Page 8 - DCAP311_DCAP607_WIRELESS_NETWORKS

Wireless Networks

Notes Introduction

Wireless network refers to any type of computer network that uses wireless (usually, but not
always radio waves) for network connections.
It is a method by which homes, telecommunications networks and enterprise (business)
installations avoid the costly process of introducing cables into a building, or as a connection
between various equipment locations. Wireless telecommunications networks are generally
implemented and administered using radio communication. This implementation takes place at
the physical level (layer) of the OSI model network structure.
Wireless networks use electromagnetic waves to communicate information from one point to
another without relying on any physical connection. Radio waves are often referred to as radio
carriers because they simply perform the function of delivering energy to a remote receiver. The
data being transmitted is superimposed on the radio carrier so that it can be accurately extracted
at the receiving end. Once data is superimposed (modulated) onto the radio carrier, the radio
signal occupies more than a single frequency, since the frequency or bit rate of the modulating
information adds to the carrier. Multiple radio carriers can exist in the same space at the same
time without interfering with each other if the radio waves are transmitted on different radio
frequencies. To extract data, a radio receiver tunes in one radio frequency while rejecting all other
frequencies. The modulated signal thus received is then demodulated and the data is extracted
from the signal.

1.1 Wireless Networking

A wireless network is a flexible data communications system, which uses wireless media such
as radio frequency technology to transmit and receive data over the air, minimizing the need
for wired connections (What is Wireless LAN, White Paper). Wireless networks are used to
augment rather than replace wired networks and are most commonly used to provide last few
stages of connectivity between a mobile user and a wired network.
Bluetooth and 802.11b have the potential to dramatically alter how people use devices to connect
and communicate in everyday life. Bluetooth is a low-power, short-range technology for ad hoc
cable replacement; it enables people to wirelessly combine devices wherever they bring them.
Conversely, 802.11b is a moderate-range, moderate-speed technology based on Ethernet; it allows
people to wirelessly access an organizational network throughout a campus location. Although
the technologies share the 2.4 GHz band, have some potentially overlapping applications,
and have been pitted against each other in the press, they do not compete and can even been
successfully combined for corporate use.
One thing is clear, wireless technologies will continue to evolve and offer organizations and end
users higher standard of life by making us more mobile and increasing our ability to interact with
each other, removing distance as a barrier. There will be a time when a traveler can sit in any
airport or hotel and surf the Web or connect to the home office and work. Users will be able to
surf or work in places such as malls, parks, or (with smaller handheld computers) just walking
down the street.

Notes Internet service providers will install larger wireless networks allowing users to
connect from anywhere in the city. All of these things are possible with wireless technology.

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