Today we have a big tend to wireless technologies usage. Basically it means data exchange without any wire communication. There are 3 basic technologies allow us to do it. It’s 3G and 4G for mobile access and Wi-Fi for shared wireless networks. Wireless communication field grows up pretty fast. But it still has some issues that can’t be solved permanently. Li-Fi networks chould become a solver of this issues. This kind of wireless networks based on data transmission through optical spectrum.
This article holds more theoretical than practical character. I`d like to introduce you into new technology. Technology which can make a worldwide revolution as Wi-Fi did before. Now technology is going through scientific investigations and not ready for mass market. But idea is definitely interesting and worth.
The transcription of Li-Fi abbreviature means Light Fidelity – over phrase of Wireless Fidelity. Technology of Li-Fi realization is called VLC (visible light communication). The main idea of VLS is exchange wireless data by using a huge range of optical spectrum. Source of this spectrum is a simple light bulb based on light-emitting diodes. All you need for Internet connection is a one bulb with LEDs and microchip for bulb condition control. And, of course hold your data receiver under light bulb. As usual, receiver role could be played by every device with photodetector. The main purpose of photodetector – recognize input data stream. It can be telephone, laptop, tablet, ever camera – doesn’t matter.
History of VLC started at 2011 year. The main inventor at that time was Harold Haas – professor of Edinburgh University. He used a fiber-optic channel for light bulb connection and sent data stream from channel to receiver using simple light. Later observations was began by consortium of Britain universities: Oxford, Cambridge, St. Andrews and Strathclyde.
Data transmission mechanism.
Light bulb can control data access through easy LED switching. As mentioned, transmission process goes through binary data exchange. If light is on – it means transmission of digit “1”. If light is off – then will be sent “0” digit. Diode switching has to pass with the highest speed, so your eyes can’t capture this process. Information like “what data should be pushed” regulated by microchip. Thus data conversion from digit form to optical form is getting by.
After conversion light stream is defined by photodetector. Detector can be embedded into device-receiver or be used apart between light and device. After primary detection data stream grows up and allows to transmit more information. Photodetector has a PIN-diode for light detection. After receiving data is converted away to digit form and sent to device. Ethernet-frames, IP-packages and other layers of information shouldn’t be changed. Everything is going on physical level.
Where is it better Wi-Fi?
1) Number of access points.
At 2016 year we have about 6 million base stations for data transmission through 3G/4G. Of course, we have more Wi-Fi access points. But sometimes it’s not enough to provide high-speed Internet access for each connected device.
Now just imagine that we can use every light bulb for Internet-connection. We’ll have hundreds of millions access point. It’ll allow to organize unobstructed data exchange with every receiver.
2) Physical component.
Once upon time we’ll reach a speed ceiling by physical laws using existed technologies. Radiowaves responsible for wireless data transmission has a low throughput limit. It won’t allow us to accelerate data streaming by every protocol or standard. Moreover, radio-receiver generally has a huge oscillations of data detection.
Li-Fi can solve both nature problems. The range of optical spectrum is bigger than radiowave spectrum in few thousand times! With existence of proper protocols we can speed up data exchange up to few terabytes per second! No, it’s not a joke. Also receiver of optical waves has much less oscillations during data detection process.
3) Energy saving.
Base stations consume a big part of energy for equipment cooling, not for data exchange. It doesn’t look like rational energy using. Light bulbs have a high exploitation term, consume small amount of energy and reduce ejection of CO2 . All this facts make a Li-Fi technology energy saving as possible at present.
4) Accessibility from every environment.
Sometimes we can’t connect to Internet when we fly in plane or sit close with special rooms in hospitals. Radiowave transimission has the same working frequency with their equipment. This fact might create interference in working processes. Also we can set a building with specific construction as a good example.
Li-Fi doesn’t have this problem. Light can’t corrupt any equipment using. You can have Internet access from any place where you have a light bulb controlled by special microchip.
Radio Waves can pass through walls and other firm objects. It allows to tackle data on the third side and use it for violent purposes. Light can’t do it, so with Li-Fi you will be as secure as it could be. There won’t any data receiver over light radiation.
Where is it worse Wi-Fi?
Optical waves disability to pass through walls as a plus for secure as a minus of scalability. With VLC technology you can’t distribute Internet-access for other devices behind the light radiation.
2) Interconnected networks development.
So, you can’t make a WLAN through Li-Fi. On “getting started” period of VLC will be scarcity of special bulbs, when people wants to use it.
Sometimes it’s necessary to build a wireless network for gadgets interconnection. Idea of “smart house” is crossing on mind at first. At this cases Wi-Fi still won’t have any alternative.
Where could it be applied?
Fiber-optic connection between medical devices seems usually complicated. Li-Fi can provide a wireless data transmission for operation equipment management.
2) Road regulations.
With automatization of self-driving cars, there could be exist data exchange between traffic lights. Traffic light can send special signals for stop or ride through optical spectrum.
3) Underwater expeditions.
It’s very hard to get an access under water. There is one way to do it: carry on many kilometers of fiber-optic. With Li-Fi we can take much less cable and compensate it by light radiation as alternative. But there should be remark. Under water we need to use the strongest light bulbs. By the point of physics has obstacles with passing through water.
4) TV entertainment.
Now user interacts with TV-box by single data streaming. It allows to make a simple operations. If we set light bulb in the end of TV Remote and set a photodetector in TV-box, we can organize a multiple data stream. It provides an opportunity to develop multifunctional applications for television. So television field is going to obtain more interactive format.
In some factories as chemical or oil-mined we can’t stretch fiber-optic around the building. Optical waves is more favourable environment for Internet access in such special fields.
And a little bit about technology expenses. Repeat myself: all you need is a light bulb and small microchip. Won’t stop on cheapness of bulb, just make a point of chip: now there is not too much accessible chips for this goal. But if investigation results will be successfull, chips will be produced on conveyor. It’s going to make the cost of chip as less as more chips will be sold.
Hope this post explained you how far can we go in telecommunication field. Perhaps I’ll reveal investigation process later.