November 01, 2020
What is 802.11AX – WiFi 6?
Year 2020
November 2020

Why do we need WiFi 6? Why do we need it?


This latest standard addresses today’s biggest Wi-Fi challenges: performance and the increasing density of devices and diversity of applications. To handle these challenges, 802.11ax increases throughput capacity by up to four times that of 802.11ac. Additional improvements include the ability to use both the 2.4 gigahertz (GHz) and 5GHz bands for a number of use cases.

 

 

KEY BENEFITS

  • Higher data rates
  • Increased capacity
  • Improved power efficiency
  • Performance in environments with many connected devices
  • Improved performance (as much as 4x) at the maximum range of an access point

 

Wi-Fi 5 (802.11AC) Wi-Fi 6 (802.11AX)

Multi-User MIMO (downlink)

Multi-User MIMO (uplink and downlink)

256-QAM modulation and coding

Higher rates (1024-QAM)

Explicit transmit beamforming

Enhanced outdoor long-range performance

5 GHz 2.4 GHz & 5 GHz

 

MULTI-USER PERFORMANCE

Arguably the most important new feature in the 802.11ax standard is an enhanced multi-user feature called OFDMA (Orthogonal Frequency Division Multiple Access). Multiple devices with varying bandwidth needs can be served simultaneously instead of the existing model where devices compete with one another to send data. With 802.11ax there is no contention as each device is simultaneously scheduled to transmit data in parallel.

Handling data packets in this way improves performance, as a large number of packets – especially those that are latency sensitive such as voice traffic – can be transmitted simultaneously. In dense environments, instead of using a single vehicle to carry traffic, it’s like using a carpool model. Traffic is pooled into a transport allowing for multiple conversations to happen at once. This allows access points to handle traffic from multiple 802.11ax devices more efficiently.

Multi-user Multiple Input/Multiple Output (MU MIMO) is another way to handle traffic from multiple devices that was originally introduced in 802.11ac. Within 802.11ax, this feature has been enhanced by allowing up to 8 devices to transmit simultaneously using a dedicated channel per device. This allows for large packets such as streaming HD video to be handled more efficiently, while shorter packets from IoT devices and voice traffic would be better handled using OFDMA.

Device contention and the battery life of clients is enhanced by a feature called Target Wake Time (TWT), which lets devices remain inactive until it’s their turn to transmit data using a scheduling scheme negotiated with the APs. Because devices can go into an inactive mode the battery life of smart phones, tablets and IoT devices is an underlying benefit. It’s like parking a vehicle in the cell phone waiting area, rather than circling the airport for arrivals. There is less congestion, energy savings and an overall better experience.

IoT handling is also enhanced with an operating mode for low-power, low-bandwidth devices like sensors, automation and medical devices. This mode will separate these devices from an 802.11ax AP using a 20 MHz-only channel that works in either the 2.4 or 5GHz bands. Similar to providing a dedicated bike lane, but without the worry of low-bandwidth traffic interfering with latency sensitive traffic.

 

CONCLUSION

IEEE 802.11ax is an exciting new step for wireless LANs. This sixth generation of Wi-Fi will not only deliver higher effective speeds, but will enable new business models and use cases, including:

  • Full service provider carrier offload
  • IT/IoT convergence
  • Real-time applications such as enterprise-grade 4K/8K video or augmented or virtual reality
  • Secure Wi-F iwithin the enterprise and open networks

As with every other recent Wi-Fi advances, 802.11ax is backward-compatible, building on existing technologies and making them more efficient. This scenario enables a graceful installed base transition with ever-increasing gains as the client base converges toward 802.11ax. 802.11ax is worth considering as soon as it’s available, even if the client density for the technology is still evolving.

In the meantime, enterprise and service provider customers looking at long-term investments in wireless LANs should strongly consider 802.11ax access points.