What you need to know about Wi-Fi 7

As Wi-Fi 7 continues to make waves in the technology world as the latest wireless technology, RUCKUS Networks has been working hard to bring all aspects of this new technology to our readers in preparation for the “wave” of new devices that has already begun to enter the market and is expected to expand further in 2024.

A flurry of products have been announced starting with CES 2023 in Las Vegas in January 2023. ARRIS also announced a Wi-Fi 7 modem at CES, the SURFboard G54. As with most technologies, it’s interesting and new, but sometimes it can be hard to tell what’s marketing hype and what’s the innovation that Wi-Fi professionals are watching.

Very high throughput (46 Gbps, 4K QAM, 320 MHz wide channels, etc.)

Starting with 802.11n (Wi-Fi 4), IEEE began to define suffixes for released PHY revisions to remind us of the focus of the revision.

For 802.11be, the suffix is ​​Extremely High Throughput, or EHT (which also supports higher bandwidths). The theoretical peak speed of the new Wi-Fi 7 is slightly over 46 Gbps, but in order to achieve higher Wi-Fi speeds, three elements are required: 4096 Quadrature Amplitude Modulation (QAM), 16 spatial streams, and 320 MHz wide channels.

Will we actually see speeds of 46 Gbps?

The answer is no. The main obstacle right now is spatial streams. 16 spatial streams looks good in theory, but in reality, the size and power required to support 16 spatial streams make it unlikely to appear in practical applications.

With the release of 6 GHz spectrum for Wi-Fi use, we meet two of the three criteria needed for 46 Gbps (4K QAM in Wi-Fi 7 and 320 MHz wide channels in 6 GHz), but the lack of 16 spatial streams in client devices means we’ll likely see devices on the market that are closer to 5 Gbps. While that may be a little disappointing, frankly, 5 Gbps is still a significant improvement in throughput over the same parameters when using Wi-Fi 6E clients and APs.

Wi-Fi 7 brings us better services to support applications such as VR, AR, online games, cloud computing and remote work.

Plug-in transmission and Wi-Fi 7

There is some inherent confusion about this feature, just as Wi-Fi itself is confusing enough. Inserting a transmission is also often referred to as "preamble insertion." Even as a Wi-Fi professional, the name is confusing, but both names are used to describe the feature.

In the Wi-Fi world, any type of RF interference is detrimental to the operation of all devices using that spectrum, including APs and clients. When considering using wider channels to achieve higher throughput, any interference on those channels will be detrimental to achieving those goals.

Why does Insert Transmit work with Wi-Fi 7?

Wi-Fi 7 introduces the concept of these narrowband "jams" which are simple insertions into the spectrum. The device is then allowed to "bridge" this insertion and recover the spectrum that was lost in the past. Of course, it's bad for an insertion to occur, but if it does occur, it would be nice to be able to just slow it down instead of catastrophically failing and destroying the network.

Multi-Link Operation (MLO)

MLO in Wi-Fi 7 introduces the concept that a client device can communicate with an AP over multiple radios and different frequency bands at the same time. This means that the AP and client devices can send data on two radios at the same time (simultaneous transmit and receive, or STR). These radios can operate on different frequency bands, including 2.4 GHz, 5 GHz, or 6 GHz, and devices can choose the mix or single band that works best when transmitting to achieve load balancing across channels.

What to do if wireless is congested?

This feature has three main modes of operation, each of which provides benefits to Wi-Fi. While not all modes directly address this problem, any improvement in how the channels are utilized will increase Wi-Fi speeds.

• Improve resilience using link redundancy
• Using link aggregation to increase throughput
• Use link selection to improve latency (or reduce latency) when the network is congested

Of all the enhancements in Wi-Fi 7, MLO offers the best chance for peak Wi-Fi performance. It also provides important clues about what 802.11bn should offer, and provides a degree of predictability for Wi-Fi over the next eight to ten years.

Enhanced quality of service for low latency

Of the four major Wi-Fi 7 enhancements, Quality of Service (QoS) is the hardest to understand and, unfortunately, the least likely to have a significant impact on actual networks. This may change over time, and while it has the best chance of success in the 6 GHz band, most people don't expect much from it.

This new version of QoS allows for an additional flag to be added to the header of the transmitted frame to reserve a time slot in the future for it to decide when it wants to use that channel. So this should mean users get a more stable Wi-Fi connection and low latency. It has potential, but like most things in Wi-Fi, it will only work if all devices accept this new feature.

What about 802.11be and RUCKUS's Wi-Fi 7?

RUCKUS Networks believes that Wi-Fi 6E has been a stepping stone to the launch and announcement of Wi-Fi 7. While the introduction of 6 GHz spectrum to the Wi-Fi world is welcome news, it still relies on 802.11ax (Wi-Fi 6) to operate, just in a new block of spectrum.

To support Wi-Fi 7, RUCKUS engineers and architects have been working to prepare partners and customers for this advancement. You can find the full white paper on the Wi-Fi 7 page on the RUCKUS Networks website.