Date Added: Sep 2009
As wireless signals traverse the path from a transmitter to a receiver, they will be diffracted, scattered and absorbed by the terrain, trees, buildings, vehicles and people that comprise the propagation environment. In the process, the signal may be distorted or impaired in various ways. The presence of obstructions along the path may cause the signal to experience greater attenuation than it would under free space conditions. If the signal is scattered by obstacles located throughout the coverage area, replicas of the signal may take multiple paths from the transmitter to the receiver. Because the replicas will arrive at the receiver after different delays, the signal will experience time dispersion.