Propagation Model Details

Common Link Budget

Each model starts with the same link budget, derives the allowed path loss, and then converts that loss into distance.

RX sensitivity mode:
Effective RX sensitivity = RX sensitivity + 10log10(channel width / 20MHz)
Required edge RSSI = effective RX sensitivity + link budget

P2P Target MCS mode:
Required RX level = source-matched profile sensitivity + configured fade margin
The profile sensitivity already includes its channel width; no extra bandwidth adjustment is applied.

Cell-edge RSSI target mode:
Required edge RSSI = cell-edge RSSI target + link margin

Allowed path loss = EIRP + RX antenna gain - required edge RSSI

Example: with EIRP 22dBm, RX antenna gain 1dBi, RX sensitivity -70dBm, and 15dB link budget at 20MHz, the allowed path loss is 78dB.

RX sensitivity mode is the default for client coverage. Cell-edge RSSI target mode is available when a design has an explicit RSSI requirement.

Free Space FSPL

Role: A standard free-space attenuation model, as used in references such as ITU-R P.525.

FSPL = 32.44 + 20log10(f MHz) + 20log10(d km)

Use: Theoretical upper-bound range under clear line-of-sight, or a baseline for model comparison.

Caution: It excludes walls, floors, people, furniture, reflection, and interference, so it is optimistic for indoor Wi-Fi design.

LOS PLE 2.2

Role: A log-distance path loss model using exponent 2.2, slightly more conservative than the free-space exponent 2.0.

d = (lambda / 4pi) * 10 ^ (pathLoss / (10 * 2.2))

Use: A modest line-of-sight estimate when the path is visible but not as ideal as free space.

Caution: The 2.2 exponent is an empirical approximation, not a regulatory or official Wi-Fi rule.

LOS empirical PLE 2.3

Role: An experience-based log-distance line-of-sight model using path-loss exponent 2.3.

d = (lambda / 4pi) * 10 ^ (pathLoss / (10 * 2.3))

Use: Advanced comparison for outdoor P2P links when a slightly more conservative LOS exponent than 2.2 is useful.

Caution: The value is an empirical planning parameter. It does not mean that PLE 2.3 is inherently more accurate than PLE 2.2, and it should be calibrated with measurements for the intended path.

Indoor High-Ceiling / HD PLE 3.3

Role: An empirical indoor log-distance model with lighter attenuation than the other indoor presets.

d = 10 ^ ((pathLoss - 40) / (10 * 3.3))

Use: Warehouses, factories, gyms, halls, and other high-ceiling spaces where line-of-sight components may remain.

Caution: It may be optimistic when metal racks, equipment, or dense occupancy dominate the environment.

Indoor Cubes Walled Office PLE 3.6

Role: An empirical indoor model for partitioned or cubicle-style office areas.

d = 10 ^ ((pathLoss - 40) / (10 * 3.6))

Use: Work areas with low partitions and relatively open office layouts.

Caution: It does not model the number or material of walls individually.

Indoor Drywall Office PLE 3.8

Role: An empirical model for typical indoor office environments. It is the most conservative of the standard indoor presets.

d = 10 ^ ((pathLoss - 40) / (10 * 3.8))

Use: Rough estimates for offices, meeting rooms, and floors with walls and furniture.

Caution: It does not replace a site survey or measured validation.

Indoor PLE convention

The indoor PLE presets use a fixed 40dB one-meter reference loss as a planning parameter. Frequency is not an input to these presets, so the same allowed path loss produces the same distance at 2.4GHz, 5GHz, and 6GHz.

This is a deliberate simplification for rough planning. It does not represent frequency-specific wall, floor, material, or device behavior.

COST-231 Hata Suburban

Role: The suburban correction of a well-known outdoor cellular empirical model. This tool treats it as an advanced reference model.

d = 1000 * 10 ^ (
  (pathLoss - 46.3 - 33.9log10(fMHz)
   + 13.82log10(hBase) + a(hMobile) - Cm)
  / (44.9 - 6.55log10(hBase))
)

Use: Outdoor or semi-outdoor reference estimates when environmental attenuation beyond FSPL is desired.

Caution: COST-231 Hata is primarily a cellular empirical model and is outside its original intended range for 5GHz/6GHz Wi-Fi. It is kept as an Advanced option, not a standard Wi-Fi model.

COST-231 Hata Urban

Role: The urban correction of COST-231 Hata. It is stricter than Suburban and produces shorter distances.

Use: More conservative outdoor or urban reference estimates.

Caution: This is also not a standard Wi-Fi design model. For normal indoor AP placement, prefer the Indoor PLE presets.

P2P receiver profiles and cable loss

Target MCS options originate from Receiver Profile data and appear only when both endpoint radios also have matching capability, MCS-specific transmit-power data, and a resolvable single-radio PHY rate. Only MCS rows published with both TX and RX values are loaded. Missing data stops the calculation rather than interpolating an MCS, creating an inferred lower-PHY mode, or silently using a manual value. Planned-distance throughput is hidden when either direction does not meet the selected target.

Receiver-profile values retain the wording and conditions stated by their source. When PER, packet-length, or guard-interval conditions are not published, they remain unspecified. The selected GI controls the PHY-rate calculation but is not presented as the receiver-sensitivity test condition. MLO and puncturing are not modeled.

Receiver-profile sensitivity is a final value for the listed channel width. Manual RX sensitivity retains the calculator's bandwidth adjustment; receiver-profile mode does not apply it again.

Cable presets interpolate only between published manufacturer attenuation points. Cable length, connector loss, and other fixed loss are added per endpoint. Frequencies outside the table stop the calculation until Manual loss is selected.

Long-distance P2P reference

The P2P detail combines smooth-earth midpoint bulge with 60% of the first Fresnel-zone radius at the planned distance. The default effective-Earth-radius K-factor is 4/3.

earth bulge = distance ^ 2 / (8 * K * earth radius)
combined vertical reference = earth bulge + 0.6 * first Fresnel radius

Caution: This is a vertical-clearance reference only. Terrain, endpoint elevations, buildings, trees, weather, and obstruction profiles are not included, so it does not determine line-of-sight feasibility or required antenna height.

Practical Use

References

• ITU-R P.525: Free-space attenuation
• ITU-R P.1238: Indoor propagation
• ITU-R P.1411: Short-range outdoor propagation and RLAN planning
• Cisco Catalyst IW6300 receiver sensitivity data
• Times Microwave cable attenuation references
• 3GPP TR 38.901: Channel models