Radio propagation model

From Wikipedia, the free encyclopedia

A Radio Propagation Model, also known as the Radio Wave Propagation Model or the Radio Frequency Propagation Model, is an empirical mathematical formulation for the characterization of radio wave propagation as a function of frequency, distance and other conditions. A single model is usually developed to predict the behavior of propagation for all similar links under similar constraints. Created with the goal of formalizing the way radio waves are propagated from one place to another, such models typically predict the path loss along a link or the effective coverage area of a transmitter.

Characteristics

As the path loss encountered along any radio link serves as the dominant factor for characterization of propagation for the link, radio propagation models typically focus on realization of the path loss with the auxiliary task of predicting the area of coverage for a transmitter or modeling the distribution of signals over different regions.

Because each individual telecommunication link has to encounter different terrain, path, obstructions, atmospheric conditions and other phenomena, it is intractable to formulate the exact loss for all telecommunication systems in a single mathematical equation. As a result, different models exist for different types of radio links under different conditions. The models rely on computing the median path loss for a link under a certain probability that the considered conditions will occur.

1 Development Methodology
2 Variations
3 See also
4 External links

[edit] Development Methodology

Radio propagation models are empirical in nature, which means, they are developed based on large collections of data collected for the specific scenario. For any model, the collection of data has to be sufficiently large to provide enough likeliness (or enough scope) to all kind of situations that can happen in that specific scenario. Like all empirical models, radio propagation models do not point out the exact behavior of a link, rather, they predict the most likely behavior the link may exhibit under the specified conditions.

[edit] Variations

Different models have been developed to meet the needs of realizing the propagation behavior in different conditions. Types of models for radio propagation include:

Models for indoor applications
Models for outdoor applications
- Ground wave propagation models
- Sky wave propagation models
- Environmental Attenuation models
- Point-to-Point propagation models
- Terrain models
- City Models

[edit] Models for Outdoor Attenuations

Near Earth Propagation Models
- Foliage Models
  - Weissberger's Modified Exponential Decay Model
  - Early ITU Model
  - Updated ITU Model
    - One Woodland Terminal Model
    - Single Vegetative Obstruction Model
- Terrain Models
- City models

[edit] Models for Indoor Attenuations

[edit] Models for Environmental Effects

Rain Attenuation Model
- ITU Rain Attenuation Model
- ITU Rain Attenuation Model for Satellites
- Crane Global Model
- Crane Two Component Model
- Crane
- Crane Model for Satellite Paths
- DAH Model