The 802.11ac Wi-Fi standard has been around for a few years now, long enough that it has found its way into all but the very cheapest phones and laptops. It's going to be the mainstream standard for at least a couple more years, but as of today, its replacement has become visible on the horizon.

Qualcomm has announced a pair of chips compatible with the new 802.11ax standard. The IPQ8074 is a quad-core 14nm SoC for wireless routers and enterprise access points, and it promises peak speeds of as much as 4.8Gbps across eight 5GHz streams and four 2.4GHz streams, though that peak theoretical speed won't necessarily be what you can expect to see from client devices. On the client side, the QCA6290 chip for laptops, smartphones, and tablets promises peak speeds of 1.775Gbps across two streams.

Qualcomm isn't the first company to announce 802.11ax products—Quantenna announced a router SoC back in October—but Qualcomm is definitely the biggest company to do so, and the QCA6290 does appear to be the first client-side 802.11ax chip that anyone has announced. The final 802.11ax specification hasn't actually been finalized yet, and it's not expected to be finished until 2019, but this is hardly the first time that device makers have attempted to get a jump on new Wi-Fi technologies by announcing and releasing "draft-compliant" devices. Because the standard is still so new, let's run through 802.11ax's main benefits and where it will improve on today's 802.11ac devices.

A brief introduction to 802.11ax

The focus in previous Wi-Fi generations was mostly about the maximum theoretical speed—54Mbps for 802.11g, 1.3Gbps for 802.11ac, and so on—and based on the figures Qualcomm is providing, we can still expect 802.11ax to improve speeds as well. But the main focus is on improving total network capacity, or the number of users that can be served at the same time. This should prove useful not just for congested home networks with multiple users and gobs of connected lightbulbs and doorbells and appliances, but also public Wi-Fi hotspots on planes and trains and in hotels and at events.

One of the ways 802.11ax will accomplish this is by standardizing MU-MIMO, or Multiple User Multiple Input Multiple Output. Most 802.11ac Wi-Fi routers today serve one device at a time, switching rapidly between connections to serve multiple users across multiple devices. This is called SU-MIMO, since the router is still using multiple inputs and outputs to hit those 867Mbps and 1.3Gbps speeds typical to 802.11ac but it can only do so for a single user at a time. MU-MIMO allows those devices to be served simultaneously, increasing the number of devices that can be served at once. And while client devices will also need to be MU-MIMO capable to see the full benefits of the technology, the time and bandwidth freed up by MU-MIMO-compatible devices should make it easier for routers to serve more SU-MIMO clients as well.

MU-MIMO is already a part of the 802.11ac specification, but it's optional, which means that you can't always expect 802.11ac routers and devices to support it. It's also only supported for downloads in 802.11ac and not for uploads. 802.11ax fixes both problems, making MU-MIMO a mandatory feature for anyone who wants to advertise compatibility with the spec and enabling it on both the downlink and uplink.

The other major capacity-boosting innovation in 802.11ax is support for "Orthogonal Frequency-Division Multiple Access" (OFDMA), a technology that is currently used to improve the capacity of LTE networks. When you connect to an 802.11ac router over a 20MHz, 40MHz, 80MHz, or 160MHz channel today, every time the router sends information to a client, it uses all of the bandwidth in that channel regardless of how much information is actually being sent. OFDMA allows those channels to be split up into sub-carriers, increasing the amount of data that can be sent and received to different devices simultaneously.

802.11ax also brings a few other improvements that should help with range and responsiveness. Where 802.11ac only supported the 5GHz band and made routers fall back on the 802.11n standard to support 2.4GHz connections, for instance, 802.11ax operates on both the 5GHz and the 2.4GHz bands. The 2.4GHz spectrum is typically more crowded, but it also tends to pass more easily through walls and offer better range than 5GHz connections. And Target Wake Time (TWT) allows the router and wireless clients to agree on a set future time and a length of time to make a connection, allowing the router to minimize overlap for devices that need regular but not continuous network connectivity. Smart devices that periodically check for updates or other information could take advantage of this to minimize network congestion.

Even with Qualcomm's announcements, don't expect 802.11ax routers or devices to come out soon, and don't expect the standard to go mainstream for a couple of years yet. Routers based on the IPQ8074 SoC should be out by the end of 2017, but client devices with the QCA6290 chip won't follow until 2018. Qualcomm wouldn't tell us when it plans to integrate 802.11ax connectivity into its Snapdragon SoCs, which will be a big driver of adoption in flagship phones. If you'd like to read more about the 802.11ax standard, National Instruments has a whitepaper that dives deeper into the standard's key features.