Only speed can keep you going! Explain the main features and advantages of Wi-Fi 6

The Wi-Fi industry is currently developing rapidly, and its growth momentum continues to be positive. As a ubiquitous infrastructure, Wi-Fi is commonly available in a variety of locations, including high-end enterprise/business occasions, school offices, stadiums, airports, hotels, communities, and transportation hubs. Fast and reliable Wi-Fi connections are now considered by many to be basic human needs. Therefore, despite the introduction of standardized data plans by mainstream operators, Wi-Fi data consumption still significantly exceeds cellular networks. According to Cisco VNI's forecast, by 2021, global Internet traffic on Wi-Fi is expected to exceed cellular networks by 2.5 times.

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The explosion in the number of devices that require a stable Wi-Fi network connection has become a catalyst for innovation in the unlicensed spectrum. In fact, the FCC voted unanimously to release an additional 1.2GHz of unlicensed spectrum in the 6 GHz band. Wi-Fi use cases have greatly expanded, and the availability of additional spectrum is timely to accommodate the plethora of Internet of Things (IoT) devices, smart homes, and outdoor deployments and high-density environments. These new use cases often feature dense aggregations of connected devices competing for airtime, which creates a noisy Wi-Fi spectrum, increases interference, and degrades the user experience.

In particular, high-density environments present a huge challenge to today’s already overloaded Wi-Fi networks. The challenging situation of limited spectrum will become more complicated as the number of wireless users and clients continues to increase, with approximately 9 billion Wi-Fi devices shipped. In addition, the number of connected devices in a typical home is expected to reach 50+ by 2022. In developed countries, it is common to see a typical home equipped with Wi-Fi smart security cameras, thermostats, smoke detectors, doorbells, sprinkler systems, and garage doors.

High-performance Wi-Fi has clearly become a key requirement for a variety of new devices, applications, and services. These applications include low-bandwidth, short-packet applications such as Wi-Fi calling, IoT sensors that push or poll data every few seconds, and bandwidth-intensive applications such as video streaming. Not surprisingly, by 2023, video is expected to account for 75% of all mobile data traffic. A large portion of this non-homogeneous traffic (downlinked to Wi-Fi networks) includes social live streaming applications that are sensitive to high link availability requirements and latency for on-demand interactive video. Multiple factors are driving the growth in video consumption, such as larger displays and faster processors, more data-intensive content, and the increasing popularity of AR/VR technologies.

So, what exactly is causing this? The explosive growth of connected devices and traffic requires more efficient wireless connectivity solutions than today's networks can provide. 802.11 evolutions (a, b, g, n, ac) provide higher and higher data rates through improved modulation, channel bonding, and MIMO. In fact, Wi-Fi 5 (802.11ac) performs very well in reaching gigabit throughput. However, there are nuances in actual Wi-Fi usage, especially in high-density scenarios, which prevent users from benefiting from higher data rates. The Wi-Fi 6 (802.11ax) standard drives this trend by focusing on efficiency rather than raw data rates. In fact, Wi-Fi 6 (802.11ax) is intelligent deterministic, and Wi-Fi 6 (802.11ax) APs can effectively utilize spectrum and optimize throughput in dense and crowded environments.

In short, a congested Wi-Fi deployment is akin to stop-and-go traffic. More vehicles on the road—sedans, SUVs, big rigs, and two-wheelers—lower average speeds and negatively impact the driver (user) experience. However, building multi-lane Wi-Fi 6 (802.11ax) highways that include carpool lanes enables higher average throughput per user by expanding capacity and optimizing efficiency. To be sure, Wi-Fi 6 (802.11ax) is designed for high-density environments and recognizes that not every vehicle on the highway has the same speed needs. For example, some devices and applications have specific latency requirements or bursty traffic demands, while other applications require long battery life. Wi-Fi 6 meets all of these requirements.

Let’s take a closer look at the key features and benefits of Wi-Fi 6 (802.11ax) APs:

• Simultaneous multi-user transmission: This is effectively achieved by focusing on the average throughput per station rather than the aggregate output using MU-MIMO and OFDMA, two technologies that have been widely used in the cellular domain. They are complementary technologies in both directions (uplink and downlink) that efficiently deliver various types of services (e.g. text messaging, video streaming, etc.) to multiple users simultaneously. While MU-MIMO is very useful when multiple users have full buffers of traffic to send, OFDMA can provide the greatest benefits when multiple users have small amounts of data.

• Uplink resource scheduling: This feature may be the most important innovation and challenge of Wi-Fi 6 (802.11ax). With uplink resource scheduling, the AP deterministically allocates resources, coordinates, and schedules simultaneous transmissions of multiple clients.

• Spatial Reuse: Multiple APs operate on a shared channel by mitigating co-channel interference. This is made possible by a spatial reuse technique called BSS coloring, which enables devices in one BSS to ignore frames from other BSSs on the same channel, usually at a distance.

• Improve power efficiency: Using a technique called target wake time (TWT), STAs can "sleep" longer, thereby reducing power consumption. The AP coordinates with the STA to wake up at specified and predetermined intervals to exchange data frames.

• Support for indoor and outdoor operations: Wi-Fi 6 (802.11ax) includes mechanisms such as long OFDM symbols to optimize multipath and support robust outdoor deployments.

• Higher-order modulation: Using 1024QAM, Wi-Fi 6 can increase capacity by 25% over 256QAM, especially at close distances.

In summary, as streaming 4K video and other forms of immersive content become the norm, it’s becoming increasingly difficult to provide fast, reliable Wi-Fi coverage in high-density deployment scenarios using older Wi-Fi 5 (802.11ac) APs. That’s exactly why the new Wi-Fi 6 (802.11ax) standard offers up to four times the capacity increase over its predecessor, Wi-Fi 5 (802.11ac). With Wi-Fi 6 (802.11ax), multiple APs deployed in dense device environments can collectively provide the required quality of service to more clients with more different usage profiles. From our perspective, Wi-Fi 6 (802.11ax) is playing a critical role in helping Wi-Fi evolve into a collision-free, deterministic wireless technology that significantly improves aggregate network throughput to meet the needs of high-density venues.