how does cellular network operate?

Answer 1

When the send button is pushed on your mobile, the call is set up using radio waves which link you to the nearest base station. The call is then monitored automatically by the exchange whilst you are talking and as you move from one area to another it hands you to the next cell automatically.

The entire country is divided into cells which vary in size from very small in city centres to large ones in the countryside which enables you to drive from one end of the country to the other with one call as it hands off between cells.