Topics covered in this article:|
|Wi-Fi 7 is on the way|
|What is Wi-Fi 6?|
|What are the enhancements of Wi-Fi 7?|
|The uncertainty facing WiFi-7 and other next-generation communication|
January 2020, the 6.0 version of the 802.11AX standard (Draft6.0) voted through the IEEE Standard Working Group, WiFi-6 technical standards are set. As the WiFi-6E for the next generation of transition products, there is already a prototype product. For the normal rhythm of technology evolution and the need for competition with other wireless communication programs, the WiFi Alliance needs to develop the technical standards of next-generation Wi-Fi 7. At present, it is most likely that the main body of the Wi-Fi 7 is the 802.11be standard. The WiFi Alliance began to establish a team for pre-research in May 2018, and officially establish the project in 2019.
802.11be project authorization requirements are Extreme High Throughput. In the pre-research stage of the project, based on 802.11ax, various discussions aimed at improving technical indicators were carried out, and some consensus was reached as a basis for subsequent research. Of course, 802.11be is very young. If all things are good, the first edition is at least 2022. Formal commercial products will appear at the end of 2023. Therefore, this paper does not ensure everything is accurate.
The development of science and technology is getting faster and faster. When we are still waiting for Wi-Fi 6 terminals, the seventh generation Wi-Fi 7 technology has been arranged. The maximum rate of Wi-Fi 7 is up to 30Gbps.
The main increase in Wi-Fi 6 is that its QAM modulation accuracy is doubled so that the single device is faster. It also introduces OFDMA technology that can accommodate more device connections. Furthermore, Wi-Fi 6 adds BSS coloring technology, which lowers signal interference between routers. It's possible to minimize WiFi power consumption by implementing the protocol's "target wake-up time design." Compared to the WiFi5 router, the maximum potential speed of Wi-Fi 6 will increase by 40% from the former, which greatly improves the data transmission speed.
Taking the home's network center router as an example, Wi-Fi 6 allows the router to communicate with more devices. It also allows the router to transfer data to multiple devices in the same broadcast. At the same time, Wi-Fi 6 is more difficult for hackers to decipher the hacker. It greatly improves the security level of WiFi because of the support of the latest security protocol WP3.
It is most likely that Wi-Fi7 is the IEEE 802.11BE standard under development. Wi-Fi 7 is intended to improve on Wi-Fi 6 (802.11ax) in the following ways:
Wi-Fi 7 supports more data streams. It introduces CMU-MIMO. Wi-Fi 6 supports up to 8 data streams. It is a major upgrade that Wi-Fi 6 introduces MU-MIMO that allows multiple devices to communicate with access points simultaneously using multiple data streams. Wi-Fi 7 will double this number. The device can support 16 data streams that will bring more powerful characteristics CMU-MIMO. Where C represents Coordinated, the 16 data streams may not be provided by an access point, but by multiple access points.
CMU-MIMO is a novel feature in wireless networks that caters to multiple access points. To expand the coverage of the WiFi network, we often use mesh networking. This is actually an increase in the number of access points. CMU-MIMO can make the user use more access points to divide 16 data streams into different access points and work at the same time.
Wi-Fi 7 has also introduced a new 6GHz band, and the three-band is simultaneously working. Wi-Fi 6 can use two frequency bands in 2.4GHz and 5GHz at the same time. And another upgrade version, that is, Wi-Fi 6e introduces a new 6GHz band. Wi-Fi 7 will continue to use this new frequency band, and strive to achieve the goal of communicating simultaneously with three frequency bands, gaining a larger communication bandwidth to increase its own rate.
It will expand the width of the single-channel, from Wi-Fi 6 160MHz multiplied to 320 MHz. Of course, this band is not BE unique, in addition to Wi-Fi 6e, 5G + or 6G may use this band. Anyway, according to the Shannon Formula:
The increase in frequency is linearly related to the rapid transmission speed.
Wi-Fi 7 upgrades the modulation method of the signal to 4096-QAM, so it has a larger data capacity. Wireless technology involves the modulation of signals. In 802.11ax, the standard uses 1024-QAM modulation. Wi-Fi 7 will continue to upgrade modulation methods, directly use 4096-QAM, further expand the transmission data capacity. The 4096-QAM lays the foundation of the highest 30Gbps.
For the application level, if the transmission speed of Wi-Fi 7 can really reach 30Gbps, it can bring more smooth and fast transport experiences. Wi-Fi 7 has greater coverage and effectively reduces transmission congestion. And it will boost the popularity of 8K products. From the user's point of view, Wi-Fi 7 will no longer dream of online playback of 8K video, and users will have better audio and video experience. In addition, faster transmission speeds will also extend more intelligent product functions, such as artificial intelligence interactions, home intelligence control.
The frequency band is the key to all next-generation wireless communication technology. Currently, China and the United States determine to use 5925-7125MHz for 6G and allow WiFi to use this band. Europe and African countries may use 6425-7125 MHz as the primary frequency band of 6G. The time of Japan's open correspondence band may be slightly delayed. Obviously, whether there is a wide enough bandwidth to support 320MHz channels, becoming one of the factors affecting Wi-Fi 7 progress. It's also possible to reach the maximum frequency width through signal attenuation. Under the premise of wireless transmission power, the greater channel band means that the power can be used for each sub-channel, resulting in a decrease in the signal-to-noise ratio. In order to ensure stability, the bandwidth will decline in the narrow state when the signal is weak, to ensure complete data transmission.
Signal strength influences the modulation strategy as well. Depending on the WiFi standard, the Error limits required for specific modulation methods can only be handled when the error vector amplitude of the signal is small to some extent. For example, according to 802.11ac (WiFi-5), if you need to achieve the highest value of 256QAM, 5/6 yard ratio (1 calibration code per five valid information), the error amplitude vector must be less than -32dB (Contrast reference vector), or the signal-to-noise ratio must be greater than 64dB.
As for the maximum 16 antennae of the router, it is independent of most ordinary users. At present, only flagship mobile phones may support 4x4mimo. Home routers that can achieve 8 antennas are expansive. These improvements are obviously for industrial and enterprise applications. In regard to MU-MIMO, legacy problems still exist. Due to post-development advantages, Wi-Fi 7 experience will be slightly better than WiFi-6. According to the measured, if the MU-MIMO router is connected to 2 devices, the total rate of these devices and router exchanges is usually less than twice that of a single device data transmission rate. When using the 802.11ac protocol, the total transmission rate of the four valid antennas of the flagship router is reduced by the number of times the number of single tables increases. Obviously, this is due to the performance of the router chip, the law of electromagnetic wave propagation.
The backward advantages of Wi-Fi 7 may have a certain increase in the throughput capacity of the chip, but the effect is not significant. In addition, MU-MIMO has a big problem. If a device connected to the MU-MIMO router only supports Su-MIMO (single users), then you cannot enjoy the advantages of MU-MIMO. Other MU-MIMO devices will compete with this SU-MIMO device. Only consciously replacing new devices can solve this problem.
We know that the 6GHz band of WiFi-7 will be shared with the next generation of mobile communication technologies (such as 6g). And WiFi is increasingly used in the same type of technique used in 4G, 5G. Also, since the 5G coverage is small, the deployment cost of WiFi and 5G and 6G in indoor applications is a problem that we need to consider. For large shopping malls, the integration of 5G, 6G, and WiFi is a possible case. For mobile terminals, the number of antennas has also reached the bottleneck. If we only consider the rate, 60GHz 802.11ay has appeared for several years, and USB3.0 can be hung in indoor applications.
What is the future of WiFi? Let us wait and see.