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What is Wi-Fi 7, and will it replace wired Ethernet?

What is Wi-Fi 7, and will it replace wired Ethernet?

The theoretical top speed of Wi-Fi 7 make it a candidate to network LANs, but only in limited circumstances.

Credit: Dreamstime

New Wi-Fi standards appear in such rapid succession that it’s often difficult to evaluate the differences between Wi-Fi 5, Wi-Fi 6, and Wi-Fi 6E—all of which are standards adopted in commercial products. And now there’s Wi-Fi 7.

Chinese networking-equipment vendor H3C has released what it says is a Wi-Fi 7 router even though the Wi-Fi 7 standard isn’t expected to be finalised until 2024.

What is Wi-Fi 7?

Wi-Fi 7 or 802.11be is the next Wi-Fi standard being worked on by the Institute of Electrical and Electronics Engineers that promises speeds of a whopping 46Gbps, nearly five times faster than Wi-Fi 6, as well as reduced latency. Wi-Fi 7 (also known as Extremely High Throughput) is expected to deliver higher spectrum efficiency, higher power efficiency, better interference mitigation, higher capacity density, and higher cost efficiency. 

How does Wi-Fi 7 work?

Just when you thought IEEE engineers were running out of ways to improve Wi-Fi, they came up with several new enhancements and combinations of techniques to deliver not just an incremental boost, but a significant jump in performance and a reduction in latency

Here’s how.

Double the channel size

Wi-Fi 7 doubles the maximum channel size from 160MHz to 320Mhz, which doubles throughput right off the bat. Wi-Fi 7 also provides flexibility so that a network can run either at two 160MHz sets of channels or one channel at 320Mhz, depending on application requirements.

Double the number of MU-MIMO spatial streams

Wi-Fi 7 increases the number of spatial streams from eight to 16, which also doubles throughput. Multiple-user, multiple-input, multiple-output (MU-MIMO) technology breaks the available bandwidth into separate streams that share the connection equally. 

MU-MIMO reduces congestion associated with multiple endpoints trying to access the wireless network at the same time. In addition, MU-MIMO supports bi-directional functionality, so the router can accept and send data at the same time. In Wi-Fi 5, MU-MIMO was limited to downlink transmissions.

Quadruple the QAM

Increasing quadratic amplitude modulation (QAM) from 1024-QAM to 4096-QAM is expected to deliver an additional 20 per cent boost in throughput. That’s how we get from 9.6Mbps in Wi-Fi 6 to 46Mbps in Wi-Fi 7.

Multi-link operation (MLO)

With MLO, devices can simultaneously transmit and receive across all of the available bands (2.4Ghz, 5Ghz and 6Ghz) and channels. This improves performance, reduces latency and boosts reliability. 

Data flows can be pre-assigned to specific channels based on application or device requirements, particularly in IoT or IIoT environments. Or the network can be configured to dynamically select the frequency band that has the lowest congestion in real time and send data over that channel.

Multi-AP operation

In prior Wi-Fi standards, each access point acted independently in terms of accepting connection requests from endpoints and moving traffic back and forth to that endpoint. 

Multi-AP operation creates a mesh-type configuration in which neighbouring APs can work in coordination to improve spectrum and resource utilisation. Multi-AP operation can be programmed so that a set of APs form a subsystem in which channel access and transmission schedules can be tightly coordinated.

Time-sensitive networking (TSN)

Wi-Fi 7 supports TSN, an IEEE standard which helps provide low latency and increased reliability. TSN technology, originally designed to reduce buffering, latency and jitter in Ethernet networks, uses time scheduling to ensure reliable packet delivery for real-time applications, such as IoT or IIOT.

Multi-RU

OFDMA (orthogonal frequency division multiple access) enables access points to communicate simultaneously with multiple clients by assigning Resource Units to individual clients. Multi-RU increases spectrum efficiency by making sure that traffic avoids interference on congested channels.

Deterministic low latency

The combination of the technologies cited above will decrease latency so that Wi-Fi 7 can support real-time applications like AR/VR and IoT. Latency will also be more deterministic, meaning it will not spike beyond a certain limit, which is important in certain industrial automation applications that cannot tolerate wide variances in latency.

Benefits of Wi-Fi 7

While Wi-Fi 5 might be sufficient today for all but the most bandwidth-intensive applications, the assumption is that wireless traffic loads will continue to increase over time, particularly as organisations embrace digital transformation.

Business processes that were once performed manually are moving into the digital world, particularly the cloud. And the amount of data that needs to be moved on the wireless network is increasing exponentially.

Digital transformation doesn’t simply mean that end users who performed a specific function with a paper document are now performing that function with a digital replica. Business processes are becoming more complex and interconnected. Data is moving across hybrid-cloud environments. 

A specific business function might span multiple applications. Data-intensive analytics are becoming more pervasive across the enterprise. Video collaboration platforms have become the norm.

Wi-Fi 7 is designed to accommodate increased traffic due to digital transformation, as well as to support specific applications that require deterministic latency, high levels of reliability, and quality of service. These might include industrial automation, surveillance, remote control, augmented and virtual reality, and video applications. 

In addition, Wi-Fi 7 and 5G will work together in edge computing scenarios, cloud architectures, and private wireless networks.

Will Wi-Fi 7 replace Ethernet?

In certain specific situations, Wi-Fi 7 could replace wired Ethernet, which would be truly game changing. For example: an all-wireless, completely unplugged office, particularly in greenfield environments where IT staff wouldn’t have to string wires in the ceiling or run cabling to each cubicle or office space.

While Wi-Fi 7’s maximum theoretical speed is 46Gbps, other estimates put real-world speeds much lower — around 6Gbps — which is still significantly faster than Gigabit Ethernet.

Of course, in wireless networks the bandwidth is shared among endpoints, while Gigabit Ethernet can deliver dedicated gigabit circuits to each endpoint, so that’s another variable to consider. 

Then again, wireless networks can use multiple antennas and multiple streams, and Wi-Fi 7 is designed to enable the meshing of multiple access points, so at the very least, analysis of its real-world performance in your environment is both necessary and extremely complex.

According to Alan Hsu, corporate vice president and general manager at Taiwanese chip maker MediaTek, "The rollout of Wi-Fi 7 will mark the first time that Wi-Fi can be a true wireline/Ethernet replacement for super-high-bandwidth applications."

MediaTek conducted a demo of Wi-Fi 7 technology in January 2022, and the company predicted that it will have Wi-Fi 7 chips shipping by next year, even before the standard is expected to be ratified. Other major chipmakers, like Qualcomm, are also leading the Wi-Fi 7 charge, with Qualcomm supplying the chips for the claimed Wi-Fi 7 router from H3C.

Mario Morales, group vice president for semiconductors at IDC, says, “Wi-Fi 7’s advances in channel width, QAM, and new features such as multi-link operation (MLO) will make Wi-Fi 7 very attractive for devices including flagship smartphones, PCs, consumer devices and vertical industries like retail and industrial.”

But it’s too early to make any kind of prediction on whether Wi-Fi 7 will actually replace Ethernet as the standard for enterprise LAN connectivity. On paper, it does seem that Wi-Fi 7 checks all the boxes when it comes to bandwidth, reliability, and security (WPA3). But inertia is a powerful force and IT teams may have more pressing priorities than switching out predictable, low-maintenance Ethernet for Wi-Fi.

However, there are specific use cases, such as IoT, industrial automation, greenfield branch-office/large-office or retail/industrial scenarios, where Wi-Fi 7 could provide quicker and easier deployment than Ethernet.

Since many IT departments have already added a wireless network on top of the pre-existing Ethernet LAN in order to provide mobility to employees, Wi-Fi and Ethernet could co-exist in a scenario in which Wi-Fi is the primary network and Ethernet sticks around as a backup.

As fast as Wi-Fi 7 may be at 46Gbps, shipments of 400 Gigabit Ethernet gear (cables, switches) doubled in 2021, according to the Dell’Oro group. And the Ethernet roadmap calls for speeds of 800G or even 1 Terabyte by 2030. So, Wi-Fi may be competing with Ethernet at the access layer, but Ethernet remains firmly ensconced in both enterprise and hyperscale data centres.

With standards-compliant Wi-Fi 7 expected to arrive just three years after Wi-Fi 6E, organisations need to take a close look at their refresh cycles in order to determine their upgrade path: If we’re on Wi-Fi 5, should we jump to Wi-Fi 6, jump to Wi-Fi 6E, or wait for Wi-Fi 7? If we’ve already committed to Wi-Fi 6, should we stick with it and only upgrade to Wi-Fi 7 if and when there is a critical business need?

According to IDC’s analysis of the enterprise WLAN market for 2021, Wi-Fi 6 accounted for 60 per cent of total units shipped, while Wi-Fi 5 sales accounted for most of the rest, which implies that many companies have committed to Wi-Fi 6, and many others are still building out their Wi-Fi 5 networks.

The road to Wi-Fi 7

Wi-Fi 7 is just the latest in a long line of Wi-Fi standards that have progressively enabled faster, safer, and more reliable wireless networking. Here is a brief description of the latest few.

Wi-Fi 5

Wi-Fi 5, which came out in 2014, tops out at 3.5Gbps and is certainly sufficient for home networks, branch offices and many enterprise scenarios.

Wi-Fi 6

Certified by the Wi-Fi Alliance in 2019, Wi-Fi 6 offers a maximum theoretical throughput speed of 9.6Gbps and is designed for dense environments like stadiums, malls, and large offices. It can also be deployed effectively in IoT environments.

Wi-Fi 6E

A 2021 extension to Wi-Fi 6, Wi-Fi 6E delivers the same speed, but takes advantage of previously unavailable wireless spectrum in the 6Ghz band to provide better performance because there’s no interference from pre-existing applications competing for the same bandwidth. 6E is intended for emerging applications like virtual or augmented reality and 4G/8G video.


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