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.
1. Distance model
The planner uses a log-distance path-loss model with a band-specific reference level and indoor path-loss exponent. This creates a realistic planning curve where signal falls as distance increases. It is not calibrated to a specific router or client antenna.
| Band | Planning reference at 1 m | Indoor exponent | Floor penalty per level |
|---|---|---|---|
| 2.4 GHz | -38 dBm | 2.6 | 9 dB |
| 5 GHz | -43 dBm | 2.8 | 14 dB |
| 6 GHz | -46 dBm | 3.0 | 18 dB |
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. Cisco’s Wireless RF Reference Guide gives typical examples of about 3 dB for drywall, 10 dB for brick and 12 dB for concrete, while stressing that metal, moisture, thickness and conductivity change the result. WatchGuard publishes similarly broad deployment estimates and shows that loss often increases at 5 GHz.
| 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 rather than a claim that every material has a fixed measured 6 GHz loss.
3. 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.
4. Wireless mesh backhaul
For a wireless mesh node, the model separately estimates the node’s connection back to the main router. A weak backhaul applies a penalty to the node’s effective coverage contribution. Wired backhaul removes that penalty. This is why the optimiser avoids suggesting a wireless node deep inside an existing dead zone.
5. What the model does not know
The browser cannot know antenna patterns, router transmit-power settings, neighbouring network interference, furniture, mirrors, pipework, precise wall thickness, moisture, rebar, low-emissivity coatings or the radio capability of every client device. It also does not model multipath reflections in three dimensions. Those omissions are material, so RouterReach is presented as a scenario-comparison tool.
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 — construction-material measurements and the variability of real barriers.
Last methodology review: 30 August 2026.
Optional measurement calibration
RouterReach can accept RSSI readings that you enter manually at known points on the plan. For each point, the tool calculates the difference between the measured value and the uncalibrated model at that location. It then applies the mean difference as a bounded global correction of no more than ±15 dB. This is intentionally simple: it does not turn the browser into a professional RF survey tool, but it can reduce systematic over- or under-estimation for scenario comparison.
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. This makes the suggested node more likely to solve the room the user actually cares about instead of maximising an undifferentiated whole-floor percentage.
Uploaded floorplans
Uploaded floorplan images are processed locally in the browser and used only as a visual tracing background. They are not uploaded by RouterReach. Scale calibration changes the plan dimensions from a known line distance; accuracy therefore depends on selecting two points whose real separation is known.