Wi-Fi 7: Five common myths and misconceptions dispelled
Wi-Fi is constantly evolving. We’ve become used to seeing a consistent stream of enhancement, with every new generation of Wi-Fi promising faster speeds, bigger channels, improved reliability, and of course a better experience for Wi-Fi users around the world. Every four to five years, the claims get bigger.
Wi-Fi 7 is the next generation set to enter the marketplace, based upon the IEEE 802.11be draft amendment, Extremely High Throughput (EHT). But does the accompanying wave of claims regarding speeds and feeds stand up? Each generation of Wi-Fi comes with its own misconceptions, but what's the truth? Here, we shed light on some of the biggest myths regarding Wi-Fi 7.
Myth #1 – we already have Wi-Fi 7
This is a simple one to dispel. The technology hasn’t yet gone through the certification testing process, meaning Wi-Fi 7 does not yet exist. This certification testing is carried out by the Wi-Fi Alliance – a global, non-profit industry association focused on ensuring the interoperability of Wi-Fi products and compatibility between Wi-Fi devices. Although the technical phase of the process is under development – the Wi-Fi Alliance announced in May 2022 that it had started defining the certification requirements – there is no Wi-Fi 7 certification yet for interoperability.
The slightly confusing part of all this is that the technology is already being developed. It’s often the case that Wi-Fi products, particularly consumer-grade products, become available before the certification program is in place. For example, in April 2022 Broadcom announced its Wi-Fi 7 ecosystem of Wi-Fi 7 chipsets and radios for residential APs and client devices such as smartphones. The company also announced Wi-Fi 7 enterprise access point chips. We expect Wi-Fi 7 smartphones to debut as soon as this year, shortly followed by consumer-grade Wi-Fi routers – with enterprise-grade Wi-Fi 7 access points likely to start appearing early in 2024.
Myth #2 – Bigger 320 MHz channels is better
When discussing Wi-Fi 7, the promise of ultra-wide 320 MHZ channels is usually one of the big talking points. A larger channel allows you to modulate more data on additional frequency space, resulting in incredibly high potential data rates. For example, 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, similar to the legacy bands, channel reuse patterns will be required in the 6 GHz band, since multiple access points (APs) are installed in an enterprise. With greater frequency space in 6 GHz introduced with Wi-Fi 6E, using wider channels is actually advantageous due to the new power spectral density criteria. 80 MHz channel reuse patterns will become prevalent in corporate networks in regions where the complete 1200 MHz of 6 GHz spectrum is accessible. Across Europe, 40 MHz will probably be more common because twelve 40 MHz channels are available for reuse, but only six 80 MHz channels.
Therefore, why not 320 MHz channels? Put simply, because you will only have one to three 320 MHz channels available, depending on the location and the amount of 6 GHz spectrum that is available. Even though it might work well for one AP in a remote location, co-channel interference (CCI) and the resulting medium contention overhead prevent this from functioning in an enterprise channel reuse design. For the same reasons, 160 MHz channels won't be utilised in the enterprise outside of special circumstances. A possible use for 160 MHz wide channels is mesh backhaul.
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.
Myth #3 – Wi-Fi 7 will accelerate wireless throughput to 46 Gbps
As the name of the IEEE 802.11be draft amendment (Extremely High Throughput) upon which Wi-Fi is based suggests, Wi-Fi 7 is destined to be the fastest generation of Wi-Fi yet. Speeds of up to 46 Gbps have been touted, largely thanks to the previously mentioned 320 MHz wide channels and 4K-QAM modulation capabilities. But, given that these are consumer-grade features, is 46 Gbps realistic or should we take the claim with a pinch of salt?
The short answer is that we won’t see real-world speeds of 46 Gbps. 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.
With every generation of Wi-Fi, a new complex modulation is introduced that promises greater data rates and increased throughput. 4096-QAM, also known as 4K-QAM, will probably need a signal-to-noise ratio (SNR) environment of 40 DB or more. Achieving this requires a pristine RF environment with an extremely low noise floor. This deployment type is likely possible in a residential environment with 6 GHz channels deployed on 1-2 access points, and when the Wi-Fi 7 client is within 5 metres and direct line-of-sight of the Wi-Fi 7 AP. But it’s not practical in enterprise deployments with numerous access points, mobile clients with greater distances from the APs, and variable noise floors depending on the deployment vertical and location.
The good news is that we are destined for greater speeds with Wi-Fi 7, due to a combination of features including the possible aggregation benefits of multi-link operation (MLO). Intel’s Carlos Cordeiro and Broadcom’s Vijay Nagarajan recently collaborated for a video demo of a cross-vendor Wi-Fi 7 demonstration with over-the-air speeds greater than 5 Gbps per second under controlled conditions, which was impressive. This suggests that real-world multi-gig Wi-Fi speeds will indeed become more common. Just don’t hold out for 46 Gbps.
Myth #4 - Wi-Fi 7 won’t have value in the enterprise
I have already mentioned 4K QAM and 320 MHz wide channels, the two Wi-Fi 7 capabilities that hold promise for consumer-grade Wi-Fi. But Wi-Fi 7 isn’t just for the consumer world. It also has features that will make it valuable in an enterprise setting. Multi-link operation (MLO), which enables multiple bands and multiple-channel connectivity between a Wi-Fi 7 AP and a Wi-Fi 7 client device simultaneously, provides one such example. MLO has enormous potential to deliver lower latency, increased reliability, and higher throughput by using multiple Wi-Fi links for things like link steering, link redundancy, and link aggregation.
Multi-link operations can be potentially synchronous or asynchronous. MLO will have a future impact in supporting mission-critical and industrial enterprise applications that require reduced latency and jitter. And the lower latency enhancements promised through MLO and other Wi-Fi 7 features will spur a renaissance of innovation in augmented reality (AR) and virtual reality (VR) applications, which will rely on Wi-Fi as their primary access method.
Myth #5 – Wi-Fi 7 will mean the end for Wi-Fi 6E
There’s a perception in certain parts of the industry that Wi-Fi 6E is a ‘niche’ generation of Wi-Fi. In fact, the opposite is true. Wi-Fi 6E is the foundational generation of Wi-Fi to bring the technology to the 6 GHz frequency band, delivering a new 6 GHz ‘superhighway’ that continues to be adopted by countries around the world. This 1200 MHz frequency superhighway provides a reliable path for the evolution of enterprise Wi-Fi, guaranteeing that Wi-Fi will continue to grow as the predominant enterprise solution for secure wireless connectivity and mobility.
That’s why the 6 GHz spectrum is the most significant thing happening in Wi-Fi right now, rather than the shiny new ‘bells and whistles’ that tend to garner the most attention. Wi-Fi 7 will bring us both consumer-grade and enterprise features, but the real value will come when these next-generation capabilities begin to prosper in 6 GHz.
In the meantime, think of Wi-Fi 6E as the foundational generation of Wi-Fi that offers 6 GHz connectivity. In the months and years to come, Wi-Fi 7 will leverage 6 GHz even further and take it to greater heights to the benefit of users everywhere.
Markus Nispel is CTO of EMEA at Extreme Networks and has worked at the cloud networking firm for 10 years. Having worked in the telecommunications and networking sector for more than 25 years, Nispel has had a front row seat observing how the industry and technology has changed and how customers benefit from those changes, as well as how vendors disrupt and get disrupted.
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