802.11 Wireless Standards
Wi-Fi standards evolution: 802.11b (2.4 GHz, 11 Mbps), 802.11g (2.4 GHz, 54 Mbps), 802.11n (Wi-Fi 4 — 2.4 and 5 GHz, up to 600 Mbps, introduced MIMO), 802.11ac (Wi-Fi 5 — 5 GHz only, up to 3.5 Gbps, MU-MIMO), 802.11ax (Wi-Fi 6 — 2.4, 5, and 6 GHz, up to 9.6 Gbps, OFDMA for better multi-device performance). Wi-Fi 6E adds the 6 GHz band (less congestion). Wi-Fi 7 (802.11be): multi-link operation.
Frequency bands: 2.4 GHz — longer range, better wall penetration, more congestion (shares spectrum with Bluetooth, microwave ovens, baby monitors, older Wi-Fi devices). 5 GHz — shorter range, less congestion, more channels, faster. 6 GHz (Wi-Fi 6E) — shortest range, least congestion, newest band. Channels: 2.4 GHz has 11 channels (US) but only 1, 6, and 11 are non-overlapping. 5 GHz has 25+ non-overlapping 20 MHz channels.
SSID (Service Set Identifier): the network name — broadcasted by the AP in beacon frames. Clients see the SSID and connect to it. SSID hiding (disabling broadcast): security through obscurity only — clients still send probe requests. Hidden SSIDs provide minimal security benefit and cause connectivity issues. BSSID: the MAC address of the access point — unique identifier of the specific AP.
Wireless Security Configuration
WEP (Wired Equivalent Privacy): original Wi-Fi security — completely broken, never use. WPA (Wi-Fi Protected Access): TKIP encryption — also compromised, avoid. WPA2-Personal: AES-CCMP encryption with pre-shared key (PSK) — the current standard for home/SOHO. PSK is the password you enter to join. WPA2-Enterprise: uses RADIUS server for individual user authentication (802.1X) — enterprise environments. WPA3: newest standard — SAE (Simultaneous Authentication of Equals) replaces PSK, forward secrecy, more secure against offline dictionary attacks.
MAC address filtering: allow-list specific MAC addresses — devices not on the list are denied. Provides very weak security — MAC addresses can be easily spoofed. Adds administrative overhead without meaningful security improvement. Not a substitute for WPA2/WPA3 encryption.
Guest networks: a separate SSID with internet access but no access to the LAN — isolates guests from internal resources. IoT devices should also be placed on a separate SSID/VLAN, not on the main network. Many consumer routers support a guest network feature.
Channel selection: automatic channel selection works for most homes. In apartment buildings or offices with many APs, manual channel assignment to non-overlapping channels reduces interference. For 2.4 GHz: use channels 1, 6, or 11. For 5 GHz: any non-overlapping channel. Wi-Fi analyzer apps show which channels neighboring networks are using.