Question:What are the advantages and disadvantages of using light, infrared, microwaves, radio and electrical signals for communication?
|Type of signal||Advantages||Disdvantages|
|Light||Can be seen. Our eye can be the receiver.||Damaging to eyes if too bright. Readily scattered by cloud, mist etc. Reqires line of sight. Cannot travel very long distances in fibers.|
|Infrared||Allows much longer distance fiber optic links because glass absorbs much less IR than visible light per mile of fiber. Is invisible and eye safe.||Strictly short range when through the air, and requires line of sight.|
|Radio||Diffracts into shadow of large objects. Can follow the curvature of the earth by reflection from ionosphere.||Cannot carry as much information due to very long wavelengths compared to other EM radiations.|
|Electrical||Relatively cheap and easy. Uses simpler technology than the others.||Requires a wired connection between sender and receiver|
|Microwaves||Can travel through clouds, fog and the various layers of the atmosphere without being completely lost.||Requires line of sight between receiver and transmitter.|