Introduction to RF Propagation
Chapter One
Introduction
As wireless systems become more ubiquitous, an understanding of radio-frequency
(RF) propagation for the purpose of RF planning becomes increasingly
important. Most wireless systems must propagate signals through
nonideal environments. Thus it is valuable to be able to provide meaningful
characterization of the environmental effects on the signal propagation. Since
such environments typically include far too many unknown variables for a
deterministic analysis, it is often necessary to use statistical methods for
modeling the channel. Such models include computation of a mean or median
path loss and then a probabilistic model of the additional attenuation that is
likely to occur. What is meant by "likely to occur" varies based on application,
and in many instances an availability figure is actually specified.
While the basics of free-space propagation are consistent for all frequencies,
the nuances of real-world channels often show considerable sensitivity to
frequency. The concerns and models for propagation will therefore be heavily
dependen ... read full excerpt from Introduction to RF Propagation ebook
