Friday, May 25, 2018

802.11ax Wi-Fi is Coming

802.11AX is coming and is set to be the next big consumer wide Wi-Fi standard. Wireless 802.11AX is looking to bring some exciting improvements to your Wi-Fi experience starting with speed. If you look at the spec on paper you might notice that the maximum theoretical speed for the previous standard, Wireless AC Wave 2 is 866 megabits per second for a single stream and then only 1201 megabits per second for wireless AX so it's higher but not a nearly the six-fold increase like when we went from N to AC but that is actually okay.


The theoretical maximum speeds for Wi-Fi are notoriously inaccurate anyway and real world performance can vary widely depending on range, obstacles, other signals in the air and the quality of your access point and your device.

To address this, Wireless AX aims to improve efficiency in a number of ways to give you consistently higher real world speeds than what you get with AC. Perhaps the biggest change is a feature called OFDMA (Orthognoal Frequency Division Multiple Access). What it does is chop up each wireless channel into many smaller partial channels which allows up to 30 different gadgets to talk to the access point at once over a single channel.

Even though these sub channels are smaller than the main channel the access point gets more flexibility allowing it to allocate bandwidth to each device based on its data needs. This should increase performance overall. OFDMA also works in tandem with multi-user MIMO. Multi-user MIMO allows an access point to address multiple devices simultaneously instead of one at a time sequentially. While multi-user MIMO was introduced for consumers with last-gen wireless-AC, wireless AX improves on it. Not only by allowing 8 simultaneous streams instead of just 4 but also by enabling it for both uploads and downloads.

Uploading photos or streaming video from a crowded area like a trade show or a concert venue with Wireless AX support should get a fair bit easier. Another cool feature is the addition of BSS color. BSS color is an identifier that is attached to each data chunk or frame to indicate what wireless network it came from. Access points typically wait to transmit if there's already another frame flying through the air. With BSS color an AP can tell which frames are coming from other networks and ignore them as long as they're below threshold of weakness to prevent interference. This should help avoid unnecessary slowdowns.

If all these improvements aren't enough Wireless AX can utilize both 2.4 GHz and 5 GHz bands with tech companies currently trying to get even more spectrum in the 6 gigahertz range allocated to Wi-Fi.

For your battery powered devices it supports yet another new feature called target wake-up time that allows gadgets to negotiate how often and for how long they will need to transmit or receive data. This allows the Wi-Fi transponder to sleep when transmission isn't necessary which should help to preserve precious battery life once AX devices are available.

The first devices to have 802.11AX will be routers as usual with earlybird network vendors like Asus planning mid 2018 launches. Since the new standard is backwards compatible you could make the Wi-Fi upgrade early if you wanted to.

As for client devices the word on the street is that phones and laptops will probably start hitting the consumer market sometime in 2019.


References: Sebastion, L. & Martin, J. (2018, February 23) What is 802.11ax? , TechQuickie