Talk:Duplex (telecommunications)

Ethernet example

Full-duplex ethernet schemes are more varied than the example given in this article. Below are some methods used to achieve full-duplex operation:

10BASE-T: two simplex twisted pairs, one in each direction.

100BASE-TX: two simplex twisted pairs, one in each direction.

100BASE-T4 (rare): four simplex twisted pairs, one in each direction and two subject to negotiation.

100BASE-T2 (rare): two duplex twisted pairs with echo cancellation.

1000BASE-T: four duplex twisted pairs with echo cancellation.

1000BASE-TX (rare): two simplex twisted pairs, one in each direction.

That's just for ethernet over twisted pairs. Some of the optical standards use wavelength-division multiplexing for full-duplex over a single fiber. There's weird older stuff like 10BROAD-36, too. —Ryan (talk) 20:02, 18 October 2009 (UTC)

The 4th paragraph of Duplex_(telecommunications)#Full_duplex seems to be a good summary. I don't think we need to introduce all this jargon. ~Kvng (talk) 19:28, 12 December 2022 (UTC)

Semi-Duplex Missing?

Why is the popular Semi-Duplex missing in this article? — Preceding unsigned comment added by 108.183.84.89 (talk) 02:41, 8 August 2013 (UTC)

Semiduplex is redirected here mentioned in the lead as a synonym for half-duplex. I'd create a Semi-duplex but there are no incoming links here through Semiduplex and this is the first time I'm hearing this term so I'm not sure how loved it is. ~Kvng (talk) 19:28, 12 December 2022 (UTC)

Silly half-duplex analogy

From the article: "A good analogy for a half-duplex system would be a one-lane road with traffic controllers at each end, such as a two-lane bridge under re-construction. Traffic can flow in both directions, but only one direction at a time, regulated by the traffic controllers."

The boldface part works fine as an analogy, no problems there. The bold-italic part doesn't track with the nature of half-duplex systems, because there is no external 'regulator' akin to traffic controllers when using half-duplex systems (at least in the few obvious examples that come to mind) - when using walkie talkies, the users themselves must manage the exchange of transmissions, analogous to road traffic (for example by ending their transmission with 'over') and likewise on the one-land road cars would just wave to each other to indicate intentions (I can't speak for the everywhere, but in England, Wales, Scotland and France (much of rural, hilly parts of Europe) I can say there are definitively one-lane, two-way roads, without traffic co-ordinators or traffic lights, and drivers must negotiate these roads themselves - they are usually short, quiet roads, and in the event two cars meet in opposite directions, the car closest to the end of the road simply acknowledges the other car and backs up).

Upon reaching the italic part of the analogy it just becomes absurd; I am sure readers with even the most basic level of education can envisage a one-lane road with two-way traffic without having to bring into the analogy a bridge and some re-construction work - even if you live in a region without such roads and have never travelled anywhere with one. To reduce it to the absurd, the bridge inclusion adds as much to the analogy as would the following "...such as a two-lane 17th century cable-stayed bridge under re-construction due to corrosion caused by decreasing pH levels in local precipitation as a result of climate change from government-backed deforestation for the purpose of clearing land for increased soybean production in order to meet the growing global economic demand." - it's entirely superfluous.

I would like to edit it, so that it reads "A good analogy for a half-duplex system would be a one-lane road that allows two way traffic, traffic can only flow in one direction at a time." or if absolutely necessary, "A good analogy for a half-duplex system would be a one-lane road with traffic-lights allowing two way traffic, traffic can only flow in one direction at a time - when the light is green at one end it is red at the other."

The reason I exposited this here instead of just making this trivial edit is that I am sure it would either be flagged as vandalism or somebody would complain without understanding my reasoning, because I happen to choose to edit anonymously from an often changing IP (having no desire to have every edit I ever make collated and searchable). I'm also rather bored so I thought I might as well. So I will check back in a few days and if nobody has complained I will make the edit then. If anybody reverts it after that, I will put the change back, and direct them here to explain why they reverted it and to wait until consensus is reached before further edits are made, as a full explanation and opportunity to object was given prior to the edit and in good time. 86.8.54.48 (talk) 00:46, 24 September 2015 (UTC)

I have implemented this suggestion. Different half-duplex systems manage the channel in different ways so it makes sense to remove discussion of traffic controllers. ~Kvng (talk) 19:28, 12 December 2022 (UTC)

Merge from Simplex communication

This is a synonym for Half duplex which is a redirect to this article. ~Kvng (talk) 15:44, 3 March 2023 (UTC)

• Support merge Joyous! Noise! 05:14, 5 March 2023 (UTC)
• Support merge with redirect, I am not convinced that they are true synonyms, but both are aspects of the same topic, neither are large. Simplex can be used to describe one-way only traffic, while half-duplex requires the possibility of two-way (as I understand it - more citations may be needed). It makes sense to describe and compare them at the same place. · · · Peter Southwood ^(talk): 05:02, 20 June 2023 (UTC)

  Y Merger complete. Klbrain (talk) 10:55, 26 November 2023 (UTC)