5 Reasons to Promote Li-Fi Technologies

This is a guest post by Liz Nelson from WhiteFence.com. She is a freelance writer and blogger from Houston.

ALi-Fi logolthough the use of light in order to transmit data can be limited in comparison to radio waves, there is a great amount of possibilities that can be developed due to this technology. In essence, a single pixel of a monitor could transmit a single channel of information to a source. Although this technology is still in its infant stages, the usefulness of this Li-Fi technology has implications for a great amount of good.

1. Distance - The sheer range of transmitting information could be worth the decrease in data speeds. The RONJA project in the Czech Republic can transmit a 10 Mbit/s Ethernet-type link just under a mile. As developments of this aspect continue, the range could be entirely up to the strength of the light which is emitting the information. Although the speeds are less than what they are for gigabit Ethernet, the power of the beam can allow DVD-quality streaming of video to any location connected to the Li-Fi device.

2. Cost - Instead of running close to a mile worth of cable, the LED-powered Li-Fi connection could be used to beam the information directly to the destination. Using a point-to-point array, office buildings can stay connected to each other without the use of additional cables being laid from one access point to another. The only problem the two buildings would be faced with is obstruction by solid objects or dense weather patterns such as heavy fog or snow.

3. Traffic Updates - Could you imagine having a car that uses a GPS system that receives information from traffic lights informing you of accidents and/or delays up ahead? There is a kind of system like that already in play for GPS navigational systems, but the traffic lights could be updating drivers using basic information or streaming video directly from news broadcasts.

4. Game Consoles - An innovative idea would be to put sensors on a television in order to receive information from game consoles. This would allow the unit to be place literally anywhere within the room as long as there is a direct line of sight to the sensor. Could you imagine a game system like the Xbox using a Kinect and all of it being completely wireless except for the power going into the unit? That will be tackled once wireless energy is perfected for practical home use.

5. Television Interaction - Instead of using apps or additional installations, you could theoretically hold your phone up as you sit on the couch and have every piece of information regarding the show or movie you are currently watching sent to your display – even recording directly to your mobile device. Of course, this may spawn some kind of copyright lawsuit because you are illegally copying a movie or television show, but you still get the idea. There are a number of reasons why investing in Li-Fi technology can have a great benefit to the future of wireless networking. Although there are a few aspects that need to be ironed out before it can be introduced on a wide scale of practicality, the future looks to be very promising. Even if the technology was merely developed as a small scale indoor application to “beam” information directly to a computer system without the use of Ethernet cable being strewn about the floor, visible-light communications could set the benchmark higher for wireless transmissions.

Questions and comments about this blog post can be sent to: liznelson17 @ gmail.com.

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Micro-LED Li-Fi

Illustra LightingThis is a guest post by Cassandra Allen of Illustra Lighting

Li-Fi is no longer a concept or an idea but a proven technology, albeit still at its infancy. Already, several experts in the field of communication have attested that Li-Fi technology would soon become a standard adjunct to Wi-Fi. That is, until its inherent limitations could be overcome.

Since it is light-based, its major drawback is that it won’t be able to penetrate solid objects such as walls. Though it could also mean privacy for the personal user, it also questions its use for large-scale delivery of data transmissions.

But despite its drawbacks researchers all over the world have been going all-out in further developing this new technology. A research was initiated by a consortium of universities that includes the Universities of Cambridge, Oxford, St. Andrews and Strathclyde in Scotland. It is led by Professors Martin Dawson, from the Institute of Photonics, and Harald Haas, from the University of Edinburgh. The goal of the consortium is to eventually make every illuminated device, such as televisions, lamps, road signs, and commercial ad boxes, transmit data to gadgets such as mobile phones.

At the University of Strathclyde, researchers have begun earnest efforts at bringing this new technology to market. Their biggest accomplishment to date is the development of LEDs that are a thousand times smaller than the smallest commercial LED. Dubbed micro-LED or micron-sized LEDs, these newer models are merely 1um2 (square micrometres) in size. This means that 1,000 more lights could be fit into the same space as a typical LED.

In addition to its size, micro-LEDs can flicker 1,000 times faster than commercial LED. Thus, in theory, a bank of 1,000 micro-LEDs flashing 1,000 times faster could transmit data a million times faster thanthat of an average LED.

At the moment, the potential advantage of micro-LEDs for Li-Fi use is staggering. While Li-Fi technology by itself is already incredible, having increased its data transfer speed that is comparable to fibre optics is what makes this new technology a major issue.

Imagine having a light source that not only provides light but also networking capability at astonishing speeds. Or a home television that communicates with every other gadget around, including the ability to project your smart phone’s display onto it for easy presentation to large groups. Or highways lighted by Li-Fi, providing motorists with real-time traffic and weather news as well as internet access to all devices inside.

The possibilities seem endless, and the potential is much broader than at first thought. With all the support pouring in, it won’t be long now before Li-Fi becomes an everyday technology.

About the author:

Cassandra Allen , Marketing Director of www.IllustraLighting.com

Cassandra is a marketing professional with over 15 years of extensive experience leading corporate marketing and internal communications for multi-national companies in diverse industries.

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Pathway to 5G: Visible Light Communications

We know from the CISCO report that the compound annual growth rate (CAGR) of mobile data usage per month is around 80%. At the same time the network spectrum efficiency of state-of-the-art cellular systems exhibits a saturating trend. Given that the available radio frequency spectrum is limited and that it is unlikely that significant new spectrum is made available for mobile communications, the only option is to increase the spectrum efficiency of wireless systems. This requires radical new research in wireless networks, and keys to solving the issues, in my opinion, are (a) the elimination of interference, (b) a massively improved reuse of the available frequency resources, and (c) utilisation of the free, vast and unlicensed infrared and visible light spectrum leading to hybrid radio frequency (RF) and optical wireless systems. All three points are inter-linked. For example, an indoor wireless link can hugely benefit from high signal-to-noise ratio stemming from an illuminated room instead of forcing an outdoor radio base station to send the radio frequency signal through multiple walls. This would either mean low signal-to-noise-ratio for the indoor user, or high transmit powers for the outdoor radio base station, or both. Wouldn’t it be better for the radio base station to serve an outdoor user or a user in a fast moving vehicle? This has four effects: (a) interference between the indoor user and the outdoor user is entirely avoided, (b) since interference is avoided, the radio base station can transmit with reduced power resulting in ‘greener’ mobile networks, (c) scarce wireless transmission resources are used in the best possible and most efficient way and (d) the radio frequency system enjoys a healthy spectrum relief resulting in improved user satisfaction. In summary, I believe that Li-Fi should be an integral element of a 5G cellular standard!

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A £5M Research Programme on Visible Light Communications…

…has just been funded by the UK’s Engineering and Physical Sciences Research Council, see: http://gow.epsrc.ac.uk/NGBOViewGrant.aspx?GrantRef=EP/K00042X/1 .

The programme, entitled ‘Ultra-parallel visible light communications (UP-VLC)’, is a collaboration between leading research groups at the Universities of Strathclyde, Edinburgh, St Andrews, Oxford and Cambridge. Its basis is the >1Gb/s modulation capability recently shown for individual micro-sized gallium nitride LEDs and the idea of aggregating such devices in high-density linear and two-dimensional arrays to enable spatial multiplexing in VLC. The programme will explore both free-space and guided wave embodiments of spatially multiplexed VLC, in particular exploring novel encoding schemes, advanced electronic control, and the development of novel systems demonstrators incorporating custom CMOS photo-detectors.

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Li-Fi on CNN International in “Make Create Innovate”

The 1st edition of Make Create Innovate airs on 27 September 2012 as part of Quest Means Business on CNN International at 19.00 – 20.00 BST.

It will also be streamed in full on the following website:

http://edition.cnn.com/TECH/specials/make-create-innovate/ from this evening.

The exciting subject for this launch episode is Li-Fi – the future of communication, using light waves from LED lightbulbs.

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Optical Wireless Communication Workshops

The 3rd IEEE Workshop on Optical Wireless Communications (OWC’12) forms part of IEEE Globecom 2012 in Anaheim California in December.

IEEE 3rd Optical Wireless WorkshopThe workshop will be held on 3rd December and the papers have now been selected and the program is likely to be released soon. It aims to bring together researchers and practitioners from academia and industry working in emerging visible light communications (VLC) and ultraviolet communications (UVC) as well as the traditional wireless infrared communications (IRC) to present, share and discuss their latest research results.

As evidence that things are hotting up in this space another workshop in OWC is taking place in Europe next month. The 2012 International Workshop on Optical Wireless Communications (IWOW) takes place in Pisa, Italy on October 22nd.

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Augmented Reality using VLC

Visible Light Communication is an ideal technology to enable Augmented Reality applications for indoor environments.

Today there are many examples of augmented reality (AR), many of these running as smart phone apps. Augmented reality in most practical implementations is simply an augmentation of useful information onto real world data, often visualised via a smart phone camera image with added notes or images.Augmented Reality Layar

Typically an augmented reality smart phone application might use the GPS location and the digital compass for positioning and orientation.  Unfortunately, these sensors suffer severe errors indoors or may simply not work in this environment.  However, VLC can function reliably to provide the necessary inputs such as location and orientation data for indoor AR apps.

Before looking into this too deeply let me present three different examples of VLC implementations that could be used for augmented reality applications.

Casio PicapiCamera

Casio’s PicapiCamera iPhone app claims to be the world’s first app to use visible light communication technology.  I first mention this in a blog post in January and a little more information has been emerging since then.

Casio are using flashing dots (red, green, blue) from a display, or even flashing coloured lights (e.g. on a Christmas tree) to convey small amounts of data (8 bits) which are received via the camera and then translated into codes relating to specific information content. Because the information rate is so low they have a look-up table that can translate the code into a longer pre-stored message,  image or URL.  In order to reuse the small number of unique codes Casio identify the general location of the smart phone first, enabling them to reuse the codes with different messages in different locations.  The claim is that this is a great alternative to QR codes and clearly this is a form of augmented reality where information can be added to the image seen by the camera. While more work is required, I like the fact that Casio have just gone out and released the app before the use case is fully developed – maybe the consumer will figure out what it can be used for!

MIT Media Labs NewsFlash

The second example from MIT Media Labs, NewsFlash uses display technology, for example on an iPad display.

In this example the display is used to convey digital information encoded as a colour sequence within an area of the image which they state is imperceptible to the human eye.  This coded sequence is received via the smart phone camera and decoded back to the original digital data which might carry a tiny URL (a compact web page address) which links to rich media content.

This is suggested to be the equivalent of an invisible QR code

PureVLC LightMessage

PureVLC  have claimed the world’s first application capable of sending a text message directly from a light bulb to a standard unmodified smart phone.

The equivalent of a text message or tweet can be transmitted from a light bulb within a second. While this is low compared with other VLC systems (about 50,000x slower than what PureVLC have demonstrated in the lab) it is both useful and considerably higher than any other application using a standart smart phone camera.


The MIT Media Labs application is in some ways similar to the Casio application in that display technology is used. However, the MIT application is more subtle in that the display does not contain a flashing colour blob.  In Casio’s favour their application also works with flashing LED light sources in addition to display technology.

Unlike Casio & MIT ML, PureVLC have not used colour information to convey the information which is an additional dimension that could be exploited in future to send more data.  Another significant difference is that PureVLC  use the illuminated area as the source of the data, i.e. reflected light, rather than the direct line of sight eliminating the need to point the phone directly at the light source or display.

PureVLC used an LED light source, the MIT Media Labs applicationrequires a display whereas the Casio application can use a display or an RGB LED source.  The Casio data rates are of the order of 1 byte per second (i.e. extremely low). On the other hand the MIT system is (by my guestimates – and I will happily correct any inaccuracy reliably reported to me) at least 10x higher than this. The PureVLC solution using just a phone app can achieve 3kbps which is almost 400x faster than the Casio app!

Uses in Augmented Reality

All of these apps use a smart phone camera as the VLC receiver. So they all receive an image, and they can all use hidden encoded information within the image to augment data onto the scene. If anything Casio’s app is closest to a traditional AR implementation, despite being the slowest and least subtle. PureVLC’s app has not been implemented in an AR sense but provides the highest data rate. The MIT Media Lab offering sits between these.

Hopefully, what I have illustrated by these examples is that AR can easily be implemented by VLC. More work is definitely required but the value of VLC in AR applications is hopefully proven.

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Li-Fi on the Gadget Show

The Gadget Show presenters Jason Bradbury and Pollyanna Woodward met with PureVLC to film their Li-Fi technology for the Channel 5 show today.

PureVLC in Mary Kings Close EdinburghJust to prove the point that they were not using any other form of data communications, PureVLC agreed to have their Li-Fi demonstration unit taken into the vaults of Mary King’s Close, deep beneath the streets of the Edinburgh Old Town. There was no Wi-Fi or cellular signals available and so this was considered a challenge since there could be no “cheating”. The location was a really cool setting (quite literally cool too) and in reality they perhaps did PureVLC a favour since there was also no light interference. However, the technology has been widely demonstrated with sunlight and with artificial light so we know this is not an issue anyway.
Jason Bradbury, Gordon Povey, Pollyanna Woodward, Gadget Show, Channel 5 The 10Mbps demo unit used for the TED Global presentation about a year ago was used for the filming and as PureVLC have pointed out they can show 10Mbps or 100Mbps+ using HD video transmission but they all looks the same on camera as a real-time transmission. Downloading a video is different as clearly one is 10x quicker than the other but the compelling demonstration is always real-time HD video and not video downloads.
I was there for the Gadget Show filming and was impressed at how a few seconds of explanation about the technology would lead an enthusiastic piece to camera by Jason and Pollyanna lasting a couple of minutes. It will be interesting to see what survives the director’s cut. Some dumbing down is inevitable but the UK Channel 5 show captures a wide audience which can do no harm for the exposure of Li-Fi.
The Gadget Show featuring PureVLC is scheduled to be broadcast in September and we can let you know via the blog when the date is finalised. If you don’t receive the UK Channel 5 it will be possible to view it on the web.

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Cisco Live is lit by Ethernet

NuLEDs Joulex Cisco PoELast week, at Cisco Live in San Diego, NuLEDs in conjuction with their partners JouleX lit the UPOE Partner Pavillion using power supplied via Ethernet cables.

UPOE is Cisco’s proprietary high power version of Power over Ethernet (PoE).

In this short video NuLED’s CEO talks about controlling lights using IP – specifically using PoE technology.

In this video produced by JouleX we see stand lighting at Cisco Live being controlled by UPOE.

It is clear that LED lighting powered and controlled via PoE is becoming a reality today. PoE (or UPOE) makes total sense for lighting in commercial environments. Add visible light communication in the form of Li-Fi and we see that PoE can carry all of the power, control and communications required within a smart building, and all down a single cable too!

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