How the RouterReach model works
Predictive Wi‑Fi planning is useful only when its assumptions and limitations are visible. This page documents the model used by the browser tool.
Predictive Wi‑Fi planning is useful only when its assumptions and limitations are visible. RouterReach is designed for scenario comparison, not false precision.
1. Distance model
The planner uses a log-distance path-loss model with a band-specific reference level and indoor path-loss exponent. The optional radio-strength adjustment shifts the reference by −6 to +6 dB for scenario testing; it does not claim to know a specific access point's EIRP or antenna pattern.
| Band | Planning reference at 1 m | Indoor exponent |
|---|---|---|
| 2.4 GHz | −38 dBm | 2.6 |
| 5 GHz | −43 dBm | 2.8 |
| 6 GHz | −46 dBm | 3.0 |
These are deliberately general planning assumptions. Actual radios, antennas and buildings vary.
2. Barrier attenuation
When the direct path crosses a wall you draw, the model subtracts a material-specific planning loss. The values are deliberately treated as planning allowances rather than universal measured constants.
| Planner material | 2.4 GHz | 5 GHz | 6 GHz* |
|---|---|---|---|
| Drywall / plasterboard | 3 dB | 4 dB | 5 dB |
| Plain glass | 3 dB | 7 dB | 8 dB |
| Brick / masonry | 9 dB | 15 dB | 18 dB |
| Concrete / dense masonry | 12 dB | 20 dB | 25 dB |
| Metal / foil-backed barrier | 18 dB | 28 dB | 32 dB |
*6 GHz values are conservative planning extensions, not a claim that every material has a fixed measured 6 GHz loss.
Open the full attenuation & obstacle reference →
3. Floor / ceiling structures
Multi-storey propagation is no longer represented by one universal floor penalty. On each upper-floor tab you can select the structure between that floor and the one below.
| Inter-floor structure | 2.4 GHz | 5 GHz | 6 GHz |
|---|---|---|---|
| Timber / lightweight | 6 dB | 8 dB | 10 dB |
| Typical mixed | 9 dB | 14 dB | 18 dB |
| Concrete slab | 15 dB | 22 dB | 28 dB |
| Reinforced / foil-heavy | 20 dB | 30 dB | 36 dB |
When a path crosses more than one storey boundary, the selected allowances are added. Real floors vary greatly with joists, rebar, underfloor heating, foil insulation, pipes and moisture.
4. Use-profile thresholds
The planner grades target-profile coverage using approximate received-signal thresholds: basic browsing −76 dBm, video −70 dBm, work/video calls −67 dBm and gaming/low-latency −65 dBm. These are planning thresholds, not guaranteed service levels. Throughput and latency also depend on interference, channel width, contention, client capability and internet connection quality.
5. Wireless mesh topology and hop penalties
Wireless mesh nodes are no longer assumed to connect directly to the main router. RouterReach builds a connected topology from the router through the strongest available upstream mesh path. Each node displays its upstream source, route quality and hop count. The route score is limited by the weakest upstream link, with a small additional planning penalty for extra wireless relay hops.
Weak route quality also reduces the node's effective coverage contribution. Wired Ethernet backhaul is modelled separately: it removes the wireless relay penalty and the interface reports wireless relay quality as not applicable.
6. Signal probe and explainability
Clicking a point in Signal Probe mode evaluates every available radio source and identifies the strongest predicted source at that point. The breakdown exposes the distance component, drawn-wall loss, selected floor/ceiling loss, mesh-backhaul penalty and calibration offset. The “why weak” summary highlights the largest contributors instead of treating the heatmap as a black box.
7. Weakest sampled point
The weakest-point result is the lowest predicted RSSI among the regular sample grid used for the active floor. It is useful for comparison, but it is not a guarantee that the precise physical weakest point has been found; changing grid resolution or real-world multipath can move the actual minimum.
8. Optional measurement calibration
RouterReach can accept RSSI readings that you enter manually at known points. For each point, it calculates the difference between the measured value and the uncalibrated model, then applies the mean difference as a bounded global correction of no more than ±15 dB. This can reduce systematic over- or under-estimation without pretending to be a professional RF survey.
9. Priority zones and optimisation
Priority zones do not change radio propagation. They change the optimiser's objective function. Samples inside a marked priority zone receive four times the weight of ordinary floor area when candidate mesh positions are scored. The optimiser now accepts a wireless candidate when it has a usable connected upstream path through either the main router or an existing mesh node.
10. Uploaded floorplans
Uploaded floorplan images are processed locally in the browser and used only as a tracing background. They are not uploaded by RouterReach. Scale calibration changes plan dimensions from a known line distance; accuracy depends on selecting two points whose real separation is known.
11. What the model does not know
The browser cannot know antenna patterns, exact transmit power, neighbouring-network interference, furniture, mirrors, pipework, exact wall thickness, moisture, rebar, low-emissivity coatings or every client's radio capability. It does not model multipath reflections in three dimensions, channel contention or throughput. These omissions are material, so RouterReach is best used to compare alternatives and then validate important rooms with real measurements.
Primary technical references
- Cisco Wireless RF Reference Guide — propagation, attenuation and common building-material examples.
- WatchGuard AP Placement and Channel Plan Best Practices — example 2.4/5 GHz attenuation ranges for deployment planning.
- NIST IR 6055: Electromagnetic Signal Attenuation in Construction Materials — measurements illustrating variability in construction materials.
Last methodology review: 1 September 2026.