TECH CORNER
Wi-Fi 7 triumphs with seven key features
By Kerstin Naser, corporate product manager, wireless at Rutronik
Wi-Fi 7, based on the IEEE 802.11be standard, utilizes more efficient frequency bands, multi-link operation and 320 MHz channel widths to deliver speeds of up to 46 Gbps, reduced latency and enhanced network reliability. Applications with real-time requirements, such as augmented, virtual and extended reality, significantly benefit from these performance improvements.
Wi-Fi 7 introduction
Following the release of Wi-Fi 6 and Wi-Fi 6E standards, the latest IEEE 802.11be standard, known as Wi-Fi 7, was introduced earlier this year. Wi-Fi 7 offers higher data transmission rates and extremely low latency times, meeting the requirements for applications like AR, VR and XR. While many users continue to use Wi-Fi 5, Wi-Fi 6 and Wi-Fi 6E have also gained a strong foothold in the market. Some suppliers already offer Wi-Fi 7-compatible products. By 2028, it is projected that there will be 2.1 billion Wi-Fi 7-enabled devices available on the market. Routers, smartphones, PCs and tablets are among the first devices to support the new standard. Table 1 shows the differences of the Wi-Fi standards from Wi-Fi 5 to the latest Wi-Fi-7.
Key applications and features
Key applications for Wi-Fi 7 include multi-user AR/VR/XR, 3D training, gaming, ultra-high-resolution video streaming, hybrid working, industrial IoT (IIoT) and automotive. Thanks to its high reliability and speed, ultra-precise applications like telediagnostics and telesurgery are also feasible.
The necessary increase in performance results from the following seven features:
1.) 320 MHz channels. Available in countries that release the 6 GHz frequency band for Wi-Fi, these ultra-wideband channels double the currently widest channel size of 160 MHz for Wi-Fi 6/6E to 320 MHz, effectively doubling the data transmission rates for individual devices.
2.) Multi-link operation (MLO). Unlike previous WLAN standards, which select a single frequency band for data transmission and switch bands only under specific conditions, Wi- Fi 7’s MLO allows devices to simultaneously send and receive data across multiple frequency bands, such as 5 GHz and 6 GHz. This results in higher data throughput, lower delay times and improved reliability.
3.) 4K QAM. Wi-Fi 7 enables a higher data transmission rate through the modulation technique called quadrature amplitude modulation (QAM). With 4,096 QAM, Wi-Fi 7 achieves up to 20 percent higher data rates compared to the 1,024 QAM of Wi-Fi 6/6E and 256 QAM of Wi-Fi 5.
4.) 512 compressed block acknowledgment. Wi-Fi 7 allows up to 512 data packets to be sent simultaneously, compared to 256 data packets with Wi-Fi 6. This reduces overhead, enhancing overall efficiency.
5.) Multiple resource units (RU) to a single station (STA). Wi-Fi 7 improves flexibility in planning spectrum resources by dividing the channel into multiple sub-channels, known as resource units (RUs). This procedure ensures that interference signals affect only a portion of the WLAN channel, allowing the remaining part to still be used for data transmission.
6.) Triggered uplink access. This feature optimizes uplink access to better handle latency-sensitive streams and meet quality of service (QoS) requirements. The stream classification service function prioritizes sensitive data such as games, voice, and video over bulk traffic.
7.) Emergency preparedness communication services (EPCS). EPCS offers users a seamless national security and emergency preparedness service experience while maintaining priority and QoS on Wi-Fi access networks. EPCS enables access points to communicate with authorized non-AP stations with higher priority.
Practical considerations and market availability
To achieve the theoretical maximum data transmission rate of 46 Gbps, WLAN stations with 16 data streams (spatial streams), i.e., 16 antennas, are required. However, this is not practical for small devices like cell phones. For typical home use, routers with fewer antennas are generally sufficient, but for large companies, smart cities, airports and hotels with numerous end users, the full capabilities of Wi-Fi 7 are highly beneficial.
Products that support Wi-Fi 7 must meet certain requirements, including being equipped with Wi-Fi 7-compatible chipsets that support the new functions and higher speeds. These products must also be able to use several frequency bands simultaneously to enhance network performance and support 4,096 QAM for higher data density and efficiency.
Wi-Fi 7-capable routers, mainboards, expansion cards, industrial modules and laptops are already available. These devices fully support the benefits of the new wireless standard, including low latency times, high reliability and high speeds. They can enable speeds of up to 5.8 Gbps and also support Bluetooth 5.4. These modules are pre-certified globally, resulting in significant cost savings for customers.
Wi-Fi 7 modules are available in various form factors, such as M.2 2230 plug-in boards and SMD M.2 LGA type 1620. These modules can support Bluetooth 5.3 and operate within a temperature range of –40°C to +85°C. The first samples of these modules are expected by the end of 2024, with series production planned for the first quarter of 2025.
Complete Wi-Fi 7 routers and mainboards are available, catering to different needs such as general home use and specialized applications like avionics. Wi-Fi 7 chips for expert developers and high-volume projects can be obtained, along with suitable Wi-Fi 7 antennas to ensure optimal performance and connectivity.
Frequency band considerations
Wi-Fi 7 supports the 6 GHz frequency band, an advantage since the 2.4 GHz frequency band is also used by other technologies such as Bluetooth, ZigBee and Thread. However, higher frequencies result in shorter ranges. To ensure comprehensive WLAN availability, it may be necessary to increase the number of access points.
Despite the backward compatibility of Wi-Fi 7 with previous standards, both routers and end devices must support Wi-Fi 7 to fully leverage its benefits.