/ˈwaɪ faɪ/
n. "IEEE 802.11 WLAN standard using OFDM/CSMA-CA for infrastructure/IBSS connectivity unlike Bluetooth piconets."
WiFi, short for Wireless Fidelity, implements IEEE 802.11 protocols across 2.4/5/6GHz bands (WiFi 7=802.11be=46Gbps via 320MHz channels + MLO), creating infrastructure BSS (AP+STA) or ad-hoc IBSS networks with CSMA/CA medium contention and 802.11r/k/v fast roaming. Contrasts Bluetooth's master-slave FHSS by using OFDM/OFDM6E with MU-MIMO+OFDMA serving 1024 QA-MOD QAM clients simultaneously, secured via WPA3-SAE (dragonfly handshake) unlike BLE's ECDH.
Key characteristics of WiFi include: OFDM Subcarriers 234/996/3.3k (20/80/320MHz) with 4096-QAM; MU-MIMO 16x16 spatial streams unlike Bluetooth SISO; OFDMA Resource Units partition channels for IoT; Target Wake Time (TWT) schedules STA sleep cycles; WPA3 Personal (SAE) + Enterprise (802.1X) authentication; 6GHz UNII-5/8 clean spectrum (WiFi 6E/7).
Conceptual example of WiFi usage:
# WiFi 6 AP monitor mode packet capture (Scapy)
from scapy.all import *
# Filter 802.11ax HE (WiFi 6) beacons
def packet_handler(pkt):
if pkt.haslayer(Dot11Beacon):
if 'HE_CAP' in pkt:
he_mcs = pkt[Dot11HECapabilities].he_mcs_nss
print(f"WiFi 6 AP: {pkt.info.decode()} 1024-QAM: {he_mcs}")
ssid = pkt.info.decode()
channel = ord(pkt[Dot11Elt:3].info)
print(f"BSS: {ssid} ch{channel}")
# Sniff 5GHz WiFi 6E channels
sniff(iface="wlan0mon", prn=packet_handler, filter="type mgt subtype beacon")
# WPA3 SAE handshake capture for analysis
# Pairwise Master Key: PMK = SAE(authentication)
# 4-way handshake derives PTK/GTKConceptually, WiFi transforms wired Ethernet into wireless LAN via AP broadcasting beacons—STA contend via CSMA/CA while WiFi 7's Multi-Link Operation bonds 5+6GHz for 10Gbps effective throughput. Stress-tested via packet generators unlike SerDes BERT, with spectrum analyzers confirming PRBS-like OFDM subcarrier flatness; powers enterprise WLAN where Bluetooth handles personal area and USB4 docks, enabling seamless WPA2/WPA3 roaming across 100+ APs.