December 31, 2015 • 45 mins
Could we solve the radio frequency spectrum crunch by switching from radio to light? How does Li-Fi actually work and in which situations is it suitable?
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Episode Transcript
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Speaker 1 (00:00):
Brought to you by Toyota. Let's go places. Welcome to
Forward Thinking. Hey guys, it's Forward Thinking. I'm Jonathan Strickland, Obama,
and we are still back. If you listen to the
previous episode Water on Mars, you know that we were
(00:22):
on hiatus for a while. We are now back and
this is the second of two episodes we recorded before
we were officially on hiatus, but we back in October,
so we're gonna tell you the future of the past.
Um yeah, this is this is something that we recorded
back in October two fifteen. It's all about LiFi and
uh so some of the references maybe a tad dated
(00:45):
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
(01:08):
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
(01:28):
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
(01:50):
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.
(02:10):
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
(02:30):
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,
(02:53):
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,
(03:18):
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
(03:39):
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
(04:02):
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
(04:23):
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
(04:46):
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,
(05:09):
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,
(05:32):
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
(05:52):
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
(06:15):
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
(06:35):
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,
(06:59):
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
(07:20):
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
(07:41):
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,
(08:03):
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
(08:25):
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
(08:48):
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
(09:09):
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
(09:30):
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
(09:50):
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,
(10:10):
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
(10:33):
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
(10:56):
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
(11:19):
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.
(11:40):
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
(12:02):
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.
(12:25):
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
(12:48):
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
(13:09):
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
(13:30):
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
(13:50):
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
(14:10):
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
(14:33):
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,
(14:54):
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.
(15:15):
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
(15:38):
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.
(16:00):
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
(16:22):
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
(16:46):
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
(17:07):
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
(17:29):
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
(17:51):
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
(18:11):
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
(18:34):
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.
(18:55):
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
(19:17):
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.
(19:37):
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
(19:58):
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
(20:20):
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
(20:44):
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,
(21:06):
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
(21:28):
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
(21:50):
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
(22:10):
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
(22:31):
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,
(22:54):
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
(23:17):
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
(23:38):
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
(23:59):
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,
(24:21):
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
(24:42):
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
(25:03):
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
(25:25):
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
(25:45):
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
(26:08):
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.
(26:28):
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
(26:50):
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
(27:10):
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
(27:33):
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
(27:56):
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
(28:19):
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
(28:42):
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
(29:02):
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
(29:23):
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
(29:45):
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
(30:07):
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,
(30:29):
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
(30:50):
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,
(31:13):
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
(31:35):
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.
(31:57):
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
(32:19):
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
(32:40):
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.
(33:02):
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
(33:23):
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,
(33:44):
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
(34:06):
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
(34:29):
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,
(34:53):
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.
(35:16):
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,
(35:41):
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
(36:02):
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
(36:24):
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
(36:47):
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
(37:07):
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
(37:28):
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
(37:51):
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
(38:14):
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
(38:38):
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
(38:59):
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,
(39:21):
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
(39:43):
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
(40:03):
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.
(40:24):
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
(40:46):
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
(41:06):
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
(41:28):
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
(41:53):
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
(42:16):
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
(42:37):
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
(42:57):
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
(43:19):
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
(43:42):
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
(44:03):
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.
(44:25):
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
(44:45):
Stuff Works dot com, or you can drop us a
line on Facebook, Twitter, or Google Plus. At Twitter and
Google Plus, we're FW Thinking, or a Facebook just search
fw thinking. Our profile will pop up. You can leave
us a message there and we will talk to you
a ends really soon. For more on this topic and
(45:07):
the future of technology, I visit Forward Thinking dot Com
Problem brought to you by Toyota. Let's Go Places,
Brought to you by Toyota. Let's go places. Welcome to
Forward Thinking. Hey guys, it's Forward Thinking. I'm Jonathan Strickland, Obama,
and we are still back. If you listen to the
previous episode Water on Mars, you know that we were
(00:22):
on hiatus for a while. We are now back and
this is the second of two episodes we recorded before
we were officially on hiatus, but we back in October,
so we're gonna tell you the future of the past.
Um yeah, this is this is something that we recorded
back in October two fifteen. It's all about LiFi and
uh so some of the references maybe a tad dated
(00:45):
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
(01:08):
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
(01:28):
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
(01:50):
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.
(02:10):
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
(02:30):
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,
(02:53):
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,
(03:18):
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
(03:39):
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
(04:02):
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
(04:23):
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
(04:46):
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,
(05:09):
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,
(05:32):
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
(05:52):
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
(06:15):
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
(06:35):
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,
(06:59):
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
(07:20):
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
(07:41):
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,
(08:03):
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
(08:25):
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
(08:48):
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
(09:09):
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
(09:30):
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
(09:50):
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,
(10:10):
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
(10:33):
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
(10:56):
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
(11:19):
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.
(11:40):
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
(12:02):
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.
(12:25):
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
(12:48):
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
(13:09):
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
(13:30):
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
(13:50):
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
(14:10):
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
(14:33):
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,
(14:54):
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.
(15:15):
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
(15:38):
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.
(16:00):
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
(16:22):
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
(16:46):
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
(17:07):
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
(17:29):
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
(17:51):
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
(18:11):
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
(18:34):
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.
(18:55):
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
(19:17):
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.
(19:37):
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
(19:58):
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
(20:20):
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
(20:44):
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,
(21:06):
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
(21:28):
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
(21:50):
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
(22:10):
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
(22:31):
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,
(22:54):
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
(23:17):
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
(23:38):
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
(23:59):
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,
(24:21):
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
(24:42):
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
(25:03):
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
(25:25):
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
(25:45):
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
(26:08):
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.
(26:28):
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
(26:50):
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
(27:10):
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
(27:33):
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
(27:56):
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
(28:19):
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
(28:42):
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
(29:02):
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
(29:23):
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
(29:45):
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
(30:07):
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,
(30:29):
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
(30:50):
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,
(31:13):
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
(31:35):
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.
(31:57):
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
(32:19):
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
(32:40):
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.
(33:02):
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
(33:23):
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,
(33:44):
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
(34:06):
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
(34:29):
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,
(34:53):
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.
(35:16):
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,
(35:41):
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
(36:02):
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
(36:24):
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
(36:47):
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
(37:07):
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
(37:28):
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
(37:51):
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
(38:14):
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
(38:38):
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
(38:59):
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,
(39:21):
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
(39:43):
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
(40:03):
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.
(40:24):
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
(40:46):
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
(41:06):
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
(41:28):
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
(41:53):
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
(42:16):
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
(42:37):
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
(42:57):
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
(43:19):
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
(43:42):
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
(44:03):
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.
(44:25):
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
(44:45):
Stuff Works dot com, or you can drop us a
line on Facebook, Twitter, or Google Plus. At Twitter and
Google Plus, we're FW Thinking, or a Facebook just search
fw thinking. Our profile will pop up. You can leave
us a message there and we will talk to you
a ends really soon. For more on this topic and
(45:07):
the future of technology, I visit Forward Thinking dot Com
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Crime Junkie
Does hearing about a true crime case always leave you scouring the internet for the truth behind the story? Dive into your next mystery with Crime Junkie. Every Monday, join your host Ashley Flowers as she unravels all the details of infamous and underreported true crime cases with her best friend Brit Prawat. From cold cases to missing persons and heroes in our community who seek justice, Crime Junkie is your destination for theories and stories you won’t hear anywhere else. Whether you're a seasoned true crime enthusiast or new to the genre, you'll find yourself on the edge of your seat awaiting a new episode every Monday. If you can never get enough true crime... Congratulations, you’ve found your people. Follow to join a community of Crime Junkies! Crime Junkie is presented by audiochuck Media Company.