6i curricula science exercise 1 page 110.0:01
Mobile phone network.0:13
Millions of people around the world use mobile phones to keep in touch with friends and family, and there is an 80% chance that you've got a mobile phone in your pocket or bag.0:24
Have you ever wondered, though, how a mobile phone network works?0:34
A mobile phone is actually a sophisticated radio that uses radio waves to communicate.0:39
Like a really good walkie talkie.0:45
A walkie talkie uses one channel and one frequency, so only one person can talk at the same time.0:47
The mobile phone uses two frequencies, one for talking and one for listening, which means both users can talk at the same time and it can use over 1,600 channels.0:54
When your mobile phone is on, the phone communicates to what we call a base station.1:06
A base station is a special antenna which can be on the top of a building or a communications tower.1:11
There are usually hundreds of base stations in cities all over the world.1:18
Sometimes telephone companies disguise their base stations so you don't even notice them.1:23
Each base station is at the center of an area called a cell.1:29
All calls and messages in that area go to the cell's base station, where a special base station controller transmits the call.1:33
Controllers can only take a certain number of calls at the same time, so if a lot of people call, some of them may not be able to get through.1:41
This doesn't happen very often though, because there are antennas everywhere.1:49
Keep an eye out for them.1:53
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