Is LIFI an alternative to WIFI?

Is LIFI an alternative to WIFI? I was asked this question by a group of executives from the Telecom, Network and IT industries ((http://cdrt.fr/).

The question seems legitimate: within seconds on the internet, you can find an abundance of LIFI literature – some of it dating back five years – implying that LIFI is a mature and widely implemented technology. It highlights the benefits: high speed data transfer, unlimited bandwidth, privacy, robustness to interference, human health, …. However, in reality, despite the buzz, no large-scale deployment has happened yet.

Is LIFI a myth? What is the actual status today and what can we expect?

As usual with new technology, there is always a lag between the initial innovation and market adoption. LIFI is no exception to this rule. The actors are getting ready for the race. Time has come to put LIFI on your radar: real progress has been made! Here is a quick technical review of LIFI as of December 2017.

Let’s start with some basic definitions. LIFI stands for Light Fidelity and comprises 2 application categories: GEOLOCALISATION services and INTERNET services.

GEOLOCALISATION is technically the easiest: the light sources continuously emit a unique “tag” - it is obviously invisible to the human eye and does not create any disturbance for the user. Any device located under the lamp will receive the “tag”, providing the necessary information to localize the device. Very simple and very accurate. The LIFI GEOLOCALISATION service is the indoor GPS! Also, it should be noted that such systems can be easily deployed in every environment where there is artificial light i.e. everywhere! Furthermore, only 10% to 20% of the light sources may need to be upgraded with a LIFI tag to deliver the service. In this configuration, the intelligence is both in the central system that knows the location of each lamp (3D map of the building) and in the application that has to be installed in the mobile devices. Interesting to note that the decoding of the tag is performed through a simple mobile camera (the same one you use for your selfies): no need for any additional hardware. So, what are the use-cases for an “indoor GPS”? Have you ever “lost” your car in a gigantic multilayer car park? Have you ever looked for a product that you purchase rarely – Tabasco, for example - in your local supermarket? Can you find your way around any subway on the planet?  Would you like to benefit from the best deal when you go shopping? Or easily retrieve information about the piece of art you are contemplating in a museum? And much, much more! Of course, the prerequisite is to adopt LED lighting! But isn’t it the case anyway (In 2017, LED lighting has now reached approximately 50% of the lamps sold worldwide)

The good news is that GEOLOCALISATION LIFI services are now ready: many pilot sites have demonstrated the benefits and the robustness of the solution in museums, supermarkets and underground transportation networks. LED Lighting fixtures are also widely available from several vendors. 

GEOLOCALISATION LIFI services create value. However, this is not the ultimate target.  What if your LED lighting would also deliver an Internet connection? This is the Holy Grail. How far are we today from this scenario?

The good news first: the internet LIFI technology has left the laboratories and is being tested in the real world. Pilot sites are flourishing: SOGEPROM (real estate subsidiary of the French bank Société Générale) and Nexity (real estate operator) have initiated trials in meeting rooms; the hospital in Perpignan deployed internet LIFI in the maternity department - sensitive area where RF signals are not desirable. Outdoor scenarios are also being tested, for example in Massy, a Parisian suburb. In each of the above cases, a full high-speed internet LIFI service is deployed. The engineers collect data and identify areas for improvement, the sales staff build their reference book and sharpen their marketing pitch, while the end users acquaint themselves with the technology and think about the potential use cases. Concretely, the technology is taking its first steps, with promising early results.

Imagine: downloading a movie within 1 minute; making sure that your data is not hacked by your neighbor; your home or office space free of RF waves; …

If the LIFI benefits are so great, why are Internet LIFI services not already deployed everywhere? Most advanced manufacturers announce impressive performance of 40 MB/s while researchers demonstrate up to 224 GB/s in their labs. There are a few reasons:

First and foremost, WIFI is delivering a superb service in most instances. WIFI has been widely deployed for over a decade and continues to expand at great speed, to the point where it reaches saturation in dense areas.  WIFI has been continuously improving in reliability, speed and security (refer to the latest 802.11ac Wave 2 that extends the bandwidth, increases the speed and allows multiuser configuration (MU-MIMO)). Its integration in all mobile devices (smartphone, tablets, …) makes WIFI the solution of mobility in conjunction with the 3/4G networks. There is no doubt: WIFI is THE universal standard TODAY. It has been replacing, with efficiency and elegance, the wired ethernet / RJ45 networks and it makes our offices and homes a wireless environment. You expect to get a “WIFI” signal at every location, even at your next holiday destination. And the reality is, WIFI is there!  

A second cause of low market penetration is the lack of awareness by the market players. LIFI is (was) mainly sponsored by the lighting industry. The IT, telecom and network players have focused on WIFI and have ignored LIFI. But of course, Internet is their territory: they sell, install and manage those local area networks. Today those players deploy, maintain and upgrade a huge WIFI installed base. The lighting industry is a newcomer to this game.  

Those external causes should, however, not hide some intrinsic issues linked to LIFI itself. Let’s flag a few of them:

-         The absence of an established standard or norm that would guaranty the interoperability of LIFI equipment. This point is well understood by the LIFI technology sponsors. They have formed a group within the IEEE 802.11 committee to drive the standardization process. Since July 2017, the “interest group” submitted its recommendation to create a “study group”. The 802.11 LC SG (“Light Communication Study Group”) started its work this fall (http://www.ieee802.org/11/Reports/lcsg_update.htm). Looking to the future, the standardization process should be complete by 2019/2020 and consequently open the path towards commercial deployment of INTERNET LIFI services as soon as 2021.  The good news is that the actors from both the IT/Telecom and Lighting worlds have joined the study group. Observing the experts from each industry talking to each other will be interesting!

-         LIFI modules are not integrated into mobile platforms. Today, the addition of a dongle is required to connect to the INTERNET LIFI service. This is indeed a true hurdle to a large-scale adoption. However, those USB dongles are familiar to everyone and act as a stepping stone towards integration into smartphones, tablets or PCs. Wasn’t it the case when WIFI started?

-         Today, there are only a handful of LIFI Internet lighting fixtures available - this is far too few to consider wide adoption. Artificial light is everywhere human beings live and work. About 40 billion light points are deployed on Earth. Such success was achieved thanks to the huge diversity of lighting fixtures and lamps produced by tens of thousands of lighting manufacturers. Aesthetics, mechanics, power, quality, norms, …. led to product catalogs that are as big as a phone book! There is still a long way to go before the lighting industry builds a comprehensive range of LIFI ready fixtures … and it will only do so when a widely accepted norm obtains momentum. To date, the limited availability of Internet LIFI lighting fixtures have restricted trials to pilot sites.  

Cost and cost!!! There are two types of cost. Let’s start with set-up costs. INTERNET LIFI lighting fixture would need to be connected to the internet network - physically connected with an Ethernet cable – and this generates a cabling cost. Second, there is the material cost on both ends: in the lighting fixtures, and in the dongle that will connect your PC, tablet or smartphone to the lighting signal. Both installation costs and hardware costs are an obvious deterrent. However, since the lighting industry adopted LEDs in replacement of incandescent, halogen, fluorescent lighting, it entered the electronic domain. There is no doubt that the cost curve of the LED lighting equipment will follow those of all other electronic devices. 

The conclusion seems obvious to me: within 2 to 3 years, LIFI will become a serious option to complement WIFI in sensitive environments or to offload the saturated WIFI areas.

The conditions for convergence of the lighting and network technologies are about to be created. This technical convergence calls for another interesting game where the actors of both worlds would have to discuss, debate … and maybe more. But this is another story! Stay tuned!