Data communication fundamentals Analog and Digital signal transmission

 

Data communication involves transforming information into electromagnetic signals for transmission over physical media. These signals can be broadly classified into two categories based on their representation of values: Analog and Digital.

 

Analog Signal Transmission
 
Analog signals represent data as continuous waveforms that vary smoothly over time. They can take an infinite number of values within a specific range.
 

Characteristics: Represented by sine waves; defined by amplitude, frequency, and phase.

Examples: Human voice, AM/FM radio, traditional telephone lines.

Pros/Cons: High density and natural representation, but highly sensitive to noise and distortion.

 

Digital Signal Transmission
 
Digital signals represent data as discrete values, typically binary states like 0 and 1. The signal jumps between fixed levels rather than flowing smoothly.
 

Characteristics: Represented by square waves; characterized by bit rate and bit interval.

Examples: Computer networks (Ethernet), digital TV, mobile phones.

Pros/Cons: Highly resistant to noise and easy to compress/encrypt, but generally requires more bandwidth.