Talk:Physical layer

missing embedded system physical layers

I'm missing embedded systems in this context. If I'm looking for ISO/OSI there is only information about TCP/IP and PC's and so on. What if I use a simple microcontroller and want to comunicate with other hardware on a PCB?

Yes, we need to mention I²S, I²C, Microwire, Serial Peripheral Interface Bus, System Management Bus, 1-Wire, X10 (industry standard) ... please add them to the article. At least the article does mention EIA-485, which is one of the more popular embedded system interfaces.

 Done ~Kvng (talk) 17:38, 25 January 2016 (UTC)

Lack of references.

I tagged this article for lack of references because the only reference given does not touch upon most of the subject matter in the article and computers, networking, and telecommunications is an area of expertise where it is easy to have misconceptions which, if material is unreferenced, will work their way into WikiPedia. I have 25 years of experience in this field an still find that I suffer from the occasional misconception concerning the details of some subjects. I have discovered some of these misconceptions while looking for references to articles that I wrote on WikiPedia so I am sure that finding references is a Good Thing :-) --mlewis000 00:56, 20 December 2006 (UTC)

I changed this to a refimprove tag, as there are 3 refs now. Widefox (talk) 17:07, 21 October 2009 (UTC)

We now have 22 total including at least one in almost every section so I've removed the tag. ~Kvng (talk) 02:03, 25 January 2022 (UTC)

Sublayers

A section about the Physical Layer Signalling (PLS) sublayer was added. That is however only used in 10Base-T Ethernet, and may be moved to that article, or described in a wider context. Different IEEE protocols divide the physical layer into several sublayers. In e.g. 100 Mbps and 1000 Mbps Ethernet versions, the PLS sublayer is replaced by a Physical Coding Sublayer (PCS). See for example the IEEE 802.3a model (page 4 at http://grouper.ieee.org/groups/802/3/ae/public/mar00/booth_1_0300.pdf).

Perhaps someone would like to make a table, with one column for each protocol version, where all sublayers are presented. You may start out from the above pdf file. Mange01 (talk) 12:37, 14 April 2010 (UTC)

Media access control

 This article incorporates public domain material from Federal Standard 1037C. General Services Administration. Archived from the original on 2022-01-22. says that media access control is handled by the physical layer. Data Link Layer says it is handled there. Data Link Layer has only one reference which does not cover this question. I'm inclined to believe the federal standard. --Kvng (talk) 13:45, 29 July 2011 (UTC)

Don't. IEEE invented the MAC sub-layer. It's mapping to the data link layer is found in IEEE Standard 802-2001, where it is mapped beneath the LLC sublayer in the data link layer. There is nothing physical about the MAC sub-layer: it has addresses for heaven's sake. — Dgtsyb (talk) 23:28, 29 July 2011 (UTC)

Actually, FS1037C does not say that media access control is handled by the physical layer: it says that it performs its function using the services of the physical layer (duh). — Dgtsyb (talk) 23:33, 29 July 2011 (UTC)

Can you please add a ref or two to Data Link Layer? --Kvng (talk) 13:50, 31 July 2011 (UTC)

Data Link Layer already refers to IEEE 802 as the source of the MAC sub-layer definitions. Also, note that IEEE 802 is the ISO data link layer (ISO/IEC 8802), just add 8000 to the IEEE number to get the ISO/IEC number. — Dgtsyb (talk) 07:24, 2 August 2011 (UTC)

Requested move, multiple

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the move request was: Move. Jafeluv (talk) 17:33, 26 October 2011 (UTC)

---

• Physical Layer → Physical layer
• Data Link Layer → Data link layer
• Network Layer → Network layer
• Transport Layer → Transport layer
• Session Layer → Session layer
• Presentation Layer → Presentation layer
• Application Layer → Application layer
• Link Layer → Link layer

– The TCP/IP and OSI layering models are not based on proper names of entities. The layers are discussed here as generic groupings, and compared across the different protocols. Many (possibly most) books have them in lower case; some mixed (uppercase "Physical" and lowercase "layer"). In general, there is little or no evidence for the acceptance or usage of these terms as proper names, even in books that capitalize them by convention (see some preliminary discussion on this at Talk:OSI model. WP style is to capitalize only proper names, not things that others capitalize for other reasons. Dicklyon (talk) 03:44, 19 October 2011 (UTC)

• Support. Investigation of the articles confirms what the proposer of the RM suggests. These are ordinary entities referred to by generic descriptive means. There is no question of proper names – if that is taken as the best or only determinant of capitalisation, which is itself debatable. In its very first sentence WP:MOSCAPS gives plain guidance, and it can be applied directly here: "Wikipedia avoids unnecessary capitalization." An aptly restricted Googlebooks search on "physical layer" "session layer" (restrictions: "Books›Jan 1, 2000–Oct 18, 2011›Search English pages›Preview and full view") shows a marked preference for lower case in "layer", except in headings. So these capitalisations must be regarded as "unnecessary", and best avoided on Wikipedia. Noetica^Tea? 04:41, 19 October 2011 (UTC)
• Support as one of the usual suspects. Noetica's contribs list is spied on daily by many editors. There is utterly no reason to capitalise the l in layer, and as he has pointed out, our long-standing house rules are to capitalise only if there's a very good reason to do so. Caps seem to be flung about all over the place in some fields and professions—perhaps it makes people feel "safe". We have more confidence here in plain English, in ordinary old common nouns that don't need dressing up. Please, let's not poke readers' eyes out with redundant capitals: it's soooo 1970s. Tony (talk) 06:53, 19 October 2011 (UTC)
• Support, obviously, as I initiated this discussion. Note that this is about lower-casing both the word 'layer' and the type of layer ('physical', 'transport' etc.). Mixed caps don't make any sense outside of the technical reasons for article names. This view is supported by the literature on the subject. --EnOreg (talk) 07:32, 19 October 2011 (UTC)

  Right, beyond the title fix, it would be all lower case in the article except at start of sentences or headings: "physical layer", as in many sources, but not in those with a more capitalizing style. Dicklyon (talk) 12:24, 19 October 2011 (UTC)

• support, since most sources use it as a generic name, including Tannenbaum. --Enric Naval (talk) 17:42, 19 October 2011 (UTC)
• Support per usage in reliable sources. --Born2cycle (talk) 06:31, 20 October 2011 (UTC)
• Support -- SchreyP ^(messages) 06:25, 23 October 2011 (UTC)
• Support —Ruud 22:38, 25 October 2011 (UTC)

The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

I've worked on updating case in a few of these articles. Review and more would be appreciated. Dicklyon (talk) 18:34, 26 October 2011 (UTC)

Thanks for helping, EnOreg. In the process, I found other related bits of over-capitalization to work on, like at Talk:Internet Protocol Suite where I did an RM to downcase that one per typically usage and sources. Also the sublayers in some of these articles need work: Talk:Logical_Link_Control#Requested_move. Dicklyon (talk) 03:12, 27 October 2011 (UTC)