What is the first thing comes to your mind when you look at a cell phone tower? Well, the concept of wireless communication has been around for a while now, we use it for almost most of the things we use on a daily basis starting from Cell phones to satellite TVs. And almost all of them work on the same principle of "Radio Wave transmission". An inventor named Reginald Fessenden was the first one to successfully transmit human voice via radio signals. And the rest is history...
How Does A cellphone work?
Whenever you turn on your cellphone and put a SIM card in it, your cellphone starts searching for towers and connects to the nearest tower respective to your location. Your cellphone is always aware of the nearest available tower. When you move from one place to another place your cellphone also switches from one tower to the other.
When you make a call your cellphone sends out an RF (Radio Frequency) signal, and it is received by the nearest cellphone tower, which is then received by a Base station, then the base station transmits the signal to a series of telecom relay equipment like cell towers or satellites until the signal reaches its final location. The base station serves as the electronic bridge between two mobile phones.
How does a base station processes the call?
When you dial a number the base station identifies the number and automatically determines the shortest possible route to the final destination. Then before it sends out the signal it encrypts the signal with some algorithms, and as the initial signal received would have been very weak it amplifies the signal before sending it further. Thus it makes it very difficult to decode a cellphone call midair.
What happens on the other side?
When the signal is received on the other side it's again become very weak and noisy, which may be due to other radio signals from other devices which interfere with the initial signal, to fix this the receiving station pass the signal through various set of filtering and amplifying circuits, and as the initial signal sent out was actually encoded with secure keys, so the destination station also has to decode the signal to make the actual voice signal clear, and then finally it connects the sender's call (You) to the receivers call (The person you are calling).
And after all these processes you can finally talk to your best friend.