Topics / Networks and Data Transmission / Synchronous and Asynchronous

Synchronous and Asynchronous

Synchronous and Asynchronous transmission are two methods (protocols) of keeping data synchronised when transmitted.

Asynchronous data transmission

Asynchronous data-transmission

  • Data is transmitted in discrete packets (usually 1 byte)
  • Each packet of data is sent with control bits
  • The control bits allow the receiver to know when the data starts and ends
  • The control bits prevent the packets of data getting mixed up
  • Packets are sent intermittently (they have uneven time intervals between them)
  • Slower than synchronous

Synchronous data transmission

Synchronous data transmission

  • A continuous stream of data
  • The data is accompanied by timing signals (generated by an internal clock)
  • The clock ensures the sender and receiver are in step with each other
  • The receiver counts how many bits were sent over a period of time then reassembles them into bytes (multiple bytes sent at once)
  • Timings have to be accurate as there are no control bits
  • Faster than asynchronous
Topics / Networks and Data Transmission / Synchronous and Asynchronous