802.11ax Wi-Fi promises to meet the growing needs of Wi-Fi end users, but at the price of a longer time to standardization with higher technical complexity.  Is there a middle path between OEMs launching new products now versus waiting for resolution of the final, approved standard?

Thanks to the popularity of Wi-Fi, networks have become more congested, slowing data transfers in crowded airports and hotels, and increasingly at work and at home as well.  Widespread use of video content has put dramatically higher demands on networks.  Additionally, Wi-Fi has now become the fabric that connects not just PCs and smartphones, but also tablets, HDTVs, webcams, thermostats, printers, smart watches, smart speakers, refrigerators, and a host of other new IoT devices, all competing for bandwidth, especially in the crowded 2.4 GHz spectrum.  The average number of Wi-Fi client devices per household in the US has reached 11 by some estimates, and globally, the number could reach 50 per household by 2022 according to the OECD.

With a focus on better spectral efficiency and support for many more simultaneous users, 802.11ax promises to improve Wi-Fi quality of service, benefiting consumers, OEMs, enterprises, and public and carrier Wi-Fi providers alike:

• 802.11ax uses OFDMA, centrally controlled scheduling, 8x8 MU-MIMO and additional techniques to improve network capacity to four times that of 802.11ac Wave 2.
• Overall, peak data rates will increase 37 percent, but users at the cell edge can experience up to four times the data rates of 802.11ac Wave 2.
• Users at businesses, college campuses, and indoor and outdoor public venues will have a better Wi-Fi experience, and so will residential users.
• 802.11ax has advanced features that substantially reduce power consumption, boosting battery life in portable devices.

The challenge is that work to improve Wi-Fi under 802.11ax is quite ambitious, at least double what was required to define and approve 802.11ac:

• The 802.11ax standard describes more than 75 new features compared to only eight new features for 802.11ac.
• The IEEE specifications for 802.11ax comprise a 600 page document, up from around 330 pages for 802.11ac.

With the high number of new features, getting the technical details ironed out has proven more time consuming than anticipated.  As a sign of this, on November 17, 2017 the IEEE 802.11ax Draft 2.0 vote failed with only 62.8 percent approval.  Voters submitted 3,374 comments on Draft 2.0 to the IEEE:

• By one estimate, more than 2,250 comments had to do with technical errors, misstatements, inconsistent variables & equations, definitions, terminology, or alleged technical problems.
• Most of the other 1,100 or so comments had to do with changes to the text to reduce ambiguity, correct spelling and punctuation, and grammatical and stylistic changes to improve clarity.

Strategy Analytics gave the comments a quick read, and a few issues caught our attention as potentially more significant than just wording:

• One challenge apparently not completely addressed is how to implement OFMDA in the 2.4 GHz band.
• A few comments point out possible inconsistencies with legacy 802.11 standards that could hamper backwards compatibility.
• Wake time intervals specified for stations (client devices) and symbol intervals are purportedly too short to realize full gains to network efficiency and multipath fading tolerance, respectively.
• The means of handling coexistence and collisions among base stations in different networks supposedly needs improvement.
• Random access for unassociated stations allegedly does not always work correctly.  For one thing, stations with stronger signals allegedly have an unfair access advantage.

When Will 802.11ax Devices Reach the Market?

With more than 300 active members in the IEEE 802.11 working group, just as for 802.11g, 802.11n, and 802.11ac, reaching consensus on 802.11ax will take time.  The IEEE has (as of January 2018) started work on addressing the significant number of comments to Draft 2.0 under Draft 3.0, with the next vote due in mid-2018.  If approved later this year, this will probably push multi-vendor certification of 802.11ax devices to October 2019 or even into 2020.  To help jump-start the process, plug-fest testing of reference designs and early 802.11ax products will start in January, 2018.

The delay in approval of 802.11ax has not stopped vendors from announcing draft-compliant access points, routers and bridges.  This is typical and in line with how the previous standards rolled out, with client devices shipping once compatible networks could be put in place.  On the client side, for example in smartphones where interoperability with different infrastructure devices is paramount and firmware updates are difficult to enforce, OEMs have yet to embrace 802.11ax, and could potentially put this off until 2020.

Whether developing infrastructure or client products, OEMs have to consider a few factors before choosing a Wi-Fi radio chipset and launching a new 802.11ax product:

• Can today’s chipsets and devices be updated through software and firmware to support all the features, or even the most critical features, of the final standard?
• How can the industry ensure end-users will perform any required interoperability software updates?
• In the post “KRACK” security vulnerability era, Wi-Fi security is taking a central place. Will these new devices support the latest WPA 3 security protocol?

In the rush to market, OEMs, especially smartphone and client OEMs, need to make sure that users do not have to hassle with incompatible networks.  OEMs should consider which features will provide immediate and considerable benefit to users, and which will work when 802.11ax reaches final, approved status.

With the standard still in development, Strategy Analytics has explored the best way for OEMs to navigate 802.11ax in a report here.  The report goes into more detail on the features, benefits, and technical underpinnings of 802.11ax, as well as available chipsets and what we believe to be essential features to support in terms of value to consumers and compatibility with the final standard.  You can find more information on the 802.11ax chipsets and suppliers here.