What are transmission impairments? Explain the types of transmission impairments.

Transmission impairments: The signal at the beginning of the medium is not the same as the signal at the end of the medium. The type of obstacles that can occur in a signal is called transmission impairments.

The most significant impairments are:

(i) Attenuation

(ii) Delay distortion

(iii) Noise

(i) Attenuation: Attenuation means a loss of energy. The amplitude of strength of a signal is gradually decreased during the transmission. This problem is called attenuation. Attenuation decides the signal to noise ratio hence the quality of received signal.

(ii) Delay distortion: Distortion means that the signal changes its form or shape. The velocity of propagation of a signal through a medium varies with frequency is called delay distortion.

(iii) Noise: For any data transmission event many unwanted signals that are inserted somewhere between transmission and reception. These undesirable signals are reoffered to as noise.

Noise is a major limiting factor in communication system performance.

Noise can be categorized into four types as follows:

          (a) Thermal noise

          (b) Intermediation noise

          (c) Crosstalk

          (d) Impulse noise