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How does a Mobile Phone Work? |
whizkidd
Joined: May 14, 2004
Posts: > 500
From: India
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This might seem stupid. But i have always been intrigued by cell phone technology. And still i haven't a clue how these phones work! And why are they called CELL phones?
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harvey172
Joined: Feb 15, 2004
Posts: > 500
From: Northern Ireland, UK
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Ur the whizkid u shud no!
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Sammy_boy
Joined: Mar 31, 2004
Posts: > 500
From: Staffordshire, United Kingdom
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Next time I take a phone apart I'll take some pics and post them if you like! 
"All it takes for evil to flourish is for good men to do nothing" - Edmund Burke
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SE Rules
Joined: Oct 07, 2004
Posts: 398
From: London
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Try dis
http://www.ieee-virtual-museu[....]ech.php?taid=&id=2345893&lid=1
Shud sort it out 4 U, gud bi of history as well....
Want to stretch your mind? Try this if you dare!!!Philips Diga > Nokia 3210 > Nokia 3650 >  K750 > Nokia N80 > K800 > K850 |
k700nut
Joined: Sep 29, 2004
Posts: > 500
From: manchester,england.
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A cell(cellular)phone is basically a transceiver(transmitter + receiver in one),that operates on microwave frequencys.voda and o2 operate on 900megs,which use cellular repeaters based in high altitude areas,whereas t mob,orange,etc,use sattelite(1.8gig)which is upper end of uhf,or really shf.phones work on duplex,where both parties can talk at once.Phones are a little like 2 way radios(but they re only simplex)with use of a hilltop repeater.
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Evil Eye
Joined: Jun 23, 2004
Posts: > 500
From: Pune, Maharashtra, India
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K700nut went right. |
blackspot
Joined: Sep 06, 2004
Posts: > 500
From: Philippines
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It's a long story but to make it short, Cellular phones, like what @K700nut said, is a transceiver but with a low power compared to VHF or CB radios. What makes it portable and also why it's called so is the fact that it relies on repeater stations that called "Cell sites" to boost it's received and transmitted signal. Without these Cell sites your cellphone is just another piece of expensive toy.
check HowStuffWorks for detailed info.
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[ This Message was edited by: blackspot on 2004-10-07 04:39 ] |
Sammy_boy
Joined: Mar 31, 2004
Posts: > 500
From: Staffordshire, United Kingdom
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I'm interested to know more about the differences between the 900 and 1800 Mhz frequencies - so from what k700nut has said, 900 Mhz operators (like O2 and Voda in the UK) can have less transmitters, but they can be larger, and the signal carries further, whilst 1800 Mhz operators (like Orange and T-Mobile) have to have more, lower-powered units dotted about as their signals don't travel as well? Is it a similar story for slightly different frequencies, like the 850Mhz and 1900Mhz that some countries use?
Does anyone have any more info on this?
"All it takes for evil to flourish is for good men to do nothing" - Edmund Burke
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k700nut
Joined: Sep 29, 2004
Posts: > 500
From: manchester,england.
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Ok,the higher the frequency,the more directional the signal normally is,hence the reason parabolic antennas(sat dishes)are used for very directional transmission.also the higher the frequency,the more line of sight you need to be with the tx(transmitter),because objects,i.e trees,buildings,etc absorb lots of signal.a typical example of directional antennas on uhf(although not a parabolic antenna),would be a tv aerial(around 480mhz).anyway,i'm just waffling now.i could go on,and on,but i'd need paper.lol
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Aled
Joined: Nov 25, 2002
Posts: 320
From: Wales
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It's all about wavelength, higher freq (more GHz) means shorter wavelengths and therefore shorter aerials/masts.
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k700nut
Joined: Sep 29, 2004
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From: manchester,england.
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A typical example of microwave signals being absorbed by a object in it's way,would be a microwave oven with a plate of food inside.this is why there are currently ongoing studies regarding the effects of a mobile phone and it's effects on the human brain,etc,etc.
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vineet_d
Joined: Apr 15, 2004
Posts: > 500
From: MumBhai
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Some nice info here by nut one must know, btw whiz if u want more of this info visit here http://www.howstuffworks.com :-)
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k700nut
Joined: Sep 29, 2004
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From: manchester,england.
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Like aled quite rightly said,the higher the frequency,the lower the wavelength.for example,a cb antenna averaged 18ft long because it was on 27mhz(low frequency),whereas a mobile stub antenna is only 0.5in or near in length,because it operates on microwave frequency(uhf,shf).all very interesting stuff to some.
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Sammy_boy
Joined: Mar 31, 2004
Posts: > 500
From: Staffordshire, United Kingdom
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I see (I think!) I also have a short-wave radio reciever, and as the short wave frequencies I believe are very low - you can pick up signals from the other side of the world (as I have done - with a normal radio antenna the SW radio came with!). And therefore as I understand it this is why radio hams have huge antennae in their back gardens?
btw I've had a look in the howstuffworks site, and picked a few things up and a general outline, I'm also interested in a bit more detail on how phones and the transmitters operate.
"All it takes for evil to flourish is for good men to do nothing" - Edmund Burke
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*Jojo*
Joined: Oct 15, 2003
Posts: > 500
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Quote:
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On 2004-10-07 01:02:23, harvey172 wrote:
Ur the whizkid u shud no!
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Posted: 2004-10-07 00:40
K750 > Nokia N80 > 
