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[edit]
The CCIR, predecessor of ITU, adopted this model in the late 1986.
Applicable to/under conditions[edit]
- 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[edit]
Frequency: Not specified
Depth of Foliage: Not specified
Mathematical formulation[edit]
The model is formulated as:
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[edit]
This equation is scaled for frequency specified in megahertz (MHz).
The depth of foliage must be in the units of meters.
Limitations[edit]
The results of this model gets impractical at high frequencies.
See also[edit]
Further reading[edit]
Introduction to RF Propagation, John S. Seybold, 2005, John Wiley and Sons.