The Problem WiFi 6 Was Designed to Solve
WiFi 5 (802.11ac) is fast in ideal conditions. One device, close to the AP, minimal interference — you'll see impressive throughput numbers. But real environments aren't ideal. A conference room with 30 laptops, a stadium, a dense apartment building — these are where WiFi 5 degrades badly. Multiple devices contending for the channel, co-channel interference from neighbouring networks, poor performance for devices on the far side of the room.
WiFi 6 (802.11ax) attacks all of these problems simultaneously. The headline speed improvements are real but secondary. The density improvements are what matter for enterprise and high-density deployments.
OFDMA — Serving Multiple Devices Simultaneously
WiFi 5 used OFDM, which gave the entire channel to one device at a time. WiFi 6 uses OFDMA (Orthogonal Frequency Division Multiple Access), borrowed from LTE cellular. It subdivides the channel into smaller resource units (RUs) and serves multiple devices in the same transmission window.
Practically: instead of the AP saying "Device A, you get the whole 80MHz channel for this transmission window, then Device B, then Device C," it says "Device A gets 26 tones, Device B gets 26 tones, Device C gets 52 tones — simultaneously." Latency drops dramatically, especially for small-packet applications like video calls, IoT sensors, and web browsing where many devices are generating small bursts of traffic rather than large sustained flows.
MU-MIMO Improvements
WiFi 5 introduced MU-MIMO (Multi-User MIMO) in the downlink only — the AP could transmit to up to 4 devices simultaneously. WiFi 6 extends this to 8 spatial streams in both downlink and uplink. Uplink MU-MIMO is significant for conference environments where multiple people are simultaneously sharing their screens or uploading.
It's worth noting that MU-MIMO benefits require multiple client devices with compatible antennas in good position. Single-device, single-user scenarios won't see improvement over WiFi 5. This is an enterprise/density technology, not a home upgrade story.
BSS Coloring — Fighting Co-Channel Interference
In a dense deployment — enterprise office, apartment building, stadium — many APs will operate on the same or overlapping channels. WiFi 5 treated any signal on the channel as a potential collision and backed off. This wasted significant airtime.
BSS (Basic Service Set) Coloring tags frames from different networks with a "colour" — a 6-bit identifier. Devices can now distinguish "this is my network" from "this is a neighbouring network." If the signal from the neighbouring network is below a threshold, the device doesn't back off — it transmits anyway. The result is dramatically improved spectrum reuse and capacity in dense environments.
Target Wake Time (TWT)
TWT allows the AP to negotiate specific wake windows with client devices. Instead of staying awake listening for potential transmissions, a device can be told "you'll receive your data at time T, go to sleep until then." For IoT devices — sensors, smart home hardware, anything on battery — this extends battery life by orders of magnitude. A temperature sensor that previously stayed in a receive-ready state continuously can now sleep 99% of the time.
TWT is also relevant for mobile devices. Smartphones and laptops connected to WiFi 6 networks see measurable battery life improvements under load.
1024-QAM — The Speed Story
WiFi 6 adds 1024-QAM modulation (up from 256-QAM in WiFi 5), packing more bits into each symbol. Combined with the wider channels and better spatial stream handling, theoretical maximum throughput reaches ~9.6 Gbps. You will never see this number. Real-world throughput in well-designed deployments with modern clients is in the 600 Mbps–1.5 Gbps range for a single device in good conditions.
The throughput improvement matters less than the density improvements for most enterprise use cases. Home users upgrading from WiFi 5 to WiFi 6 may not notice a speed difference at all if they're on a 500 Mbps internet connection — the bottleneck is the WAN link, not the wireless.
WiFi 6E — The 6 GHz Addition
WiFi 6E is WiFi 6 extended into the 6 GHz band (5.925–7.125 GHz in most regions). This opens 1,200 MHz of new spectrum — compared to the 580 MHz available in the 5 GHz band. The practical benefits:
- More non-overlapping channels: Up to seven 160MHz channels versus two in 5 GHz.
- No legacy devices: Only WiFi 6E-capable devices can use 6 GHz. No older devices dragging down the network.
- Lower interference: 6 GHz is currently uncrowded. No microwave ovens, no legacy WiFi, no Bluetooth.
- Higher throughput: 160 MHz channels are actually usable at 6 GHz without the interference that makes them unreliable at 5 GHz.
The limitation: 6 GHz has worse wall penetration than 5 GHz, which in turn is worse than 2.4 GHz. Higher frequency = shorter effective range. Dense AP deployments benefit most; single-AP home setups may see limited range improvement.
Should You Upgrade?
Enterprise/high-density: Yes. The density improvements (OFDMA, MU-MIMO uplink, BSS Coloring) are transformative in environments with many simultaneous clients. Pair with a refresh of WiFi 6E-capable APs and you'll see measurable capacity improvement.
Home/small office: Only if your current equipment is failing or you're seeing congestion in a dense residential area (apartment buildings). If your WiFi 5 setup is working well, the upgrade won't be noticeable on most everyday tasks.
IoT deployments: Yes, eventually. TWT battery savings are significant for battery-powered sensors at scale.