6 June 2020

Difference Between Serial and Parallel Communication

Both serial and parallel communication is data transmission. The main comparison between serial and parallel communication is that in serial communication data transmission occurs bits by bit at a time, while in parallel communication multiple bits transmit at a time. Here this article gives information about the main key difference between serial and parallel communication to better understand this topic.

What is serial communication?


In serial communication, data is sent bit by bit from one computer to another in bi-direction where each bit has its close pulse rate. Eight bits are transferred at a time having a start and stop bits. 0 and 1 respectively. e

What is parallel communication?


In parallel communication, the various data bits are simultaneously trasmitted using multiple communication links between the sender and receiver.

Difference between serial and parallel communication


  • Serial communication supports higher bandwidth but parallel communication supports comparatively lower bandwidth.
  • Serial communication is straight forward and simples while in parallel communication Unreialble and complicated.
  • Serial communication is efficient for high-frequency operation. while in parallel communication shows its suitability more in case of low-frequency operations.
  • Due to the presence of a single communication link the speed of data transmission is slow. While multiple links in case of parallel communication allow data transmission at a comparatively faster rate.
  • Serial communication is suitable for long-distance transmission of data as against parallel communication is suitable for short-distance transmission of data.
  • Whenever there exists a need for system up-gradation then upgrading a system that uses serial communication is quite an easy task as compared to upgrading a parallel communication system.
  • Serial communication accomplishes full-duplex communication using only two channels, while the parallel communication uses the same number of channels as bits form of half-duplex communication. 
  • Due to the existence of a single link, the problem of crosstalk is not present in serial communication. While in multiple links increase the chances of crosstalk in parallel communication.
  • Cost is comparatively low in serial communication, while in parallel communication cost is high.
  • The example of serial communication is USB, SATA, I2C, SPI, etc. While the example of parallel communication is a computer to the printer and communication between an internal component in an embedded system.
  • The number of bit transferred at 1 clock pulse 1 bit in serial communication, while in parrel communication 8 bit or 1 byte. 
  • Error and noise are low for serial communication while in parallel communication error and noise are high.
  • In serial communication, all data bits transmitted over a common channel thus proper spacing is required to be maintained in order to avoid interference. While in parallel communication the utilization of multiple links reduces the chances of interference between the transmitted bits. 
  • The cable used in a serial transmission is thinner, longer, and more economical compared to the cable used in parallel transmission.
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