While wireless networking standards IEEE 802.11ac and IEEE 802.11ax are related, there are some major differences. Both standards fall under IEEE 802.11, which is the set of standards that define communication for wireless local area networks (WLANs). The 802.11ac standard is 802.11ax’s predecessor. Also known as WiFi 5, 802.11ac delivers high-throughput WLANs on the 5 GHz band.
“Each new Wi-Fi standard has brought significant improvements in performance, with the most recent, 802.11ac, offering an impressive theoretical maximum rate of 1.3Gbps,” Neal Weinberg wrote in Network World in 2018. “Unfortunately, these gains have not been enough to keep pace with demand, leading to that exasperated cry heard across airports, malls, hotels, stadiums, homes and offices: ‘Why is the wireless so slow?’”
With a fourfold increase in average throughput per user, IEEE 802.11ax, also known as WiFi 6, solves many of these issues. Arising in 2013 as a new amendment to the IEEE 802.11 WLAN standard, 802.11ax delivers high efficiency Wi-Fi in dense environments. Why is this? As Lee Badman reports in TechTarget, some of the key differences between the two standards include:
- Whereas 802.11ac works only in the 5 GHz band, 802.11ax operates in both the 2.4 GHz and 5 GHz bands.
- While the 802.11ac standard allowed up to eight spatial streams, it cannot deliver more than 6.9 Gbps due to hardware limitations. 802.11ax, however, may be able to achieve up to 9.6 Gbps, though Badman explains this is likely only under “ideal conditions” most probably have difficulty reaching.
- At its zenith, 802.11ax uses 1024 quadrature amplitude modulation compared to 802.11ac’s 256 QAM, meaning that 802.11ax “lets more data pass through in a given operational time slot,” according to Badman.
- 802.11ax has an almost 4x reduction in spacing between the modulated sub-carriers, so that more spectrum is used for data transfer with less spent on management.
- The use of orthogonal frequency-division multiple access in 802.11ax allows an AP support various wireless clients at different bandwidth requirements at the same time.
- 802.11ax comes with bidirectional enhancements in multiuser multiple input, multiple output radio processes.
- 802.11ax contains a feature known as basic service set (BSS) coloring that handles co-channel interference.
“As good as 802.11ac is, it has no effective way to deal with interference from neighboring cells on the same channel, which can translate into reduced performance,” Badman concludes. “BSS coloring in 802.11ax adds a field to the wireless frame that overcomes issues associated with same-frequency cell coexistence, leading to increased overall capacity.”
Overall, both of these standards have greatly enhanced wireless technology. However, 802.11ax contains features that deliver superior service, particularly in dense environments.
Improving Quality of Experience with IEEE Std 802.11ax™
The work on High Efficiency Wireless Local Area Networks (WLANs) in IEEE Std 802.11ax™ started in 2013 as a new amendment to the IEEE 802.11 WLAN standard. A goal of the new amendment is to address dense deployments characterized by a large number of access points and stations placed in close proximity in a limited geographical area. Such usage scenarios impact the quality of experience (QoE) for latency-sensitive applications such as voice-over-Wi-Fi™ and video conferencing.
Join IEEE Educational Activities and IEEE Standards Association on 15 December at 12pm ET for a virtual event that describes the new IEEE 802.11ax features such as Orthogonal Frequency Division Multiple Access and Uplink multi-user transmissions together with Physical (PHY) and Medium Access Control (MAC) enhancements specific to IEEE 802.11ax to improve QoE. This event will be available on-demand when the session concludes.
Badman, Lee. (July 2021). What’s the difference between 802.11ac vs. 802.11ax? TechTarget.
Weinberg, Neal. (27 February 2018). What is 802.11ax (Wi-Fi 6), and what will it mean for 802.11ac. NetworkWorld.