Communication Media
Infrared transmission uses low frequency light waves (below the visible spectrum) to carry the data through the air on a direct line-of-sight path between two points (prone to interference from rain, smoke, fog etc.)
Microwave is an extremely high frequency radio communication beam
transmitted over a direct line-of-sight path between any two points (short wave length)
Satellite Transmission transmits data through air to a satellite 22,300 miles in space (==>propagation delay of 0.5 seconds for a round trip)