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Data Transmission

When data is transmitted from one device to another, it is sent as a large number of data bits.

Parallel transmission
  • a number of data bits (8, 16 or 32) can be sent at the same time along a number of paths.
  • used internally when data is sent along the buses
  • faster than serial transmission
  • can only be used for short distances
Serial transmission
  • bits are sent one after another along a single wire.
  • used for greater distances
  • can be fast on fibre optic cables.
Simplex Transmission of data can be in one direction only
Half-duplex Transmission can be in both directions but only one direction at a time.
Full-duplex Simultaneous transmission of data in both directions is possible.

 

Transmission speeds can also be increased using multiplexing - a method of combining and sending more than one signal at the same time. Several data streams can be combined and transmitted over the same wire.

 

  A switch connects segments of a network together.

Packets of data received by the switch from one network are transmitted into the other connecting network.