Wi-Fi Lab

Interactive tools for learning how Wi-Fi works, from how bits become a radio wave to how stations share the air. Everything runs in your browser.

Sine Wave Explorer

The building block of every radio signal. Change the amplitude, frequency, wavelength and phase, then add a second wave to see constructive and destructive interference.

  • Amplitude
  • Wavelength
  • Phase
  • Interference
Open the explorer →

Wi-Fi Modulation Simulator

See how bits become a radio wave: each constellation point sets the amplitude and phase of the carrier. Add noise to see why dense modulations need a clean signal.

  • BPSK to 4096-QAM
  • Constellations
  • Noise
Open the simulator →
AP

OFDM(A) Transmission in 3D

Watch Wi-Fi send hundreds of subcarriers at once, symbol after symbol. Change the channel width, guard interval and modulation and see what happens to the data rate.

  • Subcarriers
  • Guard interval
  • 20/40 MHz
  • Wi-Fi 5 and 6
Open the visualiser →
dBmmW 0102030 1101001,000 +10 dB = ×10

mW to dBm Calculator

Convert power between milliwatts and dBm with the formula worked through, plus a conversion table from 0 to 43 dBm.

  • dBm and mW
  • Formula
  • Conversion table
Open the calculator →
d2d · −6 dB3d · −9.5 dB

Free Space Path Loss

How much a Wi-Fi signal weakens with distance, and why. Move the receiver away, double the distance, and see the inverse square law and the frequency's effect on the loss.

  • Inverse square law
  • 2.4, 5 and 6 GHz
  • dBm and watts
Open the calculator →
Tx+4 dBi−76 dB+2 dBiRx 20 dBm24 dBm−50 dBm signal level

Power Budget Calculator

Add up every gain and loss between an AP and a client to find the received signal, the margin, and whether the link is balanced both ways.

  • Link budget
  • EIRP and RSSI
  • Uplink vs downlink
Open the calculator →
r₁ 3.80 m1 km at 5 GHz

Fresnel Zone Calculator

How much clear space a point-to-point link needs around its line of sight, with a side view of the zone and every step of the calculation.

  • Point-to-point
  • 60% clearance
  • Earth curvature
Open the calculator →

RF Propagation Simulator

A live wave simulation of how Wi-Fi signals reflect, scatter, refract, diffract and fade through walls, with real material sizes at 2.4, 5 and 6 GHz.

  • Reflection
  • Diffraction
  • Refraction
  • Scattering
  • Wall loss
Open the simulator →
AP

Multipath Simulator

See why moving a phone a few centimetres can change the signal by 20 dB. Drag an access point and a client around a room and watch the reflections add up or cancel, and how MIMO turns them to its advantage.

  • Reflections
  • Fading
  • OFDM
  • MIMO
Open the simulator →
AP A B +3 dB−8 dB

Beamforming Simulator

See how several omnidirectional antennas steer a signal: their waves add up at client A and cancel elsewhere, including at client B.

  • Transmit beamforming
  • Constructive and destructive
  • Nulls
Open the simulator →
Wi-Fi 7 · 160 MHz · 0.8 µs GI MCSModulation1 stream2 streams 764-QAM 5/6 720.6 1,441.2 9256-QAM 5/6 960.8 1,921.6 111024-QAM 5/6 1,201 2,402 134096-QAM 5/6 1,441.2 2,882.4 1,960 × 12 × 5/6 × 2 ÷ 13.6 µs = 2,882.4 Mbps

MCS Index

Data rates for every 802.11n, ac, ax and be MCS with up to four streams. See how each rate is calculated, or find the MCS behind a device's link rate.

  • Wi-Fi 4 to 7
  • Data rates
  • Link-rate lookup
Open the MCS Index →
slow client Total 212 Mbps Without it 824 Mbps

Throughput Simulator

Why one slow client can drag everyone down. Watch clients take turns on the channel, then remove the slowest or switch on airtime fairness.

  • Airtime
  • Slow clients
  • Airtime fairness
Open the simulator →
APSTA1STA2

802.11 Medium Access Simulator

Watch stations defer, count down, collide, retry and transmit on a shared channel, one microsecond at a time.

  • DCF and EDCA
  • RTS/CTS
  • Hidden nodes
Open the simulator →