Since the advent of 5G, there has been controversy over whether it is true or false. Qualcomm calls itself "real 5G" and often mocks others as "fake 5G." If we had used "true 5G" to build all base stations as Qualcomm recommended. Then we are likely to encounter the following scenario.
You were playing with your mobile phone on a bench in the woods in the park, but the signal was not very good. An old man passing by told you, "Wait until winter comes again, this is what summer is like."
While watching a play in the theater, a friend sent you a short video, but the signal was not good. You looked forward and found the reason, "Brother, can you lower your head? You are blocking my 5G signal."
Regarding the 5G band, it is currently divided into two technical directions, namely Sub-6G and high-frequency millimeter wave. Sub-6G uses the bandwidth resources of traditional bands such as 2G, 3G, and 4G to develop 5G.
The biggest advantage of high-frequency millimeter wave is its fast speed, which can reach more than ten times that of Sub-6G, but its shortcomings are also obvious. It attenuates extremely seriously in high-humidity environments, has very poor penetration ability, and the distance is not long. If you encounter rainy weather, take a walk under the woods, or turn into an alley, the network will fluctuate greatly. It cannot provide continuous coverage outside, nor can it replace WiFi through walls indoors, which seems a bit "waste".
It used to be said that the United States has taken the wrong path when it comes to 5G nodes. Now we are also developing high-frequency millimeter wave 5G. Doesn’t that mean that the United States is on the right track? In fact, the United States is the only country in the world that mainly promotes millimeter waves. Although Qualcomm says that millimeter wave is true 5G and has huge advantages, the embarrassment is also unspeakable. After all, the US military, which wins by fire and can call for air support if something goes wrong, occupies so much Sub-6G frequency band that there is not enough frequency band for 5G commercial use. This leads to the idea of ??"skipping 5G and directly developing 6G". I guess the United States still has to make up for it. It was not until August this year that the U.S. Department of Defense cleared the 100MHZ mid-band spectrum from the military communication spectrum and used it for 5G commercial use without affecting military radar.
Just when the US military was clearing frequency bands for 5G commercial use, our country had built more than 700,000 5G base stations, and the main frequency band was of course Sub-6GHz. This frequency band has long transmission distance and wide coverage. Compared with high-frequency millimeter waves, it requires fewer base stations to achieve the same coverage effect. At the same time, the Sub-6G frequency band can also follow the development route at the beginning of 4G, providing multiple network standards on one device, which can reduce the total weight of the base station. At the same time, the related radio frequency component industry chain in the Sub-6GHz frequency band is also relatively mature.
On the road to 5G development, our country has indeed led the world. In the 4G era, there are more than 6 million base stations in the world, and my country accounts for 4.5 million. If all are upgraded to 5G base stations, which country in the world can compare? It can be regarded as the world’s largest 5G application incubation market. With such a big market, what don’t you want to do on 5G millimeter wave? Moreover, key millimeter wave technologies have now achieved breakthroughs. Just on June 15, Liu Yunjie, an academician of the Chinese Academy of Engineering, said that Nanjing Network Communications and Security Purple Mountain Laboratory has developed a CMOS millimeter wave fully integrated 4-channel phased array chip and completed chip packaging and testing. The cost per channel is from 1,000 Yuan dropped to 20 Yuan.
From this point of view, our country is taking the correct route from popularizing Sub-6G to millimeter wave. Only the United States is fully betting on millimeter waves, but it has cheated itself.
Regarding millimeter waves, they are not useless. Chi Yongsheng, deputy director of China Unicom Network Technology Research Institute, believes that millimeter waves are very suitable for "three major scenarios."
First of all, millimeter waves can be used for hotspot coverage in Class A scenarios. Category A scenarios are similar to areas such as airports, universities, and four-star or above hotels. In these scenarios, a mixed high- and low-frequency networking method can be used to deploy millimeter waves for precise coverage and distribution in high-traffic areas.
Secondly, millimeter waves can be used for private network services.
The combination of millimeter waves and industry private networks can provide more flexible broadband services for industry applications than public networks. In particular, the combination of 5G millimeter wave with AI and edge computing technology will bring extensive and revolutionary applications to the industry. The so-called edge computing refers to the decentralization of data processing, application operation and even the implementation of some functional services from the network center to nodes at the edge of the network.
Finally, millimeter waves can be used for wireless backhaul links. 5G millimeter wave can provide a system peak rate of up to 800MHz bandwidth and 10Gbps. Using it as a wireless backhaul link can solve the problem that optical fiber cannot be deployed or the cost of deploying optical fiber is too high in some scenarios.
Just recently, Feng Yi, director of China Unicom’s Intelligent Network Innovation Center and 5G Innovation Center, said: China Unicom has successfully conducted 5G millimeter wave experiments in some venues (for some competitions in Beijing), and the peak rate can reach 9Gbps!
In short, the Sub-6G band can be understood as a mass application, while high-frequency millimeter waves are niche and professional applications. They are all the development directions of 5G technology and are worthy of development. Industrial innovation also has a kind of "inspired innovation", which is more dependent on the environment. What do you think?