Simplifying a complex technology is always a worthwhile process, even when it just involves a naming convention. For example, now we can stop trying to remember an alphabet soup of numbers and letters like 802.11ax and can simply say Wi-Fi 6. While the name change is welcome, it’s the innovations that the latest wireless standard brings to enterprise networks that will make a significant difference in your journey to digital business transformation.
As organizations become ever-more dependent on the ability to continuously access data, applications, and people via wireless mobile devices, Wi-Fi 6 brings advantages in speed, high-density capacity, IoT compatibility, and application performance. Integrating Wi-Fi 6 into access points (APs) and wireless controllers brings a new level of efficiency to networks that support real-world business conditions such as a mobile workforce in high-density environments and IoT deployments.
In this blog post, we’ll discuss the main technology changes in Wi-Fi 6 standard and the business benefits for:
- Improving service in high-density venues like airports, lecture halls, and sporting arenas to support a large number of users with customer engagement apps, and streaming video.
- Enabling virtual and augmented reality apps on wireless devices by providing higher data rates with lower latency.
- Extending the connectivity and battery life of IoT devices.
- Enhancing application Quality of Experience (QoE) with improved interference mitigation in high-density environments.
Efficiency is the Goal for the Wi-Fi 6 Standard
To understand how Wi-Fi 6 will enhance your organization’s digital processes, let’s briefly look at four technical changes in the new standard:
- Orthogonal Frequency Division Multiple Access (OFDMA)
- BSS Coloring
- Target Wake Time (TWT)
- Multiple Users Multiple Input Multiple Output (MU-MIMO)
Two of the most significant changes involve how APs support a large number of devices in high-density environments. Wi-Fi 6 incorporates features found in 4G LTE cellular networks by upgrading access points to Orthogonal Frequency Division Multiple Access (OFDMA) from the older OFDM (minus the Access). OFDMA divides the 802.11 channel (20, 40, 80, 160 MHz wide) into hundreds of sub-channels, also known as Resource Units (RU).
On the downlink, OFDMA enables an AP to transmit to multiple devices simultaneously by distributing the available RUs among different devices. Taking into account various factors like device capability (e.g., only 20 MHz capable), Quality of Service (QoS) requirements such as delay constraints, and packet size determines the number of RUs assigned and scheduled to each device. In previous 802.11 versions, APs could only transmit to one device at a time. In dense device environments scheduling transmissions to multiple devices simultaneously increases channel utilization.
The AP schedules multiple devices on the uplink as well by distributing the available RUs among different devices. The scheduled way of accessing the channel eliminates channel contention (as done in previous standards) among the users and increases the channel utilization. The improvements are especially significant in dense user environments.
Wi-Fi 6 also enables each AP to add a unique color—referred to as “Basic Service Set (BSS) Color”—to each transmitting channel. With 63 different colors available, coloring ensures that neighboring APs can all be assigned unique colors. With each AP transmitting a locally-unique color, a device can easily distinguish transmissions coming from its AP from that of a neighboring AP. This distinction enables a device to ignore a neighboring AP’s transmissions when attempting to transmit. Coloring leads to increased capacity by enabling simultaneous transmissions between APs on the same channel.
Another benefit of BSS Coloring is improving battery life for IoT and mobile devices. A device can ignore all transmissions with colors different than the color of the connected AP thereby increasing battery life. Both ODFMA and BSS Coloring increase the efficiency of Wi-Fi 6, not just the speed, although Wi-Fi 6 provides a significant speed increase as well via other means.
Device congestion was also a constant struggle with the previous standards as they were originally intended for internet surfing and email use in low-density situations. Today’s enterprises depend on applications that need high-bandwidth on both down- and up-links while operating in high-density and flash environments. To accommodate real-world uses and decrease congestion, Wi-Fi 6 works with both the 2.4 and 5 GHz bands to provide more channels and enable access points to pack even more data per packet. MU-MIMO (Multiple Users Multiple Input Multiple Output) enables simultaneous transmissions up to 8 users simultaneously, on both up and down links, as opposed to the previous limit of 4 users at a time only on downlinks. These enhancements translate to higher throughput, faster onboarding, less waiting, and smoother transfers among Wi-Fi zones.
Connectivity When, Where, and How You Need It.
Wi-Fi 6 is designed to benefit the growing number of mobile workers, many of whom carry multiple devices at a time, all seeking constant connectivity as they traverse buildings and campuses. Beyond the benefits to digital nomads, the world of IoT is also going to expand significantly with Wi-Fi 6, which can meet the diverse operating requirements of IoT devices. For example, some IoT sensors only require intermittent connections to transmit low-bandwidth telemetry. In those cases, saving power and extending battery life is essential.
With Wi-Fi 6, the Target Wake Time (TWT) mechanism enables each device to negotiate with APs to set how long it will sleep between transmissions, thus saving power. At the end of a sleep period, the device wakes up and waits for a trigger frame from the AP that enables the device to exchange data. The sleep/wake schedule is often periodic, with long, multi-beacon intervals (minutes, hours, or days) between activities. Since APs negotiate separately with each client, the AP can group devices to wake at the same time or separate scheduled transmissions to achieve the best traffic efficiency and accommodate traffic requirements from other types of clients.
Augmented and virtual reality applications will undoubtedly become more prevalent as soon as the speed and low latency (1+ Gbps and <10 ms respectively) of Wi-Fi 6 becomes widespread or at least available in specific locations for critical applications, such as hospitals employing remote diagnostics and imaging. Wi-Fi 6 makes new high-bandwidth applications possible using a combination of OFDMA with QoS aware schedulers, up to eight spatial streams, and wide channels of 80 and 160 MHz.
Wi-Fi 6 Will Enhance Productivity, Application QoE, and IoT Deployments
Wi-Fi 6 isn’t quite here yet as the standards committee has not finalized the documents as of this publication. However, planning to deploy the infrastructure to support the new wireless standard should start now. Cisco’s next-generation wireless controllers and access points will be ready to fire up the airwaves as Wi-Fi 6 is more fully defined, so now is the time to start thinking of how you can improve your business processes with a highly-efficient wireless fabric woven throughout your enterprise. Whether you are planning for a campus-wide wireless connectivity project, new IoT deployments, or improving application quality of experience for a mobile workforce, Wi-Fi 6 is going to provide a robust foundation for business transformation.
For more technical details on Wi-Fi 6, read the Cisco white paper IEEE 802.11ax: The Sixth Generation of Wi-Fi.
Very good read and just right info to get market excited about WiFi 6 upgrade! Time to bring those legacy 11n and 11ac wave 1 to 11ax era.
11ax – explained in a nutshell; good one!
from my cisco based wifi understanding, there is a recommended "best practive" to limit the number of ssids to around a maximum of four. there are a number of use cases where this isn't feasible.
will wifi 6 provide a mechanism to alleviate the "issue" of the "best practice" of up to four ssids?
My though is that a new best practices document should be drawn up. 802.1ax comes with a lot of new interesting technologies that change the way we will design wireless network.
Also, regarding the SSID number, we don't face the same issues with management overhead (impacting channel utilization) that we had with legacy 802.11 standards. Data rates are increasing and communications go faster. Nonetheless, I would no recommend to have a large amount of SSID if you don't need so (i.e. degraded user experience)
Very good article by the way!
Very good read!
As mentioned, Wi-Fi 6 seems to be borrowing quite a bit from cellular technology – OFDMA, BSS coloring (~ Cellular Base Station Code), TWT (~paging channel for indicating to mobiles when to wake up to look for incoming call or data) etc., and rightly so.
As Wi-Fi networks get more and more dense, they start appearing more and more similar to cellular networks and best practices from either one need to be cross pollinated! This may become even more relevant in the coming times when we have technologies like 5G & Wi-Fi-6 competing for their share of IOT devices.