Why You Should Care About IEEE 802.11ax

What is 802.11ax?

The IEEE is hard at work on the 802.11ax standard and released it publicly in 2019. You can read the specifications on the IEEE website. National Instruments’ 802.11ax whitepaper is also worth a read.

Wi-Fi 6, also known as the next-generation 802.11ax, is a recent step in the journey of nonstop innovation. 802.11ax, also known as high-efficiency wireless (HEW), is an amendment of the IEEE that defines the modifications to the previous version (802.11) and the improved high-efficiency operation in frequency bands between 1GHz and 6GHz. There are many improvements and features in 802.11ax, including greater flexibility, efficiency and scalability, which allow for higher speed and capacity.

Perhaps your question at this point is, “Why should I care about 802.11.ax?” To answer that question, let’s consider the chief benefits that 802.11ax brings to the table.

What are the benefits of 802.11ax?

MIMO-OFDM

Multiple-input, multiple-output (MIMO) technology allows a wireless access point (AP) to work with up to four separate data streams simultaneously. 802.11ax brings MIMO with orthogonal frequency-division multiplexing (OFDM) to the table. What that means is that 802.11ax routers can broadcast four MIMO spatial streams, giving you four times the maximum theoretical bandwidth per stream. 

Speed

Assuming a single 802.11ax stream of 3.5 Gbps and multiplying that by four, you’ll get a maximum theoretical bandwidth of 14 Gbps. That’s fast, but there are always mitigating factors, such as which channel width on the 5GHz band the wireless AP uses.

Why does anybody need that much network speed? Well, imagine performing any of these actions with nearly zero lag:

• Streaming 4K (ultra high-definition) video
• Downloading full retail games to your console
• Meshing your smart household appliances with no latency

Given the cost of some high-end Wi-Fi hardware, it’s good news that 802.11ax will be backward-compatible with the existing ― and in some cases older ― 802.11a/b/g/n/ac standards.

Reception

The Wi-Fi standards moved to the 5GHz band to reduce contention with 2.4GHz household appliances. 802.11ax does indeed operate on the 5GHz band, but the IEEE designed it specifically for high resiliency. The informal title of the 802.11ax specification is HEW.

The IEEE is architecting 802.11ax to provide steady, resilient performance even in Wi-Fi-dense areas. For example, think of how many wireless local area networks (WLANs) compete on both the 2.4GHz and 5GHz bands in a typical high-rise apartment building. [Related article: What Is VoIP? ]

Range

As of this writing, we know very little about the effective indoor and outdoor range supported by 802.11ax. For comparison, 802.11n ― the current-generation Wi-Fi standard ― has an approximate indoor range of 70 meters, or 230 feet. Its approximate outdoor range is 240 meters, or 820 feet. [Learn what to look for in an internet service provider.]

What are its features, and what problems does 802.11ax solve?

The standard 802.11ax brings with it a wide range of new features, including a much-needed increase in the standard quality of service, which is an industry term for how Wi-Fi resources are used. Here are some of the new and improved features you’ll see with the standard 802.11ax:

• Target Wake Time (TWT): The TWT enhancement helps to extend the battery life on smartphones and other mobile devices through better sleep and wake efficiency, which means maintaining the connections of Wi-Fi when smartphones and other mobile devices are inactive (the older version used a lot of battery life when not in use). [Read more about point-to-point wireless.]
• Better Wi-Fi experience:11ax addresses the complexity of frequency bands used in Wi-Fi. It improves the capacity and allows individual devices to connect to Wi-Fi more quickly and easily. This is especially beneficial in areas with overlapping coverage, such as school settings, apartment buildings, airports and train stations. 802.11ax has improved performance, especially in these areas of overlapping coverage.
• Downlink and uplink orthogonal frequency-division multiple access (OFDMA): OFDMA increases user data rates and reduces latency, especially devices with short frames or low data rate requirements, such as Internet of Things devices. 802.11ax has multiuser capacity, meaning a transmission can be divided in the frequency domain with various groups of subcarriers with frames for different destinations.
• Outdoor operation: Various features improve the outdoor performance, but the most important is a new packet format where the most sensitive field is now repeated. Other features include modes that introduce redundancy to allow for error recovery and longer guard intervals.

The future of 802.11ax

IEEE 802.11ax, certified in 2020, has become the standard for WLAN technology, offering better performance, coverage and battery life than its predecessor. IEEE 802.11ax is slowly entering the commercial market, and the addition of Wi-Fi 6E will be the first amendment to support the new 6 GHz radio spectrum band. However, IEEE and Wi-Fi Alliance are already planning for the future IEEE 802.11be (Wi-Fi 7). Here are the most significant improvements for Wi-Fi 7:

• MIMO enhancements: Wi-Fi 7 is expected to bring coordinated multiuser MIMO (CMU-MIMO), which will support 16 data streams on all three frequencies simultaneously.
• Multilink operation: Aims to enhance multilink operation technology by increasing throughput, lowering latency and improving reliability, enabling devices to simultaneously transmit and receive across different bands and channels.
• AP coordination: The Wi-Fi 7 Working Group plans to improve AP coordination by introducing enhancements, such as orthogonal frequency division multiple access (OFDMA), spatial reuse, time-division multiple access, beamforming and joint processing to reduce collisions and improve overall network performance.
• 320 MHz transmissions: The maximum channel size will double from 160 MHz with Wi-Fi 6 to 320 MHz, which also doubles the throughput. Wi-Fi 7 also supports 160+160 MHz, 240+180 MHZ and 160+80 MHz channels.
• Higher modulation: Typically, wireless networks utilize quadrature amplitude modulation (QAM), and it is anticipated that Wi-Fi 7 will support 4096-QAM — increasing throughput by 20%. 
• Enhanced OFDMA: Wi-Fi 6 introduced OFDMA, and it will continue with Wi-Fi 7 with more flexibility and increased spectrum efficiency. 
• Low latency: The enhancements listed above will help decrease latency, which will become less variable and more predictable.