Backscattering technique
The scattering of light in a fiber back toward the source, used to make OTDR measurements.

Bandwidth-length product
Measurement of the frequency range that can be transmitted over 1 km of FO.

Bandwith
The range of signal frequencies or bit rate within which a fiber optic component, link or network will operate.

Bending lossLoss in fiber caused by stress on the fiber bent around a restrictive radius