Shedding Light on Li-Fi

back in October two fifteen. It's all about LiFi and uh so some of the references maybe a tad dated because we were recording a few months ago, but we wanted to release it because we were really proud of it. I thought it was a good episode, and we've got lots of new episodes coming up in the next year, so we wanted to get back onto on track, get things going. And I hope you enjoy this now classic

new episode of Forward Thinking. Hey there, and welcome to Forward Thinking, the podcast that looks at the future and says there's a light over at the Frankenstein Place. I'm Jonathan Strickland and I'm Joe McCormick. Hey, so guys, you know, we talked about something, uh a year ago or so. We're recording this in October two thousand and fifteen, but about a year ago September, we talked about a problem that's happening, and it's happening across the developed world places

where the Internet has reached real penetration. And that problem is that a lot of the devices we use rely on radio signals to communicate with the infrastructure that connects to the Internet backbone. The spectrum crunch exactly, the spectrum crunch. That's a real issue. And the issue is not something where like you have an a limit that amount of radio in the entire world and it's all gonna go away. It's very much a a kind of a congestion. Think

of it like a traffic jam in a particular region. Yeah. For the same reason that they ask you to put your phone on airplane mode when you're in an airplane, is this thing that we're talking about, because signal interference

can become a very serious issue in that case. Well, not only just signal interference, but if you've got too many Like have you ever been in let's say a really crowded coffee shop and you want to connect to the WiFi there, but you occasionally find that you're being bumped off the WiFi or things are really slowing down and clogging up. Often it's because whatever WiFi router the coffee shop is using has a lower capacity than what

is being demanded of it. So, in other words, there are the devices we use have a limited ability to deal with the demand that we are placing upon them, and it's getting worse by the day because not only are we getting more smartphones and tablets and smart watches and all this other stuff that's using those radio waves, were also entering the era of the Internet of Things, which is requiring even more stuff to connect to the Your fridge in your car, tires and your cube, connect

to the internet, your cuff links, your dog's color, your hatchet. Yes, our mystical acts is um not WiFi enabled, but we're getting an upgrade, sobe is on the internet. Joe failed to solve me again, that would essentially it would just be a message like that for me all the time. Jonathan has has low spatial awareness. H so uh. The interesting thing here is that this problem is not going to go away. It's not gonna it's not gonna get

any easier. In fact, there are places like here in the United States that have recently declared broadband access as being a necessity not a luxury. There was a White House report that came out earlier in that's specifically called out broadband access as a necessity, and they defined broadband as I think twenty five megabits per second are faster, mean saying like electricity, right, yeah, yeah, Well because because

knowledge and interconnectivity is critical in this our modern world. Yes, we we rely on it for communication, we rely on it for commerce. So we have this this problem, and we have this, uh more, this increasing urgency to find a way of dealing with it. Um And there are other issues with WiFi. Besides the fact that they you can have a capacity crunch in any given time and place, depending upon demand. Another is that they're not always that

efficient to use these radio waves. In fact, that's all they do, and so you're dedicating them to this one purpose. And I think the um the percentage I saw was that they are essentially five percent efficient in the amount of energy you're using them and the amount of actual work they're doing. Yeah, energy you're pouring into these things is just being bled away. Also, like you were saying, Lauren,

you've got the problem with interference. You know. That's why you aren't allowed to use devices in on airplanes unless you've switched it to WiFi. You can't use the cellular data. Um, you can't use them in places like hospitals where it might interfere with medical equipment. That's another issue. I've got a complaint. When I wrap my computer up in aluminum foil, it can't get a WiFi signal, right, But they also can't I can't see what you're doing anymore, right, So

that is the important part. That's we call it our essay protection case. And you can't see what you're doing anymore either, so your fragile sanity. He's trying to come up with some transparent aluminum foil. I've got a movie for you to watch. Uh So another issue, and I didn't even put this in our notes, but another one needs to be addressed is the notion of security. I mean,

obviously there's the you've always heard. I'm sure you guys out there have heard that things like like open WiFi networks are risky because you never know who else is on that network and who might be intercepting your data? Right, Jonathan, Earlier you were like, you go to a coffee shop and use their WiFi. I'm like, no, you don't. Well, it depends on the coffee shop too, right, I mean it depends on It depends on multiple things, like is the is the WiFi protected in the coffee shop. Even

if it is, there's still the chance it's unsecured. But if it's secured, the password is coffee, right, or or one to three coffee or something along those lines. But you know, even with all those things, Uh, if you're not doing your banking or whatever, maybe you're not too concerned about it. But one potential solution to all of these problems is to replace the radio part of this communication, the the communication between devices and the infrastructure that connects

to the Internet backbone, with something besides radio. So a guy standing up on a table in the room holding flags up, uh, well, similar in that the communication would depend upon light. And if we wanted to use flags, then obviously light as necessary because I don't know if you've tried to communicate via semaphore and pitch darkness with unlit flags not terribly productive. What if the flags are glow in the dark, that's different then you've got but

there's some blurring issues too. I guess the flags probably would mean it would take a long time to download a file. So what's something that we're talking about like the bond modem days, So what's something that would be a little bit faster than a guy holding up flag signals? Actual light, I mean actually using light in place of radio waves, like pulses of light kind of yeah, like like changing the amplitude of light, so the intensity of light, uh,

in order to communicate, which is not the unusual. Yeah, yeah, well, I mean we we've been doing it for a very very long time. But we're talking about something that would have to move a little bit faster than for example, uh, beacons, right, yes, like the old days where you know the you're you, you are a messenger and you see that there are invaders coming in at the northern border of the country you live in, so you light the beacon to alert

everybody else. It's that's seen in the Lord of the Rings where they like the beacon to U to call the who are the writers of rowan? Yes, don't test me, buddy, I was actually just playing the Shadows of mortor game, and the Orcs use beacons in that came a boy, are they irritating anyway? Uh? Greeks and Romans were using mirrored plates to send messages using light. They would flash light in in a series of flashes to indicate one

thing or another. Uh. There's the famous story in American history during the Revolutionary War in which the Old North Church in Boston was used to alert messengers to the troop movements of British troops. The whole one if by land too, if by sea, referred to in Longfellow's poem Paul Revere's Ride, which may or may not be apocryphal. There's some arguments historically speaking about what exactly happened. Essentially,

people say that yes, lights were used. Whether or not was the Old North Church is still the matter of some debate. But at any rate, we've been using lights like this for ages. Yeah, and that that is definitely encoding data in light. But right, it's pretty limited that The fancy word which Jonathan just mentioned earlier actually is semaphore, which just means an object that can be placed in different positions or conditions to convey different messages, like like

flag signals. Yeah, if you think about it, you could even have set up a semaphour type of signaling system with office mates where you just have a quietly like a little cabal who all know that the placement of certain office equipment or or or a coutrement in certain locations, on certain desks conveys a meaning. And from your blank stairs, I can tell neither of you are in it. Never mind,

I didn't say anything. So. By the early eighteen hundreds, the United States was experimenting with a technology called helio graphs. These were solar telegraphs. They actually used sunlight and mirrors to try and send messages from signal towers. That sounds like some steam punk stuff, It does, doesn't It also reminds me of a Terry Pratchett novel in which there was a whole system set up that was competing with

mail on discworld. But at any rate, they would use morse code and flash out messages to one another and send messages down the line of signal towers to get the message to where it needs to go. Then there was a guy, you may have heard of him, Alexander Graham Bell. Yeah, uh so, he and see the guy who invented Graham crackers. Uh, it was close friend to the Kellogg's. No, he invented a device called the photo phone in and it used a vibrating mirror to encode

voice transmissions on a beam of light. And then you would have a selenium photo cell that could pick up that light and convert it back into sound. And it only worked in sun light. You had to have some light blasting down on this thing in order for you to get enough light to send the message. But it was really neat, and he invented this just four years after he patented the telephone. He had so much hope for this thing. Supposedly he wanted to name one of

his daughters after it. He was so fond of it. Uh that wanted to name her Photo Photophone. Yeah, didn't didn't work out good thing for her. Um, maybe he could have named her photo Phoenicia. Pretty Yeah, I'm not sure, but but but it was really really cool. Uh it was. It was the series of mirrors and lenses that would dire act a beam of sunlight. And yeah, they tried it with kerosene lamp light, but it didn't work well enough.

Uh so so it would direct a beam of sunlight to a mirror attached to the mouthpiece that you spoke into, which would the mirror would then bounce the light off through more lenses and onto a receiver. So when you spoke, the mirror would vibrate, thus changing the intensity of the light that was hitting the receiver. And yeah, it worked. It worked real well, very clear uh sound effects coming through.

But it also would pick up noises like a like like clouds passing across the sun right because you have an interruption in the signal. So so if you've ever been wondering what that sounds like, it's probably something akin to weird static, I would imagine. But now I really want to know. This is getting cooler and cooler. Well, it keeps getting cooler. By the nineteen fifties, we have researchers who are looking into using light through cabling systems

to create new communication technologies. So to get around this problem of only being able to use sunlight or some other visible light within uh the area to communicate, they wanted to be able to pass light through cabling, essentially creating very reflective cables that could pass a light signal down them. We're talking about the birth of fiber optics here, and in April nineteen seven we had the first optic telephone cable put into service. It was owned by General

Telephone and Electronics. Soon afterwards, other telephone companies were installing fiber optic cables and those are really the backbone of our telecommunications infrastructure at this point. Like we think of copper as a as a signal carrier quite often, but really fiber optics are that's that's the true backbone for most of the telecommunications around the world. Now, all that's cool, but what if we were able to go back to

Bell's idea of using visible light to communicate? So, in other words, what if we were to use light to transmit data through the air and not through cables, So not a system that you hook up to your computer with a physical cord, but rather light, ambient light in your environment being able to communicate data. And then that would mean we could open up the entire spectrum of visible light for communication. Is that possible? I mean, that

sounds very interesting. One of the things that I often think about is all of the data that's passing through and around us all the time. Yeah, everywhere you go, there are signals bounding around. I mean they're you're walking through the range of WiFi routers, but there are also cell towers, radio broadcast towers. Yes, stuff is going through you all the time, and it's very bizarre to think,

what if you could see all of that? Right, And then of course there are people who believe that they are their health is affected by these things, not that we've seen any real medical evidence to support such things, but there are people who truly believe, Yeah, who won't be around WiFi routers at all, Yeah, because they say that it it impacts their health in a negative way. Yeah,

it really doesn't. These things very much are in the kind of between the microwave and the radio frequency on the spectrum the electromagnetic spectrum, and they're they're very safe there. There's a very very low probability, uh, that that they are in any way affecting anyone's health, especially from a distance of more than like two centimeters. Yeah, I mean, it's non ionizing radiation. It's just not that part of the spectrum that's going to knock molecules loose and up

set your DNA. What it could possibly do is maybe heat up your skin possibly. Yeah, there there can be electromagnetic interference that can cause other issues, and we'll talk about that. And I think I think the World Health Organization has listed it as a potential carcinogen now that so you can say that. But another thing to note would be that the sun is a known carcinogen, absolutely accurate.

If you're okay going out in the sun, you should probably be okay getting around a WiFi router every now and then. You might not want to sleep with your head resting on one every day. But yeah, well, the only reason I even brought it up, and I was hesitant to bring it up because pills so comfy. Because I am very skeptical of the thought that WiFi and other radio frequency communication can have a a physical effect on people, uh, particularly at the intensities of our you know,

our WiFi routers things of that nature. I'm very skeptical of that. However, the reason, one of the reasons I brought it up is because it was one of the benefits that was being touted by LiFi using light instead of radio signals to transmit this data at this last segment between the backbone of the Internet and whatever device you want to use. That well, One of the many benefits is that you and complain about the wireless signals

hurting you because it's using visible light. If if if that hurts you, then just being in a room with a lamp would hurt you. But at any rate, let's talk about what. So one of the benefits is that it counteracts something that is probably not a problem. Yes, yes, and that was actually my very reaction that you just had. But really, let's talk about Life I. So super cool idea. You know, it's an offshoot of a broader category called optical wireless Communications or o w C, which does not

necessarily have to deal with a visible light. It could be anything in the light spectrum, so they could also involve infrared or ultra violet, something along those lines. Uh. So there is another branch, a smaller one, called visible light Communications or v l C, and Life I would be part of that. The term was coined by Harold has who is a professor and also has worked with um a company called Pure Life I to develop a system. Yeah,

he's their chief science officer. Yeah. Uh, and so this is all about using light within the visible spectrum, and the reason being that he's concentrated on that is that other types of light, like infrared, can be harmful to your eyes, and ultra violet, as we know, can cause things like skin cancer if you have too much exposure to ultra violet. Uh. So he presented a TED talk on this subject, and in that talk he called it

d light, which I thought was delightful. I put it in the notes and I had to say it too, uh and he wanted He used a system that was called orthogonal frequency division multiplexing or o f d M, which sounds pretty fancy, but honestly, it gets really simple. It's all about amplifying the signal from an l e ED light source, and you do that by varying the electric current that's flowing through the l e ED And that's all you need to do is just vary that current.

By varying the current, you've you change the amplification of that light. If you have a receiver that can pick up these minute, subtle variations, then they can then decode that as the information that you had intended to send. So you could do this like you could send a movie this way. You could have a lightbulb that has a little microprocessor attached to it and it is pulling the signal from whatever feed is coming into your home from the Internet. So let's say that you've got the

internet backbone, you've got fiber optic. Let's say that runs to your house. From there, you would have a system that would take that signal converted into the language that would be picked up by this microprocessor in a light bulb. The light bulb would then flash at the frequency the amplitude changes according to whatever data was being sent, but do so so rapidly that your human eyes would be incapable of detecting it. So we just looked like the

light bulbs on. It wouldn't look like the lightbulbs. It wasn't Yeah, it wouldn't be a disco. It wouldn't be like a ghostly light bulb. Now, it would be very subtle, to the point where, because of it it's such a high frequency, it would just seem like a steady light source to us. And meanwhile, any devices outfitted with a sensor that could pick up these subtle variations in light

amplitude would be able to accept that information. So with the movie example, you could have a home theater where you've got very dim lights on and you've got a receiver of some sort that can take it has that that sensor on it that can detect the changes in light. It's connected to your entertainment system, and you are beaming the film you're watching through light. There's no physical connection to the entertainment system. There's no radio connection. There no

radio waves going on at all. It's just light beaming that information down, which is pretty awesome, and it can do it pretty effectively. At the TED talk he demonstrated this. He had an a desk lamp set up that had a light bulb with one of these microprocessors attached to it, and the lamp was hooked up through a system that fed it the data it needed and was set on

the table. And the table had a little hole drilled into it and through that hole light would go through that little hole, and on the underside of the table was a sensor that was then connected to a projector. So he turned on the lamp and the lamp sent information to the sensor that started a video, a high definition video playing behind him as he gave his talk, And then he demonstrated by interrupting the light source. In other words, he stuck his hand over the whole and

it interrupted the data stream, so the video paused. It was as if your wireless had dropped. And if you've ever had that experience where suddenly, uh, you know, it starts to buffer or it's going through like trying to search for a signal, same sort of thing. He moved his hand and it started up again. So it was an example of yes, this is live. This is a live feed of information from a lightbulb to a computer system and showing you how that information can be transferred

just using light. Pretty awesome. Now, the reason you used L E. D S was specifically because L E Ed's work on their semiconductors and you can easily control them by varying that electric frequent are the electric current that goes to the semiconductors, so you can make minute changes very very quickly. And this is different from other types of light bulbs. Oh yeah, you cannot do this with an incandescent bulb, right, because incandescent bulbs what they do

is you have they're essentially resistors. Right, You have this filament that resists the flow of electricity. As a result, it heats up. Eventually, it heats up to a temperature that allows it to incandesse or to glow up. Yeah, yeah, it needs that time, So that would be a rave that. Yes, if you try to use it incandescent bulbs, yes, it would not be able to transmit at near the speed of an l AED bulb. And then, of course if you wanted to do this with fluorescent lights, you might

as well do the guy with the flags on the table. Yeah, same thing, because fluorescent lights, they use a gas that gets excited by electricity that then amixites another gas that then emits photons. Yeah, and those photons are usually in the ultra violet range, so you have to actually have, you know, put a a um, a substance on the inside of the fluorescent bulbs that will fluoresce in the visible spectrum once it's hit by ultra violet photons. It's

kind of a weird chain reaction. Yeah, it's like it's like a it's like a bucket brigade for for people who fight fires. So when they first started showing this off back in the TED Talk, it was pretty much at a speed of around ten megabits per second, which is that's okay, I mean it's not it's no longer what broadband is considered here in the U S No. I just for for an example of how that compares to say, my WiFi on my computer from about a

minute and a half ago. I'm currently registering download speeds about forty three negabets per second and upload speeds of about fourteen per second, so much faster. But those that was just the starting off point, and the hass himself is working on systems that are much more advanced than that, including ones that would be using not LEDs but lasers, low powered lasers. So it's not like they're going to

blind you. You know, It's not like you're going to be have a bunch of laser pointers going crazy in your house. It would be hard to sell something that blinded people. Yeah, if it as long as I hold on, what if it blinds somebody else instead of you? Right, if it's the blind o Tron two thousand, like it's specifically marketed to blind people at any rate, these lasers are not of that nature and gave a sad story

fast well. But the neat thing about the laser system is that it might be able to achieve a throughput of around a hundred gigabits per second, which is in mainly fast, right, And when we say fast, obviously once again we don't necessarily mean that the data is moving at a faster speed, more like more data can move through that pathway. At the same time, it's it's not how fast the cars on the highway are driving, but

how many lanes there are. Ye. So in this case, a hundred gigabits per second means that you would be able to have really high quality video, for example, beaming through at this with no buffering necessary. It would be pretty phenomenal. So so that process it's still in or that technology rather is still in development. Yes, the led s i've heard are closer to around UH one between one and ten gigabits per second at their current level,

which still I mean one gigabit per second. We're talking about Google fiber speeds around there, right, ten gigabits per second, it's ten times what's considered ultra fast UH download speeds according to the current state of the art here in the United States. UM and his ted talk has actually said that one of the reasons they looked at this is really that radio frequency capacity crunch. That was a

real big reason to look at it. We're adding more and more devices, and we're having more issues with local access points getting bogged down with traffic. So what if we were able to relieve some of that traffic by switching to this light method. And he pointed out that with the visible light spectrum you have about ten thousand times more capacity than within the entire radio band spectrum.

Keeping in mind that lots of the radio band spectrum are already they're already earmarked for other things that we can't touch, right, right, they're regulated by governments of various countries to say that like, oh, we we're setting this aside for this type of official communication, and this aside for television, in this aside for the right terrestrial radio or radar or whatever you know. So there there are certain sections that you just can't do anything with because

they're already dedicated for other uses. This would allow us to use a band of quency in the electromagnetic spectrum that is unregulated and has ten thousand times more capacity crently unregulated. Yes, if we were to start using it, you could be sure that sooner or later regulation would probably have to follow just to make certain that you didn't have a bunch of competing communications. Uh, systems in

a similar place that we're just going to cause confusion. Uh. So, for example, imagine that you're in a mall and the lights are all outfitted with this stuff, but they have been installed over various different times and are all working on different um different proprietary approaches, and meanwhile your device is going crazy because it's receiving all these different signals simultaneously. It's would be like everyone's yelling at the same time.

Another neat thing is that this would eliminate the possibility of someone snooping in on your WiFi as long as they're not in the same room. You are inca right because light doesn't go through walls, right, as long as you're not, like you know, in a big glass cube, or people could just walk up and hold of a device outside of your your giant glass cube. Uh, then you'd be fine. You you wouldn't have you know. It would allow for some secure communications protocols that could be

really useful in lots of different places. I mean imagine just from business standpoint, imagine having a business, um like an office outfitted with this stuff, so that way proprietary secrets would remain more secure. If someone got access to that then you would know they have access to your people, not to your technology or the access to your space.

Yeah yeah, or that you've been posting things on Google docs, right yeah, if they they found it through some other like some other loophole but not within your your actual like wireless system. Um and you could, uh, you could even use this to transmit information if you have other lights active in the area. When he was demonstrating it as ted talk, Hause showed that this lamp was on a lit stage. It wasn't as if they turn all the lights off in lamp. Still the lamp worked. They

had ambient light from other lighting sources. But because the sensor is really just looking for those those subtle modulations, it doesn't matter whether the light sources you have, assuming

they're not also modulating at a super high frequency. That could throw in some interference, especially at the same frequency of light that your sources at, because theoretically you could set the receiver to only look at a certain frequency of light and ignore everything else, in which case that would really, you know, free you up quite a bit.

In fact, it would allow you to have multiple devices all getting information from a single source as long as that single source had multiple l ed s that could all use slightly different frequencies, which is a pretty interesting in my opinion. H and he said that you could even turn down the lights low enough so that it wouldn't be perceptible to humans, like it would be at a low enough level where it would seem as if the lights are off, but would still admit enough light

for a sensitive receiver to pick up those modulations. So, in other words, you don't always have to have the lights on full blast in order for you to get the data from your light bulb to your computer or whatever. I'm just imagining this as the premise to a movie about the electronics source that drives people crazy and so like the signal, but instead of radio frequencies, it's light YEA, or or the premise behind Chuck where he sees a series of images and that somehow imprints all of the N, S,

A and C I A secrets into his brain. Not Chuck Bryant, No, no, no, the television series Chuck, which I just started rewatching, which is the only reason why it was fresh in my mind. Um, But that that I thought was pretty interesting was that, you know, again, you can play around with the levels of human perception so that you can still transmit this information without having to have all your lights on UH like full blast

UM and then like I said, pure Life. I that's the one of the companies working on this, and one that has works with UH is working on systems that could be deployed in the real world, and they're also looking at how do you make this practical, how do you make it in a way where if you were on the move between one area serviced by LiFi into another, you can have a seamless um experience because you know, like the way we use cell phones, if you're using a cell phone, if you're on the phone and you're

traveling and you move from one cell tower service area into another's, there's a handshake that goes on that has a handoff from one cell tower to the other, which allows you to continue your continue your phone call. If we didn't have this technology, once you left that first broadcast area, you're you would drop a call, you would

not be able to continue that conversation. And I'm sure that everyone has had the experience of driving through an area that's kind of slightly between two different cell towers and and therefore you miss a little bit of a I mean, maybe your call drops off in the middle.

But yeah. So they're working on creating technology that will that will let that be justice seamless with their with their life Eye products, and they demonstrated one of these products called live Flame at the Mobile World Congress in March, which was in China somewhere I forget where, but uh, it's on the market supposedly has been shipped to a few commercial buyers already and I and I think the numbers that I've read for that particular version of live

Flame are are that it has a ten megabit per second uplink and down link. That's still pretty impressive, especially, I mean, imagine that you could have this on two devices and allow those two devices to communicate securely without using radio frequencies. So, in other words, let's say that we're sitting at this table and I wanted to send a large file to Joe but didn't want to go

over the WiFi. If both of our computers had cameras and lights attached to them so that I could beam that directly to Joe, you know, it would just looked like the little led on my my computer was just lit. To us, it would just seem like it was on and that's it, but it would actually be beaming that

information with those very tiny modulations. That's another reason why people have been touting life I as a good example, a good replacement for WiFi in certain applications, because it will allow for that secure communication assuming that whomever is wanting to spy on you is not within line of sight. If they could get line of sight to a point where they could also have a receiver getting that light,

then obviously they could intercept that information as well. But I mean just a second here, I would think that you could just as easily encrypt an optical light signal and the visible spectrum as you could encrypt a radio signal. So, in other words, have an encryption so that the data is meaningless unless you have the key. Yeah, I mean, I don't see any reason why encryption would be dependent on the spectrum. Now, you absolutely could do that. You

absolutely could do that. It's just the question of whether or not you would have the direct access to the encrypted data because again, like we've said before, encryption gives you a certain level of security, but there is no such things so far as perfect encryption. If someone is determined enough and has an access to enough processors, even just using brute force, they can eventually break encryption. Yeah, I mean assuming that, assuming the person doesn't have a

quantum computer or something. Well, I mean, I'm thinking of this in the use of things like high level government officials who need to be able to send an information secretly to one another, where you're you know, that's a case where you're talking about there's enough of an incentive to go through the trouble of trying to break that encryption. Now, if it's me sending you a file of a bunch of actors from Miami connection, it's probably not going to

be as big a deal. That interesting. Yeah, uh so, um forward thinking not that interesting. It's one of the many slogans that we ultimately de and not to use for this show. Uh. We also we also want to point out that this this life I technology would really be more about replacing that WiFi point of connection, right, It's not about turning the Internet into just light. Right.

The the backbone of the Internet would remain. The backbone of the Internet infrastructure would not change because partially because of the range of this kind of thing like it's it's really only going to go about three ms before it starts becoming less than effective. Yeah, and it's really

it's about ten feet. Yeah, that the thank you. It's really also just good for one way communication for most applications, especially if you're thinking about like in your home, and let's say that you want to use Life I instead of WiFi. Well, unless you have all of your devices with bright lights that can communicate back up through the receivers, and you have receivers all over your home, this is

not that know, that's not that useful. Like if you move out from one room to another room, you would have to have these receivers in every room. It's not like WiFi where you could in theory, set up a router in one part of your house and it serves the whole house. Right, So, like, for example, I live in a house that has multiple floors. It's it's kind of like in a flat style. Ironically it's flat but has multiple floors. Anyway, I put it in the middle level of this of my house, and I get service

both in the bottom floor and the top floor. It wouldn't work that way with life I would have to have the light bulbs and receivers in all those rooms. In order to have two way communication, you must have a good router, right, I have a hard time getting a signal in the next room. Well. Also, my the way my house is designed, it's like it's almost like a chimney, and that it has a stairway, an open stairway that goes all the way from the bottom all the way to the top. So it's not like there

are doorways or anything. You you pretty much have a big chamber that's that's divided by floors. But yeah, it's it's a really quite a It seems to be a pretty decent router. I do get fine service in whatever rooms I happen to be in, but uh, Life I would be different for that. It would be really good for one way communication where you want to beam something

like movies or pictures, sound files, that kind of stuff. So, um, if you look at the pure life I page, for example, they say, well, one of the places where we're seeing a lot of WiFi crunch is in consumption. The fact that people want to use their Internet connections to watch stuff like Netflix, or they want to use it to uh to watch YouTube. You know, these things that require

a lot of data throughput video games, stuff like that. Yeah. Yeah, so it might be better to use Life I to take some of that, uh that load off of the wireless spectrum. But you would still use WiFi in your devices to communicate back up through the the Internet, So it would be kind of a tag team. And part of that is because you know, you mentioned you know, up link for this down link. In most data plans, you'll see that your down link data, your data rate

tends to be much higher down link than uplink. And it's because largely that most of us end up consuming more than we upload. Uh. The people in this room kind of an exception because we do lots of audio and video, But for most people, they're consuming more than their generating, so to them, they're more they're more interested in getting a very fast rate getting the stuff to their computers than to upload because most of the time

they're uploading relatively small files. Um so this would not be that big of a difference between those kind of plans and Life Life I. Uh So that's kind of interesting. But another potential use of LiFi that Hass pointed out actually in his TED talk was imagine that you have a system where all the headlights and cars have this technology outfitted them, and the traffic signals do too, and then you could have cars and even their brake lights

could have this too. All the cars could communicate with one another. They could also communicate with the traffic system. You could have a real time, interactive dynamic traffic system that responds to changing conditions based upon the communication that's going through when people are driving. Now, granted, this would require headlights to be on in order for this to work. Obviously, if you didn't have your headlines on, then you're not

transmitting any information. You could receive it, but you wouldn't be able to transmit it. So we're saying that the incredible feature involves a lot of cars all having their headlights on all the time, but never getting stuck at stop lights when nobody is going the other way. Possibly, possibly at least we would have a robust dynamic traffic system at night, at the very least, like if it's not during the day, they would at least be at night,

which is kind of cool. It's an interesting idea, and it was one that I had to think about for a while because I was trying to, you know, what applications would I see this being a PRAC to call for and when it comes down to my smartphone, I'm not sure that would be that practical because I could I could again watch stuff on my phone, I could pull stuff down well, as long as you were very carefully standing in a place where you were receiving the

light transmission, because if you moved, if you like, shifted so that your head was blocking right and I would block the signal. Yeah. That so this definitely has its limitations. So I think it's really important to note that right to take that into account saying all right, light is not going to completely replace WiFi and all applications everywhere.

It's not practical, but there's some that makes sense. For example, underwater, if you want to do uh like a scientific survey of an area and you're using multiple underwater rovers, then you need a way to communicate with those, and light might be better than radio because radio signals attenuate underwater. It's why we don't use radar. We use sonar underwater, not radar. But light would be very useful in that case.

You could use this uh amplification modulation to communicate between various vehicles or tools to be able to do more effective surveys underwater, all sorts of different applications there. So it maybe that when we have our underwater hotels that we talked about many many moons ago, this is how we end up communicating with each other. Um, but you know, I'm not gonna hold my breath. I see what you

did there, Jonathan, I'm almost ashamed of that. And getting back to the idea of using light instead of radio frequencies in environments where radio frequencies might not be safe, so hospitals or potentially planes, although there's a lot of people who argue that the whole plane thing is is greatly exaggerated, or in areas where electromagnetic interference could potentially cause a catastrophic event, like a petrochemical manufacturing plant, where

if you had electro magnetic interference in part of the system, it could cause an explosion. UM, light is harmless in that scenario, you could use light instead to transmit information and get around that electromagnetic frequency interference and uh, and so it could be really useful in those applications. UM, I don't know if we're going to see that, because I mean, at least for airplanes, obviously it would require

that people have devices that are compatible with this technology. Um. And unless it becomes so widespread that everything comes with it, it may that may never happen, but it might end up being something that is used to transmit information directly to an entertainment system that's embedded in the plane itself. That's a possibility. UM. So I thought that was all very interesting, and you know, it's a neat idea. It's a neat way to get around this radio frequency spectrum crunch,

at least in specific applications. And obviously it's this kind of thinking that is required for us to continue on this path of UM evolution as we add more and more demands to this internet infrastructure we've built. Yeah, I'm really excited to see whether or not it picks up. Yeah, me too. I been interested in in reading about it over the past year, and it's recently popped up again as as people have uh kind of rediscovered it or

some people have discovered it for the first time. And um, I would love to see a demonstration of this personally, like an actual demonstration. I'm so. I kicked myself that there was apparently a demonstration of a smartphone outfitted with a receiver that would allow it to take in this information at C E HAS two thousand and fourteen. You were there. I was there, and I didn't know about it. I'm kicking myself. There's so much it's c ES. It's not like you can see every single thing on the ship.

There are upwards of a dozen booths at C E S every couple of square feet. Yeah. No, C E S has a lot stuff, a lot of stuff going on. But this would have been one of those things that I wish I had known about going into it, because it would have been I clearly would have covered it. This would have been a great story for forward thinking. But here's hoping that I might see something similar to that next C E S. So hope springs eternal. But this was really fun to kind of talk about this technology.

We don't often focus on a specific tech like this. We tend to look at more broad topics, but this was kind of fun to look at a specific implementation. If you guys have anything futuristic that you want us to talk about, whether it's a specific type of technology or it's just an idea, you know, what will X be like in the future, You need to get in touch with us. Let us know we love to hear from you. Our email addresses f w Thinking at how Stuff Works dot com, or you can drop us a

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