Перший погляд на Wi-Fi 8 — та ж пікова та краща реальна швидкість
Wi-Fi 8 is still a long way off, but MediaTek’s wireless division has released some details. For the first time, the update won’t chase peak speeds.
Wi-Fi 8, now known as IEEE 802.11bn Ultra High Reliability, will replace Wi-Fi 7, which has not even been officially approved yet. The final Wi-Fi 8 specification is expected around September 2028. The main principle of the new standard is not peak but effective bandwidth.
MediaTek believes that Wi-Fi 8 will be identical to Wi-Fi 7 in several key ways: the maximum physical layer (PHY) speed will be the same — 2880 Mbps x8, or 23 Gbps. It will use the same frequency bands (2,4, 5, and 6 GHz) and the same 4096 QAM modulation in a maximum channel bandwidth of 320 MHz.
Of course, a Wi-Fi 8 router will not have 23Gbps throughput. According to MediaTek, the actual peak throughput in a «clean» environment is only 80% of the hypothetical maximum throughput, and actual results may be much lower.
Simply put, Wi-Fi 8 will deliver the same throughput as Wi-Fi 7 using the same channels and the same modulation. Each Wi-Fi standard has been backwards compatible with its predecessors. However, Wi-Fi 8 will change the way a client device interacts with multiple access points. There are several possibilities for this.
Coordinated Spatial Reuse Co-SR — technology was first implemented in Wi-Fi 6 as spatial reuse. This technology had a problem with the difference in transmission power between an access point that was «talking» to a device nearby and simultaneously communicating with a second access point at a great distance. If the first AP reduced its power to communicate with a nearby device, it was not «heard» by the other remote AP.
According to MediaTek, Co-SR Wi-Fi 8 — is «mature» Spatial Reuse technology, which does not have this drawback and allows access points to coordinate their power output. Preliminary tests have shown that Co-SR can increase overall throughput by 15-25%.
Dynamic Sub-Channel Operation (DSO) — it is known that the latest devices support the latest wireless standards. But some have better Wi-Fi antennas that deliver higher throughput. In the past, this information was transmitted to the router and stored there. This is not a problem under most conditions, but when several different devices were downloading the same file, DSO would create a dynamic script so that the faster device would get an extra subchannel to download.
The difference between the old approach and DSO in Wi-Fi 8 is that the access point will be able to better route this traffic, improving the outcome for faster devices. MediaTek believes that DSO can increase throughput by 80%.
Better speed distribution by MCS index — Wi-Fi’s modulation coding scheme helps the router determine how fast the connection needs to be to transmit data without errors. If the throughput slows down while travelingThis is partly due to the fact that the device and router «decide» how fast the device should run.
The problem, according to MediaTek, is that the «step of» to a lower speed is too large and additional gradations should be introduced. Smaller MCS steps can increase the overall data rate by 5-30%.
Wireless standards take about six years to develop, but equipment manufacturers are striving to implement new technologies faster. Wi-Fi 7 devices have been shipping since late 2023, although the standard is not yet official. That’s partly because the IEEE committee rarely makes drastic changes between the approval of a draft and the final standard. The first Wi-Fi 8 devices are expected to be available in early 2028.
Source: PCWorld with reference to the MediaTek document