Imagine wandering through an art gallery with your PDA. As you reach an interesting canvas, your PDA starts downloading information about the painting. When you move to another, your PDA displays content relative to the current piece of art. This is called content fencing – tailoring information to specific locations so that users receive information relevant to their current location.
Content fencing is impossible to achieve with Wi-Fi – radio waves have a far greater spreading power. However, this is eminently possible if electromagnetic waves of very short wavelength – such as optical beams – are used. We already have the necessary technology with us and it only requires converting LED bulbs into wireless access points as an equivalent of a wireless network. This is LI-Fi, allowing you to move between light sources for effectively remaining connected. At present, Li-Fi is only a complementary technology compared to Wi-Fi, but its potential benefits over Wi-Fi are huge.
Visible light spectrum has a huge bandwidth compared to the RF spectrum – in excess of 10,000 times. Moreover, visible light spectrum is unlicensed and free to use. RF tends to spread out over a large area causing interference, whereas, visible light can illuminate a tight area and can be well contained. This allows Li-Fi to attain over a thousand times the data density than Wi-Fi can achieve.
Low interference means more data can be transferred. Therefore, Li-Fi achieves very high data rates and devices using Li-Fi can have high bandwidths along with high intensity optical output. With illumination infrastructure already available in most places, it is relatively easy to plan for introduction or expansion of Li-Fi capacity with good signal strength.
The presence of illumination infrastructure also means negligible additional power requirements for Li-Fi, more so because LED illumination is inherently efficient. In comparison, radio technology requires additional components and energy to implement. Li-Fi works very well in water, but it is extremely difficult to implement and operate Wi-Fi underwater.
Even today, there is a raging debate about whether RF transmission is safe for life on Earth. Visible light does not court such controversy regarding health and safety, as it is the Sun’s rays that sustain life on Earth. Moreover, in certain environments, radio frequencies are considered dangerous as they can interfere with electronic circuitry. That is why people are asked to switch off their phones in flight.
The closely defined illumination area makes Li-Fi very difficult to eavesdrop. Unlike Wi-Fi that spreads its signals all over, even passing through walls, Li-Fi signals are confined to a specifically defined area. This makes Li-Fi far more secure as compared to Wi-Fi. Moreover, data flow in Li-Fi technology can be visibly directed according to requirement. You only need to point one device towards another to make them communicate. That makes it unnecessary to add a layer of security such as pairing, as is required for a Bluetooth connection.
Considering that LEDs operate more than 50,000 hours, it is necessary for manufacturers to add new services to the light they sell. Li-Fi offers massive new opportunities and myriad of different applications for the future communications market.
