Talk:Interleaving

Possible change
Latency link to engineering latency rather than generic? Comment? — Preceding unsigned comment added by 155.246.11.142 (talk • contribs) 23:15, 22 May 2007‎


 * Somebody appears to have fixed that at some point; the text I moved to forward error correction links to latency in the engineering sense. Guy Harris (talk) 22:09, 3 May 2013 (UTC)

Only one translation is needed
Hello, the german wikipedia page has a good interleaving article. If somebody could translate it into here, that would be cool. If I find time for that, I might just do it! --Bjoern.thalheim 10:43, 8 November 2005 (UTC)
 * Ok, done (well, actually I translated only the part that seemed important to me). Please someone read and debug this. Thanks! --Bjoern.thalheim 13:26, 16 December 2005 (UTC)

Translation required
The article contains the following hidden text, with a request that it be translated. (If this has already been done, please remove the hidden comment from the article.):

Interleaving bei Disketten und Festplatten
Die Technik des Interleaving wurde früher bei Festplatten angewendet, da sich die Platten mit einer bestimmten Mindestgeschwindigkeit drehen mussten, damit sich das notwendige Luftpolster zwischen Platte und Kopf bildete. Allerdings waren die Computer noch nicht schnell genug, um die Daten in der hohen Geschwindigkeit zum/vom Hauptspeicher zu übertragen. Bis ein Datenblock komplett übertragen war, waren schon mehr oder weniger viele weitere Blöcke unter dem Schreib-Lesekopf hinweggerauscht. Hätte man die Blöcke einfach in aufsteigender Reihenfolge von 1 bis n auf die Platten geschrieben, so müsste man nun nach dem Zugriff eines Blocks immer fast eine komplette Umdrehung warten, bis der nachfolgende Block wieder unter dem SL-Kopf erscheint. Da dies den Datendurchsatz extrem verlangsamen würde, hat man die Sektoren in einer anderen Reihenfolge beschrieben. Dies wird dem so genannten Interleave-Faktor angegeben. Dieser gibt an, wie viele Umdrehungen der Plattenstapel ausführen muss, um eine einzelne Datenspur einzulesen. Bei 8 Blöcken und einem Interleave-Faktor von 3 würden die Blöcke z.B. in der Reihenfolge 1 4 7 2 5 8 3 6 gespeichert, es liegen zwischen zwei logisch aufeinanderfolgenden Sektoren also stets zwei andere Blöcke. Dies gibt dem Festplattencontroller genug Zeit, die Daten eines Blockes zum Hauptspeicher zu übertragen bzw. die neuen Daten zu holen. Es benötigt drei Umdrehungen des Plattenstapels, bis die gesamte Datenspur eingelesen bzw. beschrieben ist.

Heute wird bei Festplatten ausschließlich der Interleave-Faktor 1 verwendet, d.h. es findet kein Interleaving mehr statt. Die Festplattencontroller besitzen genug Pufferspeicher, um eine ganze Datenspur mit einmal zu lesen oder zu schreiben. Außerdem wird so genanntes "Double Buffering" verwendet, das heißt, während der Inhalt eines Pufferspeichers gerade zum Hauptspeicher übertragen wird, kann der andere Puffer mit Daten von der Festplatte gefüllt werden.


 * When I moved stuff to interleaving (disk storage), the stuff I moved didn't include that hidden text; some of it might have been translated and subsequently modified. Guy Harris (talk) 22:12, 3 May 2013 (UTC)

Seminal paper on interleavers
This page does a good job explaining what an interleaver does, but it does not explain how one works. We should at least give references on how they work and where to find info. The following paper is the one to link:

C. Berrou, A. Glavieux,"Near Optimum Error Correcting Coding and Decoding : Turbo-codes", IEEE Transactions on Communication, Vol. 44, No. 10, October 1996

If you're an IEEE member you can read it here:

http://ieeexplore.ieee.org/iel1/26/11672/00539767.pdf?arnumber=539767 Speedplane 05:04, 17 May 2007 (UTC)


 * The stuff to which that applies is now in forward error correction. Guy Harris (talk) 22:13, 3 May 2013 (UTC)

"Disadvantages of interleaving" section
This section has unnecessary level of detail (an actual numerical delay value) and applies to DSL without mentioning it. It should be re-written to be more generic.


 * The stuff to which that applies is now in forward error correction. Guy Harris (talk) 22:14, 3 May 2013 (UTC)

"Interleaving in data transmission" section
First, I tried to clean up the language a little bit.

Second, the last example had a mistake in that the interleaved sentence wasn't the original sentence. I changed it. Then I also changed the error that occured so the erred reception would be clearer.

Third, there are two kinds of interleaving: block and convolutional and I think this article needs to reflect that fact. The examples here are for block interleaving, which I only mention in passing. —Preceding unsigned comment added by Serrano24 (talk • contribs) 16:24, 30 October 2007 (UTC)


 * The stuff to which that applies is now in forward error correction. Guy Harris (talk) 22:15, 3 May 2013 (UTC)

Copyedit template
I agree with the editor who put this there. In particular, the "Interleaving in data transmission" section reads too much like a how to. "Now, let's do such-and-such" might be appropriate language for a school textbook, but is not right for an encyclopedia, which should stick to the third person. -- 86.132.138.84 (talk) 17:37, 16 November 2007 (UTC)


 * The stuff to which that applies is now in forward error correction. Guy Harris (talk) 22:16, 3 May 2013 (UTC)

This does not look like what Glassine is used for
i came here from glassine as this is supposed to be what it is used for..... i find that hard to believe. —Preceding unsigned comment added by 88.106.8.57 (talk) 12:09, 6 May 2008 (UTC)


 * You're probably referring to the dictionary definition of 'interleave'. That meaning probably doesn't warrant an article in an encyclopedia? I'll remove the link from glassine. -- intgr [talk] 12:33, 6 May 2008 (UTC)

Out of date?
This article obviously talks about something very old. I came here expecting something about dual channel ram. 86.139.3.249 (talk) 19:33, 8 August 2008 (UTC)


 * Dual channel memory =! interleaving. Dual channel RAM makes the bus wider (64 -> 128 bits), it doesn't change the order of the data stored in it. 24.27.14.36 (talk) 01:20, 8 November 2008 (UTC)

Randomizers vs Interleavers
In telecommunications, both Randomizers and Interleavers are used. Interleaving is used in digital data transmission technology to protect the transmission against burst errors. These errors overwrite a lot of bits in a row, so a typical error correction scheme that expects errors to be more uniformly distributed can be overwhelmed. Interleaving is used to help stop this from happening.

However, Interleavers are not Randomizers.


 * Interleavers do not alter data, that is to say the data retains the same original number of 1's and 0's it had before it entered the interleaver.
 * Randomizers suppress excess DC components in data, an Interleaver can not do this.
 * Sometimes, in order to achive optimal signal to noise ratios using an interleaver and a randomizer is necessary.
 * The CCSDS Space Communications Protocols recommend using both an interleaver and a randomizer to protect the integrity of the downlink.
 * Interleavers create measurable and predictable time delays in the processing of data but randomizers also create delays but generally of a magnitude less than interleavers.

The above should be on the page to keep it current and from being misleading... Eyreland (talk)


 * The above should be on forward error correction, as that's where the stuff that discusses that particular flavor of interleaving is now. This page just links there. Guy Harris (talk) 22:02, 3 May 2013 (UTC)

Memory interleaving
Another flavor of interleaving worth describing is interleaving in memory, which has been around since at least the 1960s and still exists today. This involves multiple sections of memory that operate in parallel, with the controller (the CPU, for example) able to initiate memory accesses faster than the time to complete an access. An early example is the CDC 6600, with 100 ns CPU cycle time, 1000 ns memory cycle time, and 32 way interleaving. Paul Koning (talk) 18:33, 16 March 2010 (UTC)


 * Yup - now that this is a disambiguation page, it now links to interleaved memory. Guy Harris (talk) 22:00, 3 May 2013 (UTC)

Split
Interleaving main memory, interleaving disk blocks, and interleaving bits on a communications channel seem to be rather different topics. I'd say they should have separate pages. Guy Harris (talk) 11:46, 25 December 2012 (UTC)
 * Seems eminently sensible. Will you be carrying out the split? Op47 (talk) 21:46, 8 February 2013 (UTC)
 * Yes. I've already moved the stuff about disk sector interleaving to interleaving (disk storage), and updated links to this page that were referring to disk-sector interleaving to link to that page. Guy Harris (talk) 07:13, 2 May 2013 (UTC)
 * And I've moved the stuff about interleaving in forward error correction to the forward error correction page, and redirected some references here that were referring to interleaved memory to that page. Guy Harris (talk) 09:05, 2 May 2013 (UTC)

So now the remaining article is almost merely a list of bullet points. Should it be changed to a disambiguation page or how could the article evolve from here? Isheden (talk) 08:00, 2 May 2013 (UTC)


 * At this point, there's still some cleanup to be done. The remaining links to this page from articles (rather than talk pages) should be fixed to go to the appropriate place, whether it be interleaved memory, interleaving (disk storage), forward error correction or a redirection to that such as interleaver, or, if necessary, a newly-created page for whatever other type of interleaving is meant - or should be removed entirely if somebody's just talking about "interleaving" strata of rock or something such as that.


 * Once that's done, this should turn into a disambiguation page. Guy Harris (talk) 09:05, 2 May 2013 (UTC)


 * Ok, I've done most of the links, and turned this into a disambiguation page. I'll look at cleaning up some more links; hopefully others can contribute as well. Guy Harris (talk) 22:00, 3 May 2013 (UTC)