7 ms·
Electric light transmits data faster than Wi-Fi
- FergusArgyll 3y ago> Notably, Li-fi ensures robust security by exclusively transmitting data to areas illuminated by light. Can someone explain how this ensures security? Because hackers always work in the dark? /s
- transpute 3y ago> security Wi-Fi passes through walls, can be used to remotely infer keystrokes, human biometrics, position and activity. > dark Li-Fi can use infrared light, does not pass through walls.
- ReactiveJelly 3y agoIt might enable security but I wouldn't say it _ensures_ it. It just means that visible or IR light (What are they using?) won't leak through walls the way Wi-Fi does. Depending on how wide the beam is and exactly how it all works, it _might_ still leak out of windows and under doors. But it's not like someone casually wardriving outside your house will get as much as they would from Wi-Fi, I would think.
- smallnix 3y agoHow can visible light pass from a core of a star or planet to the outside, but some routers light not? I guess it's just super duper faint?
- colechristensen 3y agoVisible light does not pass from the core of a star to the outside. The sun has a radius of about 700,000 km. Only a few hundred km is transparent enough for light to pass through and has a density of about 300 mg per cubic meter. Roughly the density of air at the altitude where airliners cruise. The photons you see originate from a layer that’s just 0.5% of the radius of the sun. That layer is heated with other photons from inside. The core temp is 15 million K while the photosphere is around 5800 K. The spectrum of the core were the rest of the sun transparent would be much different and … unsafe. (Not that this really makes sense, if the rest of the star was transparent it would go nova)
- Modified3019 3y agoUsing light to heat up the walls of a home enough to start emitting significant black body radiation poses some additional engineering challenges.
- wiml 3y agoThe house's thermal mass would also limit the data rate.
- deleted 3y ago[deleted]
- tsimionescu 3y agoI think that yes, compared to the core of a star, a LiFi AP is aptly described as "super duper faint".
- Turing_Machine 3y agoYeah, you'd want blackout curtains (or better, paint) on your windows. Still cheaper and easier than making your office into a Faraday cage.
- bb88 3y agoThat assumes that Li-Fi doesn't leak RF still.
- jfoutz 3y agoWorking graveyard and renting, I learned aluminum foil is perfect. cheap, trivial to install and remove. and perfectly opaque.
- osigurdson 3y agoCan encryption not be used with LiFi?
- Turing_Machine 3y agoPoor wording. I think what they're getting at is that, unlike wifi, light doesn't pass through walls, floors, ceilings, etc. Anything that isn't directly illuminated by the light beam will have effectively no signal, making it less likely to be picked up from (say) five offices away.
- Dylan16807 3y agoThough if there's a window around that light might go further than 60GHz, which is presumably the best competitor for same-room high-bandwidth links.
- transpute 3y agohttps://spectrum.ieee.org/lifi-standards https://spectrum.ieee.org/lifi-standards > The new standard for Li-Fi, IEEE 802.11bb, is designed to provide a global framework to deploy light-based devices that are compatible with each other. It was ratified in June [2023] ... Li-Fi simply appears as if it was another band of Wi-Fi ... It can achieve data rates of 1 Gbps or more from a range of 20 centimeters to 3 meters.
- londons_explore 3y agoI would hope for bandwidths much higher than 1Gbps... Assuming conservatively you can do 1 bit/sec/Hz, we should be able to get an easy 300 Tbps in the visible light spectrum. Any thats a low estimate, because physics lets you do massive MIMO, polarization, etc to get even more throughput.
- deleted 3y ago[deleted]
- m463 3y agoor like, lasers.
- bloggie 3y agoWe are currently seeing 200 Gbps sat-to-ground but Li-Fi is targeting much lower bandwidth, as the application is different. https://www.nasa.gov/centers-and-facilities/ames/nasa-partners-achieve-fastest-space-to-ground-laser-comms-link/ https://www.nasa.gov/centers-and-facilities/ames/nasa-partne...
- slim 3y agolooks like the aim is to replace IrDA not current usage of wifi
- thrill 3y agoCaution, do not look at ElFi router with remaining eye.
- neilv 3y agoNow we know why three-leet haxorz wear hoodies up, and sunglasses indoors.
- cornholio 3y agoI cannot but feel that some part of the spectrum that is invisible, so it can work when the light is turned off, and is capable of penetrating the walls so as to not require an expensive wired repeater in every room, would still remain the best choice for providing local connectivity in general. I can see applications for LiFi, but it will not replace WiFi any time soon.
- Syonyk 3y ago> ...so as to not require an expensive wired repeater in every room... Why do you speak of the feature as though it's a bug? It's great for wiring contractors, great for LiFi vendors, what's the problem? sigh
- osigurdson 3y agoWhat you are looking for is a spectrum of light known as subter-subter-infra-red which is around 2.4GHz.
- nwiswell 3y ago> subter-subter-infra-red To think that this was right there the whole time and we settled on "WiFi" instead!
- whatshisface 3y agoIt's still not to late to call it the internet's infra-structure.
- twelvechairs 3y agoThe wifi name was created to be "a little catchier than 'IEEE 802.11b Direct Sequence'"
- mlyle 3y agoI don't think this is a candidate to replace wifi. But if it's cheap and becomes ubiquitous (unlikely) it would make wifi a lot better. The advantage of the visible light approach is that it doesn't reach through walls. It's inherently very dense, and can provide users in its footprint nearly unlimited bandwidth. If it reaches only 50% of users in a classroom or office building, then those 50% of users will have very fast connectivity, and wifi will be twice as fast for everyone else.
- deleted 3y ago[deleted]
- ammut 3y agoWhile cool I am skeptical on this tech given the light propagation. How many LiFi APs would I need to buy for a full office compared to existing WiFi?
- bloopernova 3y agoPlease can we call an Electric Light LAN an "Orchestra"?
- Arelius 3y agoI don't get it...
- defrost 3y agoNow I Can't Get It Out of My Head
- bloopernova 3y agoHey now, Don't Bring Me Down
- wiml 3y agoInterestingly, optical was one of the PHYs for the original 802.11: indirect (diffuse) infrared. I think the idea was that the AP and the individual nodes would communicate by scatter off the office ceiling. (The other two PHYs were FHSS and DSSS on 2.4GHz, the latter of which morphed into the 802.11b that gained wide popularity.)
- logtempo 3y agoIntroduced 12 years ago, is there is a technology limit or an interest limit?
- numpad0 3y agoHard to prove eye safety for a blinking ceiling light
- transpute 3y agohttps://spectrum.ieee.org/lifi-standards https://spectrum.ieee.org/lifi-standards We also had to engage with all the big Wi-Fi companies and in the end convince them of the benefits of Li-Fi. But when people began understanding that we’re not arguing for Li-Fi against Wi-Fi, but claiming a complementary use, they really began seeing the benefits of using light.” The standard was developed for Li-Fi to work alongside Wi-Fi ... Li-Fi simply appears as if it was another band of Wi-Fi ... We are enabling interoperability of Li-Fi and Wi-Fi, positioning Li-Fi as a complementary and additive technology to the existing ecosystem.
- xattt 3y agoWi-Fi consortium to the researchers: Stop trying to make fetch happen.
- nextaccountic 3y agofetch?
- Terr_ 3y agoReference to a movie-quote, where a character is (unsuccessfully) trying to promote "fetch" as a new slang synonym for "cool." Implies a questionable and quixotic quest. https://en.wiktionary.org/wiki/make_fetch_happen https://en.wiktionary.org/wiki/make_fetch_happen
- WalterBright 3y agoThe higher speed comes from visible light having a higher frequency than radio.
- aaron695 3y ago[dead]