Model channels, spacing, guards, and reuse efficiently. Measure wavelength, path loss, sensitivity, and link margin. Build cleaner band plans with confident deployment-ready frequency decisions.
| Scenario | Band Window (MHz) | Channel BW (MHz) | Guard (MHz) | Spacing Factor | Reuse | Duplex Sep (MHz) | Estimated Channels | Estimated Duplex Pairs |
|---|---|---|---|---|---|---|---|---|
| Campus bridge | 5150 to 5850 | 20 | 5 | 1.25 | 3 | 100 | 21 | 17 |
| Wide rural backhaul | 5700 to 6500 | 40 | 10 | 1.20 | 4 | 220 | 14 | 9 |
| Industrial yard mesh | 2400 to 2483.5 | 10 | 2 | 1.15 | 3 | 0 | 6 | 0 |
These are illustrative planning examples. Real counts vary with local regulation, raster rules, emission masks, and equipment support.
1) Band span
Band Span = End Frequency - Start Frequency
2) Usable spectrum
Usable Spectrum = Band Span - (2 × Guard Band)
3) Effective channel spacing
Effective Spacing = (Channel Bandwidth × Spacing Factor) + Guard Band
4) Simplex channel count
Simplex Channels = floor(((Usable Spectrum - Channel Bandwidth) ÷ Effective Spacing) + 1)
5) Wavelength
Wavelength (m) = 300 ÷ Frequency in MHz
6) Free-space path loss
FSPL (dB) = 32.44 + 20log10(Frequency in MHz) + 20log10(Distance in km)
7) Thermal noise floor
Noise Floor (dBm) = -174 + 10log10(Bandwidth in Hz) + Noise Figure
8) Receiver threshold
Receiver Threshold (dBm) = Noise Floor + Required SNR
9) Received power
Received Power (dBm) = TX Power + TX Gain + RX Gain - FSPL - Misc Losses
10) Link margin
Adjusted Margin (dB) = Received Power - Receiver Threshold - Fade Margin
11) Midpoint Fresnel radius
Fresnel Radius (m) = 8.657 × sqrt(Distance in km ÷ Frequency in GHz)
These equations are planning estimates. Compliance, interference, clutter, rain fade, antenna patterns, and terrain should be checked separately.
The guard band reduces usable spectrum and adds more separation room. Increasing it usually lowers channel count, but it can improve resilience against adjacent-channel interference and imperfect radio filtering.
Wider channels consume more spectrum per assignment. They also raise the effective spacing requirement, so the remaining band fills faster and leaves fewer non-overlapping center frequencies.
The spacing factor scales the nominal bandwidth before the reserve gap is added. Use higher values when you want a cleaner raster with more isolation between neighboring channels.
Frequency planning and link budgeting affect each other. A channel plan may look clean on paper, but the deployment still fails if path loss pushes received power below the receiver threshold.
Use zero when the network is simplex, time-division, or when you only want a generic center-frequency plan without paired uplink and downlink channel estimation.
No. It helps you design an initial band plan and link estimate. You still need real measurements for interference, DFS activity, local noise, reflections, and regulatory compliance.
Select reuse according to sector count, topology, and interference tolerance. Denser deployments usually need larger reuse values to separate co-channel neighbors and preserve performance.
That warning appears when the duplex separation does not fit neatly on the chosen channel spacing raster. The paired frequencies may still fit inside the band, but the grid should be checked carefully.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.