After the read, you will learn about:
What is millimeter-wave
What is a 5G millimeter-wave
Advantages of 5G millimeter-wave technology
Application scenarios of 5G millimeter-wave
The millimeter waves refer to electromagnetic waves with millimeter-level wavelengths, usually in the 30-300 GHz frequency band, and often include frequency bands above 24 GHz.
5G networks need millimeter waves to support higher speeds and lower delays and provide communication infrastructure for various new applications.
Compared with 4G, a key improvement of 5G is to be able to use more spectrum resources to meet different types of business needs, including the use of millimeter-wave frequency band resources to achieve extremely high bandwidth and extremely low delay.
With the continuous increase in bandwidth requirements of services, the communication spectrum continues to extend to higher frequency spectrums. 5G millimeter wave has abundant frequency resources, which is the inevitable direction of mobile communication technology evolution.
In 2020, 5G has already begun large-scale commercial use, and the entire industry has begun to focus on the key technologies deployed in the next stage of 5G. Among them, the 5G millimeter wave has attracted much attention and attention from the industry.
5G millimeter wave has outstanding advantages such as high bandwidth and low latency, which can fully release the full potential of 5G, thereby realizing the improvement of business experience and the digital transformation of thousands of industries, and truly realizing the vision of 4G changing lives and 5G changing society.
Both millimeter-wave and Sub-6GHz in the mid-and low-frequency bands have their own technical advantages. Only when 5G millimeter-wave and Sub-6GHz cooperate and complement each other can the full potential of 5G be fully released, providing key enablement for transforming user experience and promoting the digital transformation of the industry.
According to forecasts by GSMA and related market research agencies, 5G millimeter wave, as a core enabling technology for high-speed access, industrial automation, medical health, intelligent transportation, virtual reality, etc.,
It is expected to contribute 565 billion US dollars to global GDP by 2035 The contribution of 5G, accounting for 25% of the total contribution of 5G; before 2034, the economic benefits brought by the use of 5G millimeter-wave frequency bands in China are expected to reach about 104 billion U.S. dollars, of which the vertical industry sectors such as manufacturing and hydropower utilities Accounted for 62% of the total contribution, professional services, and financial services accounted for 12%, and information communications and trade accounted for 10%.
Advantages of 5G millimeter wave technology
GSMA has made a good summary of the advantages of this technology in its 5G Millimeter Wave Technology White Paper. Its most important advantage lies in its abundant frequency resources and huge bandwidth. 5G millimeter wave has more abundant spectrum resources than the 5G Sub-6 GHz frequency band (FR1), and it is the main way for 5G networks to provide gigabit connectivity. To meet the 5G maximum speed requirements, 5G millimeter waves must be used.
5G millimeter-wave networks can easily achieve Gbps-level peak throughput rates.
For example, to allocate a continuous 800MHz spectrum in the 26 GHz frequency band, four single-carrier 200MHz (4*200MHz) or eight single-carrier 100MHz (8*100MHz) can be used to implement carrier aggregation transmission.
Based on the available channel width and modulation method of the 3GPP standard, combined with advanced antenna design and radio frequency processing technology, the 5G millimeter-wave system can easily obtain peak data throughput rates above several Gbps.
At present, 5G millimeter wave has been commercialized in some countries and regions. Based on the latest measured results of the Ookla speed test, the average download rate of the 5G Sub-6GHz network is 5 times faster than the 4G LTE, and the average download rate of the 5G millimeter-wave network is the same as that of 5G Sub-6 GHz. Compared with that, it is 4 times faster, the average rate is as high as 900Mbps, and the peak rate exceeds 2Gbps.
This result was achieved in a 400MHz bandwidth, and better results are expected to be obtained using 800MHz bandwidth in the future.
Therefore, compared with 5G sub-6 GHz, 5G millimeter wave technology still has a lot of room for improvement in user peak rate.
The second advantage of the 5G millimeter wave is that it is easy to combine with beamforming technology.
The high-frequency band and short wavelength of 5G millimeter-wave give it a space advantage in design and deployment. It is very suitable for combining with beamforming technology to enhance performance and reduce interference.
In a typical antenna array configuration, assuming that the base station has 256 antenna elements, the theoretical beamforming gain that 5G millimeter waves can obtain can reach 24dB; if the terminal has 8 antennas, the gain can reach 9 dB.
For example, when performing outdoor coverage, if 5G millimeter-wave base stations and 4G LTE base stations are completely co-located, and the numbers are equal, the downlink coverage rate of 5G millimeter-wave networks can reach 77%. If the number of 5G millimeter-wave base stations is slightly increased, the downlink coverage rate can reach 95%.
The third advantage of the 5G millimeter wave is that it can achieve extremely low latency.
The air interface time slot length of the 5G millimeter-wave system is 1/4 of that of the current mainstream 5G medium and low-frequency systems, and the air interface delay is significantly reduced. It is a strong guarantee to meet the 5G air interface delay of less than 1 ms. It can realize the 5G network to the industrial Internet, AR/VR, and the quality promise of URLLC (high reliability and low latency) services such as cloud gaming and real-time cloud computing.
For example, AR/VR services require millisecond delays to ensure multi-sensory coordinated experience and interactive capabilities; typical industrial robot networks also require millisecond delays; remote real-time control on product lines also requires milliseconds The time delay guarantees the industrial vision, etc., the large-scale calculation required for the introduction of artificial intelligence often needs to be performed at a certain distance, and there are strict requirements on the sub-millisecond level of air interface delay.
The fourth advantage of the 5G millimeter wave is that it can support dense cell deployment.
The 5G millimeter-wave system can use the characteristics of beam orientation to focus the signal energy in a specific direction to reduce interference to other non-target objects and ensure the communication quality of adjacent links or adjacent cells. It is very suitable for large venues such as conference rooms, concerts, Deployment in densely populated areas such as stadiums and subway stations.
The fifth advantage of the 5G millimeter wave is that it can perform high-precision positioning.
The 5G millimeter wave has a narrow beam, good directivity, and extremely high spatial resolution. At the same time, due to the small-signal transmission period and high time accuracy, a 5G millimeter wave is expected to achieve centimeter-level positioning. Even compared with global satellite positioning and navigation systems, there are advantages in accuracy and speed. Especially in indoor environments where satellite navigation signals are weak, the positioning capabilities of 5G millimeter waves will play a more important role.
These technical advantages of the 5G millimeter wave will create business application prospects beyond imagination for the industry.
It is currently predictable that 5G millimeter waves will be used in hotspots such as indoor and outdoor transportation hubs and stadiums to cover application scenarios, fixed wireless access (FWA) in homes and office buildings, and industrial use cases such as the industrial Internet.
In application scenarios such as indoor and outdoor transportation hubs and stadiums, there are a large number of users, and the data service demand during peak periods is huge. Millimeter waves can well meet the connection needs of these hot spots.
In addition, in the network deployment of homes and office buildings, 5G millimeter waves can be used as the backhaul of low-frequency base stations or provide broadband services through CPE to achieve good support for high-definition video, AR/VR, and other services.
In the field of industrial Internet, related tests have shown that even in a complex industrial environment, 5G millimeter wave technology plus ultra-reliable low-latency communication (URLLC) technology can provide excellent performance and meet the requirements of industrial robot networks with as low as 1-millisecond delay and The stringent requirements of up to 99.9999% connection availability rate, and can provide high-definition video transmission for high-density industrial handheld devices and surveillance cameras.
Challenges and solutions of 5G millimeter wave
The 5G millimeter wave has relatively limited coverage due to its high-frequency band, high propagation loss, weak diffraction, and diffraction capabilities, and this is the biggest challenge facing the 5G millimeter-wave communication system.
According to the actual measurement results of China Unicom, the penetration loss of 5G millimeter waves is much higher than that of Sub-6GHz. At the same time, severe weather such as rain, snow, and fog also has an adverse effect on the propagation of millimeter waves.
This has caused the industry to misunderstand 5G millimeter waves, thinking that it can only achieve line-of-sight transmission and fixed transmission. However, there are many solutions to solve the problem of 5G millimeter-wave signal attenuation and blocking.
First of all, 5G millimeter-wave increases EIRP (equivalent isotropic radiated power) through advanced beamforming technology, improves coverage, and can easily achieve signal transmission of hundreds of meters and alleviate path loss problems. This technology is not only verified through simulation experiments but also fully verified in field tests and commercial deployments.
Secondly, in 5G standardization, 5G millimeter-wave beam management has become the focus of 5G millimeter-wave standardization, including beam search, beam tracking, and beam switching, so that the 5G millimeter-wave system can quickly capture when some directional signals are blocked. New beam and dynamically implement beam switching.
Finally, advances in semiconductor materials and packaging technology have also promoted the rapid development of 5G millimeter wave technology, which can integrate large-scale array antennas and RF links into a more cost-effective phased-array radiofrequency device (RFIC), which is 5G millimeter-wave in hardware the system provides strong support.
In response to these challenges, Qualcomm’s idea is to provide more effective integration and optimization through a complete system-level solution.
At present, mainstream equipment and chip manufacturers support 800M bandwidth, and Qualcomm has multiple generations of commercial millimeter-wave antenna module products that can support millimeter-wave, full-frequency bands.
Another solution to the 5G millimeter wave coverage problem is to use small cell technology.
In the 5G era, it is difficult for a single base station type to meet all communication requirements and deployment scenarios. Compared with 5G medium and low-frequency macro stations, 5G millimeter-wave Small Cell base stations have a relatively small coverage radius and a greater deployment density. The communication distance can be reduced to ensure high peak throughput, and the deployment density can be increased to fully ensure coverage.
Small Cell base stations can be deployed in a wide range of scenarios. They can be deployed indoors or outdoors. To match different deployment scenarios and usage requirements, different 5G network architectures from distributed to centralized can be used. The most typical deployment scenarios are various hot spots. Areas, such as conference rooms, large stadiums, concert halls, and various transportation hubs such as airports, railway stations, and subway stations.
The second challenge facing 5G millimeter waves is the terminal mobility management problem.
Due to the characteristics of high-frequency signal propagation, the coverage radius of 5G millimeter-wave cells is usually small, and the terminal is prone to interruption of data transmission due to frequent cell switching in the mobile state. The 3GPP standard proposes a cell handover scheme and a fast beam recovery mechanism for this problem.
In addition, operators can adopt the 5G deployment strategy of 5G Sub-6 GHz+4G LTE+ millimeter wave, and use carrier aggregation (CA) technology and dual connection (DC) technology to organically combine low frequency and 5G millimeter waves to provide the ultimate user experience.
The third challenge facing the 5G millimeter wave is the high product complexity and the difficulty of implementation, especially the antenna design.
In response to this challenge, the industry has proposed the AiP (Antenna in Package) solution. With the advancement of packaging materials and processes, the antenna, RF transceiver, and RF front end are integrated into the package to achieve system-level wireless communication functions. AiP technology conforms to the trend of increasing integration of silicon-based semiconductor processes while taking into account antenna performance, cost, and volume.
The mobilization of millimeter waves is the key, and the initial stage of 5G millimeter wave deployment focuses on smartphones. The millimeter-wave module developed by Qualcomm integrates an antenna, RF front-end, and transceiver in a very compact size. A mobile phone can use multiple such modules, which not only meet the compact and slim design requirements of smartphones but also meets power consumption. Demand and provide maximum performance.
Application scenarios of 5G millimeter wave
5G millimeter wave is suitable for three major application scenarios: indoor and outdoor transportation hubs/venues and other hot spots; industrial Internet and other industrial applications; home/office building and other wireless broadband access.
It can meet the requirements of related services for large bandwidth, low latency, precise positioning, and flexible deployment.
As of August 2020, 22 operators including the United States, Japan, and South Korea have deployed millimeter wave 5G systems, and more than 120 operators are actively investing in millimeter waves.
At present, mainstream mobile communication equipment providers have launched base station equipment that supports 5G millimeter waves, and chip manufacturers and terminal equipment manufacturers have also released more than 100 5G millimeter wave products.
ZTE and other communication manufacturers are actively carrying out 5G millimeter-wave R&D, functional testing, and field trials to prepare for large-scale millimeter-wave commercial use. It is to fundamentally solve the problem of poor millimeter wave coverage; design unique array antenna architecture, beam algorithm, and reflector technology based on the beam characteristics of millimeter-wave; actively participate in the formulation of 3GPP standards and understand the technical details.
According to the overall planning of China’s IMT-2020 (5G) Promotion Group, China will advance 5G millimeter-wave test work in three stages: in 2019, it will focus on verifying 5G millimeter-wave key technologies and system characteristics; in 2020, it will focus on verifying 5G millimeter-wave base stations and terminal functions, performance, and interoperability; from 2020 to 2021, we will carry out application verification in typical scenarios.
According to the Wireless Technology Research Institute of China Mobile Research Institute, from the perspective of China Mobile, millimeter wave is expected to have the capacity for large-scale commercial use in 2022, and the deployment of millimeter-wave networks based on SA will be an ideal choice for operators.
China Mobile will consider adopting carrier aggregation and dual-connection deployment methods to cooperate with frequency bands below 6GHz to solve the millimeter-wave deployment bottleneck.
Field test data shows that when the 3DEU structure is used in the 24.75-27.5GHz frequency band, the test bandwidth supports 100M, 200M, 400M, and 800M, the cell peak rate can reach 14.7Gbps, and the user delay is 1-1.5 milliseconds, which is consistent with the theoretical analysis value and is effective Increased confidence in millimeter waves.
Conclusion
5G millimeter wave has abundant frequency resources and large bandwidth, easy to combine with beamforming technology, can achieve extremely low delay, can support dense deployment, and can perform high-precision positioning, and other technical advantages, which can fully release the potential of 5G. It will become the core technology to be deployed in the next phase of 5G.
At present, the 5G millimeter wave industry chain and standardization organizations have proposed many innovative solutions to various problems of 5G millimeter waves. The entire industry chain from chips, modules, systems to terminals has basically reached the stage of commercialization. Starting in 2022, a 5G millimeter wave will set off another wave of a 5G boom in the global and Chinese markets.
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