Early ITU model
# Early ITU model

The ITU vegetation model is a radio propagation model that estimates the path loss encountered due to the presence of one or more trees inside a point to point telecommunication link. The predictions found from this model is congruent to those found from Weissberger’s modified exponential decay model in low frequencies.

## History

The CCIR, predecessor of ITU, adopted this model in the late 1986.

## Applicable to/under conditions

* This model is applicable on the situations where the telecommunication link has some obstructions made by trees along its way
* This model is suitable for point-to-point microwave links that has a vegetation in their path.
* Typical application of this model is to predict the path loss for microwave links.

## Coverage

Frequency: Not specified

Depth of Foliage: Not specified

## Mathematical formulation

The model is formulated as:

$L=0.2\,f^{0.3}\,d^{0.6}$

Where

    L = The path loss. Unit: decibel (dB)
    f = The frequency of transmission. Unit: megahertz (MHz)
    d = The depth of foliage along the link: Unit: meter (m)

## Points to note

This equation is scaled for frequency specified in megahertz (MHz).

The depth of foliage must be in the units of meters.

## Limitations

The results of this model gets impractical at high frequencies.

