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Chinese Professor Builds Li-Fi System With Retail Parts
alphadogg writes "The equipment is big and expensive, with the research costs at almost $500,000. But by just using retail components, Chinese professor Chi Nan has built her own Li-Fi wireless system that can use LED lights to send and receive Internet data. "I bought the lights from Taobao," she said, referring to the Chinese e-commerce site. The professor from Fudan University showed off the technology on Tuesday at the China International Industry Fair in Shanghai. Unlike traditional Wi-Fi routers that use radio signals, Chi's system relies on light to send and receive data wirelessly. Others scientists, especially in the U.K., have also been researching the technology, and dubbed it "Li-Fi". But rather than develop specialized hardware, Chi bought off-the-shelf retail parts to create her system."
Wasn't my palm pilot doing this years ago via infra red?
Only if you use laser LEDs that are powerful enough to burn through them.
Can someone tell me what all the fuss about "LiFi" is? We've had free space optical networking for decades. It's not new and it's not a good general networking solution, especially for household use, which the LiFi buzz seems to be implying.
I just don't see a broad use case for this and I don't understand why it is getting so much press. Will they, next week, "discover" that they can make it work in the dark by using infrared TV remote controls?
P.S. As someone who is jumping through hoops and going to great lengths to eliminate flicker in household LED bulbs, the thought of intentionally flickering the light, even at high frequencies, does not sit well with me.
I would bet that it's more tuned to commercial markets. For density in classrooms it's not uncommon to place two WAPs in one room for the express purposes of serving the 30+ devices in that room, and with the bleed-over between rooms all of the WAPs have to step-down their power to avoid interfering with each other.
A wireless medium that doesn't use something capable of penetrating through walls would actually be an advantage in these kinds of environments. Granted, to be practical it would require peoples' devices to have both WIFI and LIFI, but they often have both WIFI and copper capability now anyway, so more than one interface isn't a stretch.
Do not look into laser with remaining eye.
You're thinking of Japan... pornography is illegal in China, and tentacles aren't a part of their culture to begin with. Also, the "Chinaman" you speak of is a woman.
So how is it different than infrared, which has been in use for quite some time?
I thought the trend these days was to build a computer network using the built-in speakers and microphones, outside of the human hearing range. ;)
Also, that looks indeed like specialized hardware?
Ship it to the kids in Afghanistan that wanted to hook up their C-64s to the Internet to watch movies. Good thing they were stored buried underground all this time.
Nothing really. It's a new buzzword that everyone is oogling. we were getting 4mbps over IR point to point using PVC and some lenses to steal internet from the college back in the early 90's. One of the buildings was visible from our rental so we ran wires and had an old linux PC at each end using the DB15 ports on the old ethernet cards we found and set up a photodiode and an IR led on each end to set up an optical link. WE actually used visible LED's to start with to set everything up, and then went IR for stealth.
Worked great we had the fastest internet around for a house with 12 random nerds in it. I will bet that the transmitter portion is still on the roof of that school building 20 some years later.
Do not look at laser with remaining good eye.
News just in: IrDA wants its acronym back. On a more serious note, I really did like IrDA. It was slow as crap and the range sucked, but at one point in time, pretty much EVERYTHING had IrDA support. Laptops, cell phones, PDAs, HPCs, etc. You could buy serial dongles to add to any PC for $5 or so. It was the go-to fallback to transfer a file or data between two devices that had disparate storage card types (PC-Card vs CF cards, etc), or you didn't have cables to connect them up directly. Bluetooth has sort of replaced it, but you can't just bit-bang communication with a bluetooth device using a microcontroller and two 25 cent components. Plus Bluetooth has been implemented by OEMs as more of a method to connect dumb peripherals than a method of communicating directly between devices.
Better known as 318230.
The first time I saw this basic thing done, in a hacky way, was between the ham radio clubs of my university and our neighboring university, in... the late 1980s.
They took two helium-neon laser tubes (laser diodes not being as available to hackers yet), two photosensors, and two little shutter-like things that modulated light proportionally to some voltage. Then they took two acoustic modems. They hooked the sound-generation output to the thing that modulated the light and the sound input to the photosensors, lined up the beams, and got the modems talking to each other.
As I recall, they had a working 1200 baud connection from over a dozen blocks away. Didn't have any practical use, but it was kinda awesome.
(I think I've still got a box of old helium neon laser tubes in my basement somewhere.)
We have Chinese-descended people in the USA. The joke might be at the expense of the PRC, but it is not about race at all.
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
IR doesn't always need to be direct line-of-sight. Most peoples' experience with IR is from TV remotes which generally do have to be aimed, but I've got a couple of devices whose remotes are powerful enough that pointing them just about anywhere in the room will control the device. It is possible to use refraction if the setup is designed for it.
Do not look into laser with remaining eye.
Infrared currently is used as a point-to-point connection where (most of the time) there has to be a clear (as in: only air) path from one node to the other. It's mostly used as a device-to-device type of connection, not as a network of devices.
Li-Fi should integrate into the lighting plan of rooms, should be capable of operation using reflections instead of direct point-to-point. Of course, reflections and re-transmissions probably cause signal degradation if no filter capability exists so the software protocols should be able to compensate or, if unable, scale back to lower network speeds. The same for 'foreign' light sources (the sun included). Individual light points should act as repeaters with one point in a room connected to the 'regular' network being enough to provide the entire room (however large it may be) with full network access. At least, those are the 'promises' I heard about Li-Fi.
And, indeed, being unable to penetrate walls can be an advantage.
Most homes in Chinese cities are in buildings like condominiums. Only the walls are poured concrete. That's because the walls are load-bearing as part of the design. At least that's my understanding. Regardless, getting WiFi access several rooms away can be real difficult if not impossible.
If you're part if the growing middle class that plans on expanding network connectivity in the home, you really need CAT5e installed (outside the walls unfortunately).
Life is not for the lazy.
Yeah, pornography is illegal, yet whilst I was managing the I.T. department at kink.com I would constantly see a not insignificant number of mbps going to china from our CDN.
Also, what's with all the racist jokes in this thread?
Seems like an unusually high number compared to other stories involving Chinese people.
you really need CAT5e installed (outside the walls unfortunately).
You see, I got this here tool that can tunnel through walls.
The creatures outside looked from Alt-Right to Antifa; but already it was impossible to say which was which.
i only ask because homes in the USA have them
Yeah unlike those dumb Chinese huh? You're racist
The word you're looking for is bigoted. The Chinese are not a race.
Over 170 ethnic groups inhabit inside China's borders. The only race that controls China is the ultra wealthy Communist Party.
Been doing light transmission in glass fibers for decades. Early "air" transmission was signal flags & smoke, but transmitting data via in air has been done via lasers on various frequencies for decades too, initially to submerged submarines, albeit with a megawatt lasing tube.
I think it is because some people confuse "Chinese" with the Han race. It is similar to how Muslims are always classified as Arabs, even though Persians are a different ethnic group.
Yep, it's quite the opposite. If it was limited to working in complete darkness, one could save a little bit of money by getting rid of IR-pass filters that those devices need.
A successful API design takes a mixture of software design and pedagogy.
And let's not forget the clacks towers!
A successful API design takes a mixture of software design and pedagogy.
That's simply not true. Pornography is legal in Japan. The display of genitals in pornography is not, which they circumvent using pixelation. Even if what you say were true, the cultural significance of tentacles in sexuality predates laws on pornography. See: http://en.wikipedia.org/wiki/The_Dream_of_the_Fisherman's_Wife
Chinese Professor Builds Li-Fi System With Retail Parts...
...which isn't as good as pro kit.
The equipment is big and expensive, with the research costs at almost $500,000.
Research costs don't tell you anything about the cost of "the equipment," whatever that refers to. A modern mobile phone might set you back $200, but you could easily make the research costs total several billion dollars depending how far you want to go back. If someone comes along with a couple of tin cans and a piece of string, I don't really see how that's automatically newsworthy.
But by just using retail components, Chinese professor Chi Nan has built her own Li-Fi wireless system that can use LED lights to send and receive Internet data.
There are plenty of things I can do with retail components that wouldn't be possible without prior billions being spent on research. That doesn't make me the King of Awesome (I am, but it's entirely unrelated).
FWIW, Chi's system works over about 3m, the hardware is large and heavy, and it achieves a speed of about 150mbps.
systemd is Roko's Basilisk.
could anyone in the know enlighten us how the uplink is supposed to work? TFA doesn't clarify.
Because it is dependent on light, the technology can't penetrate walls or work in complete darkness. In Chi's case, the Li-Fi receiver must be within three meters of the router, and placed under the LED bulbs so that the sensor can read it.
Am I missing something here? If it can't work in total darkness, and the receiver has to be within 3 meters, what's the application for this? We have a whole bunch of other solutions, like bluetooth for example, that's low power, invisible, and go way further than that.
Sounds like a fun project, but doesn't seem more useful than building a cnc machine out of legos.
Infrared currently is used as a point-to-point connection where (most of the time) there has to be a clear (as in: only air) path from one node to the other. It's mostly used as a device-to-device type of connection, not as a network of devices.
Li-Fi should integrate into the lighting plan of rooms, should be capable of operation using reflections instead of direct point-to-point. Of course, reflections and re-transmissions probably cause signal degradation if no filter capability exists so the software protocols should be able to compensate or, if unable, scale back to lower network speeds. The same for 'foreign' light sources (the sun included). Individual light points should act as repeaters with one point in a room connected to the 'regular' network being enough to provide the entire room (however large it may be) with full network access. At least, those are the 'promises' I heard about Li-Fi.
And, indeed, being unable to penetrate walls can be an advantage.
Precisely. Instead of setting up a separate funny-looking wart on the ceiling or some such, the room light itself is a transceiver. As a bonus, for room illumination it would draw about 1/4 the power of equivalent incandescents, based on what I've seen for sale lately.
Even with IR, I routinely bounce off a wall or mirror for my remotes. Unless the room is painted black, chances are that a visible frequency will reflect even better. Of course, that also means that it will go through windows, so keep the shrubbery patrolled!
Historically, Persians were Zoroastrian, not Muslim, right?
Karma: Poor (Mostly affected by lame karma-joke sigs)
Ever hear of rain, snow, smoke, smog, fog, dust, or deciduous trees? (Ok, maybe not, this is /. But some people must emerge from their moms' basements occasionally to reload on pizza and Jolt). Long range free space optical transmission is a PITA outdoors unless you can afford to wait around a few days for the weather to change. Indoors, there may be a place for it if you can make it cheaper than cables (installed and operated). Might be a good fit for convention centres. To really work well, you'll want lots of access points that look like ordinary LED "bulbs"... Oh shit, THAT's why those things are made in China, they've gotten us to bug our own houses!
Oh, I'm sorry sir, I thought you were referring to me, Mr. Wensleydale.
"You see, I got this here tool that can tunnel through walls."
Man, that's one powerful ssh client.
http://www.rootstrikers.org/
The Western characters in anime tend to have a very different cut than the Asian characters that you say look non-Asian.
Depends on the material of the wall I would think.
My SSH client tunnels through firewalls all the time!
Out of modpoints but really liked a post? 1BDkF6TtmmeZ3yqXbz9yhdYVqRYnwFoXDj
You jest, but if the fixtures are cheap enough, it's a great way to do wireless networking *without* the myriad of security issues that plague traditional RF-based WiFi - namely, the signal escaping your house. Knowing the Li-Fi signal stops at the wall (and can probably be tuned so very little spills out the windows) means to actually break into the network requires physical presence.
WTF? My early 1990s era laptops had this. How is this NEW?
i only ask because homes in the USA have them
Yeah unlike those dumb Chinese huh? You're racist
The word you're looking for is bigoted. The Chinese are not a race.
Bigotry refers to rejecting another person's views with no consideration when they differ from your own simply because they differ from your own.
Bigotry has nothing to do with hatred or animosity. It has to do with stubbornness, ego, zealotry, etc.
Butthurt much?!
Historically, no one was Muslim before approximately 600ad. So if that's your test then Arabs fail it just the same as Persians.
=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Friends don't let friends enable ecmascript.
No. That's a feature. If an attacker can't see into your room, he can't see your network.
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
Its been done before for less
Microprocessor
http://www.linux-cae.net/Projects/Serial/Laser/laser.htm
Aurdio Laser Modem:
http://makezine.com/2008/08/13/laser-modem-with-an-ardui/
Raspberry Pi
http://www.ohmpie.com/lasermodemvideo/
You say things that offend me and I can deal with it. Can you?
Sure, but your 1990's laptop didn't manage to accomplish it by spending $500,000 of someone else's money.
I'm an American. I love this country and the freedoms that we used to have.
Even though it was an AC, the parent here was actually funny and should have been modded up.
No, it is not funny. Switching the "R" and "L" sounds is Japanese thing, not Chinese.
What the starving Chinese ...
The Chinese are not starving. This is 2013, not 1961. There are more middle class people in China than in America.
Only if you use laser LEDs that are powerful enough to burn through them.
Unfortunately lasers that powerful have to be cooled by a continuous saline solution stream.
Although I hear some research has been done in that area that involves mounting them on large, constantly moving ocean creatures.
I see even classic Slashdot is now pretty much unusable on dial up anymore.
So how is it different than infrared, which has been in use for quite some time?
It's not, it's different from infrared.
But mostly just in carrier frequency.
I see even classic Slashdot is now pretty much unusable on dial up anymore.
IR doesn't always need to be direct line-of-sight. Most peoples' experience with IR is from TV remotes which generally do have to be aimed, but I've got a couple of devices whose remotes are powerful enough that pointing them just about anywhere in the room will control the device. It is possible to use refraction if the setup is designed for it.
And if you have a white or light-colored ceiling or wall, you can use reflection as well.
We have an overhead light fixture in the same room as the main television, and it has a flat white diffuser under its 4 incandescent bulb sockets, and I can carom a remote beam off of that quite easily if I'm standing in the right spot.
I see even classic Slashdot is now pretty much unusable on dial up anymore.
Lazers.
Yep, it's quite the opposite. If it was limited to working in complete darkness, one could save a little bit of money by getting rid of IR-pass filters that those devices need.
If it's going to use "visible" light, wouldn't it need IR and UV blocking filters?
Although since using light in a completely dark room kind of does away with the whole "completely dark" thing, I may have misunderstood where you were going with that.
I see even classic Slashdot is now pretty much unusable on dial up anymore.
There are more middle class people in China than in America.
With a population about 4 times greater, I'd hope so.
The Chinese are not starving. This is 2013, not 1961. There are more middle class people in China than in America.
There are more every class people in China than in America.
Vs. anyone with more than half a brain, bullshit statistics do not work.
Violence is like duct tape. If it doesn't solve the problem, you didn't use enough.
Seriously, using light to communicate is so awesome that ... laptops STOPPED carrying the stupid IrDA port that worked like shit. Its not impressive that someone did it now with shit that radio shack has been selling kids for 30 years. I know, cause I could by the parts to build and do this at radio shack 25 years ago, I know since I did just that for my TRS-80. I wasn't the first then, since I was following the directions in some magazine.
Persistent Volume manager for Kubernetes - https://github.com/dwimsey/openshift-pvmanager
I assume the technology is for export, because line of sight in China should be good for, oh, about twenty feet or so.
Light Beam Communications, copyright 1975, Forrest Mims, ISBN 978-0672211478 Howard W. Sams
I was wondering when someone would bring him up, although I think his chief claim to fame in that area was using Light-Emitting Diodes as detectors of light, rather than just as emitters of it.
I see even classic Slashdot is now pretty much unusable on dial up anymore.
The other way round might have worked actually - there are large parts of at least the south east of China (like Fujian) that pronounce both "r" and "l" the same as "l"(meaning there is no phonetic difference).
Homes in the USA also have windows...
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
Homes in the USA also have windows...
Windows also have blinds and/or shades.
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
And even with your blinds fully closed, it's still easy to tell whether the lights are on or off.
Very few people have dark, black-out curtains, but that's want you need to be sure data isn't leaking out of the building.
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
My take is if she may well patent it as an UNDERWATER communication medium.
The "talk on a beam of light" has been a popular science fair project since LED's and photodiodes became available.
Nothing new, but the idea of having divers being able to communicate underwater, voice or texts, seems useful. You wanna text someone? Use your flashlight. Light him up. The light contains the message.
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
There is a better option
There are three kinds of falsehood: the first is a 'fib,' the second is a downright lie, and the third is statistics.
For all 'intents and' purposes. Whom has it's place and in such places no other word is appropriate.
Agreed. I think the subtext of the racism is the fear on the part of our american cousins that they are about to be usurped on the world's stage by our other cousins from China, it's a form of nervous laughter and also displays the atrociously poor reporting of non american news in the home country.
As I've seen it explained, China is a country pretty similar to the US; plus a couple of billion subsistence farmers.
Star Trek transporters are just 3d printers.
One who studies bigonometry
Star Trek transporters are just 3d printers.
Not me I tunnel with diodes.
Star Trek transporters are just 3d printers.
People who live in glass houses...
Star Trek transporters are just 3d printers.
1) correct. The /r/ /l/ differentiation distinction is problematic for Japanese and Thai speakers especially. The Thais lump the /n/ in as well. Koreans also have the problem in some phonetic contexts. /r/ is remarkably different from the western European /r/
But, I should add that the Chinese
2) while almost correct, as in "yes the Chinese today do have a robust middle class while we have a moribund and retrograde middle class"
saying that they have "more" mile class people than we do ignores the fact that they have more poor people in China than the entire population of the US. It's a matter of scale. You have to look in terms of proportion to say anything of value.
Subversion of spatial scale luxury decoration ideas.