Castration frequency band is very common in the whole mobile phone industry. Not only does Xiaomi do this, but many mobile phone manufacturers do the same. In the final analysis, it is mainly to save costs. The more frequency bands supported, the higher the cost. You can castrate some temporarily unused frequency bands or foreign frequency bands, which can save some costs.
Another reason is the immature technology. For example, the K30 5G mobile phone in Redmi does not support the n79 band, and the processor of 765 G in Snapdragon temporarily does not support the n79 band for some technical reasons. The system may be updated after the update, at least not yet.
At present, Huawei and HONOR support the most 5G frequency bands, and basically all 5G frequency bands are supported. Let's take a look at the comparison of 5G frequency bands supported by Xiaomi 10 series and Glory V30 series.
From the comparison chart, we can see that Xiaomi 10 series does not support n77 band, which is the 5G band adopted by European and Japanese operators. In other words, there may be some problems when the Xiaomi 10 version of the Bank of China is used in Europe and Japan. If you go abroad often, you should pay attention at this time. If you stay at home all the time, the use of Xiaomi 10 will not be affected.
Let's take a look at the 5G band supported by Redmi K30 5G version.
Redmi K30 5G castrated the 5G band even more seriously, only supporting two 5G bands, N401and n78, and not fully supporting the five G bands of the three major domestic operators, which is one reason why Redmi K30 5G mobile phone is so cheap.
Xiaomi 10 series is ok, but some foreign 5G bands have been castrated. The 5G frequency band operated by the three major domestic companies has not been castrated, that is, it will not go abroad. If it has been used in China, there is no problem.
But it is different for Redmi K30 5G. Redmi K30 5G lacks the n79 frequency band of China Mobile. Although China Mobile's n79 frequency band has not been used on a large scale at present, it will definitely be used on a large scale in the future. If your mobile phone card is from China Mobile, you may encounter some problems when using the 5G network, or even be unable to use the 5G network.
At present, some technologies of 5G mobile phones are not very mature, or the cost is high. In order to reduce costs, we can understand that mobile phone manufacturers are castrating the frequency band. However, I still hope that mobile phone manufacturers can indicate which 5G bands are supported and let consumers know.
Mobile phone communication technology is a civil part of wireless communication technology, and different wireless communication systems work in different wireless frequency bands, thus avoiding mutual interference between the systems.
The mobile communication technology has developed from 1G to the present 5G. ITU divides the electromagnetic frequency range used by each generation of mobile communication system, and divides the large frequency range into several small basic frequency ranges, called frequency bands, which are distinguished by different numbers. Let's take 5G as an example to illustrate the specific situation of frequency band division:
5G has two large frequency bands: FR 1(450MHz-6.0GHz) and FR2 (24.25 GHz-52.6 GHz), and the 5G frequency band number specified by 3GPP starts with "n":
FR 1
FR2
Each country either allocates each frequency band to its own operators in the form of auction (in Europe and America) or free allocation (in China).
The mobile phone purchased by the user wants to use an operator's network. In addition to purchasing the operator's mobile phone card, the user's mobile phone must meet the prerequisite of supporting the operator's network frequency band. If not, you can't use the operator's network service. The more frequency bands supported by mobile phones, the more space for users to choose operators.
Here, based on my personal experience, I will tell you about the embarrassment that the frequency band supported by mobile phones is not complete: in 20 1 1 year, I went to a country in Africa on business and brought a WCDMA mobile phone bought in China, which supports the domestic 21000 mm frequency band. What is embarrassing is that the WCDMA network of the operator project I serve uses the 900M frequency band (there are few operators in the world)
Nowadays, there are more people traveling abroad, and many people choose to open international roaming services (mostly business people). If the frequency band supported by the mobile phone is not complete, you may encounter the embarrassment that the mobile phone cannot roam normally.
Frankly speaking, the purpose of mobile phone manufacturers castrating mobile phone frequency bands is to save money! Money! Money!
The more frequency bands supported by mobile phones, the more complicated the design of mobile phone RF devices, and the more antennas built into mobile phones: the more frequency bands supported by mobile phones, the more filters in RF devices, which undoubtedly increases the procurement cost of parts departments; The increase in the number of built-in antennas in mobile phones will not only increase the cost of antennas, but also increase the design cost of mobile phones. After all, the internal space of mobile phone is so narrow.
Invited to answer questions in this industry.
The more frequency bands a mobile phone supports, the higher the cost. The castration of the frequency band is to save costs.
Which frequency band the mobile phone supports is not determined by the processor, but by the filter and antenna in the mobile phone.
With the development of mobile communication technology, 3G/4G/5G all have corresponding frequency bands, which are stipulated by organizations that make relevant standards, such as 3GPP.
In fact, the relevant frequency band is the wireless frequency submitted by various countries within the organization that can be used in their own countries. The official frequency band determined by organizations such as 3GPP is actually the approximate result finally reached by all parties through coordination.
4G supports many frequency bands:
There are also some frequency bands in 5G, including sub-6G and millimeter wave bands:
It is worth noting that the 5G standard has not been completely frozen yet, so the possibility of operators submitting new frequency bands still exists.
The filter in the mobile phone is a band-pass filter, which supports that the upper and lower limits of the passband correspond to the upper and lower limits of the wireless frequency of each frequency band. In other words, how many frequency bands a mobile phone supports requires the support of multiple filters. Because the 5G mobile phone also needs to be compatible with 2/3/4G, the number of filters inside is very large, which will increase the cost of the mobile phone.
At the same time, the antenna in the mobile phone also corresponds to different frequency bands. Because the vibrator of the mobile phone antenna corresponds to the wavelength of 1/2- 1/4 of the wireless frequency, it is necessary to configure different mobile phone antennas in the frequency band with too large frequency difference.
Now the space in the mobile phone is very precious. More antennas and filters will also reduce the space inside the mobile phone, which will also bring great challenges to the internal design of the mobile phone, or it is necessary to use a larger screen, which will further increase the cost of the mobile phone.
Xiaomi castrated the support of some frequency bands, mainly to save costs.
At present, the number of supported frequency bands can play a role in whether users can access operators in various countries when roaming around the world with this mobile phone. As far as domestic operators are concerned, domestic mobile phones basically support the existing frequency bands of operators.
For Xiaomi's main users, they are basically non-business users, or the main sales targets are not those flying business users, which also determines that Xiaomi's mobile phones sold in China can castrate the frequency bands of some foreign operators.
However, as far as the frequency bands supported by Xiaomi's 5G mobile phone are concerned, actually this N41N78 is enough to support the 5G networks of most operators, and these two frequency bands are mainly used by global operators.
3G mobile phones don't support CDMA, which is actually required by China Telecom, not forced castration by manufacturers. China Telecom tried to quit 2/3G in the 5G era. It is precisely because of this that Telecom proposed that 5G mobile phones cannot support CDMA, and at the same time, they must support Volte which supports telecom by default, and the option to turn off Volte should be hidden.
In short, as far as Xiaomi mobile phone castrates some frequency bands, the main purpose is to save costs and make its mobile phone more price-competitive. For most buyers of Xiaomi, in fact, the frequency band of Xiaomi mobile phone is enough.
Why do you feel that Xiaomi mobile phone always castrates the frequency band? Redmi K30 5G version is the most castrated frequency band of Xiaomi series, and only two frequency bands are reserved. Castration frequency band can be said to be the normal state of the whole industry. As for why manufacturers castrate some frequency bands, it is to consider the cost, and multi-frequency bands bring higher costs.
▲ Redmi K30 5G
Let's take a look at the 5G band of Redmi K30 5G series. It has only two frequency bands, N4 1 and N78. I won't talk much about the other 2G and 3G here, not only because they are 5G mobile phones, but also because these two networks will hardly be used in the future. I only talk about this 5G frequency band here.
Let's take a look at the 5G band of other mobile phones. Take Redmi K30 5G series as an example. Glory V30 series supports six frequency bands, namely N 1, N3, N4 1, N77, N78 and N79. It can be said that the 5G frequency band is very complete, as much as Huawei Mat30 PRO5G.
Let's take a look at Xiaomi's flagship Xiaomi 10 this year. It supports five frequency bands: N 1, N3, N4 1, N78 and N79, which is less than that of Glory and Huawei. Redmi K30 5G will be miserable, lacking four frequency bands: N 1, N3, N79, N4 1. Even the Glory 30S released at the end of last month supports five 5G bands.
The 5G bands of the three major operators are N4 1 and N78. Although N79 is only available on the mobile terminal at present, I think it is better to have it for the time being. Moreover, the three most basic operators of Redmi K30 5G series do not have 5G frequency bands, which is obviously worse than full-frequency 5G mobile phones on the 5G network, but it is because of its few frequency bands that it is so cheap.
Although Xiaomi's 10 series frequency band is relatively complete, it also lacks an N77 frequency band, although this frequency band is not used in China. However, if you want to go abroad, your mobile phone must still support four basic 5G bands, N4 1, N78, N79 and N77.
Therefore, castrating the frequency band is nothing more than reducing costs. If you want to use the extremely fast 5G network and become the benchmark or pioneer of 5G, you can't do it without full frequency band.
Here, I suggest that if you use the 5G package in the future, you should choose a relatively complete frequency band. It doesn't matter if you just buy a 5G mobile phone without a 5G package. After all, the price in Redmi has a great advantage, but carrots and cabbages have their own tastes, so just buy what you don't have.
Just like Xiaomi 10 flagship some time ago, it supports several 5G bands of N1/N3/N41/N78/N79, but you can find that it lacks n77 band.
Mobile phone band support is just like highway. The more bands, the wider the range of received signals. The "castration" of the 5G mobile phone frequency band is usually to save costs. Even in their own products, brands all over the world have different frequency band support options, and users do encounter the problem of incomplete frequency bands.
As mentioned above, brands all over the world have different band support options even in their own products, so it is difficult to fully consider full band coverage for reasons such as cost performance or volume. After all, more frequency bands mean more antenna support, and the cost will increase accordingly.
Theoretically, the more support for the 5G band, the better (from the consumer's point of view). The 5G frequency bands used by major domestic operators to build 5G networks are different. China Mobile has two frequency bands, N401and n79. China Unicom and China Telecom share the n78 frequency band, while China Radio and Television monopolizes the low frequency band and n79 frequency band.
That is to say, in terms of domestic use environment, supporting n4 1, n78 and n79 can actually meet the actual use in most cases. Moreover, at present, n4 1 and n78 are still the mainstream frequency bands, and it is too early to say that n79 frequency band will be commercialized on a large scale.
For example, Xiaomi 10 lacks the n77 band, but the n77 band is the 5G network band mainly used in Japan and Europe. If there is no history of frequent overseas travel, there is no harm in not supporting it. Moreover, on the other hand, it can also optimize the internal design of the mobile phone.
In the international market, the most obvious frequency band loss of some mobile phones is that they do not support millimeter wave frequency band. Because Xiaomi cooperates with Qualcomm chip, some people think it's because of Qualcomm, but it's not. X55 and X52 can support sub-6GHz and millimeter-wave bands under operators' 5G networks in 2020 and 20021year, and support all mainstream 5G bands in the world at present.
Just as Galaxy S20 5G can't support millimeter-wave frequency band, millimeter-wave antenna is small in size and thickness, and it is not easy to adapt. In the future, with the supply of smaller antenna modules, more 5G mobile phones can be packaged to support more frequency bands.
The core of the main question is why do you feel that Xiaomi mobile phone always castrates the frequency band? Our first thought is to save money. After all, these frequency bands are still useful. Although they may not be used in China, they are really useful abroad or a few years after the maturity of 5G technology. This is undeniable. After all, the difference between 5G module and 4G module lies in the higher antenna design and data throughput. Therefore, every time a frequency band is supported, it needs corresponding antennas and filters to support it. Many people say that it seems that there is not much money, but have you ever calculated that a mobile phone will cost 20 yuan more, so 654.38+00,000 sets! That's 20 million. So that's why many manufacturers seem to think that the functions we can completely add are not expensive, but they don't.
1.N79 band was castrated by Redmi K30. This is really unnecessary at present, because it is actually a frequency band of China Mobile, because this frequency band is a new one, that is, compared with the current frequency band, it starts from scratch, and its telecom and Unicom's N4 1 and N78 are actually quite mature. The reason why the N79 band is divided into mobile is because it needs higher cost, and mobile is the strongest operator. Of course, now China Radio and Television has also announced that it will enter 5G, and it will also use the N79 frequency band. After joining, if you want to use the mobile phone card of China Radio and Television, you can only use the mobile phone supporting N79 frequency band. Of course, it is still uncertain whether it is civil or commercial. Generally speaking, it is not supported now and will not affect it. However, the construction and popularization of N79 band is inevitable.
2. Xiaomi 10 castration frequency band. The distance between Xiaomi and glory has a long history. The glory executive Lao Xiong actually said it as early as the release of Xiaomi 10. Compared with honor, N77 has fewer frequency bands, and 4G has fewer frequency bands of B 18, B 19 and B26, so castration is indeed a fact.
Of course, from another angle, is N77 useful? Yes, for overseas users, mobile phones should be equipped with at least four frequency bands, namely n4 1/n78/n79/n77, which is also the minimum requirement. Among them, we know that N4 1, N78 and N79 are China Mobile's 2.6GHz, China Telecom's, China Unicom's C-band (3.4-3.6GHz), China Mobile's and China Radio and Television's C-band (4.4-5.0GHz), while N77 is a European and Japanese 5G-band and also belongs to the C-band. So to put it simply, you must support it. Only in foreign countries can you use the 5G network.
It doesn't matter if we don't support many frequency bands, but why don't other manufacturers save it! So we can only say that we want to save costs, but in addition, the cost performance of Xiaomi mobile phone is still quite high, so the cost should be controlled, and we can really understand it, so this can only be said to be your personal choice. Naturally, we suggest choosing a mobile phone with complete frequency bands, but we should also give up some other configurations.
Answer over
First of all, the so-called castration refers to castrating some common frequency bands that are needed overseas but not used by operators in Chinese mainland. For example, Redmi K30 5G did not support n79 frequency band, which caused an uproar on the Internet at that time, but actually had little impact on most consumers. In addition, some overseas frequency bands are not used at home, so castration is normal. Of course, if you often need to go abroad, you should pay attention. If your mobile phone just doesn't support a certain foreign frequency band, then you can't use the corresponding network.
Some models of Xiaomi have castrated the frequency band to a great extent to save unnecessary costs. After all, more frequency bands need more antenna support, and the corresponding cost will increase. More importantly, it may disrupt the original design of the mobile phone and occupy more internal parts space. In fact, not only Xiaomi, but also some domestic mobile phone manufacturers of Huawei often castrate the frequency band, but the experience brought to most users has not changed.
Take my millet mix2s as an example. Although it is a 4G mobile phone, the standard version does not support all frequency bands. Only the top-end version supports the global frequency band, which is one of the selling points. For the fledgling 5G mobile phone, it still needs to pay a great price to realize the full frequency band. Xiaomi, as a mobile phone brand focusing on cost performance, it is normal to castrate the frequency bands that are not commonly used in order to maintain the price.
Regarding frequency bands, Huawei is the best in China. Therefore, many people recommend Huawei before going abroad, because Huawei has the most comprehensive frequency band.
So Xiaomi's mobile phone was castrated? No, Xiaomi has a mobile phone MIX3, which many people know, but what many people don't know is that Xiaomi MIX3 has an international version, which is the most comprehensive mobile phone at present.
What do you see? Xiaomi can do all the frequency bands, but Xiaomi did not choose to do so, indicating that some frequency bands were selected by manufacturers.
However, many people still use Xiaomi mobile phones normally. To be honest, they are also "not aware of frequency band castration". Therefore, most of Xiaomi's castrations are frequency bands that we usually don't use or rarely use. Even if it is castrated, most people will not notice it.
Then Xiaomi can easily castrate these frequency bands, and usually few people can perceive them. After all, castrating the frequency band can reduce the cost, because Xiaomi has no patents in related fields, so it will definitely cost more to not castrate the frequency band and increase the cost.
This is also my personal "cost performance" of Xiaomi, which has always been the reason why I have reservations. Because ordinary consumers don't know where the manufacturer buried the pit and castrated you. Just as few people care, the soc of many mobile phones in Xiaomi has always been glue-free.
Of course, the manufacturer castrated some functions of "weak perception" and gave you the function of "stronger perception" at the same price. This is understandable, such as NFC and infrared.
So if you care about the signal, just recommend Huawei directly, and don't worry about going abroad. But if you use it at home, you don't need to worry too much about castration in these frequency bands, because it is really "imperceptible".
The cost of band antenna is high, and the patent fees of equipment and communication are easily ignored, which is a good means to save costs. Moreover, the more frequency bands there are, the more costs will be generated after the band maintenance and optimization manufacturers purchase them. Saving mobile phone space is not important, but it does have this advantage. Some manufacturers have many frequency bands and can only compromise. Xiaomi castrated a lot of frequency bands, so there won't be too many design problems. Designing a mobile phone can't come out overnight. This requires a process. I know these three, the most important thing is that the cost is very high, the second design and the third one are not easy to find, and it is easy to find if the consumer is castrated elsewhere.
In fact, the practice of "castration" is not only available on Xiaomi mobile phones, but also in the whole industry. In addition, many castration methods seem invisible to our users. After testing and comparison, I know that the frequency band is particularly important! This guy is directly related to the signal problem. For example, if you try it in a remote rural area, it will be very touching. Since the frequency band is so important, why do many mobile phone manufacturers continue to castrate the frequency band?
I think the main reasons are the cost and the difficulty of designing and manufacturing technology. Why do you say that? Because these two main factors can be seen not only in the field of mobile phones, but also in the whole manufacturing industry and even in my Internet company. Let's not talk about machines today If you talk too deeply, it may be difficult for everyone to understand. I will give several examples to illustrate the difficulty of cost and process design.
My company is an internet company, and I am a programmer. Although our products are virtual and don't have a physical object like manufacturing, our production process is the same as manufacturing. Take me as an APP! I think adding a frequency band is like adding a function.
If our project needs to add voice function to an APP and specify the online time, it is very urgent! Do I have to work overtime every day to code this function? Not only do I have to work overtime here, but also my colleagues in the testing department and the product department have to be present. Isn't this the cost? All our departments have spent time and cost. And Xiaomi adds a frequency band, I think the cost is at least tens!
Design process difficulty, such as the voice function we added this time. I didn't write the code, but my former colleague wrote it. So in order to add this voice function, should I also be familiar with the code? And should I consider refactoring after the previous code development? Because it is very likely that flashbacks and crashes will occur at any time. The business logic here is interlocking, and it is difficult to add functions to the code handled by others. It is necessary to find out why former colleagues designed and wrote the code like this.
The same is true of this extra frequency band, which needs to deal with various manufacturers, so the cost and technological difficulty are still great. For example, we all know that before the popularity of Netcom, the same chip was divided into mobile, telecom and Unicom, and the fact that the version of Netcom was more expensive can illustrate this point.
With the fierce competition in the mobile phone industry, there are few mobile phone brands left. Although it is said that you get what you want at the same price, I sincerely hope that mobile phone manufacturers will not "cut corners" where our users can't see them. Have you ever met a castrated mobile phone?