Connecting to the Internet via Wi-Fi? Do you like speed? Don't you want it faster?
Professor Harald Haas invented Li-Fi - a technology for “super-speed” information transmission that allows you to distribute the Internet through... a light bulb.
What's happenedLi— Fi Internet
Technically, this is implemented using a chip built into an LED lamp - such a “light bulb” is capable of transmitting data a hundred times faster than modems using traditional technologies.
Sounds like news from the distant future? However, this is already a reality - devices running on Haas technology are already on the market.
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What is li-fi anyway??
This is a high-speed data transmission technology that uses light in the visible spectrum as a “carrier”. During transmission, the LEDs flash, turning off and on for very short periods. The blinking frequency is so high that it is impossible to notice the flickering with the human eye, which makes it possible to use lamps with such LEDs for lighting.
What li-fi is in reality was tested by the Estonian company Velmenni. Its employees installed appropriate equipment in several production facilities and offices in Tallinn and measured the transmission speed. The result was amazing: information was transmitted via li-fi at a speed of 1 gigabit per second! For comparison, in most wi-fi networks the average transmission speed does not exceed 10 megabits per second.
I will not rush to say that this new technology is the future. Most likely, the emergence of li-fi will not cause the disappearance of Wi-Fi - these methods of transmitting information will coexist peacefully for a long time. WiFi equipment will be installed where justified and possible. And devices such as laptops, smartphones and similar gadgets will acquire an option that allows you to “seamlessly” switch between “old” 3G networks, Wi-Fi and the “newest” light Internet.
Deepak Solanki, general manager Velmenni predicts the widespread use of the “lamp” method of data transmission in the coming years. In the meantime, engineers are thinking about how to take advantage of the technology for those users who want to work on devices connected to the Internet not only with the lamps on, but also in complete darkness.
Professor Haas told the scientific world about what li-fi is five years ago. By that time, he had been developing the “light Internet” for about ten years. By the way, scientific name This technology is visual light communication (abbreviated as VLC).
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In 2011, Harald Haas demonstrated how an LED lamp equipped with a special chip transmits HD (high-definition) video to a computer. By that time, the scientist had come up with a more sonorous name for the technology, renaming VLC to li-fi (short for light fidelity).
Given the cost, availability and ubiquity of LEDs, li-fi communications promise to be a more energy-efficient and cheaper solution than wireless radio systems used today.
That part of the electromagnetic spectrum, which is visible light, is 10 thousand times wider than the radio spectrum. The potential width of the “light” transmission channel is almost unlimited. The advantages of li-fi, according to Haas, include a more stable and accurate connection of computers to networks inside buildings - the main thing is to evenly distribute the LED transmitters. This is especially important against the backdrop of a strong weakening of the signal of a conventional wi-fi router as one moves away from the modem (because of this, in offices and residential buildings zones appear with such weak connections that it becomes impossible to connect to the Internet in them).
What is lifi from a security point of view?
Visible light cannot pass through walls. This property, Professor Haas believes, makes VLC technology more reliable in matters of confidentiality of transmitted information than the popular wi-fi today.
Light Fidelity - Li-Fi technology in short - is an optical technology for wireless information transmission. The technology was developed and presented quite recently - in 2011. This happened at a TED Talk. The developer is scientist Harald Haas. The data transfer speed was then about 10 Mb/s. The scientist promised that by the end of 2011 it will be 100 Mb/s.
How does Light Fidelity technology work?
The essence of the technology is modulation of the light flow from a special LED source using a binary code. Human eye is not able to catch this process, since the modulation process occurs on high frequency. This type of optical communication is much more secure than the traditional Wi-Fi that we are all used to. Why? Let us remind you that Wi-Fi signals can be intercepted from almost any point that is within the range of the equipment. But in order for some bad citizen to be able to intercept information transmitted via Li-Fi, it is necessary to place his equipment almost “on the lap” of the owner of the Li-Fi. It is clear that this is impossible.
There is another serious argument in favor of Li-Fi technology. It can be used with virtually no restrictions in areas where there is a ban on the use of equipment that emits extraneous radio waves. It’s no secret that such waves often violate normal functioning critical equipment. As an example, we can cite the chambers intensive care medical institutions, where there is a lot of different medical equipment, airplane cabins and so on.
A little bit of history
Many readers probably remember that the idea of using light to transmit data is not new. Do you remember how back in school, during physics lessons, we were told about Alexander Bell? In 1880, Alexander Bell managed to send a message using a photophone.
Here in recent years Developers began to become interested in visible light communications. Scientists realized that the proliferation of LEDs, which can be more finely tuned than conventional incandescent lamps, would certainly make the technology more economical and easier to use. One more thing should be noted important factor- the exponentially growing popularity of wireless communication devices around the world, which should inevitably lead to a shortage of radio frequency spectrum. This gave rise to the need to look for an effective alternative.
Why was it necessary to create Li-Fi technology?
The question of the need to use wireless information transmission is not currently raised at all. We live in the age of information networks. Some ten to fifteen years ago there was no mass access to the Internet; now literally every home has its own local network transfer of information.
But almost everything developed and used in at the moment Data transmission technologies have, in addition to their advantages, serious disadvantages. We are not talking about wired connections at all, since their use is justified in cases where there is too great a distance or a stationary computer. In this case, it is enough to get the wiring once and get an acceptable result in the future. But at the same time, it is necessary to use a certified cable; in addition, you need to have knowledge basic principles laying cables and have skills in crimping ends.
Nowadays, wireless networks based on Wi-Fi technology are used in almost every home. There are hybrid networks that combine wired and wireless channels. What is the inconvenience of wireless Wi-Fi networks? The first is the question of the security of the wireless communication channel, which arises quite often. It is not uncommon to hear assurances from network device manufacturers who claim that hacking a wireless network is impossible. But these assurances raise serious doubts. Secondly, no one can guarantee that long action exposure to the human body electromagnetic waves within the operating ranges of wireless adapters it is completely harmless. Not too much yet long period humanity uses this technology, so it is impossible to draw an unambiguous conclusion. The radiation power is not too high, but there is a high prevalence and duration of exposure. Who knows what results await us in a few decades, and maybe even earlier.
What does Li-Fi technology provide?
Light Fidelity can eliminate all these disadvantages. Because, as we have already said, this technology uses visible light coming from any LED source to transmit data, this way you can maintain mobility without harm to the human body. Internet speed increases to several gigabytes, and the network coverage area expands significantly.
Since the principle of Li-Fi technology is that absolutely any LED lighting bulb is capable of “blinking” at an incredibly high speed, this allows the use of light modulation to transmit information. Look at this ingenious solution: in a home network, even an ordinary table lamp can be an information transmitter! Ceiling lighting fixtures and decorative lighting elements - yes, anything - can successfully serve as transmitters! Having a mobile gadget, you can easily move around the apartment, since we are always connected to the network!
But it is worth noting that things are much more complicated with the reverse transfer of data from the device to the network. In such cases, it becomes necessary to think through the successful placement of sensors on the walls and ceilings of the premises.
Additional equipment for Li-Fi technology is almost not needed, because you can use what has already been used for a long time: street lamps, car headlights, room lighting. For example, the well-known manufacturer of audio speakers Klipsch presented a prototype back in 2010 that can receive music data from ordinary household LED lamps.
Li-Fi technology - prospects
There is no doubt that the promise of Li-Fi technology is enormous. If you use your imagination, an alley in some city equipped with LED emitters will become an opportunity for free broadband access on the Internet for everyone.
Interestingly, Li-Fi sensors and emitters can be installed everywhere: they can be placed on street lighting poles, on trees, on the walls of buildings. At the same time, absolutely any device that is nearby also gains access to the network. In addition, it is possible to replace the traditional cellular communication we are accustomed to with a hybrid one, for example, using Li-Fi in working conditions in a large metropolis and radio waves outside the Li-Fi access zone. It is clear that considerable costs will await us here. But very soon such investments will pay off.
Are there any disadvantages to Li-Fi technology?
Perhaps the only drawback of Li-Fi technology is the need for direct visibility between the light source and the receiver.
And in conclusion, we can say: if Light Fidelity technology becomes widespread, then the electrician profession will become the most in demand and respected. This is, of course, a joke. But seriously, Li-Fi technology undoubtedly has a great future.
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What is Li-Fi
A wireless technology that works like Wi-Fi, but is many times faster and uses visible light rather than radio waves. IN laboratory conditions via Li-Fi they were able to transmit data at a speed of 224 Gbit/s, which is 22.4 times faster maximum speed the developing IEEE 802.11ax Wi-Fi standard, 30 times faster than IEEE 802.11ac (it is used, for example, in the 2015 MacBook Pro).
What does this speed allow?
In 1 second, you can download approximately 20 HD movies, an archive of 50,000 photographs, or as much text as a book depository with an area of approximately 2000 square meters contains. m.
How does this work
The role of the router is played by an LED light bulb (sometimes three: red, green and blue), flickering so quickly that the human eye sees a uniform luminous flux. The flicker transmitting information is received by a photodetector, which decrypts the information. This is how the laptop gains access to the Internet. The high speed of Li-Fi is obtained for several reasons: short wavelength, high signal density and wide transmission channel (the frequency spectrum of visible light is much wider than the spectrum of radio waves).
Why Li-Fi is worse than Wi-Fi
Li-Fi is not the most reliable connection. It works well within the room and at a distance of about 10 meters, but the router will not be able to transmit the signal to another room (oddly enough, the light does not pass through the walls). Li-Fi does not require line-of-sight operation. If you place a table between the router and the detector, then Internet access will not disappear: the light will be reflected from the walls and reach the detector, but the speed will drop to 70 Mbit/s. On outdoors the router will only work at dusk or in heavy clouds - and then at a very short distance. In bright sunlight, as with other artificial sources, or, for example, in the case of fog, the router will not be able to transmit data. Wi-Fi has no problems with this.
Why is it better than Wi-Fi?
The most important thing is that it is much faster than connections through regular Wi-Fi routers, and in theory the speed can be increased many times over. Li-Fi is difficult to hack because the signal does not leave the room. The router does not need to waste energy on heating (as is the case with Wi-Fi), so it will work economically. Since the transmission of light remains free, companies will not have to pay for radio frequency licensing.
Where can you use Li-Fi
Developers and journalists have come up with three areas where the Internet will begin to be distributed through light bulbs in the near future. Firstly, on airplanes. Wi-Fi interferes with aircraft instruments and communications, and excess cables add to the weight of the aircraft. Li-Fi looks like an ideal solution: its signal will not go beyond the passenger compartment, and the equipment weighs almost nothing. Secondly, Li-Fi can be used in banks and organizations that value secrecy. In this case, the disadvantage of a Li-Fi router (distributed only within the room) will become an additional security barrier: attackers outside the room will not be able to intercept the signal, and it will be easier to control leaks inside it. Thirdly, industry, heavy data processing and production, where a large amount of data needs to be transferred quickly.
Where is it being used right now?
So far, the system is only being tested, but at the end of last year, the Estonian startup Velmenni installed a Li-Fi network through which data was transmitted at a speed of 1 Gbit/s (for comparison: the fastest Rostelecom tariff in Moscow is 100 Mbit/s). It turned out to be difficult to completely switch to Li-Fi, so Velmenni used a combined network: Wi-Fi and Li-Fi.
Who invented this technology
The principle of operation of Li-Fi was first formulated by 46-year-old German physicist and professor at the University of Edinburgh Harald Haas. Since 2007, he and his students have been experimenting with transmitting data through an LED light bulb from IKEA, and in 2011, Haas spoke about his vision of the future at a TED conference. The professor founded the company PureLiFi, which conducts research and sometimes produces LED routers. Haas's idea was not fundamentally new - in 1880, Alexander Bell tried to transmit sound using a light signal to a device called a photophone. Haas simply derived Bell's experiments from new level and decided to transmit not sound, but information.
Why Li-Fi is needed in the future
Wi-Fi will not cope with the Internet of things, says Haas. By 2020, there will be 20.8 billion wearable devices and smart home appliances in the world, almost three for every person. If they start transmitting data via Wi-Fi in one frequency range, interference will begin to impede transmission. Today, such a drop in speed can be observed in busy places with many working routers. And by 2025–2030 the situation will become more complicated. Haas envisions a world where the Internet can be heard from every light bulb (they need to be modified to do this), videos can be downloaded from a street lamp, and cars communicate with each other through the light of their headlights.
Does Li-Fi belong to one organization?
No, he does research, promotes the idea among manufacturers and obtains funding. But there are other companies: in 2014, they were able to transmit data via light at a speed of 1.25 Gbit/s, Sisoft - at a speed of . Recently, NASA and Apple became interested in Li-Fi (iOS 9.1 code supports light transmission).
When Wi-Fi will end
Most likely not soon (at least in the near future). Even the developers of light transmission admit this. In three to four years, when the first LED routers appear on consumer market, will use a combination of Li-Fi and Wi-Fi networks. But the latter will continue to exist, since Li-Fi still has unresolved problems (outdoor transmission).
Li-Fi introduces a new data transmission technology that should provide one hundred times faster data transfer speeds than Wi-Fi. Li-Fi technology is poised to revolutionize business in the future, setting the stage for a multi-billion dollar industry by 2022. Currently, work is underway to achieve speeds using Li-Fi technology of 1 Gbit/s and higher. This will significantly outperform existing ultra-fast broadband.
At the moment, Li-Fi is just developing, but many companies already intend to invest in it. In the near future she may find wide application, replacing Wi-Fi as much as possible. It is planned that in a few years large-scale commercial use this technology.
Li-Fi technology: device
Li-Fi is an acronym for Light Fidelity, which is a wireless form of communication using visible light. This optical wireless technology enables two-way, high-speed mobile communications using LED light instead of radio waves. Binary data is transmitted through light streams. The term Li-Fi was coined by German physicist Harald Haas.
To ensure Li-Fi operation, the following hardware is required:
- LED lighting system.
- Router installed together with the lighting system.
- A receiver that is equipped with a decoder for the purpose of decoding the light signal.
Li-Fi technology is designed in such a way that electric LED light bulbs can be used as wireless routers.
Today the main components of a Li-Fi system are:
- A bright LED, which is the source of transmitted data.
- A silicon photodiode (photodetector) that can respond to visible light, it is a receiver of transmitted data.
A Li-Fi emitter system in most cases includes four main components:
- LED light bulb.
- High-frequency (HF) amplifier of the power circuit.
- PCB.
- Frame.
A printed circuit board is used to connect the inputs and outputs of the lamp. It includes a built-in microcontroller, which is used to control various functions of the lamp. The RF signal is generated by a solid-state RF amplifier in the power supply circuit, which creates a electric field. High density energy electric field allows you to bring the contents of the light bulb to the state of plasma. This controlled plasma acts as an intense light source. All of the above components are framed in an aluminum housing.
For the human eye, the flickering of the diodes is invisible, and the digital modulation method allows data transmission up to 10 Gbit per second. A special receiver is used to register transmitted packets.
Among the latest developments is a smartphone from Oledcomm, which runs Android. The smartphone has one important modification: instead of a front camera, it has a Li-Fi sensor. The said sensor receives commands from LED lamps that are located near the smartphone, which allows you to view videos or images on the device.
In addition, a prototype of a compact external Li-Fi receiver was demonstrated; it connects to a smartphone via a 3.5 mm connector. Such a receiver allows you to receive Li-Fi data on devices that are not equipped with a module. Oledcomm plans to soon introduce its development into tablets and smartphones, which will allow Li-Fi technology to become widespread.
Operating principle
When a direct current passes through the LED, a continuous stream of protons is emitted, producing a visible glow. When the voltage changes, the intensity of the glow also changes. Since LED lamps are semiconductor devices, the radiation intensity and current can be modulated at fairly high speeds.
These changes in luminescence can be captured by a special photodetector to convert them back into electric current. The human eye is not able to detect modulation of the intensity of the glow, as a result of which the connection is continuous. As a result, Li-Fi technology is capable of LED light bulb transmit streams of information incredibly high speed.
Since 2011, Harald Haas, a specialist in optical wireless data transmission, professor at the University of Edinburgh (Edinburgh, UK), has been seriously promoting a fundamentally new technology for wireless data transmission using flashing LED light. Then most university professors decided that the idea, of course, was interesting, but hardly feasible. And now, four years later, Haas finally created the first router that works according to his concept.
The technology was called Li-Fi (light" - "light", "fidelity" - "precision"). The new router showed such amazing characteristics that it surpassed Wi-Fi speed 100 times, achieving a record data transfer speed of 224 Gb/s in laboratory conditions. The tests in the laboratory were carried out by the Estonian company Velmenni. Haas even equipped his first router to make network access standalone, and the router currently maintains a steady 10Gbps through the subtle flickering of its LEDs.
In order to begin delivering the first production systems to the European market as early as December 2016, the inventor of Li-Fi, Harald Haas, merged his company pureLiFi with Lucibel in order to jointly develop and more effectively promote the innovation closer to the average consumer, so that in the end finally make Li-Fi the main way for users to access the network.
The essence of the technology is as follows. Three color channels miniature LED lamp, red, green and blue, transmit 3.5 gigabits of data per second in parallel, resulting in 10 gigabits per second. Turning the light on and off occurs at breakneck speed, generating huge amounts of binary data.
This is the so-called orthogonal frequency division digital modulation (OFDM), which allows the transmission of millions of beams of light of different intensities per second.
Professor Haas illustrates this with an example of a shower head that emits strictly parallel streams of water, and the light in a Li-Fi system behaves in a similar way.
Meanwhile, Chinese and German researchers have also shown interest in studying this technology. Back in 2011, the Germans managed to obtain data transmission at a record speed of 800 Mbit/s over a distance of 1.8 meters, and the Chinese, using only 1 watt LED, connected four computers to the Internet at a speed of 150 Mbit/s.
Professor Haas emphasizes that light wave technology is more secure than Wi-Fi. It is known that Wi-Fi network you can hack from the outside and intercept files, because radio waves pass through the walls outside the room.
At the same time, Li-Fi traffic can theoretically only be intercepted if you are in the same room where the transmitter and receiver are located, because light does not penetrate walls. Thus, a reliable barrier is put in place for intruders; they will not be able to hack or intercept anything either from the street or even from the next room. But first of all, the advantage of Li-Fi is high speed and low power consumption (the efficiency of conventional routers is best case scenario reaches 5%).
The technology definitely has prospects. Visible light waves have a very wide frequency range, four orders of magnitude wider than that of radio waves. There is no risk that the networks will be overloaded, as with Wi-Fi, neither the speed nor the performance of the networks will be lost.
LEDs are ubiquitous - the infrastructure has practically already been created, and besides, LEDs will be able to perform dual functions - a data transmitter and a light source at the same time. However, the question remains: how well can the system work in a lit room or in bright sunlight?
The developers, however, place high hopes specifically on VLC ("visual light communication") - for transmitting data using visible light, this is what Li-Fi technology is called in scientific language.
The high speed of Li-Fi already allows you to successfully transmit video in HD quality, while maintaining high energy efficiency of the system. Another advantage over Wi-Fi is the accuracy and stability of Internet connections inside buildings. Thanks to the uniform distribution of LED transmitters, the problem of weak and intermittent reception areas is essentially solved.
Andrey Povny
