Wi-Fi Standards: 802.11a to Wi-Fi 7 Compared
Wi-Fi standards are the IEEE 802.11 amendments that define how Wi-Fi works: 802.11a, b, g, n, ac, ax and be. Since 2018 the Wi-Fi Alliance has given the newer ones simpler names: Wi-Fi 4 (802.11n), Wi-Fi 5 (802.11ac), Wi-Fi 6 and 6E (802.11ax) and Wi-Fi 7 (802.11be), the newest. For CompTIA A+, Core 1 (220-1201) objective 2.2 covers 802.11 standards along with the 2.4, 5 and 6 GHz bands and channels.
The main 802.11 standards compared
| Standard | Name | Year | Bands | Max speed | Widest channel |
|---|---|---|---|---|---|
| 802.11a | — | 1999 | 5 GHz | 54 Mbps | 20 MHz |
| 802.11b | — | 1999 | 2.4 GHz | 11 Mbps | 22 MHz |
| 802.11g | — | 2003 | 2.4 GHz | 54 Mbps | 20 MHz |
| 802.11n | Wi-Fi 4 | 2009 | 2.4 and 5 GHz | 600 Mbps | 40 MHz |
| 802.11ac | Wi-Fi 5 | 2013 | 5 GHz | About 6.9 Gbps | 160 MHz |
| 802.11ax | Wi-Fi 6 / 6E | 2021 | 2.4 and 5 GHz; 6E adds 6 GHz | About 9.6 Gbps | 160 MHz |
| 802.11be | Wi-Fi 7 | 2024 | 2.4, 5 and 6 GHz | About 23 Gbps | 320 MHz |
Year is when IEEE approved each standard. Max speed is the theoretical top rate with every spatial stream on the widest channel; real connections are much slower (see below). The Wi-Fi Alliance never gave 802.11a, b or g a number. You'll often see 46 Gbps quoted for Wi-Fi 7: that figure assumed 16 spatial streams, which were considered while 802.11be was being written but left out of the final standard. At its maximum of 8 streams, it works out to about 23 Gbps.
2.4 GHz vs 5 GHz vs 6 GHz
- 2.4 GHz reaches farthest and gets through walls best, but it has only three channels that don't overlap, and it's shared with Bluetooth, cordless phones and microwave ovens. 802.11b, g, n, ax and be use it.
- 5 GHz is faster and has many more channels, with a shorter range. 802.11a, n, ac, ax and be use it. On some 5 GHz channels, access points must use dynamic frequency selection (DFS) and move off the channel if they detect radar.
- 6 GHz is the newest band: the FCC opened 5.925 to 7.125 GHz for unlicensed use in the US in April 2020. Only Wi-Fi 6E devices and Wi-Fi 7 devices with a 6 GHz radio can use it, and it has room for seven 160 MHz channels.
2.4 GHz channels: why 1, 6 and 11
In the US, 2.4 GHz Wi-Fi has 11 channels. Their centers are only 5 MHz apart (channel 1 is 2412 MHz, channel 6 is 2437 MHz and channel 11 is 2462 MHz), but each channel is about 20 MHz wide, so neighbors overlap. Channels 1, 6 and 11 are the standard set of three that don't overlap: they're 25 MHz apart, which leaves a small gap between each, so access points near each other should each use one of them.
Original 802.11b signals are about 22 MHz wide, which is why older material gives that figure. Other countries allow more channels: much of Europe uses 1 to 13, and Japan also allows channel 14, for 802.11b only. Which channels you can use, and at what power, is set by regulations, made in the US by the FCC.
Channel widths and channel selection
A wider channel carries more data but uses more of the band. 802.11a and g use 20 MHz channels; 802.11n allows 40 MHz, 802.11ac and 802.11ax allow 160 MHz, and Wi-Fi 7 allows 320 MHz, which only fits in the 6 GHz band. On 2.4 GHz, stay at 20 MHz: a 40 MHz channel there takes up two of the three clear channels.
Most access points pick a channel automatically. Channel selection by hand means checking what nearby networks use, with a Wi-Fi analyzer, and choosing the least crowded channel: one of 1, 6 or 11 on 2.4 GHz.
Wi-Fi 6 vs 6E vs 7
- Wi-Fi 6 (802.11ax) added OFDMA, which lets an access point serve several devices in one transmission, and 1024-QAM. It runs on 2.4 and 5 GHz.
- Wi-Fi 6E is the same 802.11ax technology extended into the 6 GHz band. The Wi-Fi Alliance announced it in January 2020.
- Wi-Fi 7 (802.11be) adds 320 MHz channels, 4096-QAM and multi-link operation, which lets a device use more than one band at once. Wi-Fi CERTIFIED 7 launched in January 2024; IEEE approved 802.11be in September 2024 and published it in July 2025.
- What's next: the Wi-Fi Alliance says Wi-Fi 8 raises the bar for reliability. IEEE's reliability-focused draft, 802.11bn (Ultra High Reliability), is predicted to be approved in 2028.
Why you never get the max speed
The speeds in the table are theoretical maximums: every spatial stream, the widest channel and a perfect signal. A real connection shares the channel with every other device, loses time to protocol overhead, and slows with distance and walls. Many laptops have two spatial streams, not eight, so a two-stream Wi-Fi 6 laptop's best link rate is about 2.4 Gbps, not 9.6. Cisco Meraki puts real throughput at typically half the advertised rate or less.
How to check your Wi-Fi standard
On Windows 11, open a terminal and run netsh wlan show interfaces. The Radio type line shows the standard in use, such as 802.11ax, and the Band and Channel lines show where you're connected. A Wi-Fi 6E connection still reports 802.11ax; the Band line shows 6 GHz. To see every standard your adapter supports, run netsh wlan show drivers and read the Radio types supported line.
What objective 2.2 covers
Core 1 (220-1201) objective 2.2 lists the 2.4 GHz, 5 GHz and 6 GHz frequencies; channels, including regulations and channel selection (widths, frequencies and bands); Bluetooth; 802.11 standards; NFC; and radio-frequency identification (RFID). It doesn't list the standards by letter, so know the table above: which bands each one uses and roughly how fast it is. Wi-Fi security (WPA2 and WPA3) is in Core 2 (220-1202) objective 2.3, and the Wi-Fi analyzer is a Core 1 objective 2.8 tool.
Then practise it: the free Get on the Right Band lab has you move a laptop with choppy video calls from a crowded 2.4 GHz network to 5 GHz. More hands-on labs are on the A+ labs page, and the A+ cheat sheet has the key exam tables in one place.