In the future, 5G may be the foundation of everything~
1. What is 5G?
The full name of 5G is: fifth-generation mobile communication technology . The English corresponding translation is "5th generation mobile networks" or "5th generation wireless systems". So for short: 5G !
2. The most primitive communication technology
Communication is inseparable from "waves". What is a wave?
Wave : a form of vibration propagation. For example, water waves, sound waves, electromagnetic waves.
Sound wave is our most primitive communication technology. The dialogue between people is the most basic communication.
When we speak, we control the vibration of the vocal cords to produce sound waves. The sound waves are transmitted into the air, drive the air to vibrate and spread out, so that it can be heard by others and complete the most primitive communication.
Sound waves have a big limitation. It needs a carrier to propagate, such as air. This causes the sound wave to attenuate quickly during propagation, and the propagation distance is very short. If the speaker is slightly quieter, it may not be heard 10 meters away.
3. 1G-analog communication
In order to make the communication distance farther, scientists have continued to study and found that acoustic waves and electromagnetic waves can be converted mutually through technical means.
Both sound waves and electromagnetic waves are waves. The difference is that electromagnetic waves travel very fast (equal to the speed of light in a vacuum), and they can travel without relying on a carrier, and the distance far exceeds that of sound waves. So scientists began to study electromagnetic waves and used them in communication technology.
In order to realize the conversion between electromagnetic waves and sound waves, scientists invented a device-"Big Brother", which is the original mobile phone.
In the 1G era, through this conversion technology, scientists have realized the "thousand-mile transmission", which greatly increases the distance between people.
For example, "Little A" who owns "Big Brother" wants to call "B" who also owns "Big Brother" thousands of miles away. When Little A’s voice is converted from "Big Brother" into electromagnetic waves, it is transmitted to the "base station" near Little A through the antenna. After receiving the electromagnetic waves, the base station amplifies the signal, and then transmits the amplified electromagnetic waves to nearby Base station. In this way, it passes through the base station one by one, and finally transmits to the base station near "B". After B's "Big Brother" receives the signal, it converts electromagnetic waves into sound waves and simulates the sound of Little A. This is the original-analog signal communication technology.
In old movies, we can often see big brothers using "Big Brother" communication. However, the two parties "hey, hello, hello..." for a long time, and could not hear what the other party said, or the conversation was intermittent, not clear...…
This is because, after electromagnetic waves are emitted from a base station, they have to pass through a large number of obstacles, climb mountains and wading through the water, before reaching the next base station, and the signal is easily lost or interfered during the propagation.
4. 2G, 3G, 4G-digital communications
In order to solve the problems of 1G analog communication technology, scientists continued to study and found that sound, text, pictures, video, etc. can all be converted into " binary ".
Binary, a form of data representation composed of 0 or 1 .
Through binary, scientists have converted analog signals into digital signals. The biggest advantage of digital signal is: anti-interference. Even if the signal is disturbed or seriously attenuated, the content can be accurately identified.
Therefore, in the 2G era, mobile phones have screens, and people can communicate through text messages in addition to making calls.
In fact, 3G and 4G are not much different from 2G in essence. It is nothing more than using technical means to increase the frequency and increase the frequency band on the basis of 2G , so that the signal carries more information.
3G allows people to go online and view pictures through a browser. 4G has solved the demand for watching videos online.
Five, why the Internet speed is getting faster
The speed of electromagnetic waves does not change by default, so there is no such thing as "increasing the speed of electromagnetic waves to increase network speed".
When we usually talk about faster internet speeds, we mean: more data can be transferred per unit time. Upload and download speed also refer to how much content is uploaded and downloaded per second. For example, if you download resources of the same size, the more content you download per second, the faster the overall download speed will be. This speed of uploading and downloading is called "bandwidth". The greater the bandwidth, the faster the upload and download speed, and the faster the internet speed.
Increasing the frequency can be understood as increasing the vibration speed of electromagnetic waves. The faster the vibration and the higher the frequency, the more data can be transmitted per unit time.
Increasing the frequency band can be understood as an electromagnetic wave channel with more vibration frequencies. Using one frequency band for communication is equivalent to a single lane, and using multiple frequency bands for communication is equivalent to multiple lanes. The more channels, of course, the more data will be transmitted.
Let's look at another magic formula:
This is the definition formula of the speed of light in physics, c means the speed of light, λ means the wavelength, and v means the frequency, namely: "speed of light = wavelength x frequency" .
We know that the speed of light is constant, a fixed value: 3x10^8m/s. (300,000 kilometers per second)
From the speed of light formula, we can infer: the speed of light does not change, the shorter the wavelength, the higher the frequency .
The higher the frequency, the more information it can carry. Therefore, the more content is downloaded every second. This is why 3G is faster than 2G and 4G is faster than 3G.
Six, 5G communication
With the above background knowledge, let's talk about 5G... finally 5G!
5G uses ultra-high frequency, even millimeter wave.
Let's take a look at the classification of electromagnetic waves:
In different countries, the 5G frequency bands allocated to different operators are also different.
In our country, there are three major operators: telecommunications, mobile, and China Unicom. The 5G frequency bands allocated to them are as follows:
电信：0.34GHz - 0.35GHz
移动：0.2515GHz - 0.2675GHz，0.48GHz - 0.49GHz
联通：0.35GHz - 0.36GHz
Technically, low-frequency electromagnetic waves are easier to use, so the development process from 2G to 5G is actually an expansion process from low-frequency utilization to high-frequency utilization.
Limited by technology, low-frequency electromagnetic waves were first developed and utilized. With the continuous development of science and technology, high-frequency electromagnetic waves are gradually being developed and utilized.
Up to now, we use ultra-high frequency communication, the corresponding technology is called: 5G!
END.
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