In October 2018, the Wi-Fi Alliance, which is responsible for the formulation of Wi-Fi technical standards, officially adopted the name "Wi-FiX" for the Wi-Fi standard. The 802.11ax standard corresponds to Wi-Fi6, the W802.11ac standard corresponds to Wi-Fi5, and the 802.11n standard corresponds to Wi-Fi4.
Then in 2019, the Wi-Fi 6 standard was officially released. At the same time, a number of new mobile phones, including the Samsung S10 series, Xiaomi 9 series, Apple iPhone 11 series, etc., all support Wi-Fi 6 technology. This is also the first time that Wi-Fi technology has allowed consumers to understand that Wi-Fi, which is so familiar in daily life, is also rapidly iterating like 4G and 5G mobile networks.
However, it has only been 4 years since the first batch of Wi-Fi 6 mobile phones were launched. It seems that Wi-Fi 6 has not been used for long before Wi-Fi 7 is here.
At MWC2022 in early 2022, Qualcomm officially released the world's first WiFi7 solution, FastConnect7800; subsequently, ZTE, Broadcom and other communication companies successively released their Wi-Fi7 products. In June of the same year, the world's first Wi-Fi7 home router H3C Magic BE18000 was launched; in November, TP-LINK also launched a variety of Wi-Fi7 router products.
At the beginning of this year, Xiaomi Mi 13 became the world's first mobile phone to support Wi-Fi 7. Subsequently released mobile phones using the Qualcomm Snapdragon 8gen2 platform retained support for Wi-Fi 7. In addition, Intel on the PC side is also about to launch Wi-Fi7 network card. At the press conference that just ended not long ago, Huawei also released the router BE3Pro that supports Wi-Fi7.
I can’t help but sigh, the iteration speed of Wi-Fi is really too fast!
However, contrary to the follow-up of big brand manufacturers, the implementation and development of the domestic Wi-Fi7 standard is facing a big problem. So what exactly is the upgrade of Wi-Fi7 compared to Wi-Fi6 and Wi-Fi6E? What challenges do the new standards face in the country? For ordinary consumers, is it necessary to upgrade?
Wi-Fi7VSWi-Fi6: Faster, more stable, and lower latency!
320MHz bandwidth, 46.12Gbps rate
The development of each generation of Wi-Fi is basically upgrading towards faster speeds, better connection quality, and more devices that can be accommodated. Wi-Fi7 is no exception compared to Wi-Fi6.
Source: Intel official website introduction
In the upgraded version of Wi-Fi6, Wi-Fi6E band is supported, and the latest Wi-Fi7 is no exception. Higher frequency bands can naturally bring faster transmission speeds. The Wi-Fi7 channel bandwidth that enables the 6G frequency band has been increased from 160MHz to 320MHz, and the number of effective subcarriers (which can be simply understood as units that can accommodate data) has reached 3920, which is twice that of Wi-Fi6 with only 160MHz band block. If 160MHz Wi-Fi 6 is compared to a two-lane road, then 320MHz Wi-Fi 7 is considered a four-lane road, and the number of cars that can run side by side at the same time is twice that of Wi-Fi 6.
Source: TP-LINK official website introduction
In addition to the larger bandwidth brought by higher frequency bands, Wi-Fi 7 also supports MU-MIMO technology on Wi-Fi 6, which is "multi-user multiple input multiple output". This technology allows routers to use multiple antennas at the transmitter and receiver to receive and transmit multiple data streams at the same time. To give a simple example, compare the router to a high-speed toll station, and MU-MIMO corresponds to the lane of the toll station, but this lane is a two-way lane. The more lanes, the more vehicles the toll station can handle at the same time.
Wi-Fi6 has 8*8 MIMO, which means it has 8 lanes. Wi-Fi7 increases the number of lanes to 16, which is 16*16 MIMO.
Source: Internet
In addition, Wi-Fi7 also uses a new encoding method, 4096-QAM modulation, which you can understand as a better data compression method. Compared with Wi-Fi6 modulated by 1024-QAM, each modulation symbol of Wi-Fi7 can carry 12 bits, which is 1.2 times higher than the 10 bits of Wi-Fi6. To use a simple example, compare the modulator to a truck. A Wi-Fi 7 truck can transport 12 boxes of goods at a time, while a Wi-Fi 6 truck can only transport 10 boxes.
Source: TP-LINK official website introduction
The biggest change brought about by all the improvements in Wi-Fi 7 introduced earlier is that the peak rate has been greatly increased. The theoretical peak rate of Wi-Fi 7 can reach 46.12Gbps, which is 4.8 times that of Wi-Fi6 (9.6Gbps).
Source: TP-LINK official website introduction
Obviously, the upgrade of Wi-Fi7 is not just a simple rate increase, it also introduces many new features that can improve signal delay and stability. There are three core ones, namely multi-link transmission technology (MLO), multi-resource unit (MRU) and preamble puncturing.
Multi-link transmission technology (MLO)
In the past, when we used Wi-Fi, we could usually only connect to one of the two frequency bands, 2.4G and 5G. Even if you turn on dual-band integration in the settings, it seems that there is only one Wi-Fi, but in fact you are still only connected to a single frequency band.
The multi-link transmission technology (MLO), Multi-LinkOperation, bundles different frequency bands into a new virtual link, which means that users can connect to the 2.4G and 5G frequency bands at the same time. The advantage of this is that it can provide better transmission quality and greater data throughput.
Source: Intel official website introduction
Multi-link transmission technology (MLO) supports multi-transmit single-receive mode and multi-transmit multi-receive mode. The two modes bring different improvements. In the multi-transmit single-receive mode, the router uses three different frequency bands: 2.4G, 5G, and 6G to send the same information. The system selects the best and least interfered frequency band for transmission. For example, when the 5G and 6G frequency bands are interfered, the 2.4G frequency band is automatically selected for transmission. The benefit is that it can greatly improve the reliability and quality of data transmission, and greatly optimize the delay.
Source: Ruijie Network official website introduction
Multi-send and multi-receive divides the data into three parts and uses the 2.4G, 5G and 6G frequency bands for transmission respectively. The expected benefit is that the bandwidth of each frequency band can be fully utilized, the data throughput can be greatly improved, and the transmission rate can be increased.
Multiple Resource Unit (MRU)
Before understanding multi-resource unit (MRU), we need to understand a little prerequisite knowledge. At the beginning, we mentioned that the channel bandwidth of Wi-Fi7 can reach 320MHz, and the 320MHz channel is composed of 20MHz basic channels. In other words, the 320MHz channel of Wi-Fi7 is composed of 16 20MHz channels, and the channel can actually be simply understood as a lane.
Before Wi-Fi 6, a channel, that is, a lane, could only serve a single user at the same time. That is, no matter how many cars were in the lane, the traffic jam in the lane next door could not come to borrow the lane. This undoubtedly caused a waste of channel resources.
Therefore, on Wi-Fi 6, the concept of resource unit RU (ResourceUnit) is introduced, which divides the 20MHz signal into multiple RUs of different sizes. Each RU can send information to one user, which means that the same channel can serve multiple users at the same time.
However, in Wi-Fi 6, one user can only correspond to one RU on one channel. For a simple example, compare the RU to a truck. One channel can simultaneously accommodate one truck that can carry 2 boxes of goods, two trucks that can carry 4 boxes of goods, and one truck that can load 8 boxes of goods. Now there are three users to be served, and each user can only be assigned one truck, which means that one truck is wasted.
Source: Huawei official website
Therefore, Multi-Resource Unit MRU (Multiple Resource Unit) was introduced on Wi-Fi 7. Now users can be assigned to multiple RUs on the same channel at the same time. That is, one user can be assigned to two trucks at the same time. This can undoubtedly greatly improve the resource utilization of West Island, thereby increasing the rate and reducing latency.
PreamblePuncturing
Preamble Puncturing has actually appeared in the Wi-Fi 6 standard, but it is an optional technology. Because of the high cost of the technology, most products do not use it. Wi-Fi7 will continue to list this as a mandatory standard.
We already know that the 320MHz bandwidth of Wi-Fi7 is composed of multiple 20MHz basic channel bundles. Of course, this bundling process is promoted layer by layer. Two 20MHz channels are bundled into one 40MHz channel. One of the 20MHz channels is the main channel and the other is the auxiliary channel. That is, one is the main channel and the other is the auxiliary channel. The combined 40MHz channel is combined with other 40MHz channels into an 80MHz channel according to the main channel and auxiliary channel, and so on until combined into a 320MHz channel.
Source: Xiaomi official introduction video
However, in the previous protocol, the bundled channel was required to have a clean main channel without interference in order to transmit information. Therefore, if a 20MHz auxiliary channel is interfered at this time, it will cause interference to the 40MHz main channel composed of this auxiliary channel, which will in turn cause interference to the 80MHz main channel. The original 160MHz channel will be interfered with by a 20MHz channel, and finally only the 20MHz channel will be able to transmit information. This will undoubtedly cause a great waste of resources, and is one of the reasons why when we use Wi-Fi every day, once the signal is interfered, the network speed will immediately fluctuate greatly.
Source: Xiaomi official introduction video
Preamble Puncturing solves this problem very well. It can shield the interfered 20MHz auxiliary channel, and the remaining channels are not affected and continue to be bundled. At this time, the original 160MHz bandwidth still has 140MHz. This undoubtedly greatly improves the signal's anti-interference ability, while increasing the actual rate and reducing the delay.
Source: Huawei official website
Lack of 6G frequency band? The domestic development prospects of Wi-Fi7 are still unclear
We have spent a lot of effort before to understand the improvements brought by Wi-Fi7 from a relatively popular perspective. In summary, it actually means faster speed, lower latency and better stability. From the perspective of upgrades, the prospects of Wi-Fi7 should be quite broad, so why are its development prospects in China not optimistic?The reason actually lies in the 6G frequency band.
In radio transmission, the frequency band resources are actually wired. In order to avoid mutual interference between communication technologies using different frequency bands, different countries and regions will divide the frequency bands differently. The United States, South Korea, and Brazil directly allocated all the 5.92-7.125GHz 6G frequency band to Wi-Fi6E and Wi-Fi7. Countries such as the European Union and Australia allocate the 5.925-6.425GHz low-frequency band in the 6G frequency band to Wi-Fi, while the 6.425-7.125GHz frequency band is allocated to IMT (International Mobile Communications), which is 5G and 6G mobile networks.
Source: Wi-Fi Alliance official website
The Ministry of Industry and Information Technology of my country has also allocated 6.425-7.125GHz to IMT, user 5G and future 6G system deployment. However, the Ministry of Industry and Information Technology occupies the low-frequency band 5.925-6.425GHz and does not allocate it, and it has not yet been allocated to Wi-Fi.
In the Ministry of Industry and Information Technology’s approval document for Wi-Fi7 equipment, it can be seen that the Wi-Fi7 working frequency band is only allocated to the 5G high-frequency band of 7.725-5.850GHz. 6G is likely to not support domestic Wi-Fi7 in the end.
The lack of 6G frequency band makes domestic Wi-Fi7 unable to accommodate 320MHz channels, and can only support up to 240MHz channels, and the highest transmission speed is also limited to 30Gbps. This will undoubtedly significantly weaken the real strength of Wi-Fi7.
The lack of 6G frequency bands also means that using Gigabit broadband and Wi-Fi 7 networking to achieve stronger smart home applications in home scenarios, or industrial Internet applications in industrial scenarios, is very likely to become less easy to achieve. Instead, it may need to rely on 5G and 6G mobile networks to achieve this. This is why many people are pessimistic about the development prospects of Wi-Fi 7 in China.
However, the Wi-Fi Alliance has not yet officially released the Wi-Fi 7 standard. There are still some variables in the final technical details of the Wi-Fi 7 standard. The domestic Ministry of Industry and Information Technology has just ended the solicitation of opinions on the Wi-Fi 7 standard in July. There is still some time before the final landing. Whether domestic Wi-Fi 7 can finally use 6G, there are still variables.
Is it necessary to upgrade Wi-Fi7?
So for ordinary consumers, what substantial improvements can Wi-Fi7 bring? Is there any significance in upgrading?
From the perspective of ordinary people accessing the Internet, Wi-Fi 7 is actually somewhat advanced. According to the 2022 Communications Industry Statistical Bulletin released by the Ministry of Industry and Information Technology, by the end of 2022, the total number of fixed Internet broadband access users of the three basic telecommunications companies will reach 590 million, of which 91.75 million users have access rates of 1000Mbps and above, accounting for 15.6% of the total number of users. The majority of users (78.4%) are actually still using broadband below Gigabit.
Source: Official website of the Ministry of Industry and Information Technology
Therefore, in the current situation, Wi-Fi 6 can completely fill up the broadband and meet the high-speed Internet needs of most people. Wi-Fi 7 will not be used in a short time.
Of course, the upgrade of Wi-Fi7 is not just about speed. Popular science mentioned earlier that Wi-Fi7 has also added many new features to improve transmission quality and reliability. This also means that routers that support Wi-Fi7 will have better transmission quality and anti-interference than routers that support Wi-Fi6.
It is undeniable that these improvements are very meaningful, but in the daily life of most people, the main problem of Wi-Fi may still be that it is separated by several rooms and walls, and the signal and network speed are not good. Faced with this, Wi-Fi 7 does not seem to be able to improve much. This is determined by the physical properties of radio signals. Although the 6G frequency band on Wi-Fi 7 is faster, the wavelength is shorter and the ability to penetrate walls is weaker.
So from the current point of view, the demand for Wi-Fi7 in home scenarios may mainly be some enthusiast players who want to build a home 10G intranet, as well as enthusiast gamers who frequently use wireless streaming technology to play VR games and AAA games. For these users, Wi-Fi7 should be able to provide a better low-latency experience. For most ordinary users who just use the Internet, Wi-Fi7 is still a bit far away.
Of course, the development of communication technology has always been ahead of consumer demand. As early as 2018, the Wi-Fi Alliance has begun research on IEEE802.11be, also known as Wi-Fi7. Wi-Fi7 is mainly to cope with the higher requirements for wireless transmission technology in applications and scenarios such as the Yuanverse, VR, 4K/8K ultra-high-definition video, and because it may soon begin to promote popular 10G broadband services.
How far is Wi-Fi7 from us?
The iterative development of Wi-Fi technology is actually insensible to most ordinary consumers. How many people were really aware of the iterative development of Wi-Fi technology before Wi-Fi6? After all, how many people get routers that are given away by operators when they apply for broadband, and the routers given by operators must be able to match the broadband packages that users apply for and provide up to standard speeds. At present, the basic gifts for Gigabit broadband offered by the three major operators are Wi-Fi6 routers, which also shows that Wi-Fi6 has gradually become popular.
The current Wi-Fi7 is still in a state of development. It seems that the actual experience and future prospects of Wi-Fi7 will only be known until the standard is officially implemented. And how far is Wi-Fi7 from us? When will it really become popular in our daily lives? We probably have to wait until operators start sending Wi-Fi 7 routers.