| Scenario | Band | Tx / Ant / Loss | Walls & Floors | Threshold | Typical Use |
|---|---|---|---|---|---|
| Open warehouse bay | 2.4 GHz | 18 dBm / 3 dBi / 1 dB | 1 wall, 0 floors | -70 dBm | Large open spaces, forklifts, scanners |
| Office in active build | 5 GHz | 18 dBm / 3 dBi / 1 dB | 3 walls, 0 floors | -67 dBm | Plan for meetings, CAD, and VoIP |
| Concrete core vertical link | 5 GHz | 20 dBm / 5 dBi / 2 dB | 2 walls, 1 floor | -65 dBm | Stairwells, shafts, temporary risers |
1) Effective transmit level (EIRP):
EIRP(dBm) = TxPower(dBm) + AntennaGain(dBi) − CableLoss(dB)
2) Reference loss at 1 meter (free-space):
PL₀(dB) = 32.44 + 20·log₁₀(0.001) + 20·log₁₀(f_MHz)
3) Log-distance path loss (indoor planning):
PL(d) = PL₀ + 10·n·log₁₀(d/1m) + (Walls·WallLoss) + (Floors·FloorLoss)
4) Received signal estimate (RSSI):
RSSI(dBm) = EIRP − PL(d) − FadeMargin
5) Maximum radius where RSSI meets threshold:
d_max = 10^((EIRP − PL₀ − ExtraLoss − RxThreshold)/(10·n))
- Measure the floor area you want covered (length, width, floors).
- Select the band you plan to deploy and enter access point power and antenna gain.
- Choose a receiver threshold based on your service goal (voice/video needs stronger signals).
- For indoor planning, enter an average wall count and wall loss, plus any floor penetration.
- Add a fade margin to reduce risk from interference, reflections, and moving equipment.
- Press Calculate Coverage. Review radius, area, RSSI samples, and estimated access points.
- Use CSV/PDF exports to share assumptions with your project team.
Coverage planning for construction sites
Construction environments change daily, so coverage should be sized for the working footprint, not only the drawing set. Use realistic access point height, cable losses, and antenna gain. Outdoor yards typically behave closer to free-space than enclosed interiors, while steel frames, stacked materials, and temporary partitions can increase variability. Plan for expansion zones and maintain a margin for interference.
Interpreting RSSI and service targets
RSSI thresholds translate directly to user experience. For general data access, a target near -67 dBm is common, while voice, scanning, and real-time coordination often benefits from stronger signals. The calculator converts your radio and antenna settings into an estimated edge-of-cell radius. If devices roam slowly, include overlap so users stay above the threshold while moving between access points.
Indoor obstructions and material losses
Walls and floors introduce additional attenuation beyond distance. Lightweight partitions may add only a few dB, while concrete, brick, and metal-lined barriers can be much higher. Use the wall count and floor loss inputs as an average across typical paths, then add fade margin to cover multipath and moving machinery. When the site layout changes, update the averages and re-run the estimate.
Access point quantity and overlap strategy
After estimating radius, the calculator derives effective coverage area and an access point count using overlap. Overlap accounts for real-world cell shapes, shadowing, and stronger roaming behavior. Higher overlap (for example, 1.30 to 1.50) reduces dead spots but increases access points. Use the results as a planning baseline, then adjust based on mounting constraints and cable routes.
Field validation and iteration
Validate the plan with a quick walk test or temporary deployment. Compare measured RSSI to the predicted range, especially at corners, stairwells, and equipment bays. If readings are weak, lower path loss assumptions only when evidence supports it; otherwise, increase fade margin, reduce the receiver threshold target, or add access points. Iteration is normal on active builds.
Example data
| Scenario | Band | TX Power | AP Height | Target RSSI | Path Loss n | Fade Margin | Overlap |
|---|---|---|---|---|---|---|---|
| Warehouse floor | 5 GHz | 18 dBm | 4 m | -67 dBm | 3.2 | 10 dB | 1.30 |
| Open yard | 2.4 GHz | 20 dBm | 6 m | -70 dBm | 2.2 | 8 dB | 1.25 |
1) What does the receiver threshold mean?
It is the minimum signal level you want users to have at the edge of coverage. A stronger target improves reliability but reduces the predicted radius and may increase access point count.
2) Should I pick 2.4 GHz or 5 GHz?
2.4 GHz usually reaches farther through obstacles, while 5 GHz offers more capacity and less interference. Many sites use both, with 5 GHz as primary where feasible.
3) How do walls and floors affect coverage?
Each barrier adds loss on top of distance-based path loss. Use averages for typical routes, then add fade margin to handle reflections, equipment movement, and layout changes.
4) What overlap value should I use?
Start around 1.30 for general coverage. Increase it for smoother roaming or difficult layouts. Higher overlap raises the access point estimate but reduces weak areas.
5) Why can measured results differ from the estimate?
Real sites have multipath, uneven obstructions, and interference. The calculator is a planning tool; verify with measurements and adjust fade margin, wall loss, or access point placement.
6) How should I set the path loss exponent (n)?
Use lower values for open areas and higher values for cluttered interiors. If you do not have measurements, choose a conservative value, then refine after a survey.
7) Does this replace a professional RF survey?
No. It provides a fast, structured estimate for budgeting and layout planning. For critical networks, validate with a survey and update the design before final installation.