by Dr Gordon Povey, CEO of VLC Ltd, a University of Edinburgh spin-out company specialising in Visible Light Communication. VLC were voted “People’s Choice” at IBM SmartCamp London 2011. Gordon is a wireless communications expert based in Edinburgh, Scotland and a serial entrepreneur. Twitter: @gordonpovey; Email: gordon.povey@visiblelightcomm.com.
The demand for wireless data has been insatiable over recent years. This has been driven by the proliferation of wireless devices such as smart phones, laptops & tablets, audio devices, games consoles etc. and by the shift from basic content to much richer media content. The Internet of Things will add even further to this demand in our future Smarter Planet.
Wireless data transmission has been more than doubling each year. In 2010 we transmitted 24,000 terabytes of wireless data over the mobile networks and this is set to increase to 6.3 exabytes by 2015. This is a 26 fold increase over 5 years. Now consider that the spectral efficiency of mobile technology was growing at 35% per annum but has slowed to just 12%, so to cope with the lack of capacity a lot more wireless cells will need to be installed, or a lot more radio spectrum will need to be found. In 2010 Obama pledged to almost double the amount of wireless spectrum available over 10 years, but with demand doubling every year this is clearly not enough. Spectrum is a scarce, expensive and finite resource, it cannot just be created.
Cellular operators have been encouraging the off-loading of data from their networks to alternative Wi-Fi carriers when available and increased off-loading is predicted in the future to Wi-Fi and Femto cells. The problem here is that these systems suffer the same problems (capacity, congestion and lack of spectrum) and simply multiplying the number of nodes does provide a corresponding increase in throughput due to increased interference. So how can we cope with the predicted increase in demand? If wireless provider cannot supply sufficient capacity, will we simply accept much higher tariffs designed to curb this demand?
I believe the solution lies in the use of light as an alternative transmission medium. There is massive availability of free spectrum, and surprisingly the World’s first wireless telephone call was made, not by radio but, by light in 1880 when Alexander Graham Bell demonstrated his patented photophone. Bell used sunlight as his optical source, but today we have the ability to use LED lamps which are semiconductor devices and can be switched or modulated at spectacularly high speeds. My colleague, Harald Haas, recently amazed a live audience at TED Global by showing high definition video transmitted from a standard LED light bulb.
There is greater than 5 orders of magnitude more light bulbs in the World compared to cellular access points. Due to their energy efficiency and reliability, LED light bulbs will dominate all illumination markets very soon. They will be in offices, shops, homes, in cars, road signs, street lighting, as well as illuminating displays. In the lab today we can already match Wi-Fi data transmission speeds from a standard unmodified LED light bulb and we don’t need an antenna or radio circuits to transmit and receive the information. The incremental cost to add this technology to every LED lamp would be minimal since the additional processing can be added to the silicon already used in the LED driver circuits.
Of course, there are significant challenges in deploying this game changing technology and Luddites will be ready with a list of objections and will ignore all potential benefits. However, I am so confident of this opportunity that I have quit my previous job in order head up a new company, called VLC Ltd, that launches this month and will provide visible light communications products and help drive this technology into mass-market LED light bulbs. After all, we cannot expect to create a smarter, instrumented, interconnected and intelligent planet if there are wireless data bottlenecks everywhere!
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