Talk:DECT/Archive 1

Archive 1

Range

There are DECT phones in the US but these operate on 2.4 Ghz. Presumably 1880-1900 Mhz was off limits for the FCC

The cell range of DECT is given here as 25-100 m. It should be known that Midas Communications, India, have a range of DECT based Fixed Wireless Access products that have cell ranges upto 10 km. This is based on clear Line of Sight. --Rupam.das 10:34, 16 November 2005 (UTC) This is based on outdoor, directional antennas on the uplink and less tha 60 degrees antenna segment on the BST. Handset will only be provided coverage in 150m - as for any other. Shyam has deployed DECT links (RLL) for as far as 29km. --KH Flottorp 10:28, 9 July 2006 (UTC)

Spam / commercial links

I have removed a spam / commercial link to a UK handset retailer cordless-phones.uk.com . I suspect this to be an attempt at increasing search engine ranking. Andrew Oakley 09:30, 18 September 2006 (UTC)

Searching through the history, the spam link appeared to have been added by 62.219.183.196 . Andrew Oakley 09:34, 18 September 2006 (UTC)

Multipath Interference

I have recently been trying to work out DECT isnt working well in a large ~ 80m x 20m metal clad (Walls floors ceiling) building which is mainly space with a few odds and sods of metal structures. The structure has the added feature of round (focussing) end walls.

My only possible explanation was multipath interference. At a bit rate of a shade over 1.1 Mbit / sec (I dont know where the bitrate on the main page comes from) a 90ns time difference (30m length)in paths causes a 10% encroachment between adjacent bits, according to [1] this is enough to cause problems.

Any similar experience / comments?

Glass90land 13:51, 17 October 2007 (UTC)

Multipath Interference - a response

Your problem is indeed multipath, but not between the bit symbols: the DECT GMSK modulation will work at signal/interference ratios down to about 12db, and even metal walls will struggle to produce such levels with only 10% encroachment. Instead the problem is phase interference between cycles of the carrier, which at 1.89GHz have a wavelength of about 15cm. This is normal in most environments, and leads to a phenomenon called Rayleigh fading, since the depth and distribution of the fades normally follows Rayleigh statistics. In a clad, curved metal box the fades will be much more frequent and deeper, causing a reception environment resembling nothing so much as a Swiss cheese. The normal DECT solution to fading is called antenna diversity - to have two antennae (usually but not always at the base station) about half a wavelength apart, and the signals are switched to whichever has a decent signal. Thus if one antenna is in a fade, the other is probably getting a good signal. This method was employed in DECT PABXs and DECT wireless LANs, but consumer cordless phones tend not to have two antennae.

--Andrew Bud 01:14, 30 October 2007 (UTC)

DECT with Bluetooth in the US

Is it just me or is a DECT cordless phone with Bluetooth impossible to get in the US? Would one be able to buy the Siemens SL565 (available in the UK) and use it in the US? 74.68.112.149 (talk) 10:28, 24 December 2007 (UTC)

Alas, no. DECT in the US uses a different set of frequencies to DECT in Europe. Sorry. FWIW, the Wikipedia talk: pages are primarily for discussions of the pages associated with them, not the topics. Just a friendly warning, because some people get annoyed about that kind of thing. --Squiggleslash (talk) 11:33, 24 December 2007 (UTC)

Health effects

I have moved the entire Safety Concerns section to a new article, Safety Concerns for Cellular Wireless Technologies since it is not specific to DECT (the exact same argument applies to WiFi, GSM, CDMA etc). Andrew Oakley (talk) 16:25, 13 June 2008 (UTC) Renamed Safety concerns surrounding cellular wireless technologies. There should be a short summary of that article here. --kingboyk (talk) 21:11, 21 June 2008 (UTC)

Archived discussion - please move all subsequent debate to the Talk:Safety Concerns for Cellular Wireless Technologies page.

I yanked this:

Despite its broad range of technical features, there are considerable health issues with the use of DECT or, in fact, any other wireless devices in that frequency range using pulsed microwave technology. Numerous studies have found effects of these frequencies on body cell communication and the body's hormone levels. While little is known so far on how these low-level effects influence overall health and wellness, longer-term cancer research studies point to an increase of certain types of cancers presumably related to exposure to mobile phone base stations as well as other wireless technology radiation including DECT, wLAN etc. On the basis of these scientific findings, caution should be exercised when switching to a cordless phone using DECT or to any similar wireless technologies. Emmissions to both the user and third parties (neighbours, non-using bystanders) should be avoided. Most DECT base stations do send and, thus, emit radiation around the clock, even when not in use. There are, however, a few selected models available that automatically shut down within 1 or 2 minutes after the end of a call. This will also lower the device's overall energy consumption by a significant amount per year. Strictly limiting exposure (e g by shutting off standby or disconnecting devices from power unless in use) as well as keeping base stations and handsets as far from the body as possible may yield some protection, if avoiding them altogether and repalcing them with an equally feautre-rich corded phone seems unacceptable.

Aside from being generally skeptical about the risk from mobile phones and the like - if there really was a substantial risk, DECT telephones are much lower power than cellphones. this page seems to have a fairly comprehensive analysis of the studies that have been done on cellphone risk; there seems to be very little quantitative evidence to support the case of cellphones as a cancer risk. Any comment on risk from DECT phones should take the vastly lower power levels into account, at the very least. --Robert Merkel 12:56, 12 December 2005 (UTC)

That's not a good reason to remove the paragraph. It could be better written, though, with references to criticism and so on. Btw, you're probably wrong about the comparison with mobile phones. DECT always use the same signal strength, while GSM and other modern standards can use a significantly lower signal strength than DECT when the phone is close to the base station. In addition, I'm told that DECT base stations are always transmitting at full strength, even when there's no call in progress. ABostrom 21:33, 28 September 2007 (UTC)

The following is my updated and corrected version of the above text, which again was deleted by Squiggleslash for some weird reasons. He says, "This is an article about DECT, a heavily biased rant containing dubious health claims does not belong here". If facts and recent findings about health hazards concerning DECT devices do not belong here, then where?

He also says mentioning this topic "makes a mockery of the page in its present form". It makes a mockery of Wikipedia in its present form, if argumentative issues are banned and deleted.

FYI, even a institution of German government warned about DECT phones about 2 years ago. Google translation of http://www.bfs.de/de/bfs/presse/pr06/pr0602 They demanded manufacturers to build low-radiation DECT phones, and guess what the manufacturers did? They build them. They wouldn't have if they were so sure about DECT being absolutely unperilous.

(I added some references and made corrections to the text, which I did copy from a much earlier version of this page.)

Please, someone press the "undo" button. --W-sky (talk) 06:05, 8 January 2008 (UTC)

Health issues

There are considerable health issues with the use of DECT or, in fact, any other wireless devices in that frequency range using pulsed microwave technology. Studies have found effects of these frequencies on body cell communication and the body's hormone levels. While little is known so far on how these low-level effects influence overall health and wellness, point to an increase of certain types of cancers presumably related to exposure to mobile phone base stations as well as other wireless technology radiation including DECT, Wi-Fi etc.

Most DECT base stations do send and, thus, emmit radiation around the clock, even when not in use. There are, however, handsets available that reduce signal strength when close to the base station, and base stations that reduce the continuos control signal up to a 100,000th. These are labelled as "ECO DECT" models. However, on the basis of the scientific findings, caution should be exercised when using DECT or similar wireless technologies. Still it is advisable to keep base stations and handsets as far from the body as possible, and especially far away from kids and sleeping places, if avoiding them altogether and replacing them with corded phone seems unacceptable.

Scroll down to the bottom of the Talk: page and you'll see my original reasons for yanking this. Your latest edit is no better. Let's pick it apart:

There are considerable health issues with the use of DECT or, in fact, any other wireless devices in that frequency range using pulsed microwave technology."

This is uncited, and not without reason - there is no consensus at all suggesting that any substantial portion of the scientific community believes this to be true. This statement cannot be made in Wikipedia as is. You might have gotten away with "Some concern has been expressed about health issues with...", together with cites of actual concern from reputable organizations, but the statement, as written, is frankly false.

Studies have found effects of these frequencies on body cell communication and the body's hormone levels. "

Not only is this uncited, but it's admitted to that it's uncited. Again, this statement cannot be made in Wikipedia as written.

While little is known so far on how these low-level effects influence overall health and wellness, point to an increase of certain types of cancers presumably related to exposure to mobile phone base stations as well as other wireless technology radiation including DECT, Wi-Fi etc."

This statement contradicts the first two statements. "Little is known" yet "There are considerable health issues" and "Studies have found.."? Really? I congratulate the writer on actually finding a paper of vague relevance, but the paper is talking about cellphone transmission masts, which generally transmit many thousands of watts of radiation and are incomparable to a fraction-of-a-watt DECT or Wi-fi base-station.

Most DECT base stations do send and, thus, emmit radiation around the clock, even when not in use."

The entire section is a case of "Undue weight", but even within it there are recursive examples. This is one of them. DECT base stations send very brief pulses of information every few seconds when not in use, they're not constantly transmitting, and the power, again, is a fraction of a watt. This is not mentioned, and the over-all tone of the sentence implies that DECT base stations are actually blowing out massive amounts of radiation all the time.

There are, however, handsets available that reduce signal strength when close to the base station, and base stations that reduce the continuos control signal up to a 100,000th. These are labelled as "ECO DECT" models."

There is no continuous control signal, so this sentence is blatantly misleading and the over-all affect is to make the previous sentence look, as I mentioned above, like it's implying something that isn't true.

However, on the basis of the scientific findings, caution should be exercised when using DECT or similar wireless technologies."

This is POV, original research, and apparently untrue on the basis of current scientific knowledge about DECT and other wireless technologies.

Still it is advisable to keep base stations and handsets as far from the body as possible, and especially far away from kids and sleeping places, if avoiding them altogether and replacing them with corded phone seems unacceptable."

This strikes me as alarmist, and not rooted in anything scientific. As for citations, the first source is labeled a "Scientific Study" but appears to be sourced from some kind of non-objective anti-wireless site. Reading the link, the paper contains the same hysterical exaggeration about DECT's "continuous" transmissions when idle, and while not stupid enough to repeat the "OMG, DECT might cause cancer" claim above, repeats dubious claims about DECT possibly being disruptive to sleeping patterns. It's a terrible thing to link to. The second reference is to an appeal for more research based upon apparent circumstantial evidence of a link between DECT and, well, frankly anything that can be described as an illness.

Over-all the section is wrongly located in the DECT section for the following reasons:

1. This is not a DECT specific issue. A more general article that covers health concerns (and covers them properly) might be appropriate to link to, but this is a clear case of placing "undue weight" on a specific issue.

2. The section is one-sided and biased. There is nothing in the article that implies that the general consensus is that there are no serious health issues associated with low power level wireless technologies, indeed dissent is completely ignored.

3. The section contains many statements that are completely counter to the truth.

4. The section is largely uncited, and the cites that are given are unencyclopedic.

5. The section is unencyclopedic and its presence in the article does no credit to Wikipedia.

I don't see how you can't see that. --Squiggleslash (talk) 14:56, 8 January 2008 (UTC)

Hello and thanks a lot for being so elaborate, now I do understand why the section had to be deleted (again). I'm sorry for having persisted to keep the old text. Yet I still want to add something to the discussion (and to the article).

In general: There are two ways of dealing with possible risks of new technology (and DECT, being ~12 years old, still can be considered as 'new technology'). Either you do not acknowledge any risks until there is airtight proof of health danger, or you assume the probability of health danger until it is proven completely harmless.

IMHO, the second way is preferable. The first way is how humans dealt with radioactivity, chemicals, usage of fossile fuel etc., and looking to the past, it shows that this way is not always the best way. So I think: When talking about DECT, you have to mention the possibility or likelihood of health risks. But this way of thinking concerns not only DECT, but all new technology. So there might not be a special reason why this should be mentioned in the article about DECT; it might be just the general way of how to approach new technology, and this everyone has to decide for his own... But there is a special reason. It is exactly because there are so many fears, rumours, scientific and pseudo-scientific essays about the dangers of DECT. Furthermore, especially because of the legitimate criticism of DECT base stations perpetually sending very short but full-power contact signals to their handset(s), and because both base stations and handsets always sending with full signal strength even when very close to each other.

So I think, what must be mentioned in the article is: The signal strength issue and that very new DECT phones ("ECO-DECT") have various ways of reducing emission; that people like medical professionals believe in or at least do not rule out the possibility of health risks from DECT phones; that yet there is no absolute proof of risks or the absence of risks.

What's more: Someone looking for an answer to the whirring question about DECT health risks would possibly look into this Wikipedia article, hoping to find the latest findings and actual state of affairs here.

Though I worry that I could not write this. It might be undue weighted. ;-) --W-sky (talk) 05:06, 21 January 2008 (UTC)

DECT isn't really a new technology. It's a newer standard, but TDM/TDMA/FDMA digital telephones have been used for a lot longer than the life of DECT. DECT is itself a successor to CT2, Japan's PHS is very similar, and, of course, GSM, D-AMPS, and others have been extensively used across the world for a decade and a half. To suggest there are special health issues with DECT would most definitely be placing undue weight on the subject. DECT is considerably lower power than the analog systems it replaces, both during transmissions, and inherently because even when in use the TD nature of the system means the system isn't transmitting continuously.

As I believe I've said before, there is nothing wrong with there being a properly researched article about the health effects of low-power radio technology, and there being a link in the See also: section of this article to it. That article, of course, should look nothing like the section I yanked. There is nothing about DECT however that merits a special section on DECT's dangers, especially when - new technology or otherwise - there is no serious level of concern being expressed by anyone authoritative on this issue. --Squiggleslash (talk) 18:20, 21 January 2008 (UTC)

References

"Health issues"

Please do not re-add this.

The section that was added to this article was:

• POV
• Places "undue weight" on the subject. There is no mainstream concern about the health affects of DECT
• At odds with the apparent truth, claiming that DECT is thought to cause health issues when the reverse appears to be true from the vast bulk of literature I've seen
• Is not specific to DECT so doesn't belong here in the first place.

The section is as relevant here as a section about whether porn leads to violence would be in the MPEG article. It shouldn't be put here. It clearly violates WP:NPOV and is off-topic. --Squiggleslash (talk) 02:27, 4 January 2008 (UTC)

There is a link now to "Wireless electronic devices and health" in See Also - this gives more than enough weight to these "health concerns", and is a better article than the one previously referenced. --SesquipedalianVerbiage (talk) 23:06, 21 June 2008 (UTC)

Health effects (Cont.)

I've had a look at this article as it was on 13 June 2008. It appears to me that the second half of the section (as at 13 June 2008) _is_ specifically related to DECT 6.0 (specific high frequency band used, and the "continuous" (or otherwise) nature of DECT basestation emissions). Certainly all of the section doesn't appear to be scientifically grounded or well referenced, but it does contain information not found in the "Safety concern for Celullar Wireless Technologies" article (which omits any DECT-specific information), as well as a reference to the Don Maisch article. I wonder if anyone more familiar with the issues than me could look into this and see how much really is DECT-specific, and if any of this information needs to be restored either to this article or the "Safety concerns..." article? Regardless of what position you take, on the debate, I can't see any reason why the reference to the Maisch article was removed. Fh1 (talk) 15:02, 24 June 2008 (UTC)

The removed material was poorly sourced and incorrect, and therefore correctly removed. You might want to look at the mobile phone radiation and health, electrical sensitivity, and wireless electronic devices and health articles, which cover all relevant material. The journal that published the article claiming adverse health effects in not a RS, and hence should not be reintroduced. --SesquipedalianVerbiage (talk) 15:58, 24 June 2008 (UTC)

Article too technical?

I added the "Too Technical" notice. Perhaps someone could simplify the introduction at least, making it suitable for the general public. (ie. If someone is looking at buying a phone advertised as DECT, what does that mean for them? How is it better/worse than other competing technologies?) Technical info is fine and helpful, but could be lower down in the article. — SimonEast (talk) 05:09, 16 July 2008 (UTC)

Motion to provide a bottom-line consumers' perspective seconded ;) Cheezmeister (talk) 03:05, 26 October 2008 (UTC)

Safety Concerns

I removed the following text: "There have been numerous safety issues reported surrounding DECT technology. This technology uses microwaves. In research duplicating DECT frequencies in Germany, numerous symptoms have appeared in mice. Of particular concern is the swelling of the membrane between the brain and the skull." I did so because the text is unsubstantiated, unsourced and possibly false, and reintroduces essentially the same content that has been removed on several occasions as described above. --Andrew Bud (talk) 00:53, 8 November 2008 (UTC)

-New research showed some results, they aren't in favour of DECT. Perhaps something can be written using the following source: [2]. Sorry for not being bold. -- 80.101.119.181 (talk) 22:37, 30 December 2008 (UTC)

Vulnerability

Serious security vulnerabilities in DECT wireless telephony

If you want to keep your confidential telephone calls confidential, you'd be well advised to give telephones based on the widely-used DECT (Digital Enhanced Cordless Telecommunication) wireless telephony standard a miss. Security experts at the 25th Chaos Communication Congress (25C3) in Berlin have been explaining how easy it is to eavesdrop on such conversations. According to the researchers, all that's required is a souped-up 23-euro VoIP laptop card and a Linux computer. This setup has no difficulty in intercepting DECT conversations if, as is frequently the case, encryption is not activated. Even where data transfer is initially encrypted, the card is able to deactivate the encryption by pretending to be a base station.

http://www.heise-online.co.uk/security/25C3-Serious-security-vulnerabilities-in-DECT-wireless-telephony--/news/112326 —Preceding unsigned comment added by 66.72.121.101 (talk) 09:12, 31 December 2008 (UTC)

You mean "by pretending to be a base station without encryption" (merely pretending to be a base station is not enough). So does this mean we'll have script kiddies with laptops driving around the neighborhood looking for DECT phones to eavesdrop on? Is DECT the only vulnerable protocol here? Is the popular Panasonic KX-TGA571S (non-DECT) handset vulnerable to a similar hack, for example, or does Panasonic not support unencrypted links for that phone's protocol? (Dropping encryption should only happen for phones that claim to be interoperable with other manufacturers, the situation with DECT.) --Vaughan Pratt (talk) 08:37, 15 January 2009 (UTC)

Script kiddies have no technical skills, and as the researchers had to reverse engineer the card back to a schematic and then modify the PCMCIA card at the board level plus use other reverse engineering to do this, I doubt that there's much risk of spotty oiks wandering around their council estate with laptops listening to the neighbours chatting about what just happened on Eastenders. That said, what the researchers have shown is definitely cause for concern even if the risks of exploit to joe public are vanishingly small.

Moggie2002 (talk) 19:46, 15 January 2009 (UTC)

Health Effects pseudoscience AGAIN

I have removed the entire Health Effects section on the grounds that:

• It is poorly sourced
• The section as a whole has no links
• References are not in English
• It looks like pseudoscience, walks like pseudoscience and smells like pseudoscience

If the tinfoil hat brigade are insistent on re-including this, please can they rewrite it using proper references as per WP:CITE WP:VERIFY. Otherwise it'll just get blanked again by someone else for exactly the same reasons. This is, what, the fourth or fifth time now? Andrew Oakley (talk) 15:27, 17 December 2009 (UTC)

DECT encryption cracked

I know it's breaking news, but I'm surprised this doesn't get a mention in the main article:

http://www.theregister.co.uk/2010/02/08/dect_phone_encryption_cracked/

Surely that would be a far better reason for not using it than any unproven health concerns.

Joekiki (talk) 10:21, 9 February 2010 (UTC)

Health issues

I removed [3] as it's clearly a copyvio from the source. Someone needs to rewrite from scratch if they want this to be re-included. I was originally questioning the source as EMfacts appears to be an advocacy organisation (not my words [4]), but this specific source appears to be peer-reviewed so I'll let it be if rewritten. However the claims ("are implicated with sleep disruption") are rather strong and with only this source (which even if peer-reviewed appears to be a relatively obscure journal) should probably be presented as claims of this source. It doesn't help that the source appears to contradict itself at first sayings "DECT phone’s base station continuously" and "This means that the base station" then saying "half a meter away from a typical DECT phone placed on a bed side table" (the position of the phone is surely irrelevant, the base station is what's relevant according to them). Nil Einne (talk) 19:36, 18 November 2010 (UTC)

More than one external call at a time

It is not possible to have more than one external telephone call in operation on a typical domestic DECT system. Attempts to make an external call from one handset, whilst an external call is already being taken on another handset, generally give an error or warning, such as an engaged tone. However, this is possible with a business DECT system attached to a PABX.

Here in Germany, consumer DECT systems with an ISDN connection are popular. Siemens and other companies are selling these (f.e. the "Siemens Gigaset CX450 isdn" sells for around 75 Euros). With these devices it's possible to have several internal and external calls simultaneously (using multiple handsets but only one base station). --213.39.129.112 10:38, 25 September 2006 (UTC)

The one call at a time "drawback" should be mentioned somehow in the article. One of the annoyances I found while shopping for one of these phones is that the only 2-line phones were very expensive compared to previous 2-line phone models (around $180 vs. $40 with 2.4GHz models). I've been looking on the net for references to this price gap but haven't found much. -- Suso (talk) 13:52, 27 November 2010 (UTC)

XDECT R as a "technology"

The section on XDECT R seems contradictory as to whether or not it is a "technology." Three blips from the article: "XDECT R is a Uniden technology..." "The company has demonstrated the technology..." "XDECTR is not a 'technology'..." Within a single paragraph it is called a technology twice, and deemed as not a technology once. So which is it? Nispio (talk) 06:01, 1 December 2010 (UTC)

Technical development and adoption = History

A humble suggestion to rename the "Technical development and adoption" section to "History" for the non-technical audience. I came here looking for the history of this technology. Much good historical information is included in the article section "technical development and adoption" but renaming the section to "history" might be more appropriate for a broader audience. — Preceding unsigned comment added by Dosware (talk • contribs) 01:54, 16 May 2012 (UTC)

Latency/bandwidth mis-correlation

The text in question:

"DECT was originally intended for use with traditional analog telephone networks, but DECT bases that are designed for VoIP have greater bandwidth (lower latency)[citation needed] and higher bit-rates at their disposal than traditional analog telephone networks could provide."

• You can't really compare the bandwidth of a 56 kb/s uncompressed PCM stream to a compressed data stream of variable bandwidth. It's apples to oranges. If DECT were PCM, then this would make sense.
• Assuming a properly designed network which is free from link saturation concerns, latency will be worse over an asynchronous protocol such as Ethernet.
• A POTS line uses Frame-Relay and/or SONET for inter-switch communication. Due to their simplicity, they impart undetectable levels of latency, except in the case of trans-oceanic calls.

TCP or UDP are certainly capable of higher bandwidth, but the text conflates bandwidth with latency. Kynetx (talk) 21:50, 11 June 2014 (UTC)

Interoperability

technically, DECT phones, especially those with GAP, shoudl be interoperable at a basic level. This would include placing and receiving calls, and perhaps nothing more. In practice, this does NOT usually seem to be the case, and each manufacturer's phones must be used as a closed system, with no interoperability with any other manufacturer's phones.

I've written the article text to match the above. It was reverted, reverted back, etc. The text I put in is definitely technically accurate.

If anyone has concrete info that can improve it, please post and modify. If nobody does, please leave it alone.

I have example refs such as http://www.dslreports.com/forum/r24114677-DECT-telephone-interoperability though I don't think in an article at this technical level they make very good RS. Dovid (talk) 23:41, 1 August 2010 (UTC)

The CTR regulations for issuing EU type approvals for DECT, established in about 1995 (which I helped write), included the requirement that all terminals and base stations using the DECT spectrum should be testably interoperable at the most basic level of the GAP profile. There was a lot of debate about the wisdom of this at the time, but it was mandated. ETSI standards for this testing were written and approved at the time. Therefore it is a regulatory requirement - at least in Europe - not just a technical possibility. From my personal experience with many DECT handsets and base stations from different vendors in Europe, there has not been one case in which basic interoperability has not worked. On this basis I've reverted the article. But your reference deals with the US market, of whose interoperability requirements I am ignorant. Do you have source for the definitive situation in the US, or any basis for challenging interoperability in Europe? If the situation indeed varies between continents, let's capture that in the article. Andrew Bud (talk) 17:08, 11 August 2010 (UTC)

I have seen many references in online forums of people unable to get equipment from different manufacturers to work together at all. I'm torn as to whether these can be used as RS to document the case.

Dovid (talk) 05:07, 23 August 2010 (UTC)

Online forums? No. Nil Einne (talk) 19:43, 18 November 2010 (UTC)

I've found reports on Amazon of using GE headsets and V-Tech bases together successfully. - Chrontius (talk) 18:24, 25 August 2014 (UTC)

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External links

• DECT Forum at dect.org
• DECT information at ETSI

Category:Wireless communication systems

Flint314 (talk) 13:34, 7 December 2023 (UTC)

Requested move 22 March 2024

The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this discussion.

The result of the move request was: no consensus. (closed by non-admin page mover) BilledMammal (talk) 04:22, 7 April 2024 (UTC)

---

Digital enhanced cordless telecommunications → DECT – DECT is already the redirect to here, the abbreviation is the WP:COMMONNAME here. PhotographyEdits (talk) 11:01, 22 March 2024 (UTC) — Relisting. asilvering (talk) 22:50, 29 March 2024 (UTC)

• OpposeSupport: no evidence provided for assertion. Changed after long discussion. YorkshireExpat (talk) 17:49, 23 March 2024 (UTC)

  As an example, take a look at Best Buy: https://www.bestbuy.com/site/searchpage.jsp?st=cordless+phone

  They overwhelmingly sell cordless phones as "DECT" phones, it really is the common name. PhotographyEdits (talk) 08:21, 26 March 2024 (UTC)

  Do you have any non-US examples? I accept the Best Buy (it says Bangor, Maine is my closest store, which it may well be), but I'm not finding anything in the UK. YorkshireExpat (talk) 20:40, 26 March 2024 (UTC)

  Here for example, also sold as DECT: https://www.amazon.co.uk/s?k=cordless+telphone PhotographyEdits (talk) 08:07, 27 March 2024 (UTC)

  @YorkshireExpat if you find this convincing, could you change your vote then? If not, please let me know why. PhotographyEdits (talk) 07:15, 3 April 2024 (UTC)

  It may be commonly known by the acronym in the US, but I'm not convinced it is elsewhere (Amazon has a US bias, I feel), so think it is safer to stay with the full title. The acromyn being a redirect feels right to me. YorkshireExpat (talk) 07:33, 3 April 2024 (UTC)

  The largest European manufacturer of DECT handsets is Gigaset, a German company and former Siemens subsidiary. If you look at their site, they only use the full name once in a paragraph down below the page where they explain what it means: https://www.gigaset.com/de_de/telefone/dect-telefone/ PhotographyEdits (talk) 07:48, 3 April 2024 (UTC)

  Let's take the Media Markt, a German electronics retailer: https://www.mediamarkt.de/de/search.html?query=DECT returns almost 4000 products, while the full name has zero results. PhotographyEdits (talk) 08:42, 3 April 2024 (UTC)

  Those are German language though. YorkshireExpat (talk) 10:09, 3 April 2024 (UTC)

  I looked at a couple of UK-specific shops:

  • https://www.headset-store.co.uk/yealink-dect-phones.html
  • https://www.pmctelecom.co.uk/telephones/cordless-phones/dect-cordless-phones/
  • https://www.onedirect.co.uk/business-telephones/cordless-phones/cordless-dect-phones

  I also looked at Currys, but their search engine is bad. But if you look at individual phone phone listings, it says in the specifications "DECT cordless telephone", the full name is not used: https://www.currys.co.uk/products/panasonic-kxtgj424eb-cordless-phone-quad-handsets-black-10190170.html PhotographyEdits (talk) 10:31, 3 April 2024 (UTC)

  Google is useful here, compare the following:

  • https://www.google.com/search?q=site%3Acurrys.co.uk+"DECT"
  • https://www.google.com/search?q=site%3Acurrys.co.uk+%22Digital%2Benhanced%2Bcordless%2Btelecommunications%22

  PhotographyEdits (talk) 10:40, 3 April 2024 (UTC)

  Ok then, for argument's sake let's say that is it the common name. VoIP, PSTN, and ISDN, for example, all redirect to the full expansion of their terms. Is DECT in the same bracket of recognisability as SMS and GSM? YorkshireExpat (talk) 18:20, 3 April 2024 (UTC)

  Not sure what you're referring to here. I think SMS is more 'famous' than DECT, but what we are comparing is the relative usage of the acronym versus the full name. In that sense, yes, I think DECT is in the same bracket as SMS and GSM.

  I think that the ISDN article should be moved to its acronym as well. Maybe VoIP and PSTN too, but I'd need to investigate that a bit. PhotographyEdits (talk) 22:02, 3 April 2024 (UTC)

  I'm just saying that, per MOS:ACROTITLE, decisions will have been made in the past to fully expand other acronyms and initialisms. Is DECT well enough known that using the acronym is valid. I'd say VoIP, PSTN, and ISDN are more well known, and they are fully expanded. YorkshireExpat (talk) 10:14, 4 April 2024 (UTC)

  "Is DECT well enough known that using the acronym is valid."

  Yes it is, as I've repeatedly shown with various examples. Also, it seems there is no explicit consensus for using the full name on the other articles, they were just created like that once. PhotographyEdits (talk) 06:23, 5 April 2024 (UTC)

  @PhotographyEdits ok, have it your way :D YorkshireExpat (talk) 21:26, 5 April 2024 (UTC)

  Thanks you! :-) PhotographyEdits (talk) 14:15, 6 April 2024 (UTC)

• Oppose. The article's subject seems a bit too technical for the average reader, and thus they would be unlikely to both be familiar with the subject and recognise its acronym immediately, to fulfill the high standard of MOS:ACROTITLE that ... the subject is known primarily by its abbreviation and that abbreviation is primarily associated with the subject. Zzyzx11 (talk) 17:03, 24 March 2024 (UTC)

  The full name is actually the very technical name. If you look at a web shop for these kind of phones, you'll see that they only use the acronym. PhotographyEdits (talk) 08:18, 26 March 2024 (UTC)

  Sorry, but this is still a subject that I still prefer to error on having the full name spelled out, like the example stated in MOS:ACROTITLE that current consensus still has Central Intelligence Agency spelled out in full instead of "CIA". Zzyzx11 (talk) 19:47, 30 March 2024 (UTC)

  WP:ILIKEIT is not a valid argument here. What matters is:

  • is the common name the abbreviation? (yes)
  • is the abbreviation used primarily for this subject? (yes)

  That there is a consensus for some article to keep the full name is not relevant. PhotographyEdits (talk) 20:32, 30 March 2024 (UTC)

Note: WikiProject Telecommunications has been notified of this discussion. asilvering (talk) 22:50, 29 March 2024 (UTC)

Oppose per the precedence set in the section below WP:ARTSINGLE (I don’t see a shortcut to the actual section) which outlines that acronyms in the article title is generally a no no Pdubs.94 (talk) 06:05, 3 April 2024 (UTC)

That policy says: "Abbreviations and acronyms are often ambiguous and thus should be avoided unless the subject is known primarily by its abbreviation and that abbreviation is primarily associated with the subject".

I am arguing (with proof!) that DECT is the name by which the subject is primarily known and that the abbreviation is primarily associated with the subject. PhotographyEdits (talk) 07:13, 3 April 2024 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

DECT in the United States

it would seem that there are now 1.9 ghz DECT devices in use in the US now, including the plantronics CS55 headset - http://www.plantronics.com/north_america/en_US/products/cat29880043/cat29880054/prod5430004 -Joe Zasada, May 29, 2006

It has also appeared in the US consumer market for baby monitors http://www.consumer.philips.com/consumer/catalog/tree/en/us/consumer/personal_care_gr_us_consumer/baby_care_ca_us_consumer/babys_development_su_us_consumer/ce/_productId_SCD590_54_US_CONSUMER/_activeTab_specifications/DECT_baby_monitor+SCD590?proxybuster=JXOW0ZKLBKQE1J0RMRESHQVHKFSEKI5P Ktinga 15:35 21 April 2007 (UTC)

DECT-2020 (NR+)

I would like to add here this information on the new variant of DECT. I think it will require some heading level adjustment, and adding at the beginning of the page the anchors to dect classic and dect-2020

DECT-2020 NR+

DECT-2020 is a new radio standard by ETSI for the DECT bands worldwide. The standard was designed to meet a subset of the ITU IMT-2020 5G requirements that are applicable to IOT and Industrial internet of things. . DECT-2020 is compliant with the requirements for Ultra Reliable Low Latency Communications URLLC and massive Machine Type Communication (mMTC) of IMT-2020.

DECT-2020 NR has new capabilities compared to DECT and DECT Evolution:

• Better multipath operation (OFDM Cyclic Prefix)
• Better radio sensitivity (OFDM and Turbocodes)
• Better resistance to radio interference (co-channel interference rejection)
• Better bandwidth utilization
• Mesh deployment

The DECT-2020 standard has been designed to co-exist in the DECT radio band with existing DECT deployments. It uses the same Time Division slot timing and Frequency Division center frequencies and uses pre-transmit scanning to minimize co-channel interference.

Applications

DECT NR+ (called DECT-2020 NR in ETSI) primarily focuses on addressing the needs of local area deployments for two use case areas: massive Machine Type Communication (mMTC) and Ultra-Reliable Low Latency Communication (URLLC) as defined for  5G networks application areas. The release 1 of the standard targets several applications within these use cases, including Smart Metering and Smart grid, Industrial internet of things, Building automation, and Professional audio

DECT NR+ decentralized and autonomous networking capability was specifically designed for Metering and Smart Grid applications, and mesh networking application in general. The technology can scale up to millions of devices within a single network.

The low latency communications URLLC is suitable for various use cases of Industry 4.0. These applications encompass robotics, monitoring and predictive maintenance and others. NR+ supports these use cases through its low latency and high reliability, dedicated frequency band, and high density and scalability

Regarding Professional Audio and PMSE applications, DECT NR+ offers the necessary features of low latency and high reliability. This makes it suitable for applications requiring real-time audio transmission and performance as required by professional audio systems.

Technology

DECT NR+ technology is specified by DECT committee in the ETSI. The specifications for NR+ are called DECT-2020 in ETSI.

Topologies

NR+ supports 3 topologies

1. Mesh network
2. Star network
3. Point-to-Point Link

NR+ Mesh network is based on a clustered treeIn all these network topologies the NR+ assumes that a device, called FT node, manages the radio resource usage in the cluster or link it controls.

The Point-to-point and star networks enable dedicated links, with reserved capacity for scheduled transmissions. A leaf node, called PT node in NR+, can ask for certain resource reservation for it when it associates to the FT node. As this reservation can be done only for the next link, Mesh networking with multiple relaying links in the path relies on random access channel usage where the devices needing to communicate compete for the access window defined by the FT node. This increases the communication delays in Mesh.

Co-Existence with Classic DECT

An important design criteria for NR+ was to co-exist with Classic DECT communications. This allows NR+ to use the DECT reserved radio bands 1, 2 and 9, in the frequency range of 1880-1930 MHz. DECT reserved radio bands are license free, but devices need to pass certification ensuring correct operation on the bands.

Mesh operation

The benefits of mesh networking network topology and operation are robustness for changes or errors and coverage extension.

Robustness is the result of the autonomous decisions of the devices. There is no single point of failure. NR+ also supports having multiple gateway devices, called Sinks, connecting the NR+ mesh network to Internet. All the devices autonomously measure parent FT device's radio link quality, and can switch to another FT device if a better link or shorter route to sink is available. Similarly, if a parent device is not acknowledging messages, or is not sending the periodic beacon advertisement, a device will look for alternative parents. The mesh network heals itself in error situations and changes in the network.

Each device added to the network may act as a FT device, extending the network coverage. The sinks are configured first and start advertising the network in beacon messages. Devices scan radio channels, and associate to the parent they hear advertising the network and cluster. Associated devices can act as FT devices, and extend the network by selecting a channel with least traffic and start forwarding the network advertisement beacons. This extends the coverage for each FT device that joins the network.

Figure Mesh network -- 103 636-1 Fig 5.3.2-1

NR+ Protocol Layers

Overall description of the technology and protocol layers are provided in the DECT-2020 New Radio (NR); Part 1: Overview; Release 1 specification

Figure Protocol stacks, 103 636-1 Fig 6.1-2

Convergence Layer (CVG)

Convergence layer offers identification and multiplexing of the traffic of different applications and services using the NR+ communications. CVG operates end-to-end between the NR+ network nodes. It is analogous to ports in UDP or TCP protocol. Like UDP and TCP, CVG offers both unrealiable and reliable messaging services, datagram or flow control service and segmentation and reassembly for messages.

Convergence layer provides security with encryption and integrity protection of messages end-to-end in the NR+ network.

Data Link Control Layer (DLC)

Data link control layer is the message routing service for NR+ networks. Routing decisions are done in each device in the network, there is no central routing table. DLC routing operates in 3 modes:

1. Uplink routing, to sink device: each node forwards message to parent
2. Downlink routing: from sink to FT or PT device in the network. Messages are forwarded to each FT device in the network until the destination device's parent device can deliver the message to the destination device.
3. Horizontal routing, between devices in the network with hop limited flooding

Unicast, multicast and broadcast routing is supported.

As the NR+ network has internal routing and addresses it can operate without Internet Protocol routing services. Internet protocols can be carried in NR+ networks.

Medium Access Control layer (MAC)

Medium access control main services are radio resource control and data transfer.

Radio resource control ensures the #Co-Existence with Classic DECT. To do this, FT devices periodically scan the radio channel they operate on, and map busy time slots measured to be in use assuming it is an on-going Classic DECT connection<re name="mac">. FT devices allocate the channel access time for the child devices on free time slots, preserving error free communications on the busy slots time slots. Channel access allocations are sent in beacon messages to all devices in the cluster.

MAC layer also provides link scope encryption and integrity protection.

Physical Layer (PHY)

Physical layer uses Cyclic prefix version of OFDM as the core technology. The technologies provide well-known behaviour in challenging radio conditions.

PHY layer provides error detection to higher layers, Forward error correction and HARQ with soft combining. Received messages with errors are combined with re-transmissions, making it possible to decode correct message even if the re-transmission too contained errors.

NR+ radio can operate on frequencies below 6GHz. Standard defined speeds are up to gigabits per second. Radio implementations of course vary in the speeds achieved and frequencies supported.

Security

NR+ defines message encryption and integrity protection in both CVG and MAC layers. Encryption and integrity protection use own separate keys on the 2 layers. The encryption is security is based on AES with key length of 128 bits. Integrity protection is based on same algorithm and key length NR+ does not define the key distribution mechanism "the number of key-pairs and the key distribution is outside of the scope of the present document" although it has been studied

Future work in ETSI

The DECT technical committee has started specification work for Release 2 of the standard in June 2023.

See also

• DECT
• Unlicensed Personal Communications Services