HELLO! Can You Hear Me?
When you call your friend on a landline phone, the following occurs:
⌾ Your voice is converted into an electrical signal. Sound has an audio frequency and wavelength. Your device takes that audio frequency and matches it to a frequency on the electromagnetic spectrum.
⌾ The encoded frequency is then transmitted along telephone cables running from your house to an antenna.
⌾ The transmitting antenna then sends the signal out as radio waves to a receiving antenna.
⌾ The receiving antenna then relays the signal along another set of cables running to your friend’s home.
⌾ Your friend’s phone converts (decodes) that signal back into audio and voila, you are talking to each other
A cell to cell phone communication essentially works the same way minus the cables:
⌾ Your cellphone converts your voice into an electrical signal.
⌾ The encoded frequency is then transmitted as radio waves from your cell phone to a cell tower.
⌾ The cell tower receives the signal, then sends the signal out to your friend’s cell phone, again, over the electromagnetic spectrum (may need to bounce the signal off one or more other cell towers depending on your distance from your friend).
⌾ Your friends cell phone converts (decodes) that signal back into audio and voila, you are talking to each other!
"Plain old telephone service" landlines were originally designed to transfer audio with a bandwidth of
3.6 kHz, providing a quality that was adequate enough for the conversing parties to understand each other. With the advent of 3G, 4G and 5G networks, cellular communication now occurs at frequencies of up to 39 GHz! Bigger bandwidths means that you can now do more than just talk on your phone - you can search the internet, download and watch movies, video-chat, and much more. And since all EM waves travel at the speed of light (299,792,458 metres per second), all of the above occurs pretty quickly and seamlessly!
Does WiFi work like the Cellular Network?
No. There are important differences.
WiFi does its thing at a different spot on the electromagnetic spectrum than cellular data:
WiFi is further to the right on the spectrum - higher frequency and lower wavelength - therefore, more bandwidth. This is why it is faster to download a movie over WiFi than with cellular data.