- Radio waves are used for communication, because they can reflect and refract effectively. Radio waves have a wavelength longer than approximately 10 centimetres.
- Microwaves are used for satellite communication and mobile phones. However, you need to use microwaves which can pass easily through the Earths watery atmosphere, as radio waves can't do this.
- For satellite TV, the signal from a transmitter is transmitted into space where it's picked up by the satellite's receiver dish, which is orbiting the Earth.
- The satellite transmits the signal back to Earth in a different direction (it's refracted) where it's received by a satellite dish on the ground.