The Egli model is a terrain model for
radio frequency propagation
Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmit ...
. This model, which was first introduced by John Egli in his 1957 paper,
was derived from real-world data on UHF and VHF television transmissions in several large cities. It predicts the total
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. ...
for a
point-to-point link. Typically used for outdoor
line-of-sight transmission, this model provides the path loss as a single quantity.
Applicable to/under conditions
The Egli model is typically suitable for cellular communication scenarios where one antenna is fixed and another is mobile. The model is applicable to scenarios where the transmission has to go over an irregular terrain. However, the model does not take into account travel through some vegetative obstruction, such as trees or shrubbery.
Coverage
Frequency: The model is typically applied to
VHF and
UHF spectrum transmissions.
Mathematical formulation
The Egli model is formally expressed as:
Where,
= Receive power
= Transmit power
= Absolute
gain
Gain or GAIN may refer to:
Science and technology
* Gain (electronics), an electronics and signal processing term
* Antenna gain
* Gain (laser), the amplification involved in laser emission
* Gain (projection screens)
* Information gain in de ...
of the
base station
Base station (or base radio station) is – according to the International Telecommunication Union's (ITU) Radio Regulations (RR) – a "land station in the land mobile service."
The term is used in the context of mobile telephony, wireless com ...
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 ...
.
= Absolute gain of the
mobile station
A mobile station (MS) comprises all user equipment and computer software, software needed for communication with a Cellular network, mobile network.
The term refers to the global system connected to the mobile network, i.e. a mobile phone or mob ...
antenna.
= Height of the base station antenna.
= Height of the mobile station antenna.
= Distance from base station antenna.
=
Frequency
Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is eq ...
of transmission.
Hz
Limitations
This model predicts the path loss as a whole and does not subdivide the loss into free space loss and other losses.
See also
*
Longley–Rice model
*
ITU terrain model
*
International Telecommunication Union
The International Telecommunication Union is a specialized agency of the United Nations responsible for many matters related to information and communication technologies. It was established on 17 May 1865 as the International Telegraph Unio ...
References
Further reading
* ''Introduction to RF propagation,'' John S. Seybold, 2005, John Wiley and Sons Inc.
{{Radio frequency propagation models
Radio frequency propagation model