Wireless Data Services

Because radio signals move through the air, you can set up a network connection
from any place within range of the network base station’s transmitter;
it’s not necessary to use a telephone line, television cable, or some other
dedicated wiring to connect your computer to the network. Just turn on the
radio connected to the computer and it will find the network signal. Therefore,
a radio (or wireless) network connection is often a lot more convenient
than a wired one.

This is not to say that wireless is always the best choice. A wired network
is usually more secure than a wireless system because it’s a lot more difficult
for unauthorized eavesdroppers and other snoops to monitor data as it
moves through the network, and a wired link doesn’t require as many complex
negotiations between the sender and receiver on protocols and so forth. In
an environment where your computer never moves away from your desk and
there are no physical obstacles between the computer and the network access
point, it’s often easier to install a data cable between the computer and a
modem.

So now we have a bunch of radio transmitters and receivers that all
operate on the same frequencies and all use the same kind of modulation.
(Modulation is the method a radio uses to add some kind of content, such as
voice or digital data, to a radio wave.) The next step is to send some network
data through those radios. Several different wireless data systems and services
are available to connect computers and other devices to local networks and
to the Internet, including Wi-Fi, WiMAX, and a handful of services based on
the latest generations of cellular mobile telephone technology.