• Skip to main content
  • Skip to primary sidebar

Technipages

Tutorials and fixes for smartphone, gadget, and computer problems

  • Topics
    • Android
    • Browsers
    • Gaming
    • Hardware
    • Internet
    • iPhone
    • Linux
    • macOS
    • Office
    • Reviews
    • Software
    • Windows
    • Definitions
  • Product Reviews
  • Downloads
  • About

Full-Duplex vs Half-Duplex Network Traffic

August 4, 2020 by Mel Hawthorne Leave a Comment

A lot of networking equipment will refer to its network connections as full-duplex or half-duplex. This term often isn’t explained, however, as it is assumed that people will know what it means. A duplex communication system is a system where two or more users can communicate in both directions.

Full-duplex

In a full-duplex system, both parties can communicate simultaneously. Both devices can send and receive data to and from each other at the same time.

A telephone is a well-known example of a full-duplex system, as both parties can speak and listen to the other user at the same time (regardless of their ability to understand one another while talking at the same time!)

Half-duplex

In a half-duplex system, both parties can still communicate with each other, however, only one user can transmit data at a time. For example, with walkie-talkies, a two way-radio system using push-to-talk buttons, a user can either listen or talk at any one time, not both.

A walkie-talkie defaults to being able to receive messages. If a user wants to communicate, they need to press the push-to-talk button, at which point their device is switched into transmit mode. When the push to talk button is released the device switches back into receiving mode. Other half-duplex devices operate in a similar manner, defaulting to receiving and only transmitting when they need to.

Tip: Devices that don’t require any form of duplex communication are referred to as simplex. In simplex systems, a device is either a transmitter or a receiver. Radio and TV are good examples of simplex technology.

Half-duplex systems are generally more simplistic in some ways. For example, only a single wire or radio-frequency is required for half-duplex communication channels. In comparison, a full-duplex system needs at least two wires or radio frequencies, one for transmission and one for receiving.

Collisions in half-duplex

The main issue with half-duplex systems is the risk of collisions, where more than one user or device attempts to transmit data at the same time. To prevent collisions, a collision-avoidance system, collision-detection system, or both need to be implemented.

In a collision-detection system, the transmitting devices will detect that a collision has occurred and pause transmissions for a random time before attempting to transmit again. This random pause is designed to avoid both devices attempting to re-transmit at the same time and colliding again.

In a collision-avoidance system, a device that wishes to transmit data checks if the network is free before transmitting. If the network is in use, it pauses for a random time before checking again.

Combining collision-avoidance and collision-detection systems is a generally effective way of managing half-duplex communications of networking gear and can cause negligible delays in most circumstances. In a manual system like with walkie-talkies however, the users have to perform this function manually, this has led to standards such as ending messages with the word “over”.

You Might Also Like

  • How to Configure Burp Suite to Intercept Network Traffic
    How to Configure Burp Suite to Intercept Network Traffic
  • How to Enable Half-Star Ratings in iTunes
    How to Enable Half-Star Ratings in iTunes
  • What Is Traffic?
    What Is Traffic?
  • Why Is It Important to Route DNS Traffic Over Your VPN?
    Why Is It Important to Route DNS Traffic Over Your VPN?
  • Google: How to Check Traffic to Work or Home
    Google: How to Check Traffic to Work or Home
  • Fix YouTube: Our Systems Detected Unusual Traffic
    Fix YouTube: Our Systems Detected Unusual Traffic

Filed Under: Hardware

Reader Interactions

Did this help? Let us know!

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Primary Sidebar

Recent Posts

  • How to Reset Root Password on Steam Deck
  • How to Update Steam Deck
  • Fixed Error Code: Out of Memory on Windows 11 Web Browsers
  • How to Play Minecraft on Chromebooks
  • Windows 11: How to Access and Use the Free Sound Recorder App
  • How to Enable Split-Screen in Microsoft Edge
  • How to Use Microsoft PowerToys in Windows 11/10
  • How to Turn Steam Deck Into Desktop PC

Who’s Behind Technipages?

Baby and Daddy My name is Mitch Bartlett. I've been working in technology for over 20 years in a wide range of tech jobs from Tech Support to Software Testing. I started this site as a technical guide for myself and it has grown into what I hope is a useful reference for all.

You May Also Like

  • Ring Network
  • Physical Network
  • Class B Network
  • Public Data Network (PDN)
  • Packet-Switching Network

© Copyright 2023 Guiding Tech Media · All Rights Reserved · Privacy