What is the science behind mobile phones?

An oversimplification would be to say that mobile phones are nothing more than a radio transmitter and receiver operating at the same time and using a digital form of communication where a small radio time-slice is allotted to each conversation in the same cellular area. Your slice is repeated quickly and often and your mobile selects it alone, giving rise to a slower digital audio voice stream similar to that from a CD player. Microphone and speaker give you the conversation whereas buttons and other information is sent as a data component.