WiFi 8 is coming!

The next generation of Wi-Fi - Wi-Fi 8 is currently being secretly developed. This time, the focus is not just on speed, but on improving user experience. Wi-Fi 8 (currently known as the IEEE802.11bn ultra-reliable standard) will take several years to be realized. Wireless technology is constantly evolving: every advancement in Wi-Fi evolution requires years of discussion, approval, and deployment. Wi-Fi 7 (the current standard) has not even been officially approved yet. But this has not stopped the development of Wi-Fi 8 behind the scenes, and we already know some details. According to MediaTek, they recently released some details you can look forward to, but it is important to note that the final details will only be confirmed after the final specification is released around September 2028. With Wi-Fi 8 in the background, what keywords should you think of? Not peak throughput, but effective throughput. Wi-Fi 8 is very similar to Wi-Fi 7 According to the Wi-Fi Alliance and MediaTek, it is not the United States but China that drives the development of wireless technology: China has 650 million broadband users, with over a quarter of households having a 1Gbps broadband connection. Overall, the average connection speed is 487.6Mbps, which increased by 18% in a year. Theoretically, 802.11bn / Wi-Fi 8 aims to provide enough wireless bandwidth to accommodate broadband gateways offering several gigabits per second, while considering the ability of Ethernet to provide more bandwidth. EverythingRF interprets the document from 2022 (known as a Project Authorization Request (PAR)) as being able to provide a minimum total throughput of 100Gbps. Subsequently, the PAR was approved in 2023, and the working group began finalizing more details. As of November 2024, MediaTek believes that in several key areas, Wi-Fi 8 will be almost identical to Wi-Fi 7: the maximum physical layer (PHY) rate will be the same, at 2,880Mbps x 8, which is 23Gbits/s. It will also use the same three frequency bands (2.4, 5, and 6GHz) and the same 4096 QAM modulation, with a maximum channel bandwidth of 320MHz. Of course, Wi-Fi 8 routers will not achieve a bandwidth of 23Gbps. According to MediaTek, in a "clean" or laboratory environment, the actual peak throughput will be around 80% of the assumed peak throughput, and the actual real-world results may be much lower. However, in simple terms, Wi-Fi 8 should be able to provide the same wireless bandwidth as Wi-Fi 7, using the same channels and modulation. Each Wi-Fi standard is also backward compatible with its predecessor. However, the role of Wi-Fi 8 is to change the way client devices (such as PCs or phones) interact with multiple access points. You can think of this as the evolution of how a laptop communicates with home network devices. Over time, Wi-Fi has evolved from communication between a laptop and a router through a single channel. Channel hopping directs different clients to different frequencies. When developing Wi-Fi 6, a dedicated 6GHz channel was added, sometimes used as a dedicated "backhaul" between home access points. Now, mesh networks are more common, providing your laptop with multiple access points, channels, and frequencies to choose from. How Wi-Fi 8 will improve Wi-Fi technology MediaTek sees several opportunities to improve coordination between access points and devices. (To be fair, we see these as MediaTek's efforts, just because we cannot be sure if they will be approved by the entire Wi-Fi 8 working group for 802.11bn.) Coordinated Spatial Reuse (Co-SR): This technology was originally introduced in Wi-Fi 6 for spatial reuse. Problems arise when an access point is communicating with nearby devices while simultaneously communicating with a second access point far away, and there are differences in transmission power. If the first access point lowers its power to communicate with nearby devices, the access point cannot "hear" it. MediaTek states that Co-SR in Wi-Fi 8 is a "mature" spatial reuse technology that will solve the problem by allowing access points to communicate with each other and coordinate their power outputs. MediaTek states, "Our initial experiments show that Co-SR can increase the throughput of the entire system by 15% to 25%." Coordinated Beamforming (Co-BF): There is now a trend of taking early Wi-Fi technologies and expanding them to multiple access points. Spatial zero is a feature introduced in 802.11ac (Wi-Fi 5) that allows the router to essentially stop sending signals in certain directions. By doing so, the router sends the signal to the requested location and avoids interfering with devices that do not want to communicate with the router. This technology seeks to address a fairly common issue in connected homes or Wi-Fi public spaces: when two devices are very close to each other. Coordinated beamforming allows access points to communicate with each other, determine which device needs the signal and which does not, and adjust the mesh access points to "steer" the signal away from devices that are not communicating with the network, thus refusing to transmit a signal to the area they are in. MediaTek states, "Coordinated Beamforming in the next-generation MediaTek Filogic offers significant enhancements in throughput, with throughput gains ranging from 20% to 50% in a mesh network setup with one control AP and one proxy AP." Dynamic Subchannel Operation (DSO): You may know that the latest devices support the latest wireless standards, such as Wi-Fi 7. However, some devices may still have additional or improved Wi-Fi antennas, enabling higher throughput. In the past, this information was sent to the router and stored there. In most cases, this is not a problem. But in scenarios where multiple different devices are downloading the same file, DSO creates a dynamic scenario where more advanced devices are allocated a subchannel to download the file faster. The old method contrasts with DSO in Wi-Fi 8.The difference lies in the fact that the access point will be able to make decisions, "understand" the functionality and requirements of each device, and accordingly route data.MediaTek believes that compared to not having this technology, DSO can increase data throughput by 80%. New data rates: You may not know what the MCS index is, which is the modulation and coding scheme of Wi-Fi. It is basically a table that helps your Wi-Fi router determine the link speed so that you can truly connect and transfer data without errors. If your throughput slows down while moving around at home, it is because your device and router "decide" at what connection speed your device should transmit data. MediaTek believes that the problem lies in the "step-wise" decrease in rates being too steep, and there should be additional gradation introduced, such as 2/3 coding rate of 16-QAM. The purpose of this is not to introduce a sharp decrease and increase in throughput as you move your phone or laptop around at home, but to introduce smaller increments. MediaTek believes that these finer MCS divisions can increase overall transmission rates by 5% to 30%. Changing the pace: Likewise, the evolution of Wi-Fi 8 depends on the speed at which the standard passes through regulatory procedures. Wi-Fi 7 (802.11be) was originally expected to be approved in September of this year, but has not been approved yet. Sony's PlayStation 5 may not be approved in India because the country has not approved the 6GHz wireless channels on which the Wi-Fi 7 standard relies. This will also hinder the promotion of Wi-Fi 8. The establishment of wireless standards takes about six yearshardware manufacturers with no patience rarely wait. As MediaTek pointed out, even though the standard has not been officially approved, Wi-Fi 7 products have been shipped since the end of 2023. Part of the reason is that the IEEE committee responsible for the standard rarely makes significant changes between the draft standard approval and the final standard. For Wi-Fi 8, the first batch of products is expected to be launched in early 2028, although the final approval is expected to be completed by the end of that year. However, it is worth noting that in the two different areas of the PC market, the competition for constantly increasing speed has currently paused. CPUs from Qualcomm and Intel have slowed down the pace of increasing clock speeds and are now focusing on lower power consumption. For Wi-Fi 8, the current focus seems to be on improving the overall user experience first. This article is reprinted from the WeChat public account "Semiconductor Industry Observation", author: Mark Hachman; GMTEight editor: Yan Wencai.