The black technology LiFi can access the Internet with light, what does it have to do with WIFI?

The biggest difference between LIFI and WiFi is that it does not have a certain range like the WiFi network, after this range, your device will be disconnected from the WiFi network, unless you return to this range, the WiFi network will be reconnected. Lifi is different, it relies on light to propagate, theoretically as long as there is light, you will never be disconnected after connecting to Lifi.

LIFI is a device similar to an AP (WiFi hotspot) by implanting a tiny chip on the bulb to enable the terminal to access the network at any time. This technology transmits data by changing the flickering frequency of the lighting light in the room, as long as you turn on the lights in the room, what network cables, routers, nothing is needed, turn on the lights, your mobile phone, TV, etc. can be connected to the network.

And now, there are already companies that have released such smart light bulbs, and at the recent CES 2018 exhibition in the United States, the foreign company OLEDCOMM released a desk lamp that provides Internet connectivity to nearby devices through light - MyliFi. As long as there is mylifi light, you can surf the Internet. In addition to connectivity, mylifi also offers common smart lighting features, such as the ability to control the duration of the lights and adjust the brightness and color temperature to customize the mood of the lights through the app.

So apart from the fact that LiFi is more convenient, what is better than WiFi? First of all, it's more secure, you can adjust the range and size of the light source at any time to fix the connection of your Internet device. The second is that the network is faster, as the visible spectrum is 10,000 times wider than the RF spectrum.

This means that visible light communication can lead to higher bandwidth.

Lifi is different, it relies on light to propagate, theoretically as long as there is light, you will never be disconnected after connecting to Lifi.

It can be said to be the evolved version of wifi, that is, the upgraded version, which is particularly cool to use.

WiFi can be simply understood as wireless Internet access, and almost all smartphones, tablets, and laptops support wireless Internet access.

He is actually equivalent to a wifi purifier, and also a wifi higher-level mentality.

My dad said it didn't matter, it just had the same function between the two.

This is a further high-tech product of it, and it has a very recommendable aspect.

It shouldn't matter, the wifi connected to the black technology should be faster.

It should be a little more advanced than wifi, but there are still many shortcomings in the statement that you can access the Internet with light.

One is related to light, and the other is related to line, both of which are the same for surfing the Internet.

1. LIFI principle.

Light, like radio waves, is a type of electromagnetic wave, and the basic principle of propagating network signals is the same. Equip an ordinary LED bulb with a microchip, you can control it to flash millions of times per second, with 1 on and 0 on off. Because the frequency is so fast, the human eye is not even aware of it, but the light-sensitive sensor can pick up these changes.

In this way, the binary data is quickly encoded into a light signal and efficiently transmitted. The computer under the light, through a special receiving device, reads the "Morse code" in the light.

2. Lifi

LIFI (Light Fidelity), also known as visible light wireless communication, also known as optical fidelity technology, is a technology that uses the light emitted by the light bulb to transmit data. LIFI technology uses ubiquitous LED lights to implant a tiny chip on the bulb to form a device similar to an AP (WiFi hotspot), so that the terminal can connect to the network at any time. LiFi was originally invented to challenge the original WiFi technology, but due to the limitations of this technology, LiFi can be used as a supplement to WiFi in a small space.

Photosynthetic radios are all carriers, but they just carry broadband signals on them and transmit them.

1. Solve the problem of blockage.

Wi-Fi uses radiofrequency, which is a very limited technology, and devices such as computers, laptops, printers, smart TVs, mobile phones, and tablets must compete with each other for bandwidth.

With the advent of more Wi-Fi-enabled devices such as refrigerators, watches, and cameras, and the distribution of data from mobile networks, traffic congestion has become more and more serious, and the quality of information transmission has also been affected.

Li-Fi uses the frequency of light waves, and its bandwidth is more than 10,000 times that of radio frequency, and it does not conflict with Wi-Fi.

2. Security.

Wi-Fi is known to generate electromagnetic interference (EMI) that can affect aircraft equipment and medical equipment, and is potentially hazardous for power generation, or oil and gas drilling.

Li-Fi uses light instead of radio waves, making it safe and free of electromagnetic interference.

3. Data protection.

Radio waves can penetrate walls and ceilings, but light does not, distinguishing the difference between Wi-Fi and Li-Fi in terms of data protection.

Hackers or intruders outside the building can infiltrate indoor computers that transmit via Wi-Fi.

However, the information transmitted via the Li-Fi can only be accessed within the range of the LED light.

4. Speed.

Standard Wi-Fi provides data communication speeds of up to 54Mbps, and there are technologies that can increase speeds up to 1Gbps.

However, the University of Edinburgh (PurevLC's research partner and the alma mater of Professor Haraldhaas, the father of Li-Fi) has demonstrated 3Gbps speeds using monochromatic light sources.

The use of full-color (red, green, blue) LED lights can be increased to 9Gbps.

5. Throughput.

Theoretically, Li-Fi far outperforms Wi-Fi throughput.

Pureli-Fi has just released a product that enables a single small micro-rent-to-rent LED to transmit at 8Gbps.

Now and the 5GHz band is saturated with existing devices such as wireless**, Bluetooth devices and Wi-Fi, not to mention new technologies like augmented reality, virtual reality, driverless cars and billions of IoT devices.

Lifi is a conceptual way of communication, there is no practical product, although theoretically Lufi is advanced, but no matter how advanced it is, there is no product available and meaningless.

LIFI is advanced, and the principles and differences are as follows:

1. LIFI visible light wireless communication, also known as "optical fidelity technology", English name Lightfidelity (referred to as LIFI) is a new wireless transmission technology that uses the visible light spectrum (such as the light emitted by the light bulb) for data transmission, which was invented by the chairman of the Department of Mobile Communications of the School of Electronic Communication of the University of Edinburgh and the German physicist Professor Haraldhass.

2. Wi-Fi is a technology that can wirelessly connect terminals such as personal computers and handheld devices (such as pads and mobile phones), in fact, it is a high-frequency radio signal.

Visible light wireless communication (which can be called LiFi) is the use of fast light pulses to transmit information wirelessly, and now it may be ready to compete with WiFi. It is entirely feasible to encode information in the light according to different rates, e.g. LED ON means 1, off means 0, and the information can be transmitted by means of a quick switch. Due to the luminous intensity of LEDs, the human eye will not notice the rapid changes in light.

Researchers at the Hertz Institute in Germany have achieved more than 500 megabytes of data transfer per second using standard white LEDs.

However, there are generally more wifi now.

As an emerging industry, there are still many problems with LIWI.

1 Reverse communication The photodiode emitting signals from LED bulbs to mobile phones only solves half of the problem, and how to send signals back from mobile phones to ensure that the communication link is smooth (of course, radio communication can be used as a supplement, but this makes it difficult to standardize this technology). No one wants their mobile phone to have a big light bulb on when they are admiring Wu Pa Liang**. <>

2. Environmental interference The ambient light source sometimes works in the same spectral frequency band, and if the ambient light source is relatively strong, it is very likely that the LIFI will not be able to communicate normally, because the signal-to-interference-to-noise ratio (SINR) is too poor. Can you tolerate the inability to communicate properly in the house when the sunlight is too strong - yes, the IR remote control in your hand can fail when the sunlight is too strong, and the same goes for LiFi. <>

3Communication distance Although there is a reputation for communication in the laboratory to reach a bandwidth of 1Gbps, it is actually difficult to achieve in an installation environment where there is generally no expert guidance. The bandwidth that can be expected should be in the Mbps range.

In fact, the WiFi Alliance is developing a new standard, which also has the characteristics of large bandwidth (7Gbps), short distance (10M), good security performance (unable to pass through walls) and so on at 60GHz communication. Personal experience, to know whether a technology is good or not, we must not only listen to what the advocates of the technology say, but also listen to what the competitors of the technology say. <>

5. Related technology Engaging in visible light communication means that the products made must not only meet the communication standards, but also meet the technical specifications of visible light. There is more certification work to be done for related products, which may not be completed in two years. And how to connect the communication network to each bulb through wired is not so simple, and the current more promising is to cooperate with power line communication (PLC).

It can be seen that there are still a lot of things to do in Lifi.