communications The progressive reduction in
amplitude of a
signal as it travels farther from the point of origin.
For example, an electric signal's amplitude reduces with
distance due to electrical
impedance. Attenuation is
usually measured in
decibels [per metre?].
Attenuation does not imply appreciable modification of the
shape of the waveform (distortion), though as the signal
unless the channel itself is noise free or the signal is
amplified at some intermediate point(s) along the channel.
["Networking Essentials, second edition",
Microsoft Corporation, pub. Microsoft Press 1997].
(2003-07-29)