5G technology has already approached the Shannon limit, what else can 6G do?

On May 17, China Unicom and ZTE Corporation signed a 6G joint strategic cooperation agreement. The two parties will conduct cooperative research on 6G high-potential key technologies, including space-ground integration technology, terahertz communication technology, visible light communication technology, etc., and actively promote the deep integration of 6G with satellite networks, the Internet of Things, the Internet of Vehicles, and the Industrial Internet.

6G will build a global communications network

6G technology, the sixth-generation mobile communication standard, may have a transmission capacity 100 times higher than 5G, and network latency may be reduced from milliseconds to microseconds.

On March 9, 2018, Miao Wei, Minister of Industry and Information Technology, said that China has started to study 6G. On November 3, 2019, the Ministry of Science and Technology, together with the National Development and Reform Commission, the Ministry of Education, the Ministry of Industry and Information Technology, the Chinese Academy of Sciences, and the National Natural Science Foundation of China, held a 6G technology research and development kick-off meeting in Beijing. The cooperation between China Unicom and ZTE can be regarded as the implementation of national policies at the operator and enterprise levels.

Globally, the research and development of 6G is also in full swing. As early as 2018, Finland began to study 6G-related technologies. In March 2019, the US Federal Communications Commission (FCC) unanimously voted to open the "terahertz wave" spectrum in the hope that it will one day be used for 6G services. In addition, the European Union, Russia and other countries are also carrying out related work.

The low-frequency band used by 5G (5th generation mobile communication) is essentially the same as the 4G (4th generation mobile communication) we are using now. It mainly uses multiple-input and multiple-output technology (MIMO) and non-orthogonal multiplexing technology (NOMA) to increase channel capacity. In the 6G stage, since 5G technology is approaching the "Shannon limit", it will take the approach of increasing channel bandwidth.

At present, the main 4G frequency bands of my country's three major operators are between 1.8GHz and 2.7GHz, while the mainstream 5G frequency band defined by the International Telecommunication Standards Organization is 3GHz-6GHz, which belongs to the millimeter wave band, and 6G will enter the higher frequency terahertz band.

The higher the signal frequency, the shorter the wavelength, so the diffraction ability of the signal is worse and the loss is greater. And this loss will increase with the increase of transmission distance, and the coverage range of the base station will decrease accordingly.

The frequency of 6G signals is already at the terahertz level, so the distance they propagate in space is not as far as 5G signals. 5G base stations are already much denser than 4G base stations, and the 6G era will be even denser. This will not only solve the problem of indoor navigation, but also bring about a new relationship between people and technology.

Although many industry experts call this method of increasing channel bandwidth "no G after 5G", meaning that 5G technology has already approached the "Shannon limit", the only thing left for the future development of communication technology is the quantitative expansion of technology, that is, improving channel frequencies, and there will be no technological progress.

But for the economy, society, and people’s daily lives, this is not important. As long as 6G technology can bring about enough changes, it can still be called a new generation.

In terms of coverage, in the 6G era, satellites, aviation platforms, ships, hot air balloons, etc. will jointly build a global communication network integrating ground communication, satellite communication, and marine communication. Deserts, uninhabited areas, oceans and other "blind spots" of mobile communications today are expected to achieve signal coverage.

From the application perspective, 6G has great potential in scenarios such as space communication, intelligent interaction, tactile Internet, emotional and tactile communication, multi-sensory mixed reality, machine-to-machine collaboration, and fully automatic transportation.

Do a good job in 6G research and development and strive to become a global technology leader

It should be noted that 6G is still far from being truly realized. Huawei once said that the development of 5G and 6G is parallel, but the large-scale use of 6G is still a long way off. Yu Chengdong responded: "6G is under development and it is estimated that it will take another 10 years. But even so, it is inevitable to prepare as soon as possible."

First, researching and developing one generation and commercializing one generation is a common strategy for enterprises in modern high-tech industries. In fact, most of the research and development expenses of these high-tech enterprises are used for the development of new technologies and new products. Only in this way can the competitive advantage of enterprises be guaranteed.

More importantly, 6G provides Chinese communications companies with an opportunity to accelerate development.

"First-rate manufacturers make standards, second-rate manufacturers make solutions, and third-rate manufacturers make products." This is the consensus in the communications industry. In the 3G era, CDMA stood out from the three major mobile communication standards, establishing Qualcomm's position within the industry and even in the global economy.

At that time, in addition to selling chips, Qualcomm also charged patent fees for related technologies to telecommunications equipment manufacturers and operators around the world, making a huge profit. It quickly grew from a small company founded by seven people in 1985 to one of the most important communications companies in the world.

China's communications industry was blank in the 1G era, could only follow in the 2G era, began to participate in the 3G era, ran side by side with other global companies in the 4G era, and became one of the leaders in the 5G era. Therefore, doing a good job in 6G research and development and striving to become a global technology leader is an opportunity that Chinese companies should seize in the communications field.

The ultimate goal of a company's technology research and development is to make money, not to win the championship in the competition. These are two completely different goals. The former involves global cooperation, technical compromise, calculating profits and losses, and achieving sustainable development; while the latter is more about competition, overwhelming, and not considering financial gains and losses. A large amount of subsidies make it difficult to promote such technology in the global market.

Therefore, we should keep a normal mind towards 6G. Only in this way can China's 6G research and development go better, more steadily and long-term.