Only a few weeks behind the freezing of the 3GPP Release 15 5G standards, the WiFi industry will approve its own next generation specifications, often pushed as an element of the broader 5G plat-form. On July 1, engineers at the IEEE standards body are expected to green-light the first draft of 802.11ax, which will underpin the next wave of WiFi networks, after two failed attempts.
The 802.11ax specs will boost data rates and be particularly effi-cient in very dense environment, which means they are addressing some of the key issues – multi-gigabit speeds and extreme device density – that 5G is also tackling.
But the IEEE standard has had a rockier road than Release 15 in many ways. Its first and second drafts failed to get the required 75% approval from the 11ax working group in November 2016 and September 2017, dashing some vendors’ hopes of being close enough to a full standard that they could ship early products by the end of 2017.
It is now more than four years since the 11ax process kicked off, longer than the current high-speed standard, 802.11ac, took. It will still take until late 2019 to complete the final ratification of the standard, including a sponsor ballot, though at this stage, the specs will be sufficiently frozen for vendors to feel safe to develop prod-ucts, without the risk of significant reworking to conform to the final standard and indeed some of them already have.
The physical layer specs have been stable for some time, enabling chip designers like Quantenna, Intel, Qualcomm and NEC to be sampling pre-standard 11ax units already. Most recent changes have related to the media access controller (MAC) and any further modifications should be able to be implemented with software up-dates.
The average time for an IEEE process is three years, though some WiFi generations have taken longer – for instance, 802.11n, the predecessor to 11ac, which was attempting a major step change in performance and architecture and was also beset by the politics of rival vendor approaches.
Like 11n, 11ax is very complex and has ambitious objectives. It is targeting an increase in real user data rates of up to 30%, along with a fourfold reduction in latency. It also promises to deliver up to four times more overall data in the same spectrum as 11ac.
That means harnessing OFDMA modulation with 1024QAM, plus expanded support for multiuser MIMO.
Access points based on the draft specs are expected to ship in the last quarter of this year, assuming the proposal secures its 75% approval on July 1. However, the late start means the technology will wait until 2019 to gain scale. Researchers at dell’Oro have reduced their forecast for enterprise 11ax AP shipments from 750,000 during 2018 to 250,000. They expect that first wave of sales to be driven by lower cost, pre-standard units and also by China, where Huawei and H3C, a spinout from HPE China, have expressed plans to be first to market with 11ax.
“During our interviews, we discovered that a number of key en-terprise-class system makers are delaying 11ax roll-outs from Q2 to Q4 2018 or Q1 2019,” said dell’Oro. The 11ac units will contin-ue to represent the “vast majority” of AP sales this year.
Quantenna, Intel, Qualcomm and others have been sampling pre-standard 11ax chips for nearly 18 months and Japanese MNO KDDI already offers a pre-standard 11ax AP made by NEC using its own chip, the IPQ8078.
An important next step will be for the WiFi Alliance (WFA), which certifies and sometimes extends 802.11 standards, to complete its interoperability testing (IOT) and certification programs for 11ax. It expects this to be in place by autumn 2019 and has already begun work on conducting IOT using pre-standard chips. The WFA recently voted to make WPA3, the latest version of its security extensions for WiFi, a mandatory part of 11ax certification.