Doubled bandwidth on the 6 GHz band and more data packed into every signal help Wi-Fi 7 deliver higher throughput with greater efficiency

By Alessia Autolitano, Andrea Pezzoli and Roberto Ricci

Note: This is the latest instalment in the ‘Wi-Fi explained’ series from Sisvel Technology. You can find the whole series at www.wifipatentpool.com

Wi-Fi 7 was built to handle lots of different users engaging in bandwidth-heavy activity such as high-definition streaming. One of the ways it achieves this goal is by offering wider channels within the newest spectrum allocated to Wi-Fi.

This advance was made possible in part by regulators opening up a portion of the 6 GHz band to Wi-Fi, starting with Wi-Fi 6E. The developers of the Wi-Fi 7 standard provided for channel width of 320 MHz in this spectrum – twice the maximum available under Wi-Fi 6/Wi-Fi 6E.

Accomplishing this was a key task for developers of the standard. It required addressing novel technical problems created by the interaction of wider bandwidths with existing protocol constraints.

320 MHz channels: more lanes for heavier traffic

The Wi-Fi spectrum includes the 2.4 GHz, 5 GHz, and 6 GHz bands. Before the introduction of Wi-Fi 6E in 2020, only the 2.4 GHz and 5 GHz bands were licensed for use by Wi-Fi devices. Wi-Fi 7, officially released in 2025, supports a maximum channel bandwidth of 320 MHz on the 6 GHz frequency band, as well as 20/40/80/160 MHz channel bandwidth on the 5 GHz and 6 GHz frequency bands and 20/40 MHz on the 2.4 GHz frequency band.^[1]

320 MHz channels allow Wi-Fi data to travel at blazing-fast speeds. Such improvement is comparable to a new multi-lane highway replacing an older road. Wi-Fi channels are like lanes – the more lanes, the more traffic (data) can travel without interference or slowing down (latency). Wi-Fi 7 routers with 320MHz channels can handle more data in concurrent use than ever before.^[2]

In an OFDMA (Orthogonal Frequency Division Multiple Access) transmission, a 320 MHz PPDU can be assigned to a single user with a 4 × 996 tone Resource Unit (RU), or two users each with a 2 × 996 tone RU, or another configuration taken from the vast array of other allowed combinations according to the available traffic.^[3]

Continuing the highway analogy: if the 2.4 GHz band is analogous to a narrow, single-lane road (slow, often congested), the 5 GHz band is more like a multi-lane highway (faster, but still limited), while the 6 GHz band would be an ultra-wide freeway (faster with less interference).^[2]

The number of available 320 MHz channels is subject to geographical limitations due to national regulations on bandwidth; with 1200 MHz of spectrum space available in the 6 GHz band as in US or Canada, it’s possible to achieve 3x 320 MHz wide channels. For regions with 500 MHz of available spectrum, like Europe, there is only one 320 MHz wide channel, as seen in Figure 1.^[4]

Figure 1 (source)

Because the likelihood of interference increases with channel width, operating on larger channel bandwidths makes Preamble Puncturing (an optional technology under Wi-Fi 6 that was made a mandatory requirement for all Wi-Fi 7 products) crucial for avoiding interference while maximising the use of available spectrum and ensuring a more stable and reliable connection.

Figure 2 (source)

In the ultra-wide freeway analogy, this feature allows traffic to be routed around a single closed lane instead of closing all subsequent adjacent lanes.

What this enables in the real world

The 320 MHz bandwidth is expected to be used mainly in the home. For single-family dwellings, the number of neighbouring houses is relatively small, and the attenuation from two external walls is likely to create strong RF separation between devices in different houses. Thus, each house is likely to get relatively clean access to a single 320 MHz channel, where a typical use case is to deliver streaming video traffic to multiple devices with OFDMA.^[3]

In the enterprise space, businesses running hundreds of connected devices – laptops, tablets, IoT sensors, security cameras – will get relief from network congestion. As explained above, a 320 MHz channel can be flexibly used for multiple OFDMA transmissions: one user might get a massive 4×996 tone resource unit, or two users might each get 2×996 tone units, depending on their needs. This intelligent resource management means the network adapts in real-time to who is doing what.

4096-QAM: packing more data into each signal

Quadrature amplitude modulation (QAM) is the method by which a Wi-Fi router translates digital data – the ones and zeros that make up everything from emails to video streams – into analogue radio signals that can travel through the air.

Higher order QAM is one of Wi-Fi 7’s headline technical features, and delivering it required advances across the entire signal chain. Working in concert with other features, it is a major reason why the latest Wi-Fi standard is so much more efficient than its predecessor.

How it works

Extensively used in Wi-Fi standards, QAM translates digital packets into an analogue signal that can wirelessly transfer data. By varying the phase and amplitude of radio waves, the technology improves spectral efficiency by incorporating more data into each transmission.^[6]

You can visualise QAM as a set of constellation points arranged in a square grid. Since digital telecommunications data is binary, the number of points in the grid is typically a power of 2 (like 2, 4, 8, 16…), where the power corresponds to the number of bits per symbol. A higher-order constellation – say, 256 (=2⁸) QAM – is capable of transmitting more bits per symbol than a lower-order constellation such as 64 (=2⁶) QAM. Wi-Fi 6 maxed out at 1024 QAM, corresponding to 10 bits per symbol.^[4]

Figure 3 (source)

For an analogy, think about a delivery truck hauling apples from a local orchard to the distribution centre. One way to speed up the process of delivering an entire harvest’s worth of fruit is to fit more fruit into each truck.^[5]

4K QAM (4096 QAM) is a QAM modulation using 4096 (=2¹²) constellation points arranged in a square, where each symbol carries 12 bits. In Figure 3, an exemplary 16 QAM visualisation is compared to the 4096 QAM constellation. ^[9]

4K QAM enables a 20% data rate increase in Wi-Fi 7 compared with 1024 (=2¹⁰) QAM of Wi-Fi 6. This is crucial for consistently serving a large number of clients and ensures fast and reliable Wi-Fi coverage in high-density deployment scenarios.

Returning to the fruit truck analogy, 4K QAM is comparable to reducing the size of the packaging necessary for each box of apples. Using trucks with the same cargo hold size, but with the fruit packed more efficiently, the farm can transport more apples in each delivery, and the entire harvest gets delivered much more quickly as a result. ^[5]

Figure 4

The increase in the number of bits per symbol comes at the expense of higher signal-to-noise ratio (SNR) requirements at the receiver side, which is often achieved through beamformed transmission. ^[7]

Of course, the QAM order should not be considered as a “more is better” scenario; if the environment is noisy with a small signal to noise ratio (SNR), symbols are difficult to demodulate, making the demodulation process prone to errors. This means that a lower order QAM mode is the only option in these "noisy" environments.

Put differently, if we speak too fast in a noisy environment, individual words may be drowned out.

The use of the 6 GHz band, 4096 QAM, 320MHz channels and preamble puncturing, in connection with other features, contributes to a 2.4x increase in speeds from Wi-Fi 6 to Wi-Fi 7, with lower latency in multiple device scenarios.

What this enables in the real world

Higher-order modulation brings a higher data transmission rate and spectral efficiency. This is crucial for consistently serving a large number of clients and ensures fast and reliable Wi-Fi coverage in high-density deployment scenarios. Now you can watch 4K/8K videos with impeccable fidelity or play and stream your online gaming from your home studio.

In addition, CPEs and routers complaint with Wi-Fi 7 are significant step up in sophistication, using beamforming antenna arrays rather than omnidirectional antennas to meet the high SNR requirements of 4096-QAM transmissions. This more advanced equipment is enabling new service tiers and business models for broadband providers and enterprises.

What’s next

Pushing QAM to 14 bits per symbol (16K-QAM), while possible, is considered by Wi-Fi researchers to come with SNR requirements that are too high for home and office settings. The focus instead is on half-steps between existing levels in the form of Intermediate MCS (Modulation and Coding Schemes).

MCS defines the combination of modulation formats and coding rates that set how data is encoded for transmission over-the-air, thereby determining the achievable data rate. For legacy Wi-Fi, the coarse granularity of available MCS levels limited optimal rate adaptation in fluctuating signal environments, leading to suboptimal performance. Introducing intermediate MCS levels enables finer-grained rate adaptation and allows for smoother transitions and more stable performance in scenarios where signal quality varies rapidly, like in mobile or high-density public settings.

The next big advance in modulation is Unequal Modulation (UEQM). Legacy MIMO systems are only as strong as their weakest link, forcing all spatial streams to use the same modulation level. Eliminating this constraint allows each stream to adapt its modulation based on individual signal quality. This unlocks higher throughput and greater resilience in environments with uneven signal propagation.

Alessia Autolitano, Andrea Pezzoli and Roberto Ricci are Wi-Fi experts with Sisvel Technology based in None (Turin), Italy

References:

1. [An Introduction to Key Technologies of Wi-Fi 7, Shengzhong Zhanga, Lei Yub, Yinqian Chengc]

2. [https://www.netgear.com/hub/network/wifi-7-320mhz-channels/]

3. [Wi-Fi 7 In Depth: Your guide to mastering Wi-Fi 7, the 802.11be protocol, and their deployment, A Henry, J., A Gupta, B., A Hart, B., 2024]

4. [https://documentation.meraki.com/MR/Wi-Fi_Basics_and_Best_Practices/Wi-Fi_7_(802.11be)_Technical_Guide]

5. [https://edgeup.asus.com/2023/how-wifi-7-achieves-a-faster-data-rate-with-4k-qam/]

6. [https://www.tp-link.com/us/blog/733/wi-fi-7-fundamentals-what-is-4k-qam-/]

7. [IEEE 802.11be Wi-Fi 7: Feature Summary and Performance Evaluation – Xiaoqian Liu, Yuhan Dong, Yiqing Li, Yousi Lin and Ming Gan]

8. [https://www.ruckusnetworks.com/blog/2023/wi-fi-7-extremely-high-throughput-unleash-the-power/]

9. [https://blog.wirelessmoves.com/2016/10/an-introduction-qam-modulation-for-lte.html]