There will be “7“ later: Interpretation of next-generation Wi-Fi technology

With the Wi-Fi Alliance announcing the launch of Wi-Fi 7-related certifications, we can also start talking about the new successor to Wi-Fi 6 three years after its launch. What is Wi-Fi 7? What benefits does it bring? These questions about Wi-Fi 7 will be answered in this article.

A quick look at Wi-Fi 7 highlights

Literally, Wi-Fi 7 is a new generation of Wi-Fi technology, the successor to Wi-Fi 6, based on the latest revision of the IEEE 802.11 standard, 802.11be. Compared with Wi-Fi 6, which focuses on stability, Wi-Fi 7 introduces many new technologies. Simply put, it mainly includes greater bandwidth and lower latency.

Accelerate to the ultimate speed

Every time a new Wi-Fi technology is released, "speed improvement" is always a topic that cannot be avoided. Wi-Fi 7 can reach a maximum link speed of 46Gbps under theoretical conditions, which is an increase of approximately 380% compared to the 9.6Gbps limit speed of Wi-Fi 6.

The reason why Wi-Fi 7 can achieve this is due to its major breakthroughs in channel width, number of spatial streams and QAM modulation technology.

Channel

Since the launch of Wi-Fi 6E, an improved version of Wi-Fi 6, many countries have approved Wi-Fi to use the 6GHz unlicensed frequency band. Compared with the 2.4GHz and 5GHz commonly used by Wi-Fi before, the frequency is significantly higher. Higher frequency radio waves can complete more cycle changes per unit of time, thereby carrying more information in the same time, which means faster Wi-Fi speeds.

In addition to speed, high frequency bands also mean greater bandwidth. Theoretically, the 6GHz band can provide 5925-7125 MHz, which is a full 1200MHz continuous bandwidth.

We can think of bandwidth as road width. The wider the road (the greater the bandwidth), not only can the router choose more lanes (passages), but each lane (the bandwidth that the router can occupy) can also be expanded. In the past, 2.4GHz only supported three non-overlapping 20MHz and one non-overlapping 40MHz bandwidth, while 5GHz can additionally support a larger three non-overlapping 80MHz and one non-overlapping 160MHz.

Wi-Fi 7 can easily divide into 6 non-overlapping 80MHz and 3 non-overlapping 160MHz, and the "lane" is also doubled to 320MHz. Wi-Fi 7 also allows the combination of non-contiguous spectrum, such as combining the 5GHz low-frequency 200MHz and the high-frequency 125MHz into a larger 320MHz bandwidth, further increasing the use range of the 320MHz bandwidth.

It should be admitted that higher frequency is not always better. The higher the frequency, the shorter the wavelength, and the lower the ability to penetrate walls. In addition, setting a narrower channel bandwidth in daily life can also help avoid neighbor Wi-Fi interference. Even so, changes in channel frequency are the basis for speed improvement. You can choose appropriately according to the scenario. One is better than the other.

Spatial Streaming and MU-MIMO

In layman's terms, spatial flow refers to "how many real antennas the router has." Therefore, supporting more spatial streams means more antennas, which can support higher speeds.