Indoor RF coverage · 1320 × 1066 cm plan

WiFi Planner

Drag the router across the floor plan. Coverage is recomputed from the actual wall geometry using a dominant-path model — signal takes the cheapest route it can find, through masonry or around it via doorways. This is a two-room starter plan; use Import floor plan to load your own.

Floor area
Walls
37 cm
Rooms
6

Radio

Access points

1

Click a router to select it, then drag it anywhere — including outdoors. “Find best spot” searches every reachable position for the placement with the most floor area above the target level.

Floors

1

Construction

The clutter exponent absorbs furniture, people and floor/ceiling reflections. N = 20 is pure free space; 28–30 is a heavily furnished apartment.

Doors & openings

Openings are the main way signal reaches other rooms. Drag their handles on the plan to move them along a wall.

Display

move over the plan
RoomAreaMedianWeakest CoverageSpeed at median
How the simulation works, and where the numbers come from

The model

Every point on the floor gets the strongest signal it can receive by any route. The floor is rasterised at 6 cm and a least-loss path search (Dijkstra) runs outward from the router across that raster. Each step pays two costs: geometric spreading, and whatever material it passes through. Because the search is free to route around a wall instead of through it, signal bends through doorways and along the courtyard exactly as it does in practice — which is the failure mode of naive line-of-sight ray casting, and the idea behind the Dominant Path Model of Wölfle & Landstorfer.

L = 20·log₁₀(f) + N·log₁₀(d_path) + Σ(wall losses) + L_diffraction RSSI = P_tx + G_ant − L
  • Band constant — 40.2 dB at 2.4 GHz, 47.3 dB at 5 GHz (free-space loss at 1 m). 5 GHz starts 7.1 dB behind at every distance before a single wall is counted.
  • N — distance exponent × 10. Free space is 20; the clutter slider raises it to account for furniture, people and reflections that the geometry does not describe.
  • Wall losses are integrated along the actual path, so an oblique crossing costs more than a perpendicular one. Total wall loss is capped at 60 dB (2.4 GHz) / 70 dB (5 GHz) — past that, energy always arrives by some flanking route rather than straight through.
  • L_diffraction penalises paths that detour: the further the winning path stretches beyond the straight-line distance, the more it pays, up to 14 dB. This is the cost of bending around a corner, and it saturates rather than compounding — matching what both the Dominant Path and Geodesic Path models report.
  • Noise floor — −92 dBm at 2.4 GHz, −95 dBm at 5 GHz for a 20 MHz channel, rising 3 dB per doubling of channel width. Speed comes from the standard 802.11ac/ax MCS-versus-SNR table.

Wall attenuation

Materials are specified as loss per wall crossing at this plan's 37 cm thickness, then converted to dB per metre internally. The values are whole-assembly figures — what you measure with a radio either side of a real wall — not bare-slab laboratory transmission, which understates a built wall by several dB. Masonry is where the two bands diverge hardest: NIST measured 203 mm concrete at 29 dB on 2.4 GHz and 48 dB on 5 GHz, while drywall and glass are near-identical on both.

What it deliberately does not do

This is a 2D single-floor median-field predictor. It has no ceiling or floor slab, no explicit specular reflections, no furniture, and no fast fading. Real measurements scatter around a well-calibrated indoor prediction by roughly 5–8 dB, so read the contours as bands, not lines. Treat a result within about 6 dB of the target as "probably fine, go measure it."

Reading the plan

Geometry was traced from the supplied floor plan and reconciled against its dimension chains: 37 + 400 + 74 + 98 + 136 + 538 + 37 = 1320 cm across the top, 1066 cm down the side. All six rooms reproduce their stated areas to within 2%. Interior circulation is inferred — the doors and openings are editable, and moving them changes the answer a great deal.

Sources