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A traditional, wired local area network
(LAN) sends packages of data from one
piece of equipment to another across cables
or wires. A wireless local area network
(WLAN) relies instead upon radio waves
to transfer data. These radio signals
are transferred between access points
installed at key locations in the physical
environment (such as on walls or ceilings)
and wireless adapters attached to computing
systems. A WLAN eliminates cables and
wires and takes advantage of the fact
that radio waves can pass through environmental
obstacles, such as ceilings and walls.
Wireless networks offer unprecedented
flexibility for computer users, along
with remote management capabilities for
business owners or system administrators.
There are two primary components of a
wireless network design: infrastructure
and client adapters. Wireless infrastructure
products consist of gateways and access
points, which serve as data conduits and,
where needed, provide a bridge between
wireless and existing wired networks.
Gateways are typically used for smaller
businesses, while access points serve
medium and enterprise businesses. Client
adapters provide the links between computers
and the network, as well as converting
data into a format that the network can
use. The adapter selected depends on the
type of device being used. Adapters include
WLAN PC cards, PCI cards, USB devices,
and modules. Another important consideration
in a WLAN is the antenna. Antennas serve
to direct the radio waves into the desired
area in a specific coverage pattern. For
each key component of a WLAN, the particular
equipment chosen depends on a particular
site-with its unique usage patterns and
environmental factors.
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