The Hata model is a
radio propagation model
Radio propagation is the behavior of radio waves as they travel, or are propagated, from one point to another in vacuum, or into various parts of the atmosphere.
As a form of electromagnetic radiation, like light waves, radio waves are affected ...
for predicting the
path loss
Path loss, or path attenuation, is the reduction in power density (attenuation) of an electromagnetic wave as it propagates through space. Path loss is a major component in the analysis and design of the link budget of a telecommunication system. ...
of cellular transmissions in exterior environments, valid for
microwave
Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency ran ...
frequencies from 150 to 1500 MHz. It is an empirical formulation based on the data from the
Okumura model The Okumura model is a radio propagation model that was built using the data collected in the city of Tokyo, Japan. The model is ideal for using in cities with many urban structures but not many tall blocking structures. The model served as a base f ...
, and is thus also commonly referred to as the Okumura–Hata model.
[ The 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.][ Additionally, the Hata Model applies corrections for applications in suburban and rural environments.]
Model description
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. The model is suited for both point-to-point and broadcast
Broadcasting is the distribution of audio or video content to a dispersed audience via any electronic mass communications medium, but typically one using the electromagnetic spectrum ( radio waves), in a one-to-many model. Broadcasting began ...
communications, and covers mobile station antenna heights of 1–10 m, base station antenna heights of 30–200 m, and link distances from 1–10 km.
Urban environments
The Hata model for urban environments is the basic formulation since it was based on Okumura's measurements made in the built-up areas of Tokyo. It is formulated as following:
For small or medium-sized city,
and for large cities,
where
:''LU'' = Path loss
Path loss, or path attenuation, is the reduction in power density (attenuation) of an electromagnetic wave as it propagates through space. Path loss is a major component in the analysis and design of the link budget of a telecommunication system. ...
in urban areas. Unit: decibel
The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a power or root-power quantity on a logarithmic scale. Two signals whose levels differ by one decibel have a po ...
(dB)
:''hB'' = Height of base station antenna. Unit: meter (m)
:''hM'' = Height of mobile station antenna. Unit: meter (m)
:''f'' = Frequency of transmission. Unit: Megahertz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or Cycle per second, cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, me ...
(MHz)
:''CH'' = Antenna
Antenna ( antennas or antennae) may refer to:
Science and engineering
* Antenna (radio), also known as an aerial, a transducer designed to transmit or receive electromagnetic (e.g., TV or radio) waves
* Antennae Galaxies, the name of two collid ...
height correction factor
:''d'' = Distance between the base and mobile stations. Unit: kilometer (km).
Suburban environments
The Hata model for suburban environments is applicable to the transmissions just out of the cities and on rural areas where man-made structures are there but not so high and dense as in the cities. To be more precise, this model is suitable where buildings exist, but the mobile station does not have a significant variation of its height. It is formulated as:
where
:''LSU'' = Path loss in suburban areas. Unit: decibel
The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a power or root-power quantity on a logarithmic scale. Two signals whose levels differ by one decibel have a po ...
(dB)
:''LU'' = Path loss from the small city version of the model (above). Unit: decibel (dB)
:''f'' = Frequency of transmission. Unit: Megahertz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or Cycle per second, cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, me ...
(MHz).
Open environments
The Hata model for rural environments is applicable to the transmissions in open areas where no obstructions block the transmission link. It is formulated as:
where
:''LO'' = Path loss in open areas. Unit: decibel
The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a power or root-power quantity on a logarithmic scale. Two signals whose levels differ by one decibel have a po ...
(dB)
:''LU'' = Average path loss from the small city version of the model (above). Unit: decibel (dB)
:''f'' = Frequency of transmission. Unit: megahertz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or Cycle per second, cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, me ...
(MHz).
Derivative models
There are more specific models for special uses. For example the COST Hata model
The COST Hata model is a radio propagation model (i.e. path loss) that extends the urban Hata model (which in turn is based on the Okumura model) to cover a more elaborated range of frequencies (up to 2 GHz). It is the most often cited of the COST ...
, an urban HataModel, was developed by the European Cooperation in Science and Technology
The European Cooperation in Science and Technology (COST Association) is running an EU-funded programme which enables researchers and innovators to set-up their own research networks in a wide range of scientific topics, called COST Actions. Whil ...
.Final report for COST Action 231
Chapter 4 In turn, the ITU-R P.1546 model is an enhancement to the COST-231 Model.
PCS is another extension of the Hata model. The Walfisch and Bertoni model is further advanced.
References
Further reading
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{{Radio frequency propagation models
Radio frequency propagation model