The use of visible light as a means to transmit data has increased in recent years, making it a good alternative to radiofrequency systems in environments where there are severe restrictions for EMI.
In addition, the rapid growth of LED devices (Light-Emitting Diode) has allowed conventional bulbs are being replaced by this new technology. The high speed switching of these devices has become possible to use not only as a lighting system but also as a means for transmitting information, which is known as VLC (Visible Light Communications), specified in the standard 802.15.7.
A couple of years ago, we were surprised at the news that an English university had developed a new technology called Li-Fi that used LED light bulbs to transmit data. Li-Fi is a particularization of VLC, to provide Internet access via light. In this case, attained speeds up to 1Gbps.
This appeared highly promising technology, since just by having the baby at home, we would have broadband at home without Wi-Fi. To check whether the technology is a reality or not, and if you are mature enough to reach the market soon, we discover that things are not as simple as it seems.
Visible light communication: speed, privacy and security
The reality is that it is possible today to have applications for indoor location based on VLC, but another question is to create services that require broadband deploy next generation optical devices and spectrally efficient, along with a return channel from the mobile devices, PCs and tablets.
The most important limitation of VLC is currently only possible to provide high bandwidth within walking distance or light coverage. Therefore, we must be cautious and work hand in hand with the laboratories of researchers to confirm how it behaves bandwidth depending on the distance to the transmitter, ie the LED bulb emits.
Therefore, Telefonica has undertaken an innovative project that attempts to explore this technology and its possibilities. The project has developed an indoor positioning system based on VLC.
This project is the first step to test and understand the technology. But how VLC can replace the Wi-Fi at home? For now the is no answer yet, but foresee a near future in which both technologies will coexist and relief VLC spectrum for Wi-Fi, or replace it in places where good coverage is available.
VLC has the advantage that the bandwidth is not shared, so if you are offered 100 Mbps, all users in that room will have that capability. Also, the radiation is confined by walls, which produces cellular networks are completely safe from unauthorized access.
Furthermore, these systems do not require broadcast license, which is a great advantage because the saturation of radio spectrum has increased dramatically in recent years. This technology is completely safe to the human eye because the LED lamps are non-coherent optical sources.
Once we obtain successful results in laboratories, the commercial future of communications by visible light, and thus LI-FI, is assured, thanks to the many advantages of this technology. The great strength of VLC is the ease and convenience of having the Internet with just having the baby at home, and simplicity means that communications is a more utility. This will become a huge draw for the company and for particular sectors, such as older people, who demand easy to manage solutions.