Last week, the late iPhone 12 was released. Although it was a month later than the previous year, the heat was still constant. You can see an interesting phenomenon, the new iPhone Once released make complaints about the next time, but many people will use real gold and silver certificates to show its popularity. Soon after customer service, iPhone 12 will soon be sold out. As the focus of this upgrade, 5g network support is naturally the most important point for consumers and the main factor behind the hot selling out. However, there may be many things you don’t know behind the new 5g upgrade of iphone12. It is possible that careful friends may find that this time, there is a special detail different from other versions on the iPhone 12 of the United States. Only slight differences can be observed from the appearance. There is a “small patch” on the right side of the right side of the iPhone 12. In previous releases, this patch was mistaken as touch ID Fingerprint recognition module, and after the conference, many people discussed that Apple pencil magnetic charging port In fact, it is closely related to 5g network support in the United States. It is necessary to understand that the 5g network band in the world is mainly divided into sub-6 GHz and millimeter wave. Sub-6 GHz is an electromagnetic wave with a wavelength of CM, which can be understood as “cm wave”. As its name implies, it occupies the network frequency band below 6GHz, while millimeter wave is the electromagnetic wave with millimeter level, which usually refers to the frequency range of 30-300 GHz and often includes the frequency band of 24 GHz or more. In terms of speed alone, millimeter wave has absolute advantages. In the apple conference last week, it was also said that the theoretical download rate of iPhone 12 in the US version can reach 4gbps (512mb/s) in millimeter wave network environment. That is to say, in ideal environment, I can use up to 30 GB of traffic a month, and I can use all of it in a minute At present, the United States is the country that mainly pushes 5g millimeter wave. Because of its high data throughput, it has higher requirements for signal conditions. This makes the antenna design of 5g millimeter wave more difficult, but the layout space left by mobile phone to antenna is smaller and smaller. So it is not difficult to understand why there is a signal slot on the iPhone 12 in the United States. After all, only in this way can the millimeter wave signal be stable, which is also a must. In the 5g development path of China, the sub-6 GHz scheme is the first choice. We mentioned that, due to the different characteristics of the two frequency bands, sub-6 GHz is not as fast as millimeter wave, but it can not deny the sub-6 GHz capability. The biggest advantage of this band is strong signal penetration, wide coverage and lower cost. For example, 5g in China is currently used The tariff of the package is already very affordable worldwide, and the operators are also vigorously launching 5g packages with different rates. Although it is not as fast as millimeter wave, it is much faster than the previous 4G. It is not difficult to find that sub-6 GHz is the first choice in China at this stage, and it is also the first to solve the problem of 5g network coverage, and then put 5g into practical application as soon as possible, so that most consumers can use 5g network. It is also true that we should be rich and build roads first. In contrast, millimeter wave, although the transmission speed is very fast, has a taste of “external strength and middle dry”. It not only requires high signal requirements for mobile phones themselves, but also demands on surrounding environment. Moreover, due to the small coverage of signals, it needs to lay base stations with high density, and the use cost will be much higher. In the white paper of 5g millimeter wave technology published by GSMA, the challenges faced by millimeter wave technology are emphasized. The first is the problem of signal coverage. China Unicom has measured the problem. According to the measured results, we can see that the penetration loss of 5g millimeter wave is far higher than sub-6 GHz, and the severe weather such as rain Snow and fog have negative effects on the propagation of millimeter wave. In fact, for 5g network construction, whether it is sub-6ghz or millimeter wave, there is no difference between the real and the false, but the development sequence is different. At present, China chooses sub-6 GHz as the security deposit, which is better than millimeter wave coverage and lower cost. Because the current 5g network has not been fully covered and the killer 5g application is full of unknown information, the significance of millimeter wave technology at present is not significant at this stage. But in the long run, millimeter wave is definitely the main solution in hot spot area in the future. As mentioned in the white paper on 5g millimeter wave technology, 5g millimeter wave is easier to realize intensive cell deployment than sub-6 GHz. This makes 5g millimeter wave suitable for large-scale places such as conference rooms, concerts, gymnasiums, subway stations and other densely populated areas. So 5g millimeter wave and sub-6 GHz with medium and low frequency have their own performance advantages. Their coordination and complement each other are the key to achieve 5g complete experience. At present, the development ecology of 5g millimeter wave industry in China is relatively complete, and it is qualified for deployment and commercialization. We may use 5g millimeter wave network in 2022 Winter Olympic Games. At present, mainstream mobile communication equipment providers have launched base station equipment supporting 5g millimeter wave, chip manufacturers and terminal equipment manufacturers have also released some 5g millimeter wave products. For example, the high-speed 5g millimeter wave technology performance test has been completed as soon as the mobile phone is added. It is said that “gta5” will be launched on Google cloud game platform stadia