Wi-Fi
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Wifi’ What it stands
for?
“Wi-fi suggests Wireless-Fidelity, compared with the long
established audio recording term High Fidelity or Hi-Fi.”
Wi-Fi is simply a trademarked term meaning IEEE 802.11x.
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When Wi-Fi
Originated ?
• The precursor to wi-fi was invented in
1991 by NCR Corporation in Nieuwegein,
the Netherland.
• The first wireless products were brought
on the market under the name WaveLAN
with speeds of 1 Mbit/s to 2 Mbit/s.
• Vic Hayes has been named as father of
“Wi-Fi’’.
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How Wi-Fi Works?
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What a wireless network
is made up of:
Wireless Network cards
-Radios which send and receive signals from other radios or
access points, usually PCMCIA* cards which fit into Laptop
expansion slots, or PCI Bus in case of Desktop computers. (There
are other, simpler options using USB).
PDAs like Blackberry, and Pocket PC having a compact flash slot
can also connect.
* PCMCIA – Personal Computer Memory Card International Association.
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What a wireless network
is made up of:
Base stations, Access points, or Gateways
-The base station sends and receives radio signals to and
from the Wi-Fi radio in your laptop or PC, enabling you to share
your Internet connection with other users on the network. Access
points and gateways have a wide range of features and
performance capabilities, but they all provide this basic network
connection service.
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Typical Community Wifi Constituents
High gain Parabolic grid antennas to
beam the signal to over 30km from
tower to tower..
Sector antennas to beam the signal
from the towers to the community
users
Customer Premises equipment (CPE)
to access the signal from the towers..
Other components that need to be
installed in order to put the above
systems together
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About Radio Frequency
• There is no wire connection between
sender and receiver.
• Two types of RF is used• 1-direct sequence spread spectrum radio
technology.
• 2-orthogonal frequency division
multiplexing.
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Advantages of
Wi-Fi
• Wi-fi can make access publicly available at
wi-fi hotspots.
• Does not require regulatory approval for
individual.
• Wi-fi network can support roaming.
• Wi-fi allows local area network to deployed
without wires for client devices.
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Threats of security
• Wi-fi works with no physical wired
connection between sender and receiver
by using radio frequency. The most
common wireless encryption standards,
wired equivalent privacy has been shown
to be using breakable even when correctly
configured.
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Capabilities and Uses
High data transmission rate and high reliability in all weather
conditions, and an always available (95% Uptime) network makes
wifi a robust solution suitable for high bandwidth applications….
-Online video-conferencing with greater clarity
-Telephony, using VoIP
- Revenue-model for budding start-up ISPs
- Broadband in the true sense
- Easier reach into far-flung rural areas
- Ability to add more nodes as and when required
- Less maintenance overheads, especially in Rural
areas where technical manpower is scarce.
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References…
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www.wikipedia.org
http://www.webopedia.com/TERM/W/Wi_
Fi.html
http://www.computerworld.com.au/article/
300310/csiro_settles_wireless_battle
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