Like many technologies, the evolution of Wi-Fi technology follows a consistent cyclical pattern.
Every few years, we are greeted with a new generation of Wi-Fi that promises to be bigger, better, and more powerful than the last. Claims such as faster speeds, enhanced reliability, and a superior user experience typically accompany every new Wi-Fi generation – and Wi-Fi 7 is no exception.
Based upon the IEEE 802.11be Extremely High Throughput (EHT) draft amendment, Wi-Fi 7 is coming soon to the marketplace. But all may not be as it seems. Like its predecessors, Wi-Fi 7 comes with its own set of myths and misconceptions. Let’s take a closer look at the biggest ones – and set the record straight.
- Wi-Fi 7 is already available
The short answer to “is Wi-Fi 7 available now?” is not quite. Every new generation of Wi-Fi goes through a certification testing process, carried out by the Wi-Fi Alliance – a global, non-profit industry association – to ensure interoperability and compatibility between Wi-Fi devices. Although the Wi-Fi Alliance announced earlier this year that the technical phase of Wi-Fi 7’s certification is under development, the actual testing is yet to take place. As such, there isn’t yet a Wi-Fi 7 certification for interoperability, which means it doesn’t technically exist.
However, this doesn’t mean that development work isn’t already underway. Wi-Fi technologies and products often hit the marketplace before the certification program is in place, especially consumer-grade products. For example, Wi-Fi 7 smartphones are likely to debut as early as Q2 2023, shortly followed by routers. Broadcom has already put its stake in the ground by announcing Wi-Fi enterprise access point (AP) chips, as well as its ecosystem of Wi-Fi 7 chipsets and radios for residential APs and client devices such as smartphones. On the enterprise side, we’ll likely have to wait until early 2024 for Wi-Fi 7 access points.
- It’s all about the 320 MHz channels
The promise of ultra-wide 320 MHZ channels gets a lot of hype when discussing Wi-Fi 7. A larger channel allows you to modulate more data on additional frequency space, resulting in incredibly high potential data rates. A 320 MHz channel in 6 GHz can transmit 16 times more data than a 20 MHz channel commonly used in 2.4 and 5 GHz. Sounds great, right?
However, because multiple APs are deployed in an enterprise, channel reuse patterns will be needed in the 6 GHz band—just like in the legacy bands. Wi-Fi 6E marked a new beginning with more frequency space in 6 GHz, and the new power spectral density rules actually make it advantageous to use larger channels. In countries where the entire 1,200 MHz of 6 GHz frequency space is available, 80 MHz channel reuse patterns will become common in enterprise networks. In Europe, 40 MHz will probably be more common because twelve 40 MHz channels are available for reuse, but only six 80 MHz channels.
So why not 320 MHz channels? Well, depending on the region and available 6 GHz spectrum, you will only have one or three 320 channels available. While this might work well for one AP in an isolated area, this will not work in an enterprise channel reuse pattern because of co-channel interference (CCI) and the resulting medium contention overhead. By the way, 160 MHz channels will not be used in the enterprise except in corner cases for the same reasons. Mesh backhaul is a potential use case for 160 MHz wide channels.
A 320 MHz channel is a Wi-Fi 7 consumer-grade feature for one AP deployed in a household. As a matter of fact, I fully expect 320-MHz channels to be the default setting when consumer-grade home Wi-Fi routers hit the market. The only problem with this is that consumer-grade routers set to that default will likely cause primary/secondary OBSS interference when located near enterprise deployments. Bigger is not always better.
- Expect 46 Gbps wireless throughput with Wi-Fi 7
You might have heard that Wi-Fi 7 is the fastest generation, capable of speeds of up to 46 Gbps. Although it’s true that we will certainly see faster speeds with Wi-Fi 7, is 46 Gbps realistic? To answer that question, we need to understand the two Wi-Fi 7 consumer-grade features that primarily contribute to the speeds being claimed: the previously mentioned 320 MHz wide channels and 4K-QAM modulation.
Every Wi-Fi generation sees the introduction of a new advanced modulation that offers higher data rates and throughput. 4K-QAM, alternatively known as 4096-QAM, would likely require a signal-to-noise ratio environment of at least 40 DB. A spotless RF environment with a very low noise floor is needed to make this happen. This is probably achievable in a household setting with 1-2 APs using 6-GHz channels and is likely to be the most successful when the Wi-Fi 7 client is located a maximum of 5 metres away from the Wi-Fi 7 AP with a clear line of sight. This deployment method, however, is impractical for enterprise deployments with multiple access points, mobile clients who must travel farther to reach the APs, and noise levels that vary based on the deployment’s vertical and geographic location.
But with Wi-Fi 7, are faster speeds in store for us? In the simplest of terms, yes. The improved speed is down to a number of features, including potential aggregation advantages of multi-link operation (MLO). Back in September, Intel’s Carlos Cordeiro and Broadcom’s Vijay Nagarajan worked together on an impressive video of a cross-vendor Wi-Fi 7 demonstration with over-the-air speeds greater than 5 gigabits per second, under controlled conditions.
Clearly, this is much lower than the touted speed of 46 Gbps. But that was always unlikely to be a reality, so take any such claims with a pinch (or handful) of salt. Defined data rates are always theoretical, and due to medium contention, the actual TCP throughput is usually about 50-60% of any advertised Wi-Fi data rate being used. That being said, the Intel and Broadcom video demo was impressive. This suggests that real-world multi-gig Wi-Fi speeds will indeed become more common, especially in the consumer market where multi-gig broadband initiatives are being driven.
- Wi-Fi 7 only has consumer applications
We’ve already covered the two most promising Wi-Fi 7 consumer-grade capabilities in 4K QAM and 320 MHz wide channels. But what about the enterprise? This is an area where Wi-Fi 7 will still have considerable valuable, particularly in terms of multi-link operation (MLO). MLO enables multiple bands and multiple-channel connectivity between a Wi-Fi 7 AP and a Wi-Fi 7 client device at the same time, with various applications in areas such as link steering, link redundancy, and link aggregation. The respective goals are lower latency, increased reliability, and higher throughput. Multi-link operations can be potentially synchronous or asynchronous, enabling them to support mission-critical and industrial enterprise applications that require reduced latency and jitter.
This will also drive future innovation in augmented reality (AR) and virtual reality (VR) applications. Although these technologies can be over-hyped, the latency improvements promised by MLO and other Wi-Fi 7 features will be critical for the delivery of immersive AR/VR content in applications that rely on Wi-Fi as the primary access method.
- Wi-Fi 7 will make Wi-Fi 6E obsolete
This first requires an understanding of what Wi-Fi 6E is and what it enables. Despite some within the industry claiming that Wi-Fi 6E is a “niche” generation of Wi-Fi, it actually has huge value as the foundational Wi-Fi generation that extended the technology to the 6 GHz frequency band.
This expansion to the 6 GHz spectrum is the most significant thing happening in Wi-Fi right now, and it won’t stop with Wi-Fi 7. Quite the opposite. Wi-Fi 7 will leverage this 6 GHz connectivity to even greater heights for both consumer-grade and enterprise features. In fact, we’ll continue to see greater enterprise adoption of the new 6 GHz superhighway that has debuted with Wi-Fi 6E as it becomes the predominant solution for secure wireless connectivity and mobility in the enterprise – with Wi-Fi 7 helping to take this to a new level.
So remember, it’s not always about the new “bells and whistles” or specific features that accompany the latest Wi-Fi generation. It’s about how these features work within the broader Wi-Fi ecosystem. And, with Wi-Fi 7 on the horizon, there’s plenty to be excited about.
About the Author
Markus Nispel is Office of the CTO at Extreme Networks. Extreme Networks, Inc. (EXTR) is a leader in cloud networking focused on delivering services that connect devices, applications, and people in new ways. We push the boundaries of technology leveraging the powers of machine learning, artificial intelligence, analytics, and automation. Over 50,000 customers globally trust our end-to-end, cloud-driven networking solutions and rely on our top-rated services and support to accelerate their digital transformation efforts and deliver progress like never before. For more information, visit Extreme’s website or follow us on Twitter, LinkedIn, and Facebook.
Featured image: ©Success Media
