Domestic 5G Construction is Accelerating, and Millimeter Wave Spectrum is Expected to be Commercialized

2020 is a recognized year for 5G construction in the industry. With the continuous increase of new infrastructure and policies, 5G is poised. As we all know, the 5G frequency band is mainly divided into two categories which are Sub-6GHz and millimeter wave (24GHz-86GHz). The current domestic 5G scene applications are all Sub-6GHz. As a high-frequency wave, millimeter wave has been unable to enter the operator's "eye" because its disadvantages like its short transmission distance and "a piece of paper can block the signal". However, under the Sub6GHz 5G network, the peak rate of a single user is still at the 100M level. In order to meet the expected 8 KPIs under 5G, larger bandwidth resources have to be explored in high frequency direction. The ultra-high transmission rate, large capacity and extremely low latency of the millimeter wave frequency band may become next stage important direction of 5G development.

      Millimeter wave may become the key to 5G development

According to the 3GPP agreement, 5G networks mainly use two frequency bands which are FR1 frequency band and FR2 frequency band. The frequency range of the FR1 band is 450MHz-6GHz, also known as sub-6GHz band; the frequency range of the FR2 band is 24.25GHz-52.6GHz, usually called millimeter wave (mmWave). The industry is very familiar with the frequency bands below 6GHz, and the current 4G LTE networks all operate in this frequency band, while they are unfamiliar with millimeter waves.

Millimeter wave is electromagnetic wave with wavelength of 1 to 10 millimeters. It has the characteristics of large bandwidth and narrow wave beam. In the past, it was only used in militarized fields such as satellite communications and radar positioning.

Its advantages are very outstanding, it is high-speed and high-capacity, millimeter wave can provide up to 400 to 800MHz great carrier bandwidth, which is dozens of times higher than 4G's 20MHz, and can increase the transmission rate of 5G networks to 10Gbps. Its disadvantages are also obvious, the millimeter wave has short transmission distance, it will affect the transmission if there are trees in the transmission range or meet raining or haze. This is why in the 30 years of the development of mobile communications, millimeter waves have always been in the "barren land" of mobile communications.

      With the arrival of the 5G construction wave, the advancement of millimeter wave technology will be the key. It is reported that the currently widely used 4G LTE cellular system based on the sub-6GHz frequency band can use the maximum bandwidth of 100MHz, and the data rate does not exceed 1Gbps. In the millimeter wave frequency band, the maximum bandwidth that can be used is 400MHz, and the data rate is as high as 10Gbps or even higher, such bandwidth performance can meet the needs of users for specific scenarios in the age of 5G. Generally speaking, 5G millimeter wave network speed is very fast, even faster than Sub-6GHz 5G, 5G could reach up to 20Gbit/s in ITU IMT-2020 specification requirements. It’s not possible to achieve rely on Sub-6GHz alone, need use millimeter waves.

 5G millimeter wave technology is taken seriously

  With the arrival of 5G, more and more countries and companies begin to support 5G in the millimeter wave spectrum. Some countries have taken the lead in completing 5G millimeter wave spectrum allocation such as Europe, the United States, Japan and South Korea, and some have begun commercial use, focusing on providing high-performance 5G services for high-value areas. Among them, Qualcomm from America took the lead in 5G millimeter wave research, it launched Snapdragon 865 and external X55 baseband supporting 5G chips of millimeter wave; Samsung is studying millimeter wave technology in South Korea and the United States.

     In China, the "Notification of Promoting 5G Accelerated Development" (hereinafter referred to as the "Notification") issued by the Ministry of Industry and Information Technology not long ago mentioned that it is necessary to continue to increase the research and development of 5G technology and strengthen the research and development of 5G technology and standards. Organize and carry out research and pilot projects of virtual private networks in the 5G industry to get through key links such as standards, technologies, applications, and deployment. At the same time, the "Notification" also mentioned that it is necessary to publish some 5G millimeter wave band frequency application plans timely, carry out special frequency planning studies for the 5G industry (including industrial internet), and implement frequency licenses for technical trials timely.

      Academician Wu Hequan of the Academy of Engineering said that in terms of frequency, we are now working in the frequency band below 6GHz (Giga Hertz), this frequency band is faster than millimeter wave land to build a network, but the highest peak bandwidth that can be obtained is not as good as that of millimeter wave frequency band, in the future, China will still use millimeter wave frequency bands in 5G.

     In the next few years, more than 15 countries are expected to join the 5G millimeter wave club.

   Efforts are still needed to achieve commercialization

   Millimeter wave is very important to the development of 5G in the future. At the same time, with the acceleration of 5G construction, millimeter wave will also usher in a broad space for development.

   According to forecast from the GSMA report, the deployment of 5G millimeter wave applications in Industry 4.0 scenarios and interconnected transportation scenarios will bring many benefits. Millimeter wave spectrum, especially in the 24.25-27.5GHz and 37-43.5GHz bands, can provide necessary continuous spectrum for the bandwidth applied to large data-intensive 5G.

  The report also forecasts the structure of Chinese 5G millimeter wave application scenario. Among them, manufacturing industry and utilities such as water and electricity in the vertical industry are currently the industries with the largest visible contribution, accounting for 62% of the total contribution, followed by professional services and financial services at 12%, information communication and trade at 10%, the last is agriculture and mining and public services. Driven by innovative services brought about by 5G millimeter waves, China will account for 53% of the US$212 billion economic growth in the Asia-Pacific region by 2034

  Even so, there are still some problems to be solved for millimeter wave to be commercialized at the moment. Millimeter wave in communication applications, 5G is the first time it has been applied to cellular communications, it was mainly used for point-to-point transmission or indoor WLAN previously. For cellular communications, the required industrial chain is different from point-to-point transmission, including the need for performance, the processing capacity is not completely consistent with point to point transmission, so many aspects need to be improved. Some experts said that compared with low frequency bands, the overall industry chain of millimeter wave is not sufficiently mature, including the maturity of devices, and it is necessary to further promote the maturity of the overall industry chain.

China is currently focusing on 5G commercial use at sub-6GHz. During this period, the domestic millimeter wave upstream and downstream industries should accumulate technology as soon as possible to narrow the gap with the top level abroad. At the same time, the project is ready to be set up for above 52.6GHz communication standards in R17. The communication standard of this part of the frequency has not yet been completed, but also needs to be completed. In addition, under what application scenarios can the advantages of millimeter wave be fully utilized and the disadvantages reduced, it is also a something taht the entire industry needs to fully demonstrate.