Past 802.11 wireless enhancements have delivered higher data rates and wider channels but have not addressed efficiency challenges in WiFi networks. WiFi traffic jams are still inevitable.
Despite the higher data rates and the 40/80/160MHz channels used by 802.11n/ac radios, multiple factors create traffic congestion in WiFi networks. WiFi 6 focuses on high efficiency with technology to address the inefficient use of the WiFi medium.
In my last five Industry Insights, I discussed the technology behind WiFi 6 and gave an overview of OFDMA, BSS Colouring, Mu-MIMO, TWT and 1024-QAM. In this article, I will provide you with 10 things to keep in mind about WiFi 6.
It is a WiFi paradigm shift. WiFi 6 does not just push the envelope with regard to WiFi speeds − up to 10Gbps. It introduces numerous performance improvements as well. In fact, it has been dubbed ‘high efficiency’ unlike previous versions that were labelled ‘high throughput’. WiFi 6 is not just about better throughput. WiFi 6 substantially improves capacity, provides better coverage, and reduces congestion in WiFi networks.
Look forward to a little backward compatibility. Unlike the 802.11ac standard, 802.11ax and WiFi 6 support both 2.4GHz and 5GHz wireless devices, so 802.11n (and potentially 802.11g and 802.11b) devices are able to run on WiFi 6 networks. This is critical for many legacy specialised devices, particularly in healthcare and manufacturing verticals that tend to move slowly to update their devices.
Do not confuse your multi-user technologies. The term multi-user (MU) simply means transmissions between an AP and multiple clients can occur at the same time, depending on the supported technology. However, the MU terminology can be very confusing when discussing WiFi 6. Multi-user capabilities exist for both OFDMA and MU-MIMO. There are key differences between both WiFi 6 multi-user technologies.
WiFi 6 focuses on high efficiency with technology to address the inefficient use of the WiFi medium.
Are you ready for simultaneous multi-user WiFi access? Multi-user orthogonal frequency division multiple access (OFDMA) is easily the most important new capability introduced with WiFi 6. It subdivides a channel into smaller frequency allocations, called resource units (RUs), thereby enabling an access point (AP) to synchronise communication (uplink and downlink) with multiple individual clients assigned to the RUs.
MU-MIMO enhancements are here. More MU-MIMO clients can communicate with an AP at the same time. WiFi 5 is limited to a MU-MIMO group of only four clients, whereas WiFi 6 potentially supports up to 8x8x8 MU-MIMO in both downlink and uplink, which allows it to serve up to eight users simultaneously. MU-MIMO is a great multi-user technology for PtMP wireless bridge links between buildings.
No more OBSSessing over spatial reuse. WiFi 6 radios are able to differentiate between BSSs using a BSS colour identifier when other radios transmit on the same channel. Using a procedure called spatial reuse operation (SRO), WiFi 6 radios can apply adaptive clear channel assessment thresholds. BSS colour together with SRO have the potential to decrease the overlapping basic service set (OBSS) channel contention problem that is prevalent in most enterprise WLANs.
No qualms about higher data speeds either. WiFi 6 supports 1024-QAM modulation and coding schemes that define higher data rates providing a potential 20% increase in data throughput over 256-QAM (introduced in WiFi 5).
You need more power. Many WiFi 6 APs are dual-band 4x4:4 APs, and some are even 8x8:8 APs. The extra radio chains and processor capabilities require more power. The 15.4 watts provided by standard 802.11af PoE is not adequate. 802.3at (PoE+) power often is required. PoE+ requirements for 4x4:4 APs should be considered a standard requirement. This may require upgrades of access-layer switches as well as the recalculation of PoE power budgets.
WiFi 6 is great for IOT. Many of the efficiency enhancements for WiFi 6 hold great promise for future Internet of things (IOT) devices. Target wake time (TWT) is an ideal power-saving mechanism, for mobile devices and IOT devices that need to conserve battery life. The 20MHz-only operational mode is ideal for IOT clients that may not need the full capabilities that WiFi 6 has to offer. This will allow client manufacturers to design less complex chipsets at a lower cost, which is ideal for IOT devices.
WiFi security will be better. Although WiFi 6 itself does not specify any new security enhancements or requirements, it does require WPA3 security as a prerequisite. The WiFi Protected Access Version 3 (WPA3) security certification introduces security enhancements, most importantly, Simultaneous Authentication of Equals as a replacement for WPA2-Personal’s Pre-Shared Key.
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