Hata model for urban areas

In wireless communication, the Hata model for urban areas, also known as the Okumura–Hata model for being a developed version of the Okumura model, is the most widely used radio frequency propagation model for predicting the behaviour of cellular transmissions in built up areas. This model incorporates the graphical information from Okumura model and develops it further to realize the effects of diffraction, reflection and scattering caused by city structures. This model also has two more varieties for transmission in suburban areas and open areas.^[1]

Hata Model predicts the total path loss along a link of terrestrial microwave or other type of cellular communications.

Applicable to/under conditions

This particular version of the Hata model is applicable to the radio propagation within urban areas.

This model is suited for both point-to-point and broadcast transmissions and it is based on extensive empirical measurements taken.

PCS is another extension of the Hata model. The Walfisch and Bertoni model is further advanced.

Coverage

Frequency: 150–1500 MHz

Mobile Station Antenna Height: 1–10 m

Base station Antenna Height: 30–200 m

Link distance: 1–10 km.

Mathematical formulation

The Hata model for urban areas is formulated as following:

$L_U \; = \; 69.55 \; + \; 26.16 \; \log_{10} f \; - \; 13.82 \; \log_{10} h_B \; - \; C_H \; + \; [44.9 \; - \; 6.55 \; \log_{10} h_B] \; \log_{10} d$

For small or medium-sized city,

$C_H \; = \; 0.8 \; + \; (\; 1.1 \; \log_{10} f \; - \; 0.7 \; ) \; h_M \; - \; 1.56 \; \log_{10} f$

and for large cities,

$C_H \; = \begin{cases}\;8.29 \; (\; \log_{10} ({1.54 h_M}))^2 \; - \; 1.1 \; \mbox{ , if } 150 \le f \le 200 \\ \; 3.2 \; (\log_{10} ({11.75 h_M}))^2 \; - \; 4.97 \; \mbox{ , if }200 < f \le 1500 \end{cases}$

where

$L_U\;$ = Path loss in urban areas. Unit: decibel (dB)

$h_B\;$ = Height of base station antenna. Unit: meter (m)

$h_M\;$ = Height of mobile station antenna. Unit: meter (m)

$f\;$ = Frequency of transmission. Unit: Megahertz (MHz).

$C_H\;$ = Antenna height correction factor

$d\;$ = Distance between the base and mobile stations. Unit: kilometer (km).

Limitations

Though based on the Okumura model, the Hata model does not provide coverage to the whole range of frequencies covered by Okumura model. Hata model does not go beyond 1500 MHz while Okumura provides support for up to 1920 MHz.

References

↑ Seybold, John S. (2005). Introduction to RF propagation. John Wiley and Sons. ISBN 0-471-65596-1.

External links

"On the use of the universal Okumura-Hata propagation predictionmodel in rural areas" IEEE Explore Retrieved on April 12, 2009
VOLCANO advanced radio propagation model including both direct-path and multi-path ray-tracing models