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  • Do you know

  • that we have 1.4 million cellular radio masts

  • deployed worldwide?

  • And these are base stations.

  • And we also have

  • more than five billion

  • of these devices here.

  • These are cellular mobile phones.

  • And with these mobile phones,

  • we transmit more than 600 terabytes of data

  • every month.

  • This is a 6 with 14 zeroes --

  • a very large number.

  • And wireless communications

  • has become a utility

  • like electricity and water.

  • We use it everyday. We use it in our everyday lives now --

  • in our private lives, in our business lives.

  • And we even have to be asked sometimes, very kindly,

  • to switch off the mobile phone at events like this

  • for good reasons.

  • And it's this importance

  • why I decided to look into the issues

  • that this technology has,

  • because it's so fundamental to our lives.

  • And one of the issues is capacity.

  • The way we transmit wireless data is by using electromagnetic waves --

  • in particular, radio waves.

  • And radio waves are limited.

  • They are scarce; they are expensive;

  • and we only have a certain range of it.

  • And it's this limitation

  • that doesn't cope

  • with the demand of wireless data transmissions

  • and the number of bytes and data which are transmitted every month.

  • And we are simply running out of spectrum.

  • There's another problem.

  • That is efficiency.

  • These 1.4 million cellular radio masts, or base stations,

  • consume a lot of energy.

  • And mind you, most of the energy

  • is not used to transmit the radio waves,

  • it is used to cool the base stations.

  • Then the efficiency of such a base station

  • is only at about five percent.

  • And that creates a big problem.

  • Then there's another issue that you're all aware of.

  • You have to switch off your mobile phone

  • during flights.

  • In hospitals, they are security issues.

  • And security is another issue.

  • These radio waves penetrate through walls.

  • They can be intercepted,

  • and somebody can make use of your network

  • if he has bad intentions.

  • So these are the main four issues.

  • But on the other hand,

  • we have 14 billion of these:

  • light bulbs, light.

  • And light is part of the electromagnetic spectrum.

  • So let's look at this in the context

  • of the entire electromagnetic spectrum, where we have gamma rays.

  • You don't want to get close to gamma rays, it could be dangerous.

  • X-rays, useful when you go to hospitals.

  • Then there's ultraviolet light.

  • it's good for a nice suntan,

  • but otherwise dangerous for the human body.

  • Infrared --

  • due to eye safety regulations,

  • can be only used with low power.

  • And then we have the radio waves, they have the issues I've just mentioned.

  • And in the middle there, we have this visible light spectrum.

  • It's light,

  • and light has been around for many millions of years.

  • And in fact, it has created us,

  • has created life,

  • has created all the stuff of life.

  • So it's inherently safe to use.

  • And wouldn't it be great to use that for wireless communications?

  • Not only that, I compared [it to] the entire spectrum.

  • I compared the radio waves spectrum --

  • the size of it --

  • with the size of the visible light spectrum.

  • And guess what?

  • We have 10,000 times more of that spectrum,

  • which is there for us to use.

  • So not only do we have this huge amount of spectrum,

  • let's compare that with a number I've just mentioned.

  • We have 1.4 million

  • expensively deployed,

  • inefficient radio cellular base stations.

  • And multiply that by 10,000,

  • then you end up at 14 billion.

  • 14 billion is the number of light bulbs installed already.

  • So we have the infrastructure there.

  • Look at the ceiling, you see all these light bulbs.

  • Go to the main floor, you see these light bulbs.

  • Can we use them for communications?

  • Yes.

  • What do we need to do?

  • The one thing we need to do

  • is we have to replace these inefficient incandescent light bulbs,

  • florescent lights,

  • with this new technology of LED,

  • LED light bulbs.

  • An LED is a semiconductor. It's an electronic device.

  • And it has a very nice acute property.

  • Its intensity can be modulated

  • at very high speeds,

  • and it can be switched off at very high speeds.

  • And this is a fundamental basic property

  • that we exploit

  • with our technology.

  • So let's show how we do that.

  • Let's go to the closest neighbor to the visible light spectrum --

  • go to remote controls.

  • You all know remote controls have an infrared LED --

  • basically you switch on the LED, and if it's off, you switch it off.

  • And it creates a simple, low-speed data stream

  • in 10,000 bits per second,

  • 20,000 bits per second.

  • Not usable for a YouTube video.

  • What we have done

  • is we have developed a technology

  • with which we can furthermore

  • replace the remote control of our light bulb.

  • We transmit with our technology,

  • not only a single data stream,

  • we transmit thousands of data streams

  • in parallel,

  • at even higher speeds.

  • And the technology we have developed --

  • it's called SIM OFDM.

  • And it's spacial modulation --

  • these are the only technical terms, I'm not going into details --

  • but this is how we enabled

  • that light source

  • to transmit data.

  • You will say, "Okay, this is nice --

  • a slide created in 10 minutes."

  • But not only that.

  • What we've done

  • is we have also developed a demonstrator.

  • And I'm showing for the first time in public

  • this visible light demonstrator.

  • And what we have here

  • is no ordinary desk lamp.

  • We fit in an LED light bulb,

  • worth three U.S. dollars,

  • put in our signal processing technology.

  • And then what we have here is a little hole.

  • And the light goes through that hole.

  • There's a receiver.

  • The receiver will convert these little, subtle changes in the amplitude

  • that we create there

  • into an electrical signal.

  • And that signal is then converted back

  • to a high-speed data stream.

  • In the future we hope

  • that we can integrate this little hole

  • into these smart phones.

  • And not only integrate a photo detector here,

  • but maybe use the camera inside.

  • So what happens

  • when I switch on that light?

  • As you would expect,

  • it's a light, a desk lamp.

  • Put your book beneath it and you can read.

  • It's illuminating the space.

  • But at the same time, you see this video coming up here.

  • And that's a video, a high-definition video

  • that is transmitted through that light beam.

  • You're critical.

  • You think, "Ha, ha, ha.

  • This is a smart academic doing a little bit of tricks here."

  • But let me do this.

  • (Applause)

  • Once again.

  • Still don't believe?

  • It is this light

  • that transmits this high-definition video in a split stream.

  • And if you look at the light,

  • it is illuminating as you would expect.

  • You don't notice with your human eye.

  • You don't notice the subtle changes in the amplitude

  • that we impress onto this light bulb.

  • It's serving the purpose of illumination,

  • but at the same time, we are able to transmit this data.

  • And you see,

  • even light from the ceiling comes down here to the receiver.

  • It can ignore that constant light,

  • because all the receiver's interested in

  • are subtle changes.

  • You also have a critical question now, and

  • you say, "Okay,

  • do I have to have the light on all the time

  • to have this working?"

  • And the answer is yes.

  • But, you can dim down the light

  • to a level that it appears to be off.

  • And you are still able to transmit data -- that's possible.

  • So I've mentioned to you the four challenges.

  • Capacity:

  • We have 10,000 times more spectrum,

  • 10,000 times more LEDs

  • installed already in the infrastructure there.

  • You would agree with me, hopefully,

  • there's no issue of capacity anymore.

  • Efficiency:

  • This is data through illumination --

  • it's first of all an illumination device.

  • And if you do the energy budget,

  • the data transmission comes for free --

  • highly energy efficient.

  • I don't mention the high energy efficiency

  • of these LED light bulbs.

  • If the whole world would deploy them,

  • you would save hundreds of power plants.

  • That's aside.

  • And then I've mentioned the availability.

  • You will agree with me that we have lights in the hospital.

  • You need to see what to do.

  • You have lights in an aircraft.

  • So it's everywhere in a day there is light.

  • Look around. Everywhere. Look at your smart phone.

  • It has a flashlight, an LED flashlight.

  • These are potential sources for high-speed data transmission.

  • And then there's security.

  • You would agree with me

  • that light doesn't penetrate through walls.

  • So no one, if I have a light here,

  • if I have secure data,

  • no one on the other side of this room through that wall

  • would be able to read that data.

  • And there's only data where there is light.

  • So if I don't want that receiver to receive the data,

  • then what I could do,

  • turn it away.

  • So the data goes in that direction, not there anymore.

  • Now we can in fact see where the data is going to.

  • So for me,

  • the applications of it,

  • to me, are beyond imagination at the moment.

  • We have had a century of very nice, smart application developers.

  • And you only have to notice, where we have light,

  • there is a potential way to transmit data.

  • But I can give you a few examples.

  • Well you may see the impact already now.

  • This is a remote operated vehicle

  • beneath the ocean.

  • And they use light to illuminate space down there.

  • And this light can be used to transmit wireless data

  • that these things [use] to communicate with each other.

  • Intrinsically safe environments

  • like this petrochemical plant --

  • you can't use RF, it may generate antenna sparks,

  • but you can use light -- you see plenty of light there.

  • In hospitals,

  • for new medical instruments;

  • in streets for traffic control.

  • Cars have LED-based headlights, LED-based back lights,

  • and cars can communicate with each other

  • and prevent accidents