Science article! What is 5G?

1

Let me start with the reason. Yesterday, I saw a video called "Huawei Beauty" and I felt hot all over. To be honest, I don't comment on any Chinese or Chinese manufacturers. Yesterday, I couldn't stand it anymore and forwarded it and commented on it in my circle of friends, which caused a debate. Because there are some friends in my circle of friends who play football, and I found that they have no idea what 5G is, so I thought I should explain it.

Later I found out that the video was not shot by Huawei, but by Huawei fans themselves. One fan can defeat a hundred haters!

Now everyone is talking about 5G, as if it is another extremely high-tech and cutting-edge black technology that can change the world.

After all, I have worked in communications for several years, so I will talk about what 5G is, hoping that my friends who play football with me can know about it. It is definitely not very accurate, but at least you know what it is.

2

First of all, it should be made clear that, for now, 5G will only affect mobile phone users. I cannot say whether it will affect other aspects in the future. In the foreseeable future, it will not have much impact on computer users. Why? Let me explain. The picture below is called optical fiber. You must have seen it at home:

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There are many kinds of optical fibers. All we need to know is that this thing is very fast. Now in the laboratory, we have achieved xxTbps. Please search for this xx. I think it should be a number between 10 and 99. I don’t know the exact number. Anyway, it will be very fast.

If you can use this technology at home, you can watch dozens of 4K high-definition movies at the same time, no problem at all. But there are two problems now. First, if every household uses it, the operators will not be able to bear it; second, it is inconvenient because you need to connect to the optical fiber, which can only be connected for dozens of meters, like a dog tied with a chain.

Can wireless communication be done through the air? More than 6 billion people in the world have thought of this method. The only problem is that compared to transmitting data through optical fiber, transmitting data through the air is very slow.

This is the point of 5G, how to make data transmission from the air faster. No need to be on a leash to access the Internet.

3

Transmitting data through the air must also obey the laws of physics, which we learned in junior high school or high school: Speed ​​of light = wavelength x frequency.

With current technology, it is difficult to change the speed of light. Is it easy to change the wavelength and frequency? Of course not. Just like people, it is difficult to change a person's wavelength. You may need surgery or silicone filling. Fortunately, there are many people in this world, some with long wavelengths and some with short wavelengths. You can always find a wave with the right wavelength.

So humans have found many waves to do different things. Let me give you a few examples. There are ultra-long waves, with a wavelength of up to 1,000 km, which may be used by submarines for communication; there are long waves, with a wavelength of 1-10 km, which can be used to communicate across the Pacific Ocean. There are medium waves, with a wavelength of 100 meters to 1 km, which is what we listen to on medium-wave radio. There are short waves, with a wavelength of 10-100 meters, which can also be used to listen to short-wave radio. There are also others, such as meter waves, decimeter waves, centimeter waves, millimeter waves... There are certainly more subdivided ones, but they are already used in hospitals for X-rays or chemotherapy.

Let's look at this formula again: Speed ​​of light = wavelength x frequency.

As the speed of light cannot be changed, different waves correspond to different frequencies. The longer the wave, the lower the frequency. So far, no wave with both a long wave and a high frequency has been found.

At present, human technology is limited and cannot use all frequencies for communication. We can only use limited frequencies. At present, China has begun to use 3.3-3.6G and 4.8-5G frequencies, which are 5G.

If the technology is advanced in the future, ultra-high frequency waves will also be used, that’s for sure. At present, 5G is not yet well-developed, so don’t worry about 6G, 7G, 30G… (However, I saw in the news that the laboratory is already researching waves in the 40G frequency band. Live well and don’t stay up late, you can use it!)

The frequency band used internationally is 28G. This kind of thing needs to be purchased. It is not that you can use any frequency band you want. Therefore, starting a government business is a sure-win business. For example, the following news.

The FCC recently released the particulars—including the minimum opening bid prices and the license locations—for its upcoming 28 GHz and 24 GHz spectrum auctions. And the details are somewhat surprising.

Based on the news above, if we calculate based on 28G, the wavelength is approximately 1 cm (if I am not mistaken).

Can you understand what 1 centimeter means?

4

1 cm is only a tiny bit, so anything can block the wave. If you want to block a super long wave, you have to block most of China, but it is too easy to block a 5G wave.

Here are the physical characteristics of waves.

The smaller the wavelength, the easier it is to be blocked and the shorter the propagation distance, but more data can be transmitted.

The larger the wavelength, the less likely it is to be blocked and the longer the propagation distance, but the less data is transmitted.

Therefore, everyone is fighting for the right-sized wave. It won’t work if it’s too big or too small. Only the right wave will work! Therefore, all operators are fighting for it. There are only a few golden frequency bands. If they are allocated to you, they can’t be given to me. If the frequency band is a little worse, tens of thousands or hundreds of thousands of base stations may be built, which costs a lot of money…

5

Of course, there are more details about 5G, which I don't understand. There are technologies related to antennas and beams, but it is definitely not some black technology that has fallen from the sky. I have seen many media reports about dimensionality reduction and two-dimensional foil. How can the United States be so weak?

5G may be the largest communication frequency band currently available to humans, but it must also comply with the laws of physics. It is not some black technology that only you can use but others cannot. It is more of a continuation of the technologies of 1G, 2G, 3G, and 4G, rather than a revolutionary technology.

Speaking of revolutionary technology, are there any kings, princes, generals or ministers of different species? If someone comes along who doesn't rely on waves to communicate, that's revolutionary technology!