Markus Nispel, Chief Technology Officer, (CTO) – EMEA, Extreme Networks
https://www.extremenetworks.com/
Every four to five years, a new generation of WiFi debuts with promises of faster speeds, bigger channels, enhanced reliability, and a better user experience for WiFi users across the globe. WiFi 7 is based upon the IEEE 802.11be draft amendment, Extremely High Throughput (EHT) and is coming soon to the marketplace.
With every new generation of WiFi, there are always huge claims regarding speeds and feeds. And, while some of it is true, there are always misconceptions about each generation of WiFi. But what’s the truth? Here, we shed light on some of the biggest misconceptions.
Myth #1 – WiFi 7 is already here
Everyone should understand that WiFi 7 does not yet exist because there is yet to be certification testing of the technology. The WiFi Alliance is a global, non-profit industry association whose main task is ensuring WiFi products’ interoperability by providing certification testing. The goal is to ensure compatibility between WiFi devices. In May 2022, the WiFi Alliance announced that work is underway to define requirements for WiFi 7 certification. The technical phase of the certification is under development; however, there is no WiFi 7 certification yet for interoperability.
Now, this does not mean that the technology is not being developed. And very often, WiFi products hit the marketplace before the certification program is in place, especially consumer-grade WiFi products. On April 12, 2022, Broadcom announced its WiFi 7 ecosystem of WiFi 7 chipsets and radios for residential APs and client devices, such as smartphones. What’s more, they also announced WiFi 7 enterprise access point chips. We expect WiFi 7 smartphones to debut as early as Q2 of 2023, with consumer-grade WiFi routers following closely behind. Enterprise-grade WiFi 7 access points could debut as early as Q4 in 2023, but 2024 is a safer bet.
Myth #2 – Bigger 320MHz channels are better
The promise of ultra-wide 320MHz channels gets a lot of hype when discussing WiFi 7. A larger channel allows you to modulate more data on additional frequency space, resulting in incredibly high potential data rates. A 320MHz channel in 6GHz can transmit 16 times more data than a 20MHz channel commonly used in 2.4 and 5GHz. Sounds great, right?
However, because multiple access points (APs) are deployed in an enterprise, channel reuse patterns will be needed in the 6GHz band — just like in the legacy bands. WiFi 6E marked a new beginning with more frequency space in 6GHz, and the new power spectral density rules actually make it advantageous to use larger channels. In countries where the entire 1,200MHz of 6GHz frequency space is available, 80MHz channel reuse patterns will become common in enterprise networks. In Europe, 40MHz will probably be more common because there are twelve 40MHz channels available for reuse, and only six 80MHz channels.
So why not 320MHz channels? Well, depending on the region and available 6GHz 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, 160MHz channels will not be used in the enterprise except in corner cases for the same reasons. Mesh backhaul is a potential use case for 160MHz wide channels.
A 320MHz channel is a WiFi 7 consumer-grade feature for one AP deployed in a household. As a matter of fact, I fully expect 320MHz channels to be the default setting when consumer-grade home WiFi 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 – WiFi 7 will bring us wireless throughput of 46Gbps
You might have heard that WiFi 7 is the fastest generation, capable of speeds of up to 46Gbps. WiFi 7 is indeed based upon the IEEE 802.11be draft amendment, Extremely High Throughput (EHT), whose very name implies that we are destined for faster speeds. And we will see faster speeds, but is 46Gbps realistic?
The two WiFi 7 features that currently get a lot of buzz are the previously mentioned 320MHz wide channels and 4K-QAM modulation. Both features contribute to some of the shocking claims of theoretical speeds of up to 46Gbps. However, 4K-QAM and 320MHz wide channels are consumer-grade features.
With every generation of WiFi, 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 40DB or more. Achieving this requires a pristine RF environment with an extremely low noise floor. This is likely possible in a residential environment with 6GHz channels deployed on 1-2 access points. And possible, when the WiFi 7 client is within 5m and in direct line-of-sight of the WiFi 7 AP. However, this deployment type is not practical in enterprise deployments with numerous access points, mobile clients with greater distances from the APs, or variable noise floors depending on the deployment vertical and location.
But are we destined for greater speeds with WiFi 7? The short answer is yes due to a combination of features, including the possible aggregation benefits of multi-link operation (MLO). Recently, Intel’s Carlos Cordeiro and Broadcom’s Vijay Nagarajan collaborated on a video of a cross-vendor WiFi 7 demonstration with over-the-air speeds greater than 5Gbps.
Only 5Gbps? First, let’s be honest, there will not be real-world speeds of 46Gbps. When you digest that marketing claim, please take it with many grains 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 WiFi data rate being used. That being said, the Intel and Broadcom video demo was impressive, with speeds of 5Gbps under controlled conditions. Real-world multi-gig WiFi speeds will indeed become more common, especially in the consumer market where multi-gig broadband initiatives are being driven.
Myth #4 – WiFi 7 is strictly a consumer-grade generation of WiFi
I have already mentioned 4K-QAM and 320MHz wide channels, the two WiFi 7 capabilities that hold promise for consumer-grade WiFi. But are there any WiFi 7 features that will have value in the enterprise? Yes, multi-link operation (MLO) has enormous potential. When discussing MLO, think of multiple bands and multiple-channel connectivity between a WiFi 7 AP and a WiFi 7 client device at the same time. The multi-link operation has many potential methods where multiple WiFi links could be used for 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. MLO will have a future impact in supporting mission-critical and industrial enterprise applications that require reduced latency and jitter. Although often hyped, we will see a renaissance of innovation in augmented reality (AR) and virtual reality (VR) applications whose primary access method will be WiFi. The lower latency enhancements promised as a result of MLO and other WiFi 7 features will be critical for AR/VR.
Myth #5 – WiFi 7 will make WiFi 6E obsolete
There has been talk in some corners that WiFi 6E is a “niche” generation of WiFi. Nothing could be further from the truth. WiFi 6E is the foundational generation of WiFi to bring the technology to the 6GHz frequency band. Countries across the globe continue to adopt the new 6GHz superhighway that has debuted with WiFi 6E. This 1200MHz frequency superhighway provides a reliable path for the evolution of enterprise WiFi. The advent of WiFi in the 6GHz frequency band guarantees that WiFi will continue to grow as the predominant solution for secure wireless connectivity and mobility in the enterprise.
Sometimes we get too caught up with the new “bells and whistles” of various generations of WiFi. It’s not always about features and updates, and the most significant thing happening in WiFi right now is that it’s all about the 6GHz spectrum. WiFi 7 will bring us both consumer-grade and enterprise features, but the real value is when these futuristic features begin to prosper in 6GHz.
In the meantime, think of WiFi 6E as the foundational generation of WiFi that offers 6GHz connectivity. WiFi 7 will be the next generation that leverages 6GHz to even greater heights.
