Could a bright new alternative one day replace wi-fi? David Crookes talks to LiFi pioneer, Professor Harald Haas
There is no denying that wi-fi has revolutionised our lives, allowing us to speedily access the internet while on the move and removing the hassle of wired connections. It has saved us lots of money by letting us conserve our mobile data plans, and it has become a utility just like electricity and water for so many of us. You only have to gauge our reaction when it slows or stops working: we get on the phone and argue the toss with the service provider and we become stroppy at the sheer inconvenience of it all.
At the same time, though, wi-fi is not perfect. Since it uses radio waves to transmit data, it is inherently limited and there is a set bandwidth too, which can cause problems when many devices are used at the same time. Wi-fi is also hackable, especially when the waves penetrate beyond the walls of your home and office and allow others to see and potentially access it. What’s more, as more and more devices become wi-fi enabled, the issues are only likely to worsen as the signal interferance increases. We may rely on wi-fi today, but experts know that it’s important to develop other systems too, and one of them may just be the long-term answer.
Step forward LiFi, one of the latest systems looking to compete with wi-fi. Short for ‘Light Fidelity’, it uses light to transmit data rather than radio waves by making use of the semiconductors that are built into ordinary, off-the-shelf LED light bulbs. It may sound bizarre, but by exploiting the change in brightness – so modulating the intensity of the LED by turning the light on and off at very high speeds – it is possible to create binary information, which can then be interpreted by a receiving device. The result is data transmission that will allow computers, tables and smartphones to connect to the internet.
This is achieved by beaming out the 1s and 0s created by the LEDs to light receivers on various devices which then translate the signal into real-time data. While LiFi currently offers real world transfer rates of around 150Mb/s, tests have shown connections can be anything up to 10Gb/s – some 250 times faster than the average broadband speed. It is little wonder that people have been getting rather excited about it.
Among those who have worked hard on the technology is Harald Haas, a professor of engineering at the University of Edinburgh. It was he who coined the term LiFi and it was he who got the ball rolling some four years ago when he gave a TED Talk about the subject in 2011. Discussions about the technology soon gathered pace, and it has become one of the most important emerging methods of data transfer. In fact, Prof Haas is so convinced of its future, he has co-founded a spin-out company called PureLiFi which has been working on products that take advantage of LiFi. It has been valued at more than £14 million and it recently raised £1.5 million in its latest round of investment.
“The idea of LiFi is a fairly old idea – even Alexander Graham Bell had thought of using light for communication when he developed the photophone in 1880,” Prof Haas tells Micro Mart. “But the real idea of LiFi basically emerged when LED lights came out because they added a new twist, allowing the capability of transmitting data really fast. I saw this when I started a project 12 years ago in my university to try and find out if there is a way to transmit data very quickly using modulation technique algorithms to encode information on LEDs. That experiment proved to be very successful.”
Prof Haas believes consumer units are no more than five years away from market, and he also reckons each of us will be commonly using this technology alongside 4G, 5G and wi-fi. He says there are 14 billion pre-existing LED light bulbs out there, which only need an additional Ethernet-wired ceiling-based device to be attached in order to make them compatible with the new technology. With such a strong infrastructure, it only seems a matter of time before LiFi is taken on board in homes and businesses around the world.
One of the key elements to this technology is that it merely adds to what is already there: the core functionality of the light bulb will not be affected by its additional roll and, since the flashes are so fast, it looks as if the light is always on. That means that people will still see normal uninterrupted illumination from their bulbs, with the only snag being that LiFi bulbs would have to be kept on in order to transmit data – though they could be dimmed to the point that they here not visible to humans, and yet still be functional. It makes LiFi a very neat solution and one that is sure to be attractive to lighting companies looking to incorporate wireless technology into their products in the future.
At the same time, there is also a lot more scope with the technology. By making the semiconductors work at ever faster speeds, the rate of transmission can be increased. This means that LiFi has the capability of becoming one of the fastest connections around and, if you’re still not convinced that LiFi is actually feasible, then consider this: we have been using this sort of tech in a familiar form for a while now.
Pick up your remote control and change the channel. You’ve just seen a low-level form of LiFi in operation. As Prof Haas explains to us, remotes contain infrared LEDs which, when turned on and off, create a low-speed data stream that operate at up to 20,000b/s. But by transmitting thousands of data streams in parallel as in LiFi rather than just a single stream as with remote controls, the speed is increased and the amount of information that can be sent back and forth is also boosted.
“The visible light spectrum is 10,000 times larger than that of the radio spectrum,” he continues. “This means LiFi becomes a big resource – a big fat pipe if you want – through which data can shuffle through.” The infrastructure is also much larger. As we already know, we have lights all around us. They are in our home appliances, our cars, in the streets, within lamps and, of course, in our ceilings too. The 14 billion LEDs out there more than dwarf the 1.4 million radio cellular base stations that are installed. It may well be that, in due course, we don’t need as many radio masts, saving money and the environment. This is particularly useful as technology advances.
“For the second generation of communication, the distance between radio masts was 35km maximum but with 4G the distance between the masts has become 200 to 500 metres and with 5G that will go down to 50 metres,” he tells us. “So imagine a city where you have a radio mast, albeit a small one, every 50 metres and imagine this is essential for transmission in order to provide ubiquitous coverage. If you have a lighting system and you have replaced lights with LEDs, you don’t need this. It is also a very green technology because you could use a street lamp and save energy. You’d be reusing and repurposing these lights for data communication.”
In the UK, more and more street lamps are indeed being converted to LED technology as the local authorities look to reduce carbon emissions. You may even have such a system in your street – they are certainly noticeable given their hallmark is a crisp white light rather than an orange glow of sodium. While some feel they give off less light and so make for darker streets, they are cheaper to run. They also give off much less light pollution and, as a by-product, will be able to deliver the internet to your devices while you are out and about. “Every street lamp could be a free access point,” Prof Haas told his TED audience. He also says that LED lighting on aeroplanes will allow people to use the internet in flight.
The possibilities appear endless. “Absolutely so,” he asserts. “We are at the start and we are just where we saw the first mobile phones – those huge devices that are quite unlike what we see today. LiFi is still fairly big and it is not mass market ready, but in five years time it will grow on a very large scale.”
In order to take advantage of this, PureLiFi is working on its third generation of products and efforts are at an advanced stage. “We demonstrated a fully networked LiFi network at the Mobile World Congress,” he says. “It was the same as wi-fi but you can move and you can have a lamp that is transmitting to multiple users. It’s called LiFlame.” The system provides a 10Mb/s downlink and a 10Mb/s uplink over a range of up to three metres with standard light fixtures. It creates a data rate density of 2Mb/s per square metre.
“We have been piloting an installation for the early adopters in the defence and security industry as well,” Prof Haas continues. “We also have it in the lighting and communication industry.” One of the most eye-catching developments has been a potential deal with the Golden State Warriors basketball team in California. Prof Haas wants to see LiFi technology used in a new cutting edge sports and entertainment complex in San Francisco by 2018. LiFi street lamps will transmit data when people pass beneath them. “We are hoping to get this technology up and running within their new Arena,” he says. “With a high density of people there is a need for individualised replays for teams: wi-fi doesn’t have the bandwidth but LiFi in such an environment will do.”
It is highly likely that the full extent of the possibilities of LiFi will not be seen for a few years yet, though. There has been talk of cars being able to communicate with each other via their LED headlamps and of kitchen appliances being linked to the internet through LiFi. The market is projected to be worth as much as $9bn by 2018, but the figure continues to rise as more and more companies take an interest. Major providers and technology companies have to be on board, and there are signs that they will be. “We have been speaking to a number of service providers – the main service producers across the country,” Prof Haas adds.
In the meantime, he is keeping his eyes well and truly open to the possibilities. “Every time I walk out and I see a light I see LiFi and I see what we can do in terms of services. Every new connection enables up to 100 new applications and connectivity enables huge additional differences in application development on top of it. We have seen this with the iPhone – a little device that connects people. See how many applications are running on it. Now imagine the lighting system in your home and the applications that the lights could provide. This could monitor patients and it could help to boost the economy.”
As well as Prof Haas and the University of Edinburgh, top brains from other educational establishments are involved. There is a programme called Ultra-Parallel Visible Light Communication which includes experts from Universities in St Andrews, Strathclyde, Oxford and Cambridge as well as Edinburgh – and this had helped put the UK at the forefront of LiFI technology, and will hopefully keep it there. Prof Haas wants Edinburgh in particular to be seen as the City of LiFi. Scotland, he says, will benefit enormously from the systems uptake.
Will LiFi replace wi-fi, 4G and all of the rest and become the dominant technology, though? Prof Haas has a surprising answer: “No.” Yet he does think that it will become one of a number of ways in which people will connect over the years and that it is important to have new and varied methods of getting online. “It will be an integral part of how people connect,” he says. “Everyone will be used to it and it will be a part of the mix of wireless communication.”
He points to ever-changing technology and the ways in which we have adapted to them. Now, he says it is about getting devices to talk to each other more efficiently. “We now have different ways of communication between humans with the iPhone and social networking but we will see a massive communication between machines to make our environment smarter,” he offers. “So, if we connect all of the things around up to the internet, I think we will see a massive load of data will be carried by light. It provides an additional level of connectivity that otherwise wouldn’t exist because radio’s bandwidth is too limited. But we will see this as part of the mix of wireless connectivity 10 years from now. It’s hugely exciting.”
How To Improve Your wi-fi
It would appear LiFi is a few years away from being available for consumers so, in the meantime, it’s worth looking at ways to make your wi-fi that little bit better.
1. Make sure you’re up-to-date
In order to get the fastest wi-fi you ppossibly can, you will need to ensure that your device supports the latest wi-fi standards. You will see the same number prefixing all of them – 802.11 – but it’s the letters at the end which are the most important part. The current best standards are 802.11n and 802.11ac, the latter delivering the fastest speeds. Check your router to see what it can deliver and think about upgrading if it doesn’t support either of these and you require more speed or a more reliable signal. Sometimes, a simple call to your internet service provider will bag you an upgraded router.
2. Get the router in the open
If you want your router to beam out the best wi-fi signal, then you’re going to have to meet it half way by helping it out a little bit. That means locating it in a spot that allows the signal a better chance to reach your connected devices. Think about where you will use the wi-fi the most and consider how many walls, doors and floors are situated between the devices you use most and the router. At the same time, you need it close to where your phone connection is. Look into getting signal boosters, or even HomePlug technology, if you get wi-fi blackspots in your home.
3. Remove any interference
There are certain appliances most of us now have that have the potential to ruin the signals we get from our wi-fi. The list of such devices includes, but is not limited to, microwaves and cordless phones (our friends at the website Alphr produced a handy guide to these devices: tinyurl.com/njdymah), so don’t place your router close to those items because the signal you get will suffer. The microwave, especially, can wreak havoc because it operates close to the 2.4GHz band that 802.11n also operates on. Then again, if it is proving to be too much of an issue, get the microwave checked out because it may mean that its shield has become damaged.
4. Get the right channel
If you have ever called an ISP about dodgy wi-fi, we’d wager that one of the things they will have asked you to do is change the wireless channel upon which your router is transmitting. The idea behind this that to the hope that you’ll move to a choose a channel that no-one else in the area will be on so that any interference is kept to a minimum. Play around with the different channels or use a program such as WiFi Analyzer to seek out the most free channel. You can find such programmes by going to tinyurl.com/95zyxpn. There are also guides dedicated to explaining the channel changing process for various popular routers online including Sky (tinyurl.com/o4calr7), Virgin Media (tinyurl.com/owjx2m6) and BT (tinyurl.com/d9lvc9s).
5. Lock down your wi-fi
One of the benefits of LiFi over wi-fi is that the range is better directed and so people can’t simply pick it up when they pass by. This gets around the issue of people being able to hack your wi-fi, an action that will inevitably slow down your connection. Make sure you have set up your wireless security so that only you and those you wish to are able to access your wi-fi. If you want to know more about this, go to the wi-fi Alliance website at www.wi-fi.org/discover-wi-fi/security.
Wi-Fi Aware
Although work is progressing on LiFi, that does not mean that wi-fi is not pushing new frontiers. One of the new technologies includes Wi-Fi Aware, which looks to extend wi-fi capabilities so that it allows nearby smartphones to find each other even if there is no cellular, GPS or hotspot connection.
With no infrastructure access point, it will allow fellow users to pinpoint each other with uncanny accuracy. App developers will be able to work with Wi-Fi Aware so that, for example, two gamers playing the same title will be able to instantly hook up when they are passing each other. Thankfully, it will be appcentric and users will be able to control their privacy and opt-in or out of identify disclosure.
Wi-Fi Aware is currently undergoing certification and the smart money is on smartphones and tablets having the technology available for consumers in the nextgeneration, so some time next year, we’d imagine.
Wi-fi In Numbers
• 11Mb/s – the data speed delivered by 802.11b
• 2000 – the year wi-fi was coined as a term
• 2 billion – number of wi-fi devices reached by 2013
• 25,000 – number of products certified by wi-fi Alliance
• 5,600,000 – number of public wi-fi hotspots in the UK
• 1 – countries to have banned wi-fi in nurseries (France)
Why LiFi Is More Secure Than Wi-Fi
As we have seen, LiFi uses LED lights to create data that is then transmitted to devices for interpretation. A tiny hole on the device receives the light and converts what Prof Haas says are subtle changes in the amplitude into an electrical signal which is then converted back to a high-speed data stream.
In order to work the data receiver would have to be in sight of the transmitter-bulb as visible light does not penetrate solid material. This has an advantage, however. LiFi is able to establish a secure, almost personal connection. “It is really safe and it also provides more secure wireless communication because light doesn’t go through walls and that is opposite to what you see with wi-fi,” Prof Haas offers.
“When you check for available wi-fi networks you will typically find 10, 15, 20 of them all around your and this means that people can basically hack into them if they really wanted to. With LiFi that doesn’t really happen because the walls block the light.” It means your next door neighbour or the people across the street are not going to suddenly find their way into your wireless connection.
Where Can You Use LiFi?
LiFi appears to be a very flexible wireless connection, which is able to perform well in some of the strangest of locations. Since it uses light to transmit data, it is entirely safe and so it means that it will be fine on oil platforms and in any situation where risk needs to be minimised. It will even be okay to use LiFi on planes – the LED lights would simply transmit what you need at high-speed without fear of bringing the aircraft crashing back down to Earth.
What may be surprising, though, is that LiFi can also work underwater. This has already been noticed by the U.S. Navy, which is funding a research programme that is looking to develop the technology. It is possible that LiFi could be used to significantly improve on existing methods of communication between submarines, as when it is refined it should work better than radio waves, which distort underwater.