Wireless communications
systems provide anytime, anywhere communications. When
you talk on a wireless phone, it transmits low energy
radio waves to a local antenna site, which connects you
with the landline or wireless location you are calling.
That same antenna also sends signals back to your
wireless phone. A computerized system monitors each
call and ensures that the phone always receives the
strongest available signal at all times. If the signal
is too weak, the system does a "hand-off" to
another tower of which is offering a stronger signal.
This is done so fast that it is almost imperceptible to
the customer.
Cellular Phones connect
to multiple transceiver sites linked to a central
computer. The sites, or "cells" as they are
also known, cover a range from one (1) to six (6) miles
in each direction. The cells overlap one another’s
coverage area and operate at different frequencies to
eliminate crosstalk when transmitting from one cell to
another cell. Each cell can accommodate up to 45
different voice channel receivers for the strongest
signal and locks onto it. While in motion, if the
signal begins to fade, the telephone will automatically
switch signal frequencies or cells as necessary without
operator assistance. If it fails to find an acceptable
signal, it will display an "out of service"
or "no service" message, indicating it has
met the limit of its range and is unable to communicate
any further.
Further within this
book, we will get down to the meat and potatoes of what
you need to know about cellular phones and you. We hope
that what you read from this point on will allow you to
feel that you have the information necessary to make an
educated decision.
