The basic structure of a mobile phone includes a casing with a speaker and microphone, a battery for power supply, a key pad and display for user operation, a receiver and antenna, and an integrated computer to control the phone’s functions and store data. The SIM card is also important, as it identifies the phone within the network.
When someone makes a call with a mobile phone, digital radio signals are sent from the phone to the nearest base station and then travel via a cable connection or microwave link to the mobile switching centre. From here, the data are either transmitted to the landline telephone network or to another mobile switching centre, which sends the data to the base station nearest to the recipient of the call or message so that they can then be passed on to the intended mobile phone.
Saskia Blank of the Ideas 2020 team answered this question.