Understanding Wi-Fi Standards: 802.11n, 802.11ac, and Wi-Fi 6 (802.11ax) Explained
By WifiInfoView Engineering Group • Published August 2025 • 7 min read
When running a wireless scan using WifiInfoView, one of the most critical columns in the report is PHY Type. While consumers recognize marketing labels like Wi-Fi 5 or Wi-Fi 6, wireless chipsets communicate using technical IEEE 802.11 Physical Layer (PHY) specifications. Understanding these modulation modes is essential to troubleshooting speed bottlenecks.
The Evolution of Wi-Fi PHY Specifications
| Marketing Name | IEEE Standard | Frequency Bands | Max Theoretical Speed | Channel Widths |
|---|---|---|---|---|
| Legacy 802.11b | 802.11b (HR-DSSS) | 2.4 GHz | 11 Mbps | 20 MHz |
| Legacy 802.11g | 802.11g (ERP-OFDM) | 2.4 GHz | 54 Mbps | 20 MHz |
| Wi-Fi 4 | 802.11n (HT) | 2.4 GHz / 5 GHz | Up to 600 Mbps (4x4) | 20 MHz, 40 MHz |
| Wi-Fi 5 | 802.11ac (VHT) | 5 GHz | Up to 3.46 Gbps (8x8) | 20, 40, 80, 160 MHz |
| Wi-Fi 6 / 6E | 802.11ax (HE) | 2.4 GHz, 5 GHz, 6 GHz | Up to 9.6 Gbps | 20, 40, 80, 160 MHz |
| Wi-Fi 7 | 802.11be (EHT) | 2.4 GHz, 5 GHz, 6 GHz | Up to 46 Gbps | Up to 320 MHz |
How Legacy Devices Degrade High-Speed Networks
Wi-Fi is a shared half-duplex medium: only one device can transmit on a given channel at any microsecond. When an older 802.11b or 802.11g smart device connects to your modern access point, the access point must enable Protection Mechanisms (such as RTS/CTS or CTS-to-self) and broadcast legacy preamble headers.
The Legacy Airtime Trap:
Transferring a 10 MB file over an old 802.11g link takes 15 times longer than over an 802.11ax connection. During that entire transmission, the wireless airtime is monopolized, forcing fast Wi-Fi 6 laptops to wait in queue!
Reading PHY Types in WifiInfoView
With WifiInfoView, identifying what protocol each nearby router is using takes seconds:
- 802.11n: Indicates High Throughput (HT). Usually broadcasts on 2.4 GHz or older 5 GHz routers.
- 802.11ac: Indicates Very High Throughput (VHT). Operates exclusively on 5 GHz spectrum with 80 MHz channel widths.
- 802.11ax: Indicates High Efficiency (HE) — modern Wi-Fi 6 routers featuring OFDMA (Orthogonal Frequency-Division Multiple Access) and 1024-QAM.
Check Your Local Wi-Fi PHY Types Now
WifiInfoView displays accurate real-time PHY types, RSSI, and BSSID hardware addresses. 100% free download for Windows.
Next Steps: Master your router setup by reading how to find the best Wi-Fi channel or review how to detect hidden Wi-Fi networks.