What You Need to Know about Wi-Fi 7

Brian Santo for Mouser Electronics

Demand for high-performance Wi-Fi® has never been greater. Gaming, streaming services, and the proliferation of remote work are increasing demand for faster and more robust residential wireless connectivity. In commercial settings, the pursuit of greater operational efficiencies and lower energy consumption is driving increased automation, the evolution of smart factories, and wider adoption of predictive maintenance techniques—all of which rely on the communication and analysis of vast amounts of data.

So, it comes as no surprise that Wi-Fi networks are evolving rapidly. The introduction of Wi-Fi 6 and Wi-Fi 6E, plus the development of Wi-Fi 7 within two years of one another is proof enough. But it can be difficult to keep up with change at this pace. Wi-Fi 7 (officially the IEEE 802.11be amendment to the Wi-Fi standard) is being heralded as one of the biggest speed increases in wireless communication in the history of the standard. But what does that mean for electronics engineers and end users, and what benefits can we expect?

How much of an improvement is Wi-Fi 7? Let’s begin by reviewing the characteristics of Wi-Fi 6 and 6E, and then comparing what Wi-Fi 7 has to offer in terms of technological innovations and the performance capabilities those innovations will make possible.

Wi-Fi 6/6E—Opening Up Wireless

Wi-Fi 6 and 6E are both manifestations of the IEEE 802.11ax standard. They represent a significant improvement in capability from Wi-Fi 5 and were urgently needed to support the burgeoning demand for faster wireless connectivity.

The transition of Wi-Fi from a “nice-to-have” to a “must-have” service meant that Wi-Fi professionals were struggling to accommodate increasing demand with a limited spectrum allotment. In response, additional spectrum was allocated for Wi-Fi 6, which operates in two distinct frequency ranges: 2.4GHz and 5GHz. Wi-Fi 5 had a theoretical maximum data rate of gigabits per second (Gbps), but in practice, Wi-Fi 5 connections were rarely faster than hundreds of megabits per second (Mbps). Wi-Fi 6 increased to speeds of up to 9.6Gbps. Even with those performance upgrades, demand for faster and more reliable wireless connectivity led to the arrival of Wi-Fi 6E within twelve months.

Wi-Fi 6E extends operational efficiency by adding yet more spectrum, this time in the 6GHz band, which helps circumvent network interference and congestion issues. In 2021, the first hardware to support all three bands (2.4GHz, 5GHz, and 6GHz) emerged, giving Wi-Fi professionals the widest possible options for implementation.

Examples of such hardware include TDK's wide range of RF components for Wi-Fi 6E bands up to 7.25GHz. These diplexers, baluns, and filters are suitable for mobile, consumer IoT, medical, and industrial wireless communications applications, these solutions feature low insertion loss and come in a variety of sizes, from 1mm×0.5mm and a minimum thickness of 0.33mm.

TDK DPX diplexers are suitable for band switching in dual-band systems in applications such as cell phones, wireless LAN, and Bluetooth® communications. Small and lightweight, these diplexers offer a low profile and low insertion loss, with no adjustment required for use. The surface-mount DPX series features 50Ω impedance and includes models that cover a frequency range of 650MHz to 5.95GHz 7.125GHz.

TDK RF baluns offer an extensive range of SMD/SMT models with impedances ranging from 50Ω to 200Ω. These multilayer chip transformer baluns are constructed with low-temperature, co-fired ceramics (LTCC), converting signals from balanced to unbalanced, and vice versa. They use leading-edge miniaturization technology while providing exceptional electrical characteristics for 2.4GHz and 5GHz WLAN.

TDK DEA RF filters use LTCC material to create a resonance frequency that allows certain frequency ranges to pass through while blocking, or attenuating, other unwanted frequency ranges. These devices include high-pass and low-pass filters, as well as bandpass filters with frequencies ranging from 5MHz to 8GHz. TDK DEA RF filters are used in products with wireless communications such as WLAN, Bluetooth, cellular, GPS, Zigbee®, and WiMAX, in both licensed and unlicensed frequencies.

In addition to offering standard general-use filters, TDK works with chipset partners to design custom-matched filters for specific chipsets, including low-insertion-loss (i.e., energy-saving) filters for battery-operated devices as well as high-attenuation/high-performance products for devices with a power connection.

Manufacturers like TDK are now poised to support the next generation of wireless communications: Wi-Fi 7.

Wi-Fi 7—A Potential Game-Changer

Wi-Fi 7 was designed to provide even greater data transmission speeds than Wi-Fi 6, while reducing latency. At the same time, Wi-Fi 7 increases overall network capacity for clients. It is intended to accommodate the imminent arrival of 8K video streaming and will be ready to support immersive, low-latency extended reality (XR) applications for industrial and gaming purposes once they become widely available.

Wi-Fi 7 is backward compatible with Wi-Fi 5/6/6E, so purchasing a new Wi-Fi 7 router will not make existing wireless equipment entirely obsolete. However, older routers will need to be connected to the routers with a Wi-Fi 7-based client to provide all the new standard's performance advantages.

The three most significant improvements between Wi-Fi 6E and Wi-Fi 7 are the theoretical maximum speed, increased channel width, and a higher order of quadrature amplitude modulation (QAM) (Table 1).

Table 1: Comparison of Wi-Fi 7, Wi-Fi 6, and Wi-Fi 6E. (Source: https://www.tomshardware.com/news/wi-fi-7-explained; Recreated by Mouser Electronics)

Wi-Fi 6E’s maximum speed of 9.6Gbps is impressive enough, but Wi-Fi 7 is expected to have a maximum speed of 46Gbps for a single client, which is practically warp drive in the Wi-Fi world.

The maximum bandwidth per channel of Wi-Fi 6E was 160MHz, but the new spectrum in the 6GHz band will see this increase to a channel bandwidth of 320MHz, providing more bandwidth to move more data. The increase from 1024 QAM channels in Wi-Fi 6E to an anticipated 4096 QAM with Wi-Fi 7 combined with the 320MHz-wide channels will make 46Gbps possible.

That’s the short version. Let’s take a deeper dive into the technological advances inherent in Wi-Fi 7.

Multi-Link Operation

One of the most impressive capabilities in Wi-Fi 7 is multi-link operation (MLO), which was not available with Wi-Fi 6/6E. MLO enables transmission between the access point and the client on different radios if radio frequency conditions allow it.

Essentially, MLO exploits the fact that the existing 5GHz band and new 6GHz band are comparatively closer than the preceding 2.4GHz and 5GHz bands, so for practical purposes, they have the same speeds.

MLO will therefore allow a device to connect to both a 5GHz channel and a 6GHz channel at the same time and use both to send and receive data with virtually no lag—an innovation in the overall evolution of 802.11 standards. This leads to reduced latency, higher data rates, better load balancing, and duplicate packets across links to improve the reliability of the network.

Quadrature Amplitude Modulation

QAM is a modulation technique that maximizes the number of bits that can be sent at once by transmitting two carriers that are out of phase from each other by 90° (hence the quadrature in the description).  

Wi-Fi 6E supports 1024 QAM, while Wi-Fi 7 increases this to 4096 channels (or 4K) QAM—correlating with a 20% throughput increase. The result is higher efficiency, higher capacity, and higher data transmission rates with reduced latency compared to Wi-Fi 6/6E.  

Note that when Wi-Fi 7 becomes available, there will be differences between regions. The available spectrum that can be dedicated to Wi-Fi varies between countries, depending on how local regulatory agencies have assigned it. For example, while multi-link operations in the United States will be able to use the channels at 5GHz and 6GHz, Wi-Fi devices in China will use two different channels in the 5GHz band.

Automated Frequency Coordination

The decision to make the 6GHz band available for Wi-Fi raised some issues, which automated frequency coordination (AFC) aims to resolve.

The fundamental problem is that 6GHz is already a well-used part of the spectrum. US federal agencies like NASA and the Department of Defense, as well as global weather radar systems and radio astronomers, rely on this band for vital communications. Wayward Wi-Fi signals would be most unwelcome. Fortunately, the preexisting uses of 6GHz microwaves are largely predictable, localized, and stationary. AFC allows Wi-Fi into the band by making it possible to coordinate with and work around existing use cases.

AFC makes it possible for Wi-Fi 7 networks to operate in the vicinity of weather radar, radio telescopes, and other established users of 6GHz spectrum by preventing transmissions in bands that would interfere those users. At the same time, it frees Wi-Fi 7 networks to broadcast at a higher power when they detect that there are no preexisting spectrum user nearby. Though AFC actually debuted with Wi-Fi 6E, Wi-Fi 7 will have a more comprehensive accounting of wireless devices that are certified for AFC.

When there are no existing users already using the 6GHz band nearby, Wi-Fi 7 networks will be able to transmit in that spectrum using 63 times as much power (according to some estimates) compared to the uniform low-level transmission power employed when incumbent users are detected. Higher power signals will be stronger, more reliable, have greater throughput, and will propagate farther.

Multiple Resource Unit

Closely allied to AFC is multiple resource unit (MRU), a new feature in Wi-Fi 7 that improves upon orthogonal frequency division multiple access (OFDMA), a feature first introduced in Wi-Fi 6. OFDMA establishes independently modulating subcarriers within frequencies, allowing for simultaneous transmissions to and from multiple clients. The result is increased throughput and reduced latency.

Wi-Fi 7’s MRU feature provides enhanced interference mitigation and OFDMA efficiency, further reducing multiple-user latency. By making it possible to selectively puncture overlapping portions of the spectrum, MRU ensures that data travels only on clear frequencies, increasing data rates and reliability in congested Wi-Fi environments.

Multi-User, Multiple-Input, Multiple-Output

Multi-user, multiple-input, multiple-output technology (MU-MIMO) allows a Wi-Fi router to communicate with multiple devices simultaneously. Wi-Fi 6/6E brought bidirectional MU-MIMO into practical usage and doubled the number of spatial streams to eight, compared to Wi-Fi 5’s 4×4 MU-MIMO. In practical terms, this allows up to eight simultaneous connections to access the internet without losing the speed throughput. Wi-Fi 6/6E employs bi-directional 8×8 MU-MIMO. Wi-Fi 7 will increase the number of spatial streams to sixteen, allowing up to sixteen devices to transmit and receive data at high speeds.

Conclusion

Wi-Fi 7 promises to deliver high performance by means of increased speed, more bandwidth, improved reliability, and super-low latency. In addition to the selection of Wi-Fi 7-compatible products from TDK, Broadcom and Qualcomm are among the companies who have already announced that they are committed to delivering Wi-Fi 7 components; but there is a little way to go before a sufficient range of Wi-Fi 7-enabled equipment is available and the network infrastructure is optimized. Initially, at least, Wi-Fi 7 is likely to benefit larger enterprises with complex and demanding wireless network requirements. For everything else, there is Wi-Fi 6E.