10 Questions About Cellular Phones
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- What's the difference between analog and digital
- What is a Dual Band Phone?
- What type of battery has the longest life?
- What's the difference between the Stand-by time
and Talk time?
- What is a roaming charge?
- What are peak and off peak hours?
- What are anytime minutes?
- Do I pay for the call when someone calls me?
- Should I buy a cell phone or look for a free cellular
- What to do if you want to upgrade/downgrade or cancel
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Articles - VoIP
VoIP 101: Voice over IP for Beginners
by Rich McIver
For those who have never heard about the potential of
VoIP, be prepared to radically change the way you think
about your current long-distance calling plan. VoIP (Voice
over Internet Protocol) is very simply, a method for taking
ordinary analog audio signals and turning them into digital
signals that can be sent over the Internet.
So what? Well, for those of you who are already paying
a monthly fee for an Internet connection, this means that
you can use that same connection to place free long distance
phone calls. This process works by using already available
VoIP software to make phone calls over the Internet, essentially
circumventing phone companies and their service charges.
Interestingly, VoIP is not an entirely new thing. In fact,
a number of providing companies have been around for some
time. But it has only been with the more recent explosion
of high-speed internet access usage, that VoIP has gotten
any attention. Now the major telephone carriers are setting
up their own VoIP calling plans throughout the US, another
testament to the potential of the technology.
How VoIP Is Used
While there are a number of ways that VoIP is currently
being used, most individual callers fall into one of three
categories: ATA, IP Phones, and Computer-to-Computer.
ATA or Analog Telephone Adaptor, is the most common way
of using VoIP. This adaptor actually allows you to hook
up the phone that is already in your house, to your computer,
and then your Internet connection. What the ATA does,
is turn the analog signals your phone sends out into digital
signals that can be sent over the Internet. Setting up
this system is quite simple. It simply requires that you
order an ATA (its an adaptor remember), plug the cable
from your phone which would normally go into the wall
socket into the ATA, and then the ATA gets plugged into
your computer, which is connected to the internet. Some
ATAs include software that has to be installed on your
computer before its ready, but basically it's quite a
simple process. Then you are ready to make some calls.
The next type of VoIP usage utilizes IP Phones instead
of your home phone. The IP Phone looks just like a normal
phone, with all the same buttons and cradle, the only
difference is that instead of having a normal wall jack
connector, it has an Ethernet connector. This means, that
instead of plugging in your IP phone to the wall jack
like you would with a regular analog phone, it gets plugged
directly into your router. This option allows you to circumvent
your personal computer, and it also means that you will
not have to install any software, because its all built
in to the handset. In addition, the fact that Wi-Fi IP
phones will soon be available, which will allow subscribing
callers to make VoIP calls from any Wi-Fi hot spot, make
this option an exciting possibility.
The simplest and cheapest way to use VoIP is through computer-to-computer
calls. These calls are entirely free, meaning no calling
plan whatsoever. The only thing you need, is the software
which can be found for free on the internet, a good internet
connection, a microphone, speakers, and a sound card.
Except for your monthly internet service fee, there is
literally no cost for making these calls, no matter how
many you make.
For large companies, VoIP also offers some very unique
possibilities. Some larger companies are already utilizing
the technology by conducting all intra-office calls through
a VoIP network. Because the quality of sound is comparable
to and in some cases surpasses that of analog service,
some international companies are using VoIP to route international
calls through the branch of their company nearest the
call's destination and then completing it on an analog
system. This allows them to pay local rates internationally
and still utilize the same intra-office VoIP network that
they would if they were calling someone in the next cubicle
Other Advantages of VoIP
While your current long-distance plan covers you for only
one location, say calls made from your office, with VoIP,
you can make a call anywhere that you can get a broadband
connection. That is because all three methods above, unlike
analog calls, send the call information via the Internet.
This means you can make calls from home, on vacation,
on business trips, and almost anywhere else. Anywhere
you go, with VoIP you can bring your home phone along
with you. In the same way, computer-to-computer connections
mean that as long as you have your laptop and a connection,
you're ready to go.
There are also some nifty benefits to having your calls
transmitted over the Internet. For example, some VoIP
service providers allow you to check your voicemail via
your e-mail, while others allow you to attach voice messages
to your e-mails.
How VoIP Works
The current phone system relies on a reliable but largely
inefficient method for connecting calls known as circuit
switching. This technique, which has been used for over
100 years, means that when a call is made between two
people a connection is maintained in both directions between
callers for the duration of the call. This dual directional
characteristic gives the system the name circuit.
If, for example, you made a 30-minute call the circuit
would be continuously open, and thus used, between the
two phones. Up until about 1960, this meant that every
call had to have an actual dedicated wire connecting the
two phones. Thus a long distance call cost so much, because
you were paying for pieces of copper wire to be connected
all the way from your phone to the destination phone,
and for that connection to remain constant throughout
the call. Today, however, your analog call is converted
after leaving your house to a digital signal, where your
call can be combined with many others on a single fiber
optic cable. While this system is certainly an improvement
over the past copper wire system, it is still quite inefficient.
This inefficiency is due in part to the fact that the
telephone line can't distinguish between useful talking
and unneeded silences. For example, in a typical conversation
while one person is talking the other person is listening.
Thus the current analog system uses roughly half its space
sending useless messages like this silence. But there
is also more information, even down to pauses in speech,
which under a more efficient system can be effectively
cut out rather than wasting the circuit space. This idea
of only transmitting the noisy bits of a telephone call
and saving a great deal on circuit space, is the basis
of Packet-Switching, the alternative method to circuit
switching that the VoIP phone system uses.
Packet-Switching is the same method that you use when
you view a website. For example, as you read this website,
your computer is not maintaining a constant connection
to the site, but rather making connections to send and
receive information only on an as needed basis (such as
when you click on a link). Just as this system allows
the transfer of information over the Internet to work
so quickly, so also does it work in the VoIP system. While
circuit switching maintains a constant and open connection,
packet switching opens connections just long enough to
send bits of data called packets from one computer to
another. This allows the network to send your call (in
packets) along the least congested and cheapest lines
available, while also keeping your computer or IP phone,
free to send and receive messages and calls with other
computers. This way of sending information, not to mention
data compression, makes the amount of information which
must be transmitted for every call at least 3-4 times
less for VoIP than the exact same call in a conventional
telephone system. For this reason, VoIP is so much cheaper
than conventional calling plans.
The Future of VoIP
While most analysts believe it will be at least a decade
before companies and telephone providers make the full
switch to VoIP, the potential for the technology's use
today is already quite astounding. A report by the Forrester
Research Group predicts that by the end of 2006, nearly
5 million U.S. households will be using VoIP phone service.
With the savings and flexibility that the technology already
offers, and new advances just ahead on the horizon, we
can expect those numbers will only increase in the future.
About the Author
Rich McIver is a contributing writer for VoIP Now: Voice
over IP News. Learn more at http://www.voipnow.org