Introduction - If you have any usage issues, please Google them yourself
		 
The characteristics of wireless signal changes as it travels the transmitter antenna to the receiver 
antenna. These characteristics depend upon the distance between the two antennas, the path(s) taken 
by the signal, and the environment (buildings and other objects) around the path. The profile of 
received signal can be obtained that of the transmitted signal if we havea model of the medium 
between the two. This model of the medium is called channel model.