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Half duplex

Half duplex definition

A half-duplex system is a communication system that allows data transmission in both directions but not at the same time. In other words, a half-duplex system can either send or receive data at any given time.

While half-duplex systems have their applications, full-duplex systems (that allow simultaneous transmission and reception) are generally preferred for many modern technologies due to their efficiency in communication.

See also: transmitter, session layer, physical layer

Half duplex uses

  • Walkie-talkies. These devices use half-duplex communication where only one person can talk at a time while the other listens.
  • CB (citizens band) radios. Used often by truck drivers, these radios function in a half-duplex mode.
  • Certain radio communication systems. Many radio systems use the same frequency for transmitting and receiving. As a result, transmission and reception cannot occur simultaneously.

Half duplex benefits

  • Resource efficiency. Half-duplex systems use the same channel for both transmitting and receiving data. This can make more efficient use of limited resources (like bandwidth or frequencies) compared to full-duplex systems that need separate paths for sending and receiving data.
  • Reduced power consumption. Since data transmission and reception do not occur simultaneously, half-duplex systems often consume less power than full duplex. That makes them a more energy-efficient choice in certain applications.
  • Simpler hardware design. Devices designed for half-duplex operation often have simpler and less expensive hardware. That's because they don't need the extra components required to handle sending and receiving data at the same time.