What would we do without cellphones? These days, they can do just about anything! From music to movies and Googling to gaming, cellphones have evolved over time in what we now like to call smartphones. But with all of these new features, it’s easy to forget why they were created in the first place – to make and receive phone calls! So how exactly does this work? Let’s take a look!
When you speak into your cellphone during a phone call, it converts your voice into an electrical signal, which is then transmitted to the other person’s cellphone in the form of radio waves (more on radio waves in our post on the Car Radio History). Once these radio waves reach the other person’s cellphone, it converts them back into audible sound. Think of a cellphone as being similar to something like a CB radio or a set of walkie talkies! Cellphones are small, portable devices and because of this, they only have relatively small antennas built in, meaning they are only capable of sending signals over short distances (much like a walkie talkie).
This is where your network provider comes in, by providing masts that amplify the signal from your cellphone and enable it to travel to other masts all around the country and even the world! The mast that is closest to the person you’re calling will be the one that is used to transmit the signal and this will change to another mast if the person is on the move. There are a limited amount of radio frequencies available to network providers, but a cellphone needs only two frequencies to hold a call – one to make the call and one to receive it.
Sometimes, a large concentration of cellphone users in one area might affect the signal. You may have noticed that during busy times, such as New Year’s Eve, that cellphone signal isn’t as reliable as normal. This is because a large amount of people in one area, using their phones all at the same time, may use up all the available frequencies and slow down the network!
Inquiry – Digging Deeper
Do you know who made the very first call on a cellphone and when it was made? Check out the video above to see how Marty Cooper changed the world in 1973!
Did you know that inventor, Nikola Tesla considered the possibility of cellphone technology way back in 1901! Read about it!