List and explain the three main sources of transmission errors.

What will be an ideal response?

Answer: There are three main categories of transmission errors:
? Interference: Electromagnetic radiation emitted from devices such as electric motors and
background cosmic radiation cause noise that can disturb radio transmissions and signals
traveling across wires.
? Distortion: Wires have properties of capacitance and inductance which block signals at some
frequencies while admitting signals at other frequencies. All physical systems distort signals.
As a pulse travels along an optical fiber, the pulse disperses.
? Attenuation. As a signal passes across a medium, the signal becomes weaker. Signals on wires
or optical fibers become weaker over long distances, just as a radio signal becomes weaker
with distance.