Talk:Simplex communication

Reason for ANSI standard?

Back in the day (ever since Edison's patent at least), a telephone was a single circuit, used to send in both directions, but only one way at a time. That's just the way things worked. When cabling was developed that allowed traffic in both directions at the same time, that was called duplex, and the old way was referred to as simplex.

Given that duplex has a path always open in each direction, half of that would be a path always open in one direction. Assuming the words mean anything, that would seem to be the definition of half-duplex that makes sense.

A source I trust says that IBM got the definitions of "simplex" and "half-duplex" backwards in one of their glossaries, and that glossary was adopted as the standard. Of course most web sites now parrot the ANSI standard point of view. Is there any good reason other than a mistake behind the ANSI version of the definition? Dpv 15:48, 12 May 2006 (UTC) 1 . Simplex(One way always) like a broadcast radio station. 2 . Simplex(One way at a time) like two way radio with one frequency 3 . Half duplex(One way at a time)like two way radio with two frequencies and 4 . Full duplex two way simultaneously with two frequencies.

—Preceding unsigned comment added by 212.70.33.213 (talk) 11:13, 29 March 2010 (UTC) 

dual-simplex?

I'm looking for an exact definition of dual-simplex, which probably should be mentioned on this page. I think that I know how it relates to simplex and duplex, but it would be great to have someone who knows for sure add it in explicitly. Cashannon 16:22, 6 June 2007 (UTC). probably you are talking about simplex with one frequency. Four categories are as follows: 1 . Simplex :One freq-One way always like radio broadcast. 2 . Simplex-dual:One frequency, two way but one at a time. 3 . Half duplex: two frequencies, two way but one at a time and 4 . Full duplex: two frequencies both way simultaneously.

Clarify

"In both cases, the other definition is referred to as half duplex."

What does this mean? I see two definitions of "Simplex" the ITU-T definition and the ANSI definition. So do ITU-T and ANSI define "half duplex" as well? Egriffin 20:20, 30 November 2007 (UTC)

I don't know whether the official definitions address that point but hope my little addition of last week made the two usages a bit clearer. Jim.henderson (talk) 04:28, 12 December 2007 (UTC)

122.168.214.130 (talk) 20:27, 4 September 2008 (UTC)Acctually the simplex is used for one way communication at one time while the duplex can communicate another at other instant.

I am unable to find an ITU-T definition of simplex that is equivalent to half-duplex. See, for example, this page : Query Definitions.

This appears to be consistent with the definition attributed to ANSI.

ITU-T also appear to have a definition for duplex (which matches my understanding of full-duplex as capable of simultaneous transmission in two directions) and of half-duplex Query Definitions

The only area of confusion is thus the use of the word duplex vs full-duplex. There is no actual conflict.

81.105.8.110 (talk) 11:00, 16 December 2009 (UTC)

I agree with 81.105.8.110 and Bigpeteb. I found many reliable sources online defining these terms and almost all of them define "simplex" as one-way communication, not one direction at a time. 24.8.10.46, your recent change [1] may be consistent with an earlier definition of the term, but it doesn't seem to agree with modern definitions. I think it should be changed back. --Chetvorno^TALK 21:43, 6 April 2017 (UTC)

Reverted above change and 24.8.10.46 reverted my revert. @24.8.10.46: you need to provide references supporting your change. See WP:VERIFIABILITY: "All content must be verifiable. The burden to demonstrate verifiability lies with the editor who adds or restores material... Any material lacking a reliable source directly supporting it may be removed and should not be restored without an inline citation to a reliable source."

Also, when there is disagreement, before changing the article you need to discuss the change here. Wikipedia works by WP:CONSENSUS. Reverting others' edits without discussion is called WP:EDIT WARRING, and can get you blocked from Wikipedia. Let's talk about this. --Chetvorno^TALK 23:28, 6 April 2017 (UTC)

Chetvorno, the same editor (24.8.10.46) has been doing similar unsourced edits to Duplex (telecommunications). I'd appreciate if you could give that page a look and share your opinion. --Bigpeteb (talk) 14:33, 12 April 2017 (UTC)

I reverted all said and added some stuff on the talk page about why. The IP has been block for about a week already. Dicklyon (talk) 14:51, 12 April 2017 (UTC)

Added some authoritative sources to Duplex (telecommunications): ITU and ATIS, and some textbooks. From these, it looks like the definition is more complicated and/or is not completely consistent between the standards organizations. In two-way radio systems with repeaters, according to ATIS, a system with a single half-duplex channel is called simplex. Haven’t time right now to sort this out; maybe someone else can. --Chetvorno^TALK 18:06, 3 March 2023 (UTC)

Merge this article and Duplex

I support the recent proposal to merge Simplex and Duplex. It would eliminate redundancy, and the need to keep both articles consistent. Ideally I would like to see them merged into a new article Simplex and duplex, with redirects from each of the individual terms, but would support a merge into either term. --Chetvorno^TALK 18:27, 3 March 2023 (UTC)