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JerrrryD.
Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT ( talk) 00:05, 18 January 2022 (UTC)
with up to 10 GBit/s: https://www.ipms.fraunhofer.de/de/research-development/wireless-microsystems/LiFi/lifi-gigadock.html
I think light very fast fade underwater versus longwawes radio... And it's unuseful underwater. — Preceding unsigned comment added by Mogwaika ( talk • contribs) 18:24, 13 December 2016 (UTC)
Is it like you can access the internet in visible light, not in the darkness? Or is it like the infrared or like invisible spectrum also can be used ?
Yes but it works in the darkness too, as long as the led is not completely switched off, the data will transmit, and an LED can be dimmed so far, the human eye perceives it as off though it is just very dim.
The idea is that your computer would have a sensor that can detect the flickering of an LED lightbulb. The data would be encoded in the flickering light instead of going through radio waves as it does in wifi. I'm not sure how your computer is supposed to talk back to the lamp, though.
It uses the same technology as there is a sensor elsewhere to receive outgoing data
The introduction paragraph needs cleaning and elaboration. It says "Li-Fi should not be confused with the more general term visible light communications (VLC), which is the use of the visible light portion of the electromagnetic spectrum to transmit information," but it fails to explain what it is. If it is not similar to infra-red or fiber optics, what is it? What portion of the light spectrum is used? How does it overcome the line-of-sight issue? — Preceding unsigned comment added by 24.223.156.13 ( talk) 14:29, 19 October 2013 (UTC)
I guess it could use either visible or non-visible light. It doesn't matter. They would both work as well.
To talk back, the computer can have it's own LED. It's not as if the LED *must* be a light bulb on the ceiling.
The line-of-sight issue is handled by it being able to use scattered light. Eg. If you switch on a light bulb you can see the light is blocked by objects and creates shadows, but the shadows aren't completely black. There is still some light in the shaded area coming from reflections of the wall and ceiling etc. , and switching the bulb on and off will still have an visible effect in the shadow. The light signal is of course much weaker (maybe 10 or 100 times) and this will slow the data rate but not reduce it to zero.
Line of sight is more of a problem outdoors when there are no objects nearby to reflect the signal or where the distance between the stations is so great that the reflections are not strong enough. The OFDM technology also helps to make the scattered signals readable. (used by WiFi, 4G wireless and DVB-T and DAB digital TV and Radio broadcasting. — Preceding unsigned comment added by 220.244.92.239 ( talk) 07:03, 21 October 2013 (UTC)
The article has great relevance in this moment, since LiFi can become a significant technology, but the article at this moment sounds like an advert for pureVLC, so we need to change this to reflect the fact that a consortium is being formed and this technology is being pushed as forward.
Just like 3Com for Ethernet, pureVLC could be the company that makes it real, but we need other examples for it to become relevant as a encyclopedic entry, which would mean other players and an interoperable standard chiefly if they get IEEE standards body certification. — Preceding unsigned comment added by 187.163.127.19 ( talk) 00:17, 20 October 2013 (UTC)
It is not about advertising a single company, rather it is about establishing the true meaning behind Li-Fi. The IEEE 802.15.7 standard and many of the others are not true Li-Fi systems. There are no high data rate system that are implemented with this technology. pureVLC/pureLiFi are the only ones that are working toward a real solution. The goal is to clarify why the standard is not as good as it could be and clearly distinguish between Li-Fi and VLC. — Preceding
unsigned comment added by
Nikola.serafimovski (
talk •
contribs)
19:46, 18 December 2013 (UTC)
In evaluating whether there is a need for this concept, it would be interesting to analyse why IrDA has all but died out, and what the difference is.
OK : IrDA was slow, one-to-one and one-metre line-of-sight - what has changed now ? Why didn't IrDA just evolve ? Why is it being re-launched ? Call me skeptical, but I think this will not take off, because WiFi worked whereas IrDA didn't ... Yes 2.4GHz is congested (also used for Bluetooth, CCTV, keyboards, mice, radio microphones, microwave ovens etc), but isn't 5GHz Dual-Band WiFi underused and taking off ? (In Europe ...)
-- 195.137.93.171 ( talk) 12:46, 11 November 2013 (UTC)
IrDA died because of a number of reasons. These include the fact that you could not effectively receive anything because it was only line of sight and you couldn't really see where the optimal location was. In addition, the power constraints for an IR system are not applicable in this context because light can be as bright as you like. Furthermore, the IrDA was using outdated technology. This is the key differentiator between pureLiFi and other potential Li-Fi competitors. — Preceding
unsigned comment added by
Nikola.serafimovski (
talk •
contribs)
19:49, 18 December 2013 (UTC)
With regard to the 5 GHz for Wi-Fi, it does not matter how much more bandwidth is allocated. The demand for mobile data is growing exponentially and the supply is finite. The FCC (from the US), OFCOM (from the UK) and many other regulatory bodies have clearly pointed to this trend and warn that something must be done now. The largest growth in data rates over the last few decades has come from increased spatial bandwidth reuse, ie., smaller cell sizes, not from gains in the spectral efficiency (the bits/s/Hz of a system). Li-Fi is merely the logical progression of this trend. ([User talk: Nikola.serafimovski]) — Preceding unsigned comment added by Nikola.serafimovski ( talk • contribs) 19:53, 18 December 2013 (UTC)
I'm not sure about the timmings, but using light to carry data isn't new, so some background research is appropriate. /info/en/?search=RONJA 10 Mbps full duplex over 1.4 km with BER 10^-9 RONJA was released as a DIY openssource guide in 2001 http://ronja.twibright.com/ https://www.prnewswire.com/news-releases/visible-light-communication-vlcli-fi-technology--free-space-optics-fso-market-2013-2018---by-component-led-image-sensor-opto-couplers-application-indoor-networking-underwater-communication-location-based-service--187265961.html http://ronja.twibright.com/tetrapolis/spec.php — Preceding unsigned comment added by 27.109.113.242 ( talk) 22:38, 8 December 2020 (UTC)
Why are these words in bold:
networked, mobile, high-speed communication
I don't believe they should be in bold.
Because it is critical that people distinguish Li-Fi from VLC. Li-Fi means networked, mobile and high-speed along multiple users. VLC is even low-rate, one direction/broadcast only applications. The readers should be educated to understand the difference.
Next thing:
This part of a sentence is so complicated:
Although Li-Fi can be used to off-load data from existing Wi-Fi networks, implementations may be used chiefly to provide capacity for the greater downlink demand
Can we make this easier to read?
I have rephrased this sentence. -- Wyn.junior ( talk) 15:53, 18 December 2013 (UTC)
This sentence is now improved, though still very complicated:
Li-Fi can be used to off-load data from existing Wi-Fi networks to provide capacity for the greater downlink demand as complementary to the existing wireless or wired network infrastructure.
What does "downlink" mean?
--
Wyn.junior (
talk)
20:47, 18 December 2013 (UTC)
All data flows in two directions. One from the server to the user, which is called downlink. The other is from the user to the servers, this is called uplink. It is fairly well known wording for anyone in communications. — Preceding unsigned comment added by Nikola.serafimovski ( talk • contribs) 20:57, 18 December 2013 (UTC)
I don't believe I have heard "downlink", though I have commonly used the word "download" for that purpose.
Does the sentence mentioned above mean that Li-Fi provides greater capacity for downloading data only and not for uploading?
--
Wyn.junior (
talk)
22:16, 18 December 2013 (UTC)
Another issue of understanding could be because we probably live in different countries (I live in USA). Same English language, though different terms and sentences of expression are used.-- Wyn.junior ( talk) 22:20, 18 December 2013 (UTC)
Because everything in the electromagnetic spectrum travels at the speed of light, shouldn't all internet be the same speed?-- Wyn.junior ( talk) 03:38, 28 February 2014 (UTC)
User:Jeh deleted this paragraph, saying "this makes no sense. Cable and DSL providers have nothing to do with control of the radio spectrum"
Here is the paragraph:
"Unlike
radio waves, of which 96% of the country's broadband access is controlled by DSL and Cable providers,
[1] visible light waves are not regulated, owned or controlled by any person, private company or government organization."
If
User:Jeh is correct, then only part of this paragraph should have been deleted. It could read like this:
"Unlike
radio waves, visible light waves are not regulated and are free to use."
I am not sure that
User:Jeh is totally correct though. The part about cable and DSL providers is referenced. Here is an exerpt from the source (
http://www.theregister.co.uk/2007/08/01/fcc_opens_up_us_wireless_spectrum/):
"Google and its coalition of public advocates are working to provide consumers with more online choices, arguing that big name telecoms like AT&T and Verizon have too much control over the wireless spectrum as well as the broadband internet market. DSL and cable providers, they argue, control 96 per cent of the country's broadband access, and if the U.S. radio spectrum is opened up, it could give consumers a viable third option."
--
Wyn.junior (
talk)
04:52, 5 March 2014 (UTC)
References
Can this be used as a reference?-- Wyn.junior ( talk) 01:55, 29 March 2014 (UTC)
About the News release template at the article. In February 2014 user:Jeh added the tempĺate... I agree, that version of the article reads like a news release.
Then many edits later, by many other users (the mine are little but other have some effort)... It is better (!). Not perfect, but better... So, suggestion: to remove the template. -- Krauss ( talk) 21:59, 18 June 2014 (UTC)
PS: I have splitted the text with new sections where we can see that the problem is not an "advertising style"... ṕerhaps needs only good english and some didactic approach.
I don't really like the tone of this article, it makes it sound like the professor invented the concept of using light for communications. When all that he has really done is to add some specific protocols to an already well known technique, and figured out a way to market his package as if it were something new. For example, back in the 1980's in Byte Magazine, Steve Circia's (sp?) Circuit Cellar column published a How To project for linking computers together over a distance of several miles using infrared light emitting diodes. The technology itself was already well known even then. I recall in the mid 1990's looking at a commercial product that used a laser beam. It was designed as a solution to the massive expense of putting cables under the street in order to connect the networks of two buildings together. As long as you could get line of sight from either a window or the rooftop, you could use their laser beam communication system to send IP packets between the buildings. There is nothing new under the sun, and I resent that this guy appears to be claiming to have invented something that is in fact quite old (or at least this article conveys that impression). He may have created a cutesy name for it and defined a protocol to ensure device inter-operation, but the actual technology has been around for many decades. Also it has been known for an equally long time that light can be bounced off of walls. Anyone who has ever aimed their tv remote at the wall behind them has already experienced this in action. As far as IrDA goes, it suffered from two major problems. Transmission speeds were typically quite low and most setups were for one way communication. This lead to a lack of enthusiasm and resulted in a lack of software and hardware support. As I recall, at one point a number of laptops added an IrDA as a feature. I recall being excited about it at the time, when I bought a computer that had this. But they provided no software to run it, you had to write our own. On top of that it was (typically) not hooked up to a UART thus the software had to do a lot of bit banging, which is complicated and inefficient. Nobody ever found a killer app for IrDA, IMHO the closest they came was to use it for wireless printing, but it never reached critical mass and the protocols weren't standardized. Once WiFi got established it made far more sense to use the existing infrastructure of WiFi for communication to devices like printers. One of the reasons for the WiFi crisis is the on-coming Internet of Things. You just can't have billions of devices all transmitting on the limited WiFi spectrum. LiFi would make a lot of sense for that application. I just feel that the article should make it clear that LiFi does not create any new technologies, all it does is define a Trademark for a group of Inter-operable protocols, which are implemented using well known (and quite old) technologies. codeslinger@compsalot (too lazy to login).
I have a problem with the use of the word "medium" in the 1st sentence in the "Technology details" section:
This OWC technology uses light from light-emitting diodes (LEDs) as a medium to deliver networked, mobile, high-speed communication in a similar manner to Wi-Fi.[3]
It is the light itself that is the "medium" and not the LED's. I also do not like the use of the word "bulbs" two sentences later:
Visible light communications (VLC) works by switching bulbs on and off within nanoseconds,[5]
LEDs are not bulbs, nor are they the medium and both of these statements are both technically wrong, as well as wrong in the sence that they will not do anything but confuse the layperson.
the on/off switch of the light bulbs are so fast and the off time will be so long that you can't see it.
or you can use infrared which you can't see at all.
Is there any citation for li-fi being a contraction of "light-fidelity"? "Light-fidelity" doesn't mean anything. — Preceding unsigned comment added by Apepper ( talk • contribs) 14:26, 19 January 2016 (UTC)
"Li-Fi" was chosen for the similarity to "Wi-Fi"; "Wi-Fi" is a combination of "Wireless" and "Hi-Fi", not "Fidelity". Matthias Alexander Jude Shapiro ( talk) 14:23, 24 July 2016 (UTC)
Many spammers are making edits to this post which is seriously affecting the quality of the post. — Preceding unsigned comment added by RyanAfrish7 ( talk • contribs) 03:44, 24 August 2016 (UTC)
Imagine a world where every one of the billions of lightbulbs in use today is a wireless hotspot delivering connectivity at speeds that can only be dreamed of with Wi-Fi. That's the goal of the man who invented such a technology, and this week Li-Fi took a step out of the domain of science fiction and into the realm of the real when it was shown to deliver speeds 100 times faster than current Wi-Fi technology in actual tests.
An Estonian startup called Velmenni used a Li-Fi-enabled lightbulb to transmit data at speeds as fast as 1 gigabit per second (Gbps), which is about 100 times faster than current Wi-Fi technology, meaning a high-definition film could be downloaded within seconds. The real-world test is the first to be carried out, but laboratory tests have shown theoretical speeds of 224 Gbps.
So, just what is Li-Fi, how does it work, and will it really revolutionize the way we connect to the Internet?
Li-Fi refers to visible light communications (VLC) technology, which delivers high-speed, bidirectional, networked mobile communications in a manner similar to Wi-Fi. It promises huge speed advantages, as well as more-secure communications and reduced device interference. — Preceding unsigned comment added by Harshalkamble1996 ( talk • contribs) 08:44, 20 October 2016 (UTC)
How Does Li-Fi Work?
This is how pureLiFi describes the operation of its technology:
When a constant current is applied to an LED [light-emitting-diode] lightbulb, a constant stream of photons are emitted from the bulb which is observed as visible light. If the current is varied slowly, the output intensity of the light dims up and down. Because LED bulbs are semiconductor devices, the current, and hence the optical output, can be modulated at extremely high speeds which can be detected by a photodetector device and converted back to electrical current. The intensity modulation is imperceptible to the human eye, and thus communication is just as seamless as RF [radio frequency technology]. Using this technique, high-speed information can be transmitted from an LED lightbulb. — Preceding unsigned comment added by Harshalkamble1996 ( talk • contribs) 08:49, 20 October 2016 (UTC)
According to the IPA in the article the pronunciation of Lifi is /liː-faɪ/ - the first i is pronunced as the two e's in "seed". Shouldn't it be /ˈlaɪfaɪ/ as pronunced in the TED video of Prof. Harald Haas and with the same vowel as light ( /laɪt/)?
Made some bigger changes on the page, especially regarding promotional info, by removing a lot of mentions/references to individual companies and their achievements when not mentioned in the History context. I think it's a lot less promotional in tone, but will wait a bit before removing the advertisement warning. Abraxxass12 ( talk) 12:41, 15 June 2022 (UTC)
123456 124.106.197.105 ( talk) 06:19, 9 June 2023 (UTC)
![]() | This article is rated Start-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||||||||||||||||||
|
This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available
on the course page. Student editor(s):
JerrrryD.
Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT ( talk) 00:05, 18 January 2022 (UTC)
with up to 10 GBit/s: https://www.ipms.fraunhofer.de/de/research-development/wireless-microsystems/LiFi/lifi-gigadock.html
I think light very fast fade underwater versus longwawes radio... And it's unuseful underwater. — Preceding unsigned comment added by Mogwaika ( talk • contribs) 18:24, 13 December 2016 (UTC)
Is it like you can access the internet in visible light, not in the darkness? Or is it like the infrared or like invisible spectrum also can be used ?
Yes but it works in the darkness too, as long as the led is not completely switched off, the data will transmit, and an LED can be dimmed so far, the human eye perceives it as off though it is just very dim.
The idea is that your computer would have a sensor that can detect the flickering of an LED lightbulb. The data would be encoded in the flickering light instead of going through radio waves as it does in wifi. I'm not sure how your computer is supposed to talk back to the lamp, though.
It uses the same technology as there is a sensor elsewhere to receive outgoing data
The introduction paragraph needs cleaning and elaboration. It says "Li-Fi should not be confused with the more general term visible light communications (VLC), which is the use of the visible light portion of the electromagnetic spectrum to transmit information," but it fails to explain what it is. If it is not similar to infra-red or fiber optics, what is it? What portion of the light spectrum is used? How does it overcome the line-of-sight issue? — Preceding unsigned comment added by 24.223.156.13 ( talk) 14:29, 19 October 2013 (UTC)
I guess it could use either visible or non-visible light. It doesn't matter. They would both work as well.
To talk back, the computer can have it's own LED. It's not as if the LED *must* be a light bulb on the ceiling.
The line-of-sight issue is handled by it being able to use scattered light. Eg. If you switch on a light bulb you can see the light is blocked by objects and creates shadows, but the shadows aren't completely black. There is still some light in the shaded area coming from reflections of the wall and ceiling etc. , and switching the bulb on and off will still have an visible effect in the shadow. The light signal is of course much weaker (maybe 10 or 100 times) and this will slow the data rate but not reduce it to zero.
Line of sight is more of a problem outdoors when there are no objects nearby to reflect the signal or where the distance between the stations is so great that the reflections are not strong enough. The OFDM technology also helps to make the scattered signals readable. (used by WiFi, 4G wireless and DVB-T and DAB digital TV and Radio broadcasting. — Preceding unsigned comment added by 220.244.92.239 ( talk) 07:03, 21 October 2013 (UTC)
The article has great relevance in this moment, since LiFi can become a significant technology, but the article at this moment sounds like an advert for pureVLC, so we need to change this to reflect the fact that a consortium is being formed and this technology is being pushed as forward.
Just like 3Com for Ethernet, pureVLC could be the company that makes it real, but we need other examples for it to become relevant as a encyclopedic entry, which would mean other players and an interoperable standard chiefly if they get IEEE standards body certification. — Preceding unsigned comment added by 187.163.127.19 ( talk) 00:17, 20 October 2013 (UTC)
It is not about advertising a single company, rather it is about establishing the true meaning behind Li-Fi. The IEEE 802.15.7 standard and many of the others are not true Li-Fi systems. There are no high data rate system that are implemented with this technology. pureVLC/pureLiFi are the only ones that are working toward a real solution. The goal is to clarify why the standard is not as good as it could be and clearly distinguish between Li-Fi and VLC. — Preceding
unsigned comment added by
Nikola.serafimovski (
talk •
contribs)
19:46, 18 December 2013 (UTC)
In evaluating whether there is a need for this concept, it would be interesting to analyse why IrDA has all but died out, and what the difference is.
OK : IrDA was slow, one-to-one and one-metre line-of-sight - what has changed now ? Why didn't IrDA just evolve ? Why is it being re-launched ? Call me skeptical, but I think this will not take off, because WiFi worked whereas IrDA didn't ... Yes 2.4GHz is congested (also used for Bluetooth, CCTV, keyboards, mice, radio microphones, microwave ovens etc), but isn't 5GHz Dual-Band WiFi underused and taking off ? (In Europe ...)
-- 195.137.93.171 ( talk) 12:46, 11 November 2013 (UTC)
IrDA died because of a number of reasons. These include the fact that you could not effectively receive anything because it was only line of sight and you couldn't really see where the optimal location was. In addition, the power constraints for an IR system are not applicable in this context because light can be as bright as you like. Furthermore, the IrDA was using outdated technology. This is the key differentiator between pureLiFi and other potential Li-Fi competitors. — Preceding
unsigned comment added by
Nikola.serafimovski (
talk •
contribs)
19:49, 18 December 2013 (UTC)
With regard to the 5 GHz for Wi-Fi, it does not matter how much more bandwidth is allocated. The demand for mobile data is growing exponentially and the supply is finite. The FCC (from the US), OFCOM (from the UK) and many other regulatory bodies have clearly pointed to this trend and warn that something must be done now. The largest growth in data rates over the last few decades has come from increased spatial bandwidth reuse, ie., smaller cell sizes, not from gains in the spectral efficiency (the bits/s/Hz of a system). Li-Fi is merely the logical progression of this trend. ([User talk: Nikola.serafimovski]) — Preceding unsigned comment added by Nikola.serafimovski ( talk • contribs) 19:53, 18 December 2013 (UTC)
I'm not sure about the timmings, but using light to carry data isn't new, so some background research is appropriate. /info/en/?search=RONJA 10 Mbps full duplex over 1.4 km with BER 10^-9 RONJA was released as a DIY openssource guide in 2001 http://ronja.twibright.com/ https://www.prnewswire.com/news-releases/visible-light-communication-vlcli-fi-technology--free-space-optics-fso-market-2013-2018---by-component-led-image-sensor-opto-couplers-application-indoor-networking-underwater-communication-location-based-service--187265961.html http://ronja.twibright.com/tetrapolis/spec.php — Preceding unsigned comment added by 27.109.113.242 ( talk) 22:38, 8 December 2020 (UTC)
Why are these words in bold:
networked, mobile, high-speed communication
I don't believe they should be in bold.
Because it is critical that people distinguish Li-Fi from VLC. Li-Fi means networked, mobile and high-speed along multiple users. VLC is even low-rate, one direction/broadcast only applications. The readers should be educated to understand the difference.
Next thing:
This part of a sentence is so complicated:
Although Li-Fi can be used to off-load data from existing Wi-Fi networks, implementations may be used chiefly to provide capacity for the greater downlink demand
Can we make this easier to read?
I have rephrased this sentence. -- Wyn.junior ( talk) 15:53, 18 December 2013 (UTC)
This sentence is now improved, though still very complicated:
Li-Fi can be used to off-load data from existing Wi-Fi networks to provide capacity for the greater downlink demand as complementary to the existing wireless or wired network infrastructure.
What does "downlink" mean?
--
Wyn.junior (
talk)
20:47, 18 December 2013 (UTC)
All data flows in two directions. One from the server to the user, which is called downlink. The other is from the user to the servers, this is called uplink. It is fairly well known wording for anyone in communications. — Preceding unsigned comment added by Nikola.serafimovski ( talk • contribs) 20:57, 18 December 2013 (UTC)
I don't believe I have heard "downlink", though I have commonly used the word "download" for that purpose.
Does the sentence mentioned above mean that Li-Fi provides greater capacity for downloading data only and not for uploading?
--
Wyn.junior (
talk)
22:16, 18 December 2013 (UTC)
Another issue of understanding could be because we probably live in different countries (I live in USA). Same English language, though different terms and sentences of expression are used.-- Wyn.junior ( talk) 22:20, 18 December 2013 (UTC)
Because everything in the electromagnetic spectrum travels at the speed of light, shouldn't all internet be the same speed?-- Wyn.junior ( talk) 03:38, 28 February 2014 (UTC)
User:Jeh deleted this paragraph, saying "this makes no sense. Cable and DSL providers have nothing to do with control of the radio spectrum"
Here is the paragraph:
"Unlike
radio waves, of which 96% of the country's broadband access is controlled by DSL and Cable providers,
[1] visible light waves are not regulated, owned or controlled by any person, private company or government organization."
If
User:Jeh is correct, then only part of this paragraph should have been deleted. It could read like this:
"Unlike
radio waves, visible light waves are not regulated and are free to use."
I am not sure that
User:Jeh is totally correct though. The part about cable and DSL providers is referenced. Here is an exerpt from the source (
http://www.theregister.co.uk/2007/08/01/fcc_opens_up_us_wireless_spectrum/):
"Google and its coalition of public advocates are working to provide consumers with more online choices, arguing that big name telecoms like AT&T and Verizon have too much control over the wireless spectrum as well as the broadband internet market. DSL and cable providers, they argue, control 96 per cent of the country's broadband access, and if the U.S. radio spectrum is opened up, it could give consumers a viable third option."
--
Wyn.junior (
talk)
04:52, 5 March 2014 (UTC)
References
Can this be used as a reference?-- Wyn.junior ( talk) 01:55, 29 March 2014 (UTC)
About the News release template at the article. In February 2014 user:Jeh added the tempĺate... I agree, that version of the article reads like a news release.
Then many edits later, by many other users (the mine are little but other have some effort)... It is better (!). Not perfect, but better... So, suggestion: to remove the template. -- Krauss ( talk) 21:59, 18 June 2014 (UTC)
PS: I have splitted the text with new sections where we can see that the problem is not an "advertising style"... ṕerhaps needs only good english and some didactic approach.
I don't really like the tone of this article, it makes it sound like the professor invented the concept of using light for communications. When all that he has really done is to add some specific protocols to an already well known technique, and figured out a way to market his package as if it were something new. For example, back in the 1980's in Byte Magazine, Steve Circia's (sp?) Circuit Cellar column published a How To project for linking computers together over a distance of several miles using infrared light emitting diodes. The technology itself was already well known even then. I recall in the mid 1990's looking at a commercial product that used a laser beam. It was designed as a solution to the massive expense of putting cables under the street in order to connect the networks of two buildings together. As long as you could get line of sight from either a window or the rooftop, you could use their laser beam communication system to send IP packets between the buildings. There is nothing new under the sun, and I resent that this guy appears to be claiming to have invented something that is in fact quite old (or at least this article conveys that impression). He may have created a cutesy name for it and defined a protocol to ensure device inter-operation, but the actual technology has been around for many decades. Also it has been known for an equally long time that light can be bounced off of walls. Anyone who has ever aimed their tv remote at the wall behind them has already experienced this in action. As far as IrDA goes, it suffered from two major problems. Transmission speeds were typically quite low and most setups were for one way communication. This lead to a lack of enthusiasm and resulted in a lack of software and hardware support. As I recall, at one point a number of laptops added an IrDA as a feature. I recall being excited about it at the time, when I bought a computer that had this. But they provided no software to run it, you had to write our own. On top of that it was (typically) not hooked up to a UART thus the software had to do a lot of bit banging, which is complicated and inefficient. Nobody ever found a killer app for IrDA, IMHO the closest they came was to use it for wireless printing, but it never reached critical mass and the protocols weren't standardized. Once WiFi got established it made far more sense to use the existing infrastructure of WiFi for communication to devices like printers. One of the reasons for the WiFi crisis is the on-coming Internet of Things. You just can't have billions of devices all transmitting on the limited WiFi spectrum. LiFi would make a lot of sense for that application. I just feel that the article should make it clear that LiFi does not create any new technologies, all it does is define a Trademark for a group of Inter-operable protocols, which are implemented using well known (and quite old) technologies. codeslinger@compsalot (too lazy to login).
I have a problem with the use of the word "medium" in the 1st sentence in the "Technology details" section:
This OWC technology uses light from light-emitting diodes (LEDs) as a medium to deliver networked, mobile, high-speed communication in a similar manner to Wi-Fi.[3]
It is the light itself that is the "medium" and not the LED's. I also do not like the use of the word "bulbs" two sentences later:
Visible light communications (VLC) works by switching bulbs on and off within nanoseconds,[5]
LEDs are not bulbs, nor are they the medium and both of these statements are both technically wrong, as well as wrong in the sence that they will not do anything but confuse the layperson.
the on/off switch of the light bulbs are so fast and the off time will be so long that you can't see it.
or you can use infrared which you can't see at all.
Is there any citation for li-fi being a contraction of "light-fidelity"? "Light-fidelity" doesn't mean anything. — Preceding unsigned comment added by Apepper ( talk • contribs) 14:26, 19 January 2016 (UTC)
"Li-Fi" was chosen for the similarity to "Wi-Fi"; "Wi-Fi" is a combination of "Wireless" and "Hi-Fi", not "Fidelity". Matthias Alexander Jude Shapiro ( talk) 14:23, 24 July 2016 (UTC)
Many spammers are making edits to this post which is seriously affecting the quality of the post. — Preceding unsigned comment added by RyanAfrish7 ( talk • contribs) 03:44, 24 August 2016 (UTC)
Imagine a world where every one of the billions of lightbulbs in use today is a wireless hotspot delivering connectivity at speeds that can only be dreamed of with Wi-Fi. That's the goal of the man who invented such a technology, and this week Li-Fi took a step out of the domain of science fiction and into the realm of the real when it was shown to deliver speeds 100 times faster than current Wi-Fi technology in actual tests.
An Estonian startup called Velmenni used a Li-Fi-enabled lightbulb to transmit data at speeds as fast as 1 gigabit per second (Gbps), which is about 100 times faster than current Wi-Fi technology, meaning a high-definition film could be downloaded within seconds. The real-world test is the first to be carried out, but laboratory tests have shown theoretical speeds of 224 Gbps.
So, just what is Li-Fi, how does it work, and will it really revolutionize the way we connect to the Internet?
Li-Fi refers to visible light communications (VLC) technology, which delivers high-speed, bidirectional, networked mobile communications in a manner similar to Wi-Fi. It promises huge speed advantages, as well as more-secure communications and reduced device interference. — Preceding unsigned comment added by Harshalkamble1996 ( talk • contribs) 08:44, 20 October 2016 (UTC)
How Does Li-Fi Work?
This is how pureLiFi describes the operation of its technology:
When a constant current is applied to an LED [light-emitting-diode] lightbulb, a constant stream of photons are emitted from the bulb which is observed as visible light. If the current is varied slowly, the output intensity of the light dims up and down. Because LED bulbs are semiconductor devices, the current, and hence the optical output, can be modulated at extremely high speeds which can be detected by a photodetector device and converted back to electrical current. The intensity modulation is imperceptible to the human eye, and thus communication is just as seamless as RF [radio frequency technology]. Using this technique, high-speed information can be transmitted from an LED lightbulb. — Preceding unsigned comment added by Harshalkamble1996 ( talk • contribs) 08:49, 20 October 2016 (UTC)
According to the IPA in the article the pronunciation of Lifi is /liː-faɪ/ - the first i is pronunced as the two e's in "seed". Shouldn't it be /ˈlaɪfaɪ/ as pronunced in the TED video of Prof. Harald Haas and with the same vowel as light ( /laɪt/)?
Made some bigger changes on the page, especially regarding promotional info, by removing a lot of mentions/references to individual companies and their achievements when not mentioned in the History context. I think it's a lot less promotional in tone, but will wait a bit before removing the advertisement warning. Abraxxass12 ( talk) 12:41, 15 June 2022 (UTC)
123456 124.106.197.105 ( talk) 06:19, 9 June 2023 (UTC)