Mobile Phones Working Princple

It's radio waves, electromagnetic radiation, same as TV, radio, Radar, light etc...
It is at a specific frequency. There is a transmitter and receiver, powered from a battery.
Del

In my corner of the world cell phones apparently work via some obscure principle involving provider executives wallowing around naked in the huge piles of cash collected through annoying voice/text/data plans.

It's kind of similar to how cable TV works. Except that unlike the channel package system you don't always have to pay to talk to people you don't want to talk to in order to talk to those you do.

This was answered before by me

the cell phone gets its name from the cell sites set up to maintain the system.

You start by picking a frequency that doesn't travel very far so UHF 800 MHz and low power.

you then set up masts with antenna about say half a mile apart, so you get a pattern that looks like a bees nest ie cells

now it gets complicated.

the hand set is 2 transceivers running together at different frequencies so as not to jam each other.

one frequencies is voice out and and one voice in and mixed in with these or laid on these is a control channel and the sms or text channel, with me so far.

you turn on the handset and the Sim sends out its identity to the network if the signal strength is good.

the network checks Sim data against data it has on record to see if Sim is blocked or ok if ok the network sends the go signal to the phone, and your network comes up.

ps even if the Sim is blocked the network will allow any mobile with or with out a Sim to dial the emergency services ( in the UK anyway)

so you have a good Sim a good signal, so you dial the network picks up the dialing and relays the calling code to the desired phone by micro wave links or land lines from the receiving mast

and you start talking.

now if you move the base station monitors your signal strength and if the signal weakens the base station tells the hand set to turn its power up, which it does at the same time the base also checks with cell sites around you to see if your signal is being picked up by them, if so the system now knows in which direction your going and reserves a spare frequencies on the next cell it thinks you will need.

when the signal is stronger on the new site compared with the original site you phone is told to hand over and it changes sites by switching frequencies to the new site, you can sometimes hear this as a short burp sound.

and now your on the next cell and so on.

the reason there are so many cells is down to the need to keep every one happy if you only had one cell you could only have about 20 people on the phone at anyone time but if you have say 20 cells each with a capability of 20 calls thats now a lot of calls and the quality of reception is kept high

the texting part is for the system a bonus, as it was never intended to be used by anyone other than engineers to help test the system, the texting runs on one of the control channels.

in case your very technical and are wondering how you can have so many channels operating at the same time on one ariel its done by multiplexing the signals, that is compressing the information and sending it out in timed bursts.

oh and the newer digital phones also scramble the voice channels as well.

the old analouge ones didnt and you could listen in on them

Simple really isnt it?

Missed a Bit

http://science.hq.nasa.gov/kids/imagers/ems/waves2.html

http://physics.bu.edu/~duffy/PY106/EMWaves.html

http://physics.info/em-waves/

http://www.howeverythingworks.org/radio.html

Thanks Peter for ur benificial reply.

Please will it be ok if i get back to u again for more query on same .

Yes if i can answer, Its been a few years since i worked on them

But feel free to ask