Hata Propagation Model

A closed-form empirical model that estimates median land-mobile path loss from frequency, distance, antenna heights, and environment-specific corrections inside a declared validity envelope.

Version

v1 · 2026-08-30 · History

Domain-specific #

1984

Origin domain

radio propagation

Subdomain

land mobile path loss

Aliases

Okumura–Hata model

Core Idea

The Hata propagation model is a closed-form empirical estimator of median transmission path loss for VHF/UHF land-mobile links. Masaharu Hata fitted formulas to the measurement-based Okumura method so that planners could compute urban loss from carrier frequency, transmitter–receiver distance, effective base-station antenna height, mobile antenna height, and an environment correction without reading families of curves. Suburban and open-area forms subtract calibrated corrections from the urban baseline.

The identity includes its empirical envelope. Hata's original paper states 100–1500 MHz, 1–20 km, base height 30–200 m, mobile height 1–10 m, quasi-smooth terrain, and isotropic-antenna propagation loss; many engineering summaries use a conservative lower frequency of 150 MHz.

Scope of Application

Hata was designed for land-mobile system planning where a base antenna stands substantially above a vehicular or portable terminal. Engineers use the model for early coverage contours, link-budget comparison, candidate-site screening, and sensitivity studies across distance, height, frequency, and broad clutter class. Its computational simplicity made the Okumura measurement program usable in large planning calculations.

The urban equation is the reference. A small/medium-city mobile-height correction differs from the large-city piecewise correction. Suburban and open forms modify urban loss. Uses should state which branch was chosen and why the terrain and morphology resemble its calibration class.

Clarity

For a small or medium city, the urban median-loss equation is

\[ L_U=69.55+26.16\log_{10}f-13.82\log_{10}h_b-a(h_m) +(44.9-6.55\log_{10}h_b)\log_{10}d, \]

with

\[ a(h_m)=(1.1\log_{10}f-0.7)h_m-(1.56\log_{10}f-0.8). \]

Manages Complexity

The model compresses a difficult environment-dependent propagation field into a few interpretable coordinates. Frequency, distance, two antenna heights, and a morphology branch replace exhaustive drive-test curves at the preliminary-planning stage. The distance coefficient itself changes with base height, so the model retains an interaction that a single universal path-loss exponent would discard.

Abstract Reasoning

Within the envelope, increasing distance increases predicted loss because the distance coefficient remains positive for allowed base heights. Raising the base antenna generally lowers the predicted loss, though the full change includes its effect on distance slope. Increasing frequency generally raises the urban baseline in this range. Applying the suburban or open correction lowers loss relative to the urban reference for the same numeric inputs.

Knowledge Transfer

The exact model transfers among qualifying land-mobile planning cases because the same variables, coefficients, branches, and median-loss output recur. It transfers from urban to suburban or open settings through defined correction formulas, not by metaphor. COST-231 and other derivatives demonstrate instrument lineage, but their altered ranges and coefficients keep them distinct models.

The portable skeleton—signal source, medium, attenuation, distance, and reach—belongs to Propagation. Empirical calibration and prediction travel more broadly as modeling practices, but a traffic forecast or epidemiological spread curve does not instantiate Hata.

Relationships to Other Abstractions

Current abstraction Hata Propagation Model Domain-specific

Parents (1) — more general patterns this builds on

• Hata Propagation Model presupposes Propagation Prime

  The minimal parent is Propagation: the model estimates how a radio signal attenuates while spreading from a source through a cluttered environment.

Hierarchy path (1) — routes to 1 parentless root

• Hata Propagation Model → Propagation

Neighborhood in Abstraction Space

Hata Propagation Model sits in a sparse region of the domain-specific corpus (90^th percentile for distinctiveness): few abstractions share its structure, so a faithful description tends to retrieve it precisely.

Family — Unclustered & Miscellaneous (1565 abstractions)

Nearest neighbors

• Rugosity — 0.80
• Wireless triangulation — 0.79
• Ziggurat Algorithm — 0.79
• Variogram — 0.79
• Floor Effect — 0.78

Computed from structural-signature embeddings · 2026-09-08