📶
WiFi Standards Cheat Sheet
802.11 wireless standards comparison from 802.11a to Wi-Fi 7
2.4 GHz
Longer range, more interference
5 GHz
Faster speeds, shorter range
6 GHz
Newest band, least congestion
MIMO
Multiple antennas = more speed
| Standard | Year | Frequency | Max Speed | Range | Modulation | Key Features |
|---|---|---|---|---|---|---|
| 802.11a | 1999 | 5 GHz | 54 Mbps | ~35m indoor | OFDM | First 5 GHz standard, less interference but shorter range |
| 802.11b | 1999 | 2.4 GHz | 11 Mbps | ~35m indoor | DSSS | First widely adopted Wi-Fi standard |
| 802.11g | 2003 | 2.4 GHz | 54 Mbps | ~38m indoor | OFDM/DSSS | Backward compatible with 802.11b |
| 802.11n (Wi-Fi 4) | 2009 | 2.4/5 GHz | 600 Mbps | ~70m indoor | OFDM | First to use MIMO, dual-band support |
| 802.11ac (Wi-Fi 5) | 2013 | 5 GHz | 6.9 Gbps | ~35m indoor | OFDM | MU-MIMO, beamforming, 80/160 MHz channels |
| 802.11ax (Wi-Fi 6) | 2019 | 2.4/5 GHz | 9.6 Gbps | ~35m indoor | OFDMA | Better in dense environments, TWT for power saving |
| 802.11ax (Wi-Fi 6E) | 2021 | 6 GHz | 9.6 Gbps | ~30m indoor | OFDMA | Extends Wi-Fi 6 to 6 GHz band, less congestion |
| 802.11be (Wi-Fi 7) | 2024 | 2.4/5/6 GHz | 46 Gbps | ~30m indoor | OFDMA | 320 MHz channels, 4K QAM, multi-link operation |
📈 Speed Evolution
802.11a
802.11b
802.11g
802.11n
802.11ac
802.11ax
802.11ax
802.11be
🎯 Exam Tips
- • Know which standards support 2.4 GHz, 5 GHz, or both
- • Wi-Fi 6 (802.11ax) introduced OFDMA and TWT
- • Only 3 non-overlapping channels on 2.4 GHz (1, 6, 11)
- • 802.11n was first to use MIMO technology
📝 Key Acronyms
- MIMO - Multiple Input Multiple Output
- OFDM - Orthogonal Freq Division Multiplexing
- OFDMA - OFDM + Multiple Access
- TWT - Target Wake Time (power saving)