This article is reproduced from the [Semiconductor Industry Observation] public account
A Google search for "famous members of Gen Z" will appear under a variety of names I've never heard of (though, I do recognize Greta Thunberg). But another name that is conspicuously absent is IEEE 802.11, which is what we usually call Wi-Fi.
Born in 1997, Wi-Fi has had a far greater impact on human life than any other Gen Z celebrity. Its steady growth and maturity gradually liberated network connectivity from the old system of cables and connectors, so much so that wireless broadband Internet access – which was unthinkable in the dial-up age – was often taken for granted.
My age makes me remember enough that the RJ45 plug brings a satisfying click, which marks a successful connection with the rapidly expanding online multiverse. I barely need RJ45s now, and the tech-saturated teenagers I know may not even know they exist.
The preference of the general public for Wi-Fi is not surprising. Compared to the immense convenience of wireless, Ethernet cables look almost barbaric. But as an engineer who only cares about data link performance, I still think Wi-Fi is inferior to a wired connection. Will 802.11be bring Wi-Fi closer to completely replacing Ethernet? Introduction to Wi-Fi standards: Wi-Fi 6 and Wi-Fi 7
Wi-Fi 6 is the public name for IEEE 802.11ax. Wi-Fi 6 was fully approved in early 2021, and thanks to more than two decades of cumulative improvements to the 802.11 protocol, Wi-Fi 6 is a powerful standard that doesn't seem to be suitable for quick replacement.
A Qualcomm blog post summarized Wi-Fi 6 as "a collection of features and protocols designed to drive as much data simultaneously as possible for as many devices as possible." Wi-Fi 6 introduces a variety of advanced features that increase efficiency and throughput, including frequency domain multiplexing, uplink multiuser MIMO, and dynamic sharding of packets.
Wi-Fi 6 uses OFDMA (Quadrature Frequency Division Multiple Access) technology to improve spectral efficiency in multi-user environments. Image courtesy of Cisco So why is the 802.11 working group already on the road to developing a new standard? Why have we seen headlines about the first Wi-Fi 7 demo? Although Wi-Fi 6 collects the most advanced radio technology, at least in some respects, Wi-Fi 6 is considered impressive in two important ways: data rate and latency.
By improving Wi-Fi 6's data rates and latency performance, Wi-Fi 7 architects want to provide a fast, smooth, and reliable user experience that is easier to achieve than using An Ethernet cable.
About data rates and latency for wi-Fi protocols
Wi-Fi 6 supports data transfer rates close to 10 Gbps. Whether this is "good enough" in the absolute sense is a very subjective question. However, in a relative sense, Wi-Fi 6's data rates are objectively sluggish: Wi-Fi 5's data rates are 1000% higher than its predecessor, while Wi-Fi 6's data rates are less than 50% higher than Wi-Fi 5's.
Theoretical streaming data rates are definitely not a comprehensive means of quantifying the "speed" of network connections, but they are important enough to deserve close attention from those responsible for the continued commercial success of Wi-Fi.
Comparison of the protocols of the past three generations of Wi-Fi networks. Image courtesy of Intel Latency as a general concept refers to the delay between input and response.
In the case of a network connection, excessive latency can degrade the user experience and even exceed the limited data rate – if you have to wait five seconds in front of a web page, the extremely 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 with glitched videos, lagging games, and dragging machine interfaces.
Data rate and latency for Wi-Fi 7
The IEEE 802.11be Project Authorization Report includes explicit goals to increase data rates and reduce latency. Let's take a closer look at these two upgrade paths.
Data rate and quadrature amplitude modulation
Architects of Wi-Fi 7 want 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 improved data rates are 320 MHz channel width, multilink 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. A channel width of 320 MHz increases the maximum bandwidth and theoretical peak data rate by a factor of two relative to Wi-Fi 6.
In multilink operations, multiple client stations with their own links function together as "multilink devices" that have an interface to the network logical link control layer. Wi-Fi 7 will have access to three frequency bands (2.4 GHz, 5 GHz, and 6 GHz); Wi-Fi 7 multilink devices can send and receive data simultaneously across multiple bands. Multilink operations have the potential to significantly increase throughput, but it presents some significant implementation challenges.
In multilink operations, a multilink device has a MAC address, even though it contains multiple STAs (representing a station, representing a communication device such as a laptop or smartphone). Image courtesy of IEEE
QAM stands for Quadrature Amplitude Modulation. This is an I/Q modulation scheme where a specific 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's "constellation" (see figure below).
This is the constellation chart for 16-QAM. Each circle on the complex plane represents a phase/amplitude combination corresponding to a predefined binary number. Picture provided by IEEE Wi-Fi 6 uses 1024-QAM, which supports 10 bits per symbol (because 2 10 = 1024). If you use 4096-QAM modulation, the system can transmit 12 bits on each symbol, provided it can implement enough SNR at the receiver for successful demodulation.
Latency features: MAC layer and PHY layer
The threshold for applying reliable functionality in real time is a worst-case latency of 5-10 milliseconds; in some use cases, a latency as low as 1 millisecond is beneficial. Achieving such low latency in a Wi-Fi environment is not an easy task.
Features that run on the MAC (Media Access Control) layer and physical layer (PHY) will help bring Wi-Fi 7 latency performance into areas 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 the IEEE Recent research suggests that multilink aggregations included in the general title of multilink operations 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 yet know exactly what Wi-Fi 7 will look like, but it will undoubtedly contain impressive new RF and data processing technologies. Is all this research and development worth it? Will Wi-Fi 7 revolutionize wireless networking and completely offset the few remaining benefits of Ethernet cables? Feel free to share your thoughts in the comments section below.