Wireless standards tend to get proposed, drafted, and finally accepted at what seems like a glacial pace. It’s been roughly 17 years since we began to see the first 802.11b wireless routers and laptops. In the intervening time, we’ve only seen three more mainstream standards take hold since then: 802.11g, 802.11n, and now 802.11ac. (I’m leaving out some lesser-used ones like 802.11a for the purposes of this story.). The easiest way to think of 802.11ax is to start with 802.11ac — which allows for up to four different spatial streams (MIMO) — and then to massively increase the spectral efficiency.
Now a new standard looms over the horizon. And if you thought that your new 802.11ac router’s maximum speed of 1,300Mbps was already fast, think again. With 802.11ac fully certified and out the door, the Wi-Fi Alliance is looking at its successor, 802.11ax — and it looks pretty enticing. While you may have a hard time getting more than 400Mbps to your smartphone via 802.11ac, 802.11ax should deliver real-world speeds above 2Gbps. And in a lab-based trial of technology similar to 802.11ax, Huawei hit a max speed of 10.53Gbps, or around 1.4 gigabytes of data transfer per second. Clearly, 802.11ax is going to be fast. But what is it exactly?
The easiest way to think of 802.11ax is to start with 802.11ac — which allows for up to four different spatial streams (MIMO) — and then to massively increase the spectral efficiency (and thus max throughput) of each stream. Like its predecessor, 802.11ax operates in the 5GHz band, where there’s a lot more space for wide (80MHz and 160MHz) channels.
Let’s say we take the more conservative 4x estimate, and assume a massive 160MHz channel. In that case, the maximum speed of a single 802.11ax stream will be around 3.5Gbps (compared with 866Mbps for a single 802.11ac stream). Multiply that out to a 4×4 MIMO network and you get a total capacity of 14Gbps. If you had a smartphone or laptop capable of two or three streams, you’d get some blazing connection speeds of 1GB per second or more.
In a more realistic setup with 80MHz channels, we’re probably looking at a single-stream speed of around 1.6Gbps, which is still a reasonable 200MB/sec. If your mobile device supports MIMO, you could be seeing 400 or 600MB/sec. And in an even more realistic setup with 40MHz channels (such as what you’d probably get in a crowded apartment block), a single 802.11ax stream would net you 800Mbps (100MB/sec), or a total network capacity of 3.2Gbps.
Not every use-case requires you to read or write data to a slow storage medium. But even so, alternate uses like streaming 4K video still fall short of these multi-gigabit speeds. Even if Netflix begins streaming 8K in the next few years (and you thought there wasn’t enough to watch in 4K!), 802.11ax has more than enough bandwidth. And the bottleneck isn’t your WiFi there; it’s your internet connection. The current time frame for 802.11ax certification is 2018 — until then, upgrading to 802.11ac (if you haven’t already) should be a nice stopgap.
