Wi-Fi & wireless knowledge, tools and ideas

Low signal.
High expectations.

Wi‑PHY decodes wireless down to the PHY. Knowledge, hands‑on tools, and experiments for people who actually read the spec.

Tools
802.11n / ac / ax / be / bn01

MCS Index

An interactive HT/VHT/HE/EHT/UHR modulation & coding scheme table. Pick a standard, width, streams and guard interval to get instant data rates.

Open tool
Blog
Wi-Fi · Simulation06

Set Up Virtual OpenWrt on Ubuntu with Simulated Wi-Fi Radios

Run OpenWrt in a QEMU/KVM VM with working APs you can manage from LuCI. No router, no antennas, no wireless card.

Read post Wi-Fi · MAC05

Non-Primary Channel Access (NPCA) in Wi-Fi 8

When a neighbor blocks your primary 20 MHz, Wi-Fi 8 lets a station relocate to clean spectrum it already owns. The triggers, timers and math.

Read post Wi-Fi · PHY04

Why SIFS Is 10µs in 2.4 GHz and 16µs in 5 GHz

SIFS looks like it changes with the band, but it depends on the PHY type. The story of DSSS, OFDM and 802.11g Signal Extension.

Read post Wi-Fi · PHY03

The Math Behind Wi-Fi Airtime Calculation

Where does 192 microseconds of airtime come from? A step-by-step trace from payload to OFDM symbols, from first principles.

Read post Wi-Fi · Simulation02

Simulate a Full Wi-Fi Network in Software with mac80211_hwsim

Run a complete 802.11 network. AP, client, association, monitor mode and live capture in Wireshark with zero Wi-Fi radios.

Read post Wi-Fi · Capture01

Wi-Fi Frame Capture on Samsung (S24/S25) in Monitor Mode

Capture 802.11 frames in monitor mode on Samsung Galaxy devices with no root and no special permissions. A step-by-step guide.

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