Turn a 5G small-cell RF link budget into a free-space coverage radius. Enter carrier frequency, transmit power, antenna gains, receiver sensitivity, installation losses, and fade margin to find the distance where received power reaches the modeled threshold. This is a transparent upper-bound calculation for early planning; dense urban clutter, indoor penetration, interference, antenna height, and local power limits require a detailed propagation study.
The main result is the free-space distance at which modeled received power reaches the sensitivity threshold after losses and fade margin. It is an upper-bound planning figure, not a coverage promise.
The free-space path-loss equation assumes an unobstructed far-field path. Use an environment-specific propagation model and comply with applicable power and spectrum rules.
At 3.5 GHz, 30 dBm transmit power, 5 dBi transmit gain, 0 dBi receive gain, -95 dBm sensitivity, 3 dB losses, and 15 dB margin, maximum path loss is 112.0 dB. The free-space radius is 2.71 km.
No. It is a free-space link-budget estimate. Buildings, foliage, terrain, interference, antenna height, and local regulations can reduce usable coverage.
Free-space path loss rises with frequency for the same distance, so the same link budget reaches a shorter distance.
Use the device or modem sensitivity for the required channel bandwidth, modulation, coding, and performance target. A best-case data-sheet value may overstate coverage.
Reserve margin for shadowing, fading, weather, interference, and modeling uncertainty. Larger margin produces a more conservative radius.
Not by itself. Cell count also depends on site geometry, overlap, indoor penetration, traffic capacity, handover design, exclusions, and terrain.
| Variable | Meaning | Unit |
|---|---|---|
| Frequency | Carrier used in free-space path loss | GHz |
| Tx power | Conducted transmitter output | dBm |
| Antenna gains | Directional gain at each end | dBi |
| Sensitivity | Minimum modeled receive level | dBm |
| Losses | Feedline and miscellaneous attenuation | dB |
| Fade margin | Reserve for variation and uncertainty | dB |