In Waveguides and Cables
Guided media such as coaxial and twisted pair electrical cable, radio frequency waveguide and optical fiber have losses that are exponential with distance.
The path loss will be in terms of dB per unit distance.
This means that there is always a crossover distance beyond which the loss in a guided medium will exceed that of a line-of-sight path of the same length.
Long distance fiber-optic communication became practical only with the development of ultra-transparent glass fibers. A typical path loss for single mode fiber is 0.2 dB/km, far lower than any other guided medium.
Read more about this topic: Link Budget
Famous quotes containing the word cables:
“It is not a piece of fine feminine Spitalfields silk—but is of the horrible texture of a fabric that should be woven of ships’ cables & hausers. A Polar wind blows through it, & birds of prey hover over it. Warn all gentle fastidious people from so much as peeping into the book—on risk of a lumbago & sciatics.”
—Herman Melville (1819–1891)