How mobile phones work is interesting, but a little complicated to explain. To help you, Im going to explain what happens when you pick up your phone and make a phone call.

So youve got your phone in your hand. Im sure you know that the signal bars on the screen indicate how good a signal your phone is getting. What determines this is how close you are to a base station that is, an antenna that is connected to a real, wired phone network.

Base stations are the core of a mobile phone network, and there are a lot of them. In a city, they can be as little as a quarter of a mile apart, and even far out in the countryside there tends to be one every five miles or so. You dont tend to see them, because theyre cleverly disguised often inside church towers, sometimes even posing as trees but they are absolutely everywhere.

In reality, when you pay your mobile phone bill, its these antennas that youre paying for and if you campaign against having a new one built near your house, the chances are that youre campaigning against your own phone signal.

Wherever you are, then, theres an antenna nearby for you to connect to if there isnt, or if youre out of its line of sight (underground, for example), then you get no signal and cant make any calls. When you move out of range of one base station, it quickly notifies the next one along to look out for you, allowing you to move quickly between areas without losing your signal for even a second. Thats why the networks are known as cellular: its because a lot of individual parts make up an unbroken network, just the same way as a huge number of cells make up your body.