Shorter range Megahertz Types of waves Advantages Disadvantages Microwaves (very Pass through the ionosphere, Absorbed very easily by natural, e.g. short wave so are suitable for satellite to rain, and made objects, e.g. concrete. length radio Earth transmission. They are also absorbed by living tissue waves) Can be modified to carry and may harm by their cooking many signals at one time, effect. including data, television Need special aerials to receive them. pictures and voice messages. waves Some are reflected off the The of frequencies that can be ionosphere, so can travel accessed by existing technology is around the Earth. limited, so there is a lot of competition Can carry a message amongst companies for the use of the instantaneously over a wide frequencies. area. Aerials to receive them are simpler than for microwaves. Both microwaves Wires are not needed as they Travel in a straight line, so repeater and radio waves travel through air, thus, a stations may be needed. cheaper form of communication. verbal nonverbal talking body language public address systems radar mobile phone sonar cable television cable television Internet Internet short distance long distance talking cable television public address systems radar body language Internet sonar mobile phone mobile phone electronic non-electronic public address systems talking mobile phone body language cable television radar
Shorter range Megahertz Types of waves Advantages Disadvantages Microwaves (very short wave length radio waves) Pass through the ionosphere, so are suitable for satellite to Earth transmission. Can be modified to carry many signals at one time, including data, television pictures and voice messages. Absorbed very easily by natural, e.g. rain, and made objects, e.g. concrete. They are also absorbed by living tissue and may harm by their cooking effect. Need special aerials to receive them. waves Some are reflected off the ionosphere, so can travel around the Earth. Can carry a message instantaneously over a wide area. Aerials to receive them are simpler than for microwaves. The of frequencies that can be accessed by existing technology is limited, so there is a lot of competition amongst companies for the use of the frequencies. Both microwaves and radio waves Wires are not needed as they travel through air, thus, a cheaper form of communication. Travel in a straight line, so repeater stations may be needed. verbal nonverbal talking public address systems mobile phone cable television Internet body language radar sonar cable television Internet short distance long distance talking public address systems body language sonar mobile phone cable television radar Internet mobile phone electronic non-electronic public address systems mobile phone cable television radar talking body language