This year's iPhone 12 has resumed the grand occasion of picking up goods at a price increase. Last year, users who held money on the sidelines because iPhone 11 did not have 5G, finally had a reason to change.
At the press conference, Apple also introduced 5G as the most important highlight. iPhone 12 supports almost all current 5G frequency bands, surpassing mainstream Android models, but only the US version supports millimeter wave frequency bands.
Some netizens wondered whether the National Bank version that does not support millimeter wave is a castrated version of iPhone 12? The answer is no, this will not affect domestic users to use 5G on the iPhone 12, and domestic 5G networks do not support millimeter waves.
However, there are indeed differences in the 5G experience between the iPhone 12 that supports millimeter waves and the National Bank version that uses low-frequency sub-6GHz. Let’s talk about the topic of 5G millimeters today. This article attempts to clarify several questions:
- What is the difference between the 5G experience of the US version of iPhone 12 and the National Bank version?
- Who is "True 5G" in millimeter wave and sub-6GHz?
- Does iPhone 12 5G consume fast power, does it have anything to do with millimeter wave?
- Why does the US 5G network support millimeter wave but China does not?
- Is the current 5G millimeter wave really unavailable?
- Will China use millimeter waves in the future?
What is the difference between the 5G millimeter wave exclusive to the US version of iPhone 12 and the Bank of China?
The millimeter wave exclusive to the US version of iPhone 12 and the sub-6GHz supported by the National Bank version are actually the two major branches of the current global 5G network frequency band.
As the name implies, the frequency wavelength of millimeter waves is less than 10 mm, and generally refers to the frequency band above 24 GHz. Sub-6 GHz is the network frequency band below 6 GHz, because the wavelength is centimeter level, it is also called "centimeter wave."
Millimeter wave and centimeter wave, the name seems to be millimeter wave winning, just as the millimeter-level positioning in the navigation satellite is obviously more accurate than the centimeter-level positioning, then 5G millimeter wave is also more powerful than sub-6GH?
Indeed, millimeter wave has the unmatched advantage of sub-6GHz, which can be reflected in the most intuitive network speed.
According to the measured data of the network speed measurement platform Ookla , the download speed of 5G millimeter wave terminals is 4 times that of the frequency band below 6GHz, with an average rate of 900 Mbps and a peak rate of more than 2Gbps.
At the press conference last month, Apple stated that the iPhone 12 can achieve a peak downlink rate of up to 4Gbps, which also refers to millimeter waves. At present, domestic packages within 200 yuan can provide up to 60 G of data, which can be used up in 2 minutes at this rate.
Of course, this is a theoretical peak, which is generally not achieved in actual use. In SpeedSmart's 5G network test on iPhone 12, Verizon iPhone 12 using millimeter wave 5G has significantly higher download and upload speeds than iPhone 12 using sub-6GHz.
Since the millimeter wave is so strong, is it more cost-effective to buy a US version of the iPhone 12?
Don't worry, although millimeter wave can easily crush sub-6GHz at network speed, it has a fatal flaw. That is, the signal attenuation is large and the coverage area is small.
According to common sense in physics, the higher the frequency of electromagnetic waves, the shorter the wavelength, the shorter the transmission distance, and the longer the signal attenuation when crossing obstacles. For example, the signal attenuation in the 28GHz frequency band is 1600 times higher than that of 700MHz.
Therefore, 5G mobile phones using millimeter waves may be blocked by anything. Trees, rain and fog can block most of the signal, and even the human body’s loss of millimeter waves can reach 11~28dB, which can reproduce the "death grip" of iPhone 4 , Let alone go through the wall.
Although there have been many technical solutions to solve the problems of millimeter wave signal attenuation and blocking, the performance in commercial applications is still not ideal.
Google has tested the 5G coverage of the same range and the same number of base stations in the United States. The results show that the 5G network deployed by millimeter wave can cover 11.6% of the population at a rate of 100Mbps, and can cover 3.9% of the population at a rate of 1Gbps. ；
The sub-6GHz 5G network can cover 57.4% of the population at a rate of 100Mbps, and 21.2% of the population at a rate of 1Gbps.
▲ The picture above shows the coverage of millimeter wave, and the picture below shows the coverage of sub-6GHz. Picture from: Google
It is precisely because of the high loss of millimeter wave signals that traditional antennas cannot be used when integrated into mobile phones. More antennas need to be installed, and higher requirements are still placed on baseband digital processing capabilities. The "patch" on the side of the US version of iPhone 12 is Millimeter wave antenna module.
More complicated manufacturing processes bring higher costs. According to Guo Mingchi, the sub-6 and millimeter wave 5G components used in the iPhone 12 series cost US$75-85 and US$125-135, respectively.
In addition, it has recently been revealed that the iPhone 12 consumes electricity quickly in the 5G state, which is also related to the antenna design of the 5G mobile phone.
5G terminals generally use Massive MIMO (large-scale multiple-input multiple-output) antenna technology to improve network transmission efficiency and compensate for signal attenuation. Millimeter waves cannot be separated from this technology for commercial use.
However, Massive MIMO technology reduces transmission power consumption at the expense of higher computing costs. Mobile phones need to integrate more antennas. Multiple antennas simultaneously transmit (multiple output) and receive signals (multiple input) mean higher power consumption. Naturally, it consumes more power.
Simply put, the millimeter wave is like a sprinter, with strong explosive power but limited distance. The sub-6GHz is a long-distance runner who runs slower but farther. Its own advantages are also the opponent's shortcomings.
Although Qualcomm insinuated that Huawei's 5G does not support millimeter waves last year, it is not true 5G , but in fact, this is just a propaganda method between the two sides in the 5G route dispute. The millimeter wave and sub-6GHz do not actually conflict, on the contrary, 5G services will be provided in a collaborative networking manner for a long time in the future.
Why does the US use millimeter waves, but China does not?
As mentioned earlier, the commercialization of 5G millimeter waves faces many problems. So why does the United States deploy 5G networks based on millimeter waves? Don’t American operators know the defects of millimeter waves?
In fact, American operators do not want to use the low-frequency sub-6GHz, but most of this frequency band has been used for military communications and defense communications. Even if it is to be vacated for commercial use, clearing the frequency band will not be completed in a short while.
In this context, operators can only bet on millimeter waves. Among them, Verizon, which provides 5G millimeter wave services for the iPhone 12, is also the world's first operator of commercial 5G services. As early as 2018, it provided 5G services in 4 cities in the United States and stated that "millimeter wave spectrum is the cornerstone of 5G ultra-wideband networks." .
Subject to 5G millimeter wave supporting technologies that are not yet fully mature, the popularity of 5G in the United States is relatively slow. According to data from M-Science, a subsidiary of Wall Street investment bank Jefferies , as of mid-July 2020, the number of 5G users in the United States was 4.082 million, less than half of the number of 5G users in South Korea.
On a global scale, most operators have first adopted Sub-6G as a 5G networking solution. A report from S&P Global Ratings shows that as of September this year, only 12% of the 113 operators that have been commercialized in 52 markets around the world use millimeter wave frequency bands.
Obviously, before the millimeter wave completely solves the problems of signal attenuation and coverage, sub-6GHz is an effective solution to allow 5G to cover a wider range in the short term.
In fact, the United States has also realized this problem and has begun to go back and deploy sub-6GHz 5G networks. Not long ago, the United States auctioned the 100MHz mid-band spectrum originally used for military purposes to operators, and plans to start commercial use in mid-2022.
In the report " 5G Ecosystem: Risks and Opportunities to the US Department of Defense " published by the Defense Innovation Committee of the US Department of Defense , it also pointed out:
Due to propagation and cost constraints, millimeter waves cannot be deployed on a large scale in the United States at this stage. Sub-6 GHz IF spectrum (in the range of 3 GHz and 4 GHz) will become the global standard for wide area networks in the next few years.
Chinese operators are much happier. my country has relatively abundant resources in the Sub-6 frequency band and can allocate continuous test frequencies of 100 MHz or above to several major operations, while foreign operators mostly rely on auctions to obtain frequency bands. Often hundreds of millions.
Although China does not have to rush to use millimeter waves because of frequency band resources, it is also actively researching and deploying millimeter waves. Because millimeter waves, which seem a bit tasteless now, are the real future of 5G.
5G without millimeter wave is indeed incomplete
In the 5G video about the famous classmate He of UP at station B, he once said that speed is actually the most boring application of 5G.
▲ Picture from: Tiger Sniff
At present, our perception of 5G is mainly due to the fact that 5G still lacks killer applications. Some netizens also ridicule that the killer application of 5G networks today is speed measurement software.
In fact, in the three major application scenarios of 5G, in addition to enhanced mobile broadband (eMBB) to increase network speed, there are also massive machine communications (mMTC) and ultra-reliable low-latency communications (URLLC).
To realize the last two 5G application scenarios, millimeter waves are indispensable.
For example, for Mass Machine Communication (mMTC), the connection density of devices must reach 1 million units/km2, so that even in crowded subways and stadiums, everyone’s devices can surf the Internet smoothly. It requires the use of 5G millimeter wave technology with large bandwidth, The advantages of high instantaneous rate and large system capacity are realized.
Application scenarios that require low latency, such as AR/VR, cloud games, and industrial robots, are also the same. The air interface time slot length of 5G millimeter wave systems can be as small as 0.125ms, which is only a quarter of the current mainstream 5G low-frequency systems.
As the Global System for Mobile Communications Association (GSMA) mentioned in the " 5G Millimeter Wave Technology White Paper ", 5G millimeter wave is the inevitable direction of the evolution of mobile communication technology, and millimeter wave can fully release the full potential of 5G .
The technology to improve 5G millimeter wave coverage is also becoming more mature. In addition to the Massive MIMO mentioned earlier, beamforming technology is also a common solution.
The difference between traditional 4G base stations and beamforming 5G base stations is like a light bulb and a flashlight.
The signal from the 4G base station is divergent like a light bulb, while beamforming can aim the radio waves at the terminal that needs to move the network, like a flashlight, illuminate the light beam to the target and move with the target, which can greatly Increase the communication distance of millimeter wave.
In addition, millimeter waves can deploy a large number of small base stations, reducing the communication distance to ensure high peak throughput, thereby increasing the coverage, which is lower than the cost of 5G medium and low frequency tower-sized macro base stations.
In September, Qualcomm joined forces with Ericsson and Casa Systems to expand the millimeter wave communication range to 3.8 kilometers, which is currently the longest millimeter wave transmission distance.
Xu Hao, Qualcomm's head of R&D in China, once said that a millimeter wave capability is a complete 5G, and the deployment of 5G millimeter wave is an important step to realize the entire vision of 5G .
The above-mentioned technologies have brought the 5G that truly changed our lives closer.
When will China use 5G millimeter wave?
Although China's 5G was officially commercialized only in June last year, according to data from the Ministry of Industry and Information Technology, as of the end of September, more than 690,000 5G base stations had been opened and constructed nationwide, and China's 5G users exceeded 150 million.
At present, there are only more than 800,000 5G base stations deployed globally, and the total number of 5G users worldwide is less than 200 million. It can be seen that China is already in a leading position in the progress of 5G construction.
While 5G continues to spread, China's millimeter wave applications have also been put on the agenda. According to the plan of China's IMT-2020 (5G) Promotion Group, the 5G millimeter wave will be promoted in three stages:
- In 2019, we will focus on verifying 5G millimeter wave key technologies and system characteristics;
- In 2020, focus on verifying the functions, performance and interoperability of 5G millimeter wave base stations and terminals;
- From 2020 to 2021, we will carry out application verification in typical scenarios.
At the Beijing Winter Olympics in 2022, China Unicom will adopt a networking solution based on 5G millimeter wave technology to provide network services for the Winter Olympics venues.
In addition to operators, hardware manufacturers are also preparing for the commercial use of millimeter waves. The millimeter wave customized version OnePlus 8 has become China's first smartphone to support 5G millimeter wave. Huawei Mate X also has a millimeter wave version, but it is not on sale.
In the related industry chain, Chi Yongsheng , vice president of China Unicom Network Technology Research Institute, pointed out that the domestic millimeter wave industry chain is relatively weak compared to foreign countries, and the degree of localization of core technologies and core devices is relatively low .
However, China has also made breakthroughs in 5G millimeter wave chips. The millimeter wave chip developed by Nanjing Network Communications and Security Purple Mountain Laboratory has reduced the cost per channel from 1,000 yuan to 20 yuan, and is expected to be commercially available in 2022.
Not only China, but more than 120 operators around the world have invested in millimeter wave research and development. What they are looking at is the huge application prospects of 5G millimeter waves and the considerable commercial potential.
According to GSMA's forecast, the contribution of millimeter wave 5G to global GDP will increase exponentially from 2020 to 2034. It will contribute US$565 billion to global GDP and US$152 billion in tax revenue in 2034.
By then, when people mention 5G, they may no longer think of mobile phones, and even have devices that replace smart phones.
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