Will Wi-Fi 7 be a revolution?

A Google search for "notable members of the Z generation" brings up various names I've never heard of (though I did recognize Greta Thunberg). But another name that was conspicuously absent was IEEE 802.11, or Wi-Fi as we commonly refer to it. Born in 1997, Wi-Fi has had a far greater impact on human life than any other Z-generation celebrity. Its steady growth and maturity gradually liberated Internet connectivity from the old system of cables and connectors, to the point where wireless broadband Internet access - unthinkable in the dial-up era - is often taken for granted. I'm old enough to remember the satisfying click of the RJ45 plug that signaled a successful connection to the rapidly expanding online multiverse. Now I hardly need RJ45s, and the technologically saturated teenagers I know may not even know they exist. The general public's preference for Wi-Fi is not surprising. Compared to the enormous convenience of wireless, Ethernet cables seem almost barbaric. But as an engineer who cares only about data link performance, I still think Wi-Fi is not as good as wired connections. will 802.11be bring Wi-Fi closer to replacing Ethernet altogether? Introduction to Wi-Fi standards: Wi-Fi 6 and Wi-Fi 7 Wi-Fi 6 is the public name for IEEE 802.11ax. Fully approved in early 2021, Wi-Fi 6 is a robust standard that seems unsuitable for rapid replacement, thanks to more than two decades of cumulative improvements to the 802.11 protocol. A Qualcomm blog post summarises Wi-Fi 6 as "a collection of features and protocols designed to drive as much data as possible to as many devices as possible at the same time". Wi-Fi 6 introduces a variety of advanced features to improve efficiency and increase throughput, including frequency domain multiplexing, uplink multi-user MIMO and dynamic packet fragmentation. Wi-Fi 6 uses OFDMA (orthogonal frequency division multiple access) technology to improve spectrum efficiency in a multi-user environment. Image courtesy of Cisco So why is the 802.11 working group well on its way to developing a new standard? Why are we already seeing headlines about the first Wi-Fi 7 demos? While Wi-Fi 6 collects the most advanced radio technology, at least in some respects, people find Wi-Fi 6 impressive in two important ways: data rate and latency. By improving the data rate and latency performance of Wi-Fi 6, the architects of Wi-Fi 7 hope to provide a fast, smooth, and reliable user experience that is easier to achieve than using Ethernet cables. About Wi-Fi Protocol Data Rates and Latency Wi-Fi 6 supports data transfer rates approaching 10 Gbps. Whether this is "good enough" in an absolute sense is a very subjective question. However, in a relative sense, Wi-Fi 6's data rates are objectively depressed: Wi-Fi 5's data rates are 1000% higher than its predecessor, while Wi-Fi 6's data rates are less than 50% higher compared to Wi-Fi 5. Theoretical streaming data rates are by no means a comprehensive means of quantifying the "speed" of a network connection, but they are important enough to warrant close attention from those responsible for Wi-Fi's continued commercial success. A comparison of the last three generations of Wi-Fi network protocols. Image courtesy of Intel Latency as a general concept refers to the delay between input and response. In the case of network connectivity, excessive latency can degrade the user experience and even exceed limited data rates - if you have to wait five seconds in front of a web page, then a very fast bit-level transfer won't do much to help you start loading. Latency is especially important for real-time applications such as video conferencing, virtual reality, gaming, and remote device control. Users have only so much patience for glitchy videos, lagging games and dragging machine interfaces. Wi-Fi 7 Data Rates and Latency The IEEE 802.11be project license report includes increased data rates and reduced latency as explicit goals. Let's take a closer look at these two upgrade paths. Data rate and orthogonal amplitude modulation The architects of Wi-Fi 7 expect to see a maximum throughput of at least 30 Gbps. We don't know what features and technologies will be included in the finalized 802.11be standard, but some of the most promising candidates for increased data rates are 320 MHz channel width, multi-link operation, and 4096-QAM modulation. By accessing additional spectrum resources in the 6 GHz band, Wi-Fi can increase the maximum channel width to 320 MHz. 320 MHz channel width increases the maximum bandwidth and theoretical peak data rate by a factor of two compared to Wi-Fi 6. In multi-link operation, multiple client stations with their own links function together as "multi-link devices" with an interface to the network's logical link control layer. Wi-Fi 7 will be able to access three frequency bands (2.4 GHz, 5 GHz and 6 GHz); Wi-Fi 7 multi-link devices can send and receive data in multiple bands simultaneously. Multi-link operation has the potential to significantly increase throughput, but it poses some significant implementation challenges. In multi-link operation, a multi-link device has one MAC address, even if it contains multiple STAs (representing stations, indicating communication devices such as laptops or smartphones). Image courtesy of IEEE QAM stands for quadrature amplitude modulation. This is an I/Q modulation scheme where a particular combination of phase and amplitude corresponds to a different binary sequence. We can (theoretically) increase the number of bits transmitted per symbol by increasing the number of phase/amplitude points in the system "constellation" (see figure below). This is the 16-QAM constellation diagram. Each circle in the complex plane represents a phase/amplitude combination corresponding to a predefined binary number. Image courtesy of IEEE Wi-Fi 6 uses 1024-QAM, which supports 10 bits per symbol (since 2 10 = 1024). If 4096-QAM modulation is used, the system can transmit 12 bits per symbol, provided it can achieve sufficient SNR at the receiver to achieve successful demodulation. Delay characteristics: MAC layer and PHY layer The threshold for real-world application reliability is a worst-case delay of 5-10 ms; in some usage scenarios, delays as low as 1 ms are beneficial. Achieving such low latency in a Wi-Fi environment is not an easy task. Features running on the MAC (Media Access Control) layer and the physical layer (PHY) will help bring Wi-Fi 7 latency performance into the realm of less than 10 milliseconds. These include multi-access point coordinated beamforming, time-sensitive networking, and multi-link operation. Key features of Wi-Fi 7. Image courtesy of IEEE Recent research suggests that multi-link aggregation, included in the general heading of multi-link operation, may help enable Wi-Fi 7 to meet the latency requirements of real time applications. Are you optimistic about the future of Wi-Fi 7? We don't know exactly what Wi-Fi 7 will look like, but it will undoubtedly include impressive new RF technologies and data processing techniques. Will Wi-Fi 7 revolutionize wireless networks and completely offset the few remaining advantages of Ethernet cables? Feel free to share your thoughts in the comments section below. Translated with www.DeepL.com/Translator (free version)