB) per source of the loss. The following table shows typical signal loss values for fiber-optic cabling. These rough values are useful for estimating total signal loss, which you calculate by simply adding the loss for each element in the light path.
|Source of Loss||Approximate Signal Loss|
6 dB/1000 meters
Increases with decreasing bend radius
The total end-to-end signal loss of a light path through a fiber-optic cabling system is known as the optical power budget. If this value is greater than the power launch rating of your line driver, your system won’t work.