IEEE 802.11

IEEE 802.11 is the family of wireless networking standards that define how Wi‑Fi operates at the Physical Layer (Layer 1) and Data Link Layer (Layer 2) of the OSI model. These standards specify radio frequencies, modulation techniques, channel widths, data rates, security mechanisms, and interoperability requirements for wireless LANs.

What IEEE 802.11 Defines:

• Radio frequencies (2.4 GHz, 5 GHz, 6 GHz)
• Channel widths (20/40/80/160/320 MHz)
• Modulation schemes (DSSS, OFDM, QAM, OFDMA)
• MIMO / MU‑MIMO / beamforming
• Authentication and encryption (WEP, WPA, WPA2, WPA3)
• Power levels and regulatory compliance
• Backward compatibility between Wi‑Fi generations

Common IEEE 802.11 Amendments:

• 802.11a — 5 GHz, 54 Mbps
• 802.11b — 2.4 GHz, 11 Mbps
• 802.11g — 2.4 GHz, 54 Mbps
• 802.11n (Wi‑Fi 4) — 2.4/5 GHz, MIMO
• 802.11ac (Wi‑Fi 5) — 5 GHz, MU‑MIMO
• 802.11ax (Wi‑Fi 6/6E) — 2.4/5/6 GHz, OFDMA
• 802.11be (Wi‑Fi 7) — 2.4/5/6 GHz, 320 MHz channels, 4096‑QAM

Why It Matters: IEEE 802.11 ensures that Wi‑Fi devices from different manufacturers can communicate reliably. Every router, access point, laptop, phone, and IoT device that uses Wi‑Fi is built on top of these standards.