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A cell phone is nothing more than a sophisticated radio.
A good way to understand the sophistication of a cell phone
is to compare it to a CB radio. A CB radio is a simplex device.
A simplex device is one in which two people communicate on
the same frequency, so only one person can talk at a time.
A cell phone is a duplex device, so it uses one frequency
for talking, and a second separate frequency for listening.
A CB radio has 40 channels. A cell phone can communicate on
1,664 channels. Cell phones also operate within cells and
they can switch cells as they move around. Cells give cell
phones incredible range. A CB radio can transmit about 5 miles.
Someone using a cell phone, on the other hand, can drive clear
across a city and maintain a conversation the entire time.
Cells are what give a cell phone its incredible range. Cellular
phone system technology is amazing in that a city can be chopped
up into small cells that can allow extensive frequency re-use
across a city. Frequency re-use is what lets millions of people
own cell phones without problems. It works because the carrier
chops up an area to about 10 square miles.
Cell phones have low-power transmitters in them. The base
station also transmits at low power. The advantage of low
power transmission is that the power consumption of the cell
phone, which is normally battery-operated, is relatively low.
Low power means small batteries, and this is what has made
hand-held cellular phones possible. Another advantage is that
the transmissions of a base station and the phones within
its cell do not make it very far outside the cell. The same
frequencies can be reused extensively across a city. Cellular
phone systems require a large number of base stations in each
city regardless of the size. The average large city can have
hundreds of towers. In addition to towers, each carrier in
each city also runs one central office called the Mobile Telephone
Switching Office (MTSO). This office handles all of the cellular
phone connections to the land-based phone system and controls
all of the base stations in the region.
Cell phone technology is amazing and improving everyday.
It is hard to imagine life without this little gadget.
©copyright2004 Levetta Rivera, How Cell Phones Work.
All rights reserved.
About the Author
Levetta Rivera is a successful author and publisher of http://www.freecellphones-bestdeals.com.
An informational resource site to cellular phone deals, cell
phone accessories and service plans.
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