MULTIPATH FADING occurs when a transmitted signal divides and takes more than one path to a
receiver and some of the signals arrive out of phase, resulting in a weak or fading signal.
Some TRANSMISSION LOSSES that affect radio-wave propagation are ionospheric absorption,
ground reflection, and free-space losses.
ELECTROMAGNETIC INTERFERENCE (emi), both natural and man-made, interfere with
The MAXIMUM USABLE FREQUENCY (muf) is the highest frequency that can be used for
communications between two locations at a given angle of incidence and time of day.
The LOWEST USABLE FREQUENCY (luf) is the lowest frequency that can be used for
communications between two locations.