Wi-Fi & Wireless Systems
How electromagnetic radio frequencies, 1024-QAM modulation, CSMA/CA half-duplex contention, and beamformed MIMO antennas transmit gigabits of data through the air without physical wires.
Pieces in this series
How Wi-Fi Actually Works
Electromagnetic radio waves, 2.4/5/6 GHz channels, CSMA/CA collision avoidance, and orthogonal frequency division multiplexing
Wi-Fi does not broadcast continuous streams of light or mystical internet fog. It converts digital bits into microscopic phase and amplitude shifts across high-frequency electromagnetic radio waves (2.4 GHz, 5 GHz, and 6 GHz), negotiated over a strict half-duplex etiquette called CSMA/CA and focused in space using constructive wave interference (beamforming).
Why Wi-Fi Gets Worse Through Walls
Dielectric attenuation, skin depth, Fresnel zone obstruction, and dynamic modulation fallback
Wi-Fi signals do not merely weaken with distance; they lose energy exponentially through dielectric absorption, reflection off metallic steel rebar, and diffraction around doorframes. When obstacles degrade signal-to-noise ratio (SNR), the router's rate adaptation algorithm steps down from 1024-QAM to simpler modulations like QPSK, collapsing speed by up to 90% to maintain connection integrity.