8. Sınıf Tutku Yayınları İngilizce Ders Kitabı Sayfa 42 Cevabı 2017 – 2018 Yeni Müfredat
8. Sınıf Tutku Yayıncılık İngilizce Ders Kitabı Sayfa 42 Cevabı
Look at the picture. How do you think a mobile phone network works? Listen and read the text to find out.
Millions of people around the world use mobile phones to keep in touch with their friends and family, and there is an 80% chance you’ve got a mobile phone in your pocket or bag. How does a mobile phone network work?
A mobile phone is actually a sophisticated radio. It uses radio waves to communicate, like a walkie-talkie. Only one person can talk with a walkie-talkie because it uses one channel and one frequency. The mobile phone uses two frequencies, one for talking and one for listening, and two people can talk at the same time.
When your mobile phone is on, the phone communicates to a base station. There are usually hundreds of base stations in cities all over the world. Sometimes telephone companies disguise their base stations, so you don’t notice them. Each base station is at the centre of a cell. All the calls and messages in that area go to the cell’s base station. A special base station controller transmits the call. Controllers can 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. This doesn’t happen very often.