Life without a cell-phone… how did we survive without them? From
a fashion statement, status symbol, luxury to a necessity, the journey
of cellular telephones has been one of great technological
advancement. But do we, who take these "cells" for granted, ever think
of the technology behind it? A cell phone service is based on a simple
idea. It is like a two-way radio, turned into a circuit switched
telephone network, comparable in functionality to its landline
counterpart. We had wireless sets before, used by security, police,
organizers etc. but cell phones were not only accessible easily, they
were more personal.
THE CELLULAR TECHNOLOGY
There is a type of low power two-way
radio base station, which serves a coverage area, divided into many
smaller zones (cells). Telephone handsets continuously search for the
closest base station, and hop from base station to base station if the
user was on the move. This strategy of replacing one high power
base station with many low power base stations distributed throughout
the coverage area made it possible to handle far more subscribers, and
reduced the power requirements for wireless telephones.
Reducing the amount of power needed to carry a conversation through
the airwaves, made it possible for manufacturers to produce much
smaller phones. While solid state circuitry advances have played an
important role in reducing the size and weight of portable phones, the
reduction of power requirements eliminated the need for bulky, heavy
batteries to power handsets.
The first cellular telephone network put to widespread use was an
analog system called AMPS. An AMPS is an analog, frequency modulation
scheme (the same scheme used in FM radio). At the time cellular was
introduced, FM modulation/demodulation circuitry was a commodity
product, and so this was the most cost effective way to introduce
cellular service. Digital cellular did not become cost effective until
the 1990s when DSP based platforms came down in price enough to make
it practical to create an all-digital telephone handset.
HOW IT WORKS:
- Scan Channels: A scan for
the closest cell site near you is made, so that you can get the
strongest signals possible due to your location at the moment.
- Send Message: The phone
then sends a short message to the cell site verifying the MIN, ESN,
and the number that you have just entered to call.
- Assign Channel: After
verifying the above information and your number, the base assigns
a message to your phone, telling it where the conversation is.
Talk: The phone then gets on that channel and begins to ring.
A cell phone has become easily accessible today, as it can fit in most
pockets. (pun intended!) a decent cell-phone will be available
starting Rs. 5000/- and of course, the sky is the limit if you want an
expensive model. Another thing to note is that cell phone prices are
going down as the market becomes more competitive.
Small is in. At least where the cell phones go. The new tiny
single-chassis phones are called "candy bar" models, a reference to
their shape. Many weigh less than 200 grams, battery included. The
familiar squat flip-phones -- those that open like communicators from
the old "Star Trek" -- also are ultra-light.
Batteries are getting smaller too. New nickel metal hydride (NiMH)
batteries are smaller and lighter than the Nickel Cadmium (NiCad)
batteries, but often provide about 40 percent less power. The latest
batteries are the Lithium Ion (Li-Ion) and the Lithium Polymer
batteries, which are of superior quality.
The Cellular Telecommunications Industry Association (CTIA) is a
standard performance testing association for cell phones. Like an ISI
seal, it too has an approval seal.
WHAT CAN GO WRONG WITH A CELL
Your cell phone is tailor-made to deal
with tough conditions, which come from the fact that it is a mobile
service. But nonetheless, the instruments can take only so much abuse,
and are susceptible to breaking.
- If your phone gets wet, or if you
dial the numbers with wet hands, and water gets into the buttons
and internal corrosion may occur. Make sure your phone is dry,
especially when it is switched on.
- Using a belt-clip or a holster
keeps the cell phone firmly in its place, and prevents it from
falling off accidentally.
- Try not to stuff your phone in
with all your other worldly possessions, it may cause the glass
display screens to crack.
- Extreme heat can cause damage to
the cell phone electronics and the cell phone battery. Extreme
cold can also cause a temporary loss of the display screen.
SAFE USAGE OF CELL PHONES
- Do not use the cell phone in heavy
- Do not dial while driving, if it
is so important, ask someone to call for you. If you are alone,
pull over on the side and dial.
- Use your cell phone for short
- Be prepared to end your phone call
- Use memory-dialing options. Learn
to use your phone without having to look at it.
- Never take notes while driving.
- Make sure your phone is easily
reachable when driving.
The normal subscription system, where you get a monthly bill for all
Prepaid Cellular Phone:
You pay for the service in advance, where the amount in your account
is debited with per call made. When the account has been used, you
have to get a new card. A pre-paid phone service does not require the
initial investment as the monthly service. However, the per call cost
is more in a pre-paid. Also, benefits like free night-talk, and others
are not available.
Cellular Phone Accessories:
Extra batteries, vehicle antennas, battery chargers / conditioners,
battery eliminators, hands free kits, and leather cases, are all the
An important safety feature that's included with most of today's
mobile phones. It permits drivers to use their cellular phone without
lifting or holding the handset to their ear. You can speak into your
handset by placing it near you during a conversation.
Voice Activated Dialing:
A feature available only on selected phones and hands-free car kits
that permits you to dial numbers by calling them out to your cellular
phone, instead of dialing them manually. This function is especially
convenient for making calls from your vehicle while driving.
THINGS YOU CAN DO WITH YOUR
How to use
your phone as a modem:
You can go online to send faxes and e-mail using your cellular phone
as a wireless "modem" for your laptop. To do this, you'll need a phone
that can function as a modem, a cable to connect your phone to your
laptop, and a carrier that offers Internet or data options. For
cellular phones without a built-in modem, you'll need to purchase a
cellular-compatible PC card modem that works with your laptop. You'll
also need a compatible cable to connect the card modem in the laptop
to your cell phone. Sometimes the PC card and cable are packaged
together as a kit i.e. You can click on the Service Plans tab to see
which carriers in your market sell that phone.
Newer phones have built-in modem capability, so your laptop doesn't
need a PC card, but you'll still have to purchase a compatible cable
to connect the phone to your laptop's serial port.
Getting Web Updates on your phone:
Some carriers offer news, stock and sports updates with activation of
a Web-messaging option or service plan. Other carriers provide free
news updates as long as you subscribe to text-messaging services.
When you sign up for these services, carriers require you to establish
an account either on their Web site or on a Web site designed to
provide your updates. Once you establish an account, you will be able
to select and modify your updates, including when you receive them,
simply by accessing your account via the Web site.
The updates arrive as text messages (also called short messaging
service), so your phone needs to support this feature. Depending on
the carrier, updates are subject to character limitations ranging from
100 to 150 characters.
Alarm Clocks on phones:
With most phones, you simply select the alarm option and enter a time.
Some alarms will work even when the phone is turned off. Usually, the
phone's alarm will sound just like your ringer alert.
E-mail and Faxes on your phone:
You can also send and receive data/fax documents, access the internet,
email accounts and corporate databases whenever you are on the move.
All you need is a compatible phone and computer and the connecting
accessories (unless you use infrared). Your mobile acts as a phone
line. Calls are normally charged at the same rate as voice calls. You
can ask for this facility from your phone service, for just a little
extra charge. And then, you become truly global! In touch with the
world at your fingertips!
Screening your calls:
A caller ID displays the caller's number on your phone's screen. It is
standard with many digital cellular and PCS (Personal Communications
Service) carriers. Some callers can't be identified, depending on how
their call is routed to you.
Locking your Phone:
Locking your cell phone is a great way to ensure you're the only one
using your handset. Once you activate the lock mode, you must enter a
four-digit code on the keypad each time you turn on the phone. This
prevents anyone else from making calls or accessing the phone's memory
or menu functions.
Tracking Battery Strength:
Your phone can indicate on its screen when your battery is almost out
of power. The indicator can be a battery icon, a "battery low" message
or a red light.
CELLULAR PHONES AND HEALTH
Although no conclusive evidence has
been found linking mobile phone exposure to brain cancer, several new
studies suggest that the potential threat to health is greater than
previously thought. Another cause for concern is the effect on health
due to Radio Frequency (RF) exposure. RF can penetrate exposed tissue,
is absorbed by the body and produces heat although the body's normal
thermo regulating process carries this heat away.
According to new WHO (World Health
Organisation) guide rules:
- Mobile phone users should limit
their exposure to harmful radio frequencies by cutting the length
- Hands-free devices cut exposure by
keeping the instrument away from the head and body.
- Driving cum mobile phone talking
should be banned.
- Mobile phones should not be used
in Intensive Care Units of hospitals as they can pose a danger to
patients by interfering with the working of pacemakers and
- People with hearing aids should
not use mobile phones.
- Base stations, which have low
powered antennae on their terrace to communicate with cell phones,
should not be located near children's schools and playgrounds.
personal phone be personal:
Be discreet about giving out your number
Only give your number to people you actually know, it's your money
you'll be spending when they ring you up.
A cell phone should be used as a device
for communicating. Your chats can be left for a landline. Use your
phone smartly to save on your bills.
Buy smart, talk smart, and save money on your cell-phones. Cell phone
technology has gone on to make the world smaller, and at your
fingertips. Also people can keep in touch and trace each other with
much more ease. So go ahead, and keep your date, even if you missed
her at the taxi stand. Just talk!!
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