In the old days, telephones used lines to transmit sound.

Cell phones are being used more and more in our lives, but they don't have lines. How does it work? It turns out that a cell phone is a wireless phone, and sound signals are transmitted via radio waves.? The radio waves cover many areas, each with a base station, directional antenna, and separate control system.?

Each base station has three sector antennas, like a telephone exchange. They can connect to every phone line around them, receiving and sending radio signals so we can talk to people on our cell phones as much as we want.? However, because cell phones transmit sound through radio waves, which are susceptible to interference from external electromagnetic waves, sometimes cell phones don't transmit sound as clearly as regular phones.?

What is a cell phone used for besides making phone calls? Today's cell phone is no longer just a single communication tool, but an intelligent machine with multiple functions.

First, the phone has a headset and a microphone. The magnetic ring in the microphone converts human sound waves into electromagnetic waves, which are then converted into electrical waves. The electrical waves are then transmitted through a line to the other end of the headset. The headset has the same magnetic ring. When it receives the electrical waves, it converts them into electromagnetic waves, which are then converted into sound waves so that we can hear each other. There was no way to put up telephone lines in two remote places separated by mountains and water.

To make a phone call, the telephone office uses a transmitter to send radio waves into the air. When the radio waves are received at another location, the telephone office sends it to the receiver of the phone.? This way, no matter how far away you are, you can always make a phone call. Similar to the principle of wireless communication, except that the airwaves are converted into radio waves. Which is how cell phones work today.