harald haas

harald haas

intro’d to Harald here – tedgloballondon 2015:

A breakthrough new kind of wireless Internet

digital divide… 4.3 billion people w/o internet access

can only work if almost energy neutral.. need to use as much existing infrastructure as possible.. solar and/or led

rich infrastructure of leds around us.. how to use existing infrastructure to receive data.. ie: solar cell/panels.. solar cell absorbs light and converts into electrical energy.. why we can use solar cell to charge mobile phone… data encoded in subtle changes of the brightness of the led.. so if incoming light fluctuates so does energy harvested from solar cell.. principal mechanism in place to receive info from light.. and by the solar cell because fluctuations correspond to data transmitted.. but can we do this fast..? yes… faster than most broadband connections these days..

demo – through handkerchief/fog still works

whats really important.. solar cell has become receiver… for highspeed while signal is encoded in light.... while it maintains its primary function of energy harvesting device… so now… solar roofs, lampposts, tops of cars… windows… (can do both)… won’t have to keep recharging…

closing digital divide… connecting all devices to internet w/o massive energy consumption


tedglobal 2011

Wireless data from every light bulb

we have 1.4 million celluar radio masts worldwide (base stations)… more than 5 billion cell phones… we transmit more thant 600 terabytes (6 to 14th zero) every month… we use it everyday… this importance… because so fundamental..

1\ one issue is capacity.. radio waves are limited.. scarce.. expensive.. this limitation doesn’t cope with demand… we are running out of spectrum

2\ another problem.. efficiency… most energy not used to transmit.. but to cool station… efficiency is only about 5%

3\ another problem… availability.. flights and hospitals.. have to turn phones off..

4\ security issues

on the other hand 14 billions light bulbs… light is part of the electromagnetic spectrum

light is safe to use… wouldn’t be good to use that for wireless communication… we have 10000 times more there to use

we have the infrastructure there already… can we use them for communication… we have to replace these lightbulbs with led bulbs… good of led.. can work at very high speeds

ie: remote control..  what we have done… allow to submit not just one data stream but 1000s at once..

simfodm.. spacial modulation..

demo – video transmitted through light beam

you don’t notice with a human eye… the receiver is interested in these subtle changes

1\ capacity – 10000 more..data thru illumination – comes for free

3\ energy efficiency – if whole world – save100s of power plants

4\ availability – have lights in hospital/aircraft.. everywhere.. phones have flashlights

5\ security – light doesn’t penetrate through walls.. no one on other side of room could read it.. only data where there is light

for me.. applications are beyond imagination at the moment

being used now – below ocean… hospitals.. streets… cars can communicate et al… street lamps as a free access point.. lifi…. aircraft cabins… each light could be transmitter…

all we need to do is fit a small microchip to every potential illumination device.. combine illumination and data this symbiosis could solve 4 essential problems.. not only 14 billion light bulbs.. but 14 bill lifis


2014 – My Li-Fi Revolution

we have 7.3 bill smart phones.. more than pop of planet.. perhaps we can live w/o electricity but not without phones.. called smart phones.. but more like small computers

problem: cisco… by 2018 16 exebytes of data thru network…  equiv to 1.8 mill yrs of high def video sent through mobile every month

i of t – by 2020 – about 1000 mobile devices used by every person on planet

problem: energy consumption… equiv to entire global air traffic… mobile biggest energy consumer next to train. use radio base stations… many base stations are still diesel powered..

my vision – not so many radio stations.. but street lamps… led based street lamps.. ie: reduction in co2 emissions… turn energy efficient radio based systems into street lamps

bell – believed telephone wasn’t biggest invention.. but photo phone

7 min – angular changes… 1880 –  he believed this was his biggest invention…. light/mirror/data…. natural problems if relying on sunlight… but with led this can revive into something… bell might have appreciated . new communication system…

go outside of box to see what is entire electromagnetic spectrum we have available for our wireless systems

11 min – add chip (to led) and turn into highspeed broadband communication device

spectrum: unregulated (free); huge; safe (we’ve used light forever); existing infrastructure (ie: street lamps); inexpensive devices (led light costs now 1-3 pounds)

how does it work… data encoded in the intensity… binary 0s and 1s.. turn on light 1.. turn off light 0..

14 min – 100 mill time per second we turn it on and off

receivers are photodiodes.. photo sensitive semi conductors.. first lifi receiver chip 49 photodiodes integrated.. size of chip 2.8×2.8 millimeters… compared to smart phone antenna… 20 times more space… so we can integrate into tiny units… and we can imitate nature as well.. 15 min – imitate eyes of an insect..

16 min – might say – all very good – we already have that at home… ie: remote control… but that’s not sufficient… (that’s only one at a time and low rate)… algorithms that turn a light bulb into a device that sends 1000s of data streams in parallel at very high speeds… so can increase data rates by orders of magnitude

18 min – been doing this for 10 yrs… started 2003 – trying to turn disadvantage into advantage… using particular algo could enhance data rates… took ikea lamp.. put in led bulb.. able to send pics via a desklamp 2006

19 min – what could transform our everyday lives… 100 ideas… one was speaking lives – recognition we received in 2007

21 min – pure lifi – bi directional lifi communication.. from an idea to commercialization

23 min – fully networked lifi – spacially re using the light spectrum many many times in the room.. (ie: wifi could only install one otherwise would interfere) without interfering with each other.. results in tremendous changes in the data rate that a user would perceive… vision: lifi not going to replace radio freq systems… will be an addition.. ie: radio base stations still serving ie: rural spaces… then if enter a house/office/uni.. covered by lifi router.. handed over from outside to inside…

25 min – if user enters room with light fixtures.. fat data pipes.. others use radio freq…  auto cell system

27 min – graph of enhancement we would get .. ie: in a building… getting a 1000 times more… sending a video in that case would take seconds rather than minutes

30 min – what can be done with light enabled communication… every street lamp used… completely new intelligent transport systems…

32 min – radio freq doesn’t operate under water.. but light does… (can go through foggy ness) – divers could use torches to talk to one another

33 min – can hook up kettle/fridge et al to internet… the applications… enabling more intelligent energy handling… 10% of energy consumption at home.. could make big savings..

energy ness – let’s do this first

34 min – now also possible.. indoor navigation…

35 min – shopping windows..? virtual reality..  led lights with coupons on windows… you could pull in customers in a total diff way.. blending high street shopping with online shopping

ugh. yuck.

my fav: wearables… not sure what to do with it.. but it’s possible.. ie: clothes hooked up to internet

37 min – then museums… and another .. intrinsically safe environments… lights don’t use antennas so can’t create spark.. so can be used in petro chemical plants.. oil platforms…… places you see the crossed out mobile symbol..

38 min – research with aircraft carrier… where use lights where now we have to turn phone off… light levels at diff regions of aircraft cabins… lifi also works in non line of light… (so can use high density from ceiling for under seat low density)

43 min – on cyber security.. w/lifi system (image at 44 min) – wall prevents light to go through

44 min – cutting edge research last 3 months: we thought we could do same w/solar cell as we did with light bulb..  what if take opposite of light emitter.. solar cell.. as receiver as broadband lifi data stream… encoded in intensity.. 7 mega bits of data can be recovered by a solar cell.. and not yet optimized..

46 min – what about sunlight.. i’ve always said.. maybe we can filter it out… but now.. the sunlight we use to conduct… constant sunlight provides energy…

47 min – possible applications: places with no wifi.. problem.. distance large.. area of receiver small… so ie: wind, slight change of angle.. light beam misses target. now imagine solar cell on roof.. and point lightbeam.. solar cells would power transceiver and be the receiver of data stream…  possible now… long range communication high speed..

48 min – solar cell into mobil.. energize and recieve

solar cells are bendable/flexible… so now a self-powered transceiver that you can stock everywhere..

always need two cables for wifi… data and power.. assume you can throw them away.. and use a light link..

wallpaper could be wifi transmitter..

50 min – lifi is one idea.. but applications are manifold

51 min – industrial implications: terrestrial, underwater, space… lifi markets


smart cities… w/in next 10 yrs.. every bubble is at least one company.. that’s why we talk about a lifi industry.. what is the market value of lifi in 2018 – about 6 billion dollar.. spread across diff markets.. a huge industry that’s not existant


53 min – lifi r and d centre…. business.. health

54 min – then patents collab’s new industry.. and that’s the most important.. new industry in scotland


56 min – bi directional communication system to serve the internet

57 min – works because we have a non line of sight technology

59 min – misconceptions: lights can’t be dimmed (we have figured how to go so low that light is off and still emit photons to carry info); lights flicker (no.. rate of change so fast that human eye can’t see change of intensity but receiver can); this is for downlink only; there will be interference from sunlight (now tech can energy harvest); lights need to be on so this is inefficient (yes..but can turn them down and are led lights.. require less power than a rf system); this is a line of sight tech (no it’s not… tried to give demo today for that)

1:01 – lifi has power for new industry

i thought the goal was equity..? access to wifi ness

1:02 – not research.. but my desire: on putting into body… better than radiation… and wouldn’t interfere with ie: pacemaker.. would it be possible to do some research where you can mend broken nerves via lifi

1:07 – on q & a – on competition.. we are leading now.. but worried about finances…since more are taking up this research after my ted

1:10 – q: could you scale this to the moon being a satellite to reflect to entire globe a: yes.. that’s my next research

1:13 – radio freq entirely orthogonal to what we’re doing (to q on carcinogenic s)

1:14 – Tam Dalyell – the importance of being awkward.. he’s giving haas an award


1:15 – from dale: only thing i can add is.. next project.. what haas would do with patent lawyer… has 26 patents…


find/follow Harald:

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lifi site:



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lifi centre:

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The Li-Fi R&D Centre is leading the global development of Li-Fi technology, creating a pipeline for innovative ideas, technologies, products and partnerships.

Edinburgh, Scotland, UK


wikipedia small

Li-Fi is a bidirectional, high speed and fully networked wireless communication technology similar to Wi-Fi. Coined by Prof. Harald Haas, Li-Fi is a subset of optical wireless communications (OWC) and can be a complement to RF communication (Wi-Fi or Cellular network), or a replacement in contexts of data broadcasting.

It is wireless and uses visible light communication or infra-red and near ultraviolet (instead of radio frequency waves) spectrum, part of Optical wireless communications technology, which carries much more information, and has been proposed as a solution to the RF-bandwidth limitations. A complete solution includes an industry led standardization process.


imagining… full energy from light.. and full energy from people- via app chip ness

a nother way to leapfrog to equity


Alex Lidow