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Definition
Wi-Fi, or Wireless Fidelity is freedom :it allows you to connect to the internet
from your couch at home, in a hotel room or a conferance room at work without
wires . Wi-Fi is a wireless technology like a cell phone. Wi-Fi enabled computers
send and receive data indoors and out; anywhere within the range of a base station.
And the best thing of all, it is fast. However
you only have true freedom to be connected any where if your computer is configured
with a Wi-Fi CERTIFIED radio (a PC card or similar device). Wi-Fi certification
means that you will be able able to connect anywhere there are other Wi-Fi CERTIFIED
products - whether you are at home ,office , airports, coffee shops and other
public areas equipped with a Wi-Fi access availability.Wi-Fi will be a major face
behind hotspots , to a much greater extent.More than 400 airports and hotels in
the US are targeted as Wi-Fi hotspots. The
Wi-Fi CERTIFIED logo is your only assurance that the product has met rigorous
interoperability testing requirements to assure products from different vendors
will work together. The Wi-Fi CERTIFIED logo means that it is a "safe"
buy. Wi-Fi certification comes from the Wi-Fi
Alliance, a non profit international trade organisation that tests 802.11 based
wireless equipment to make sure that it meets the Wi-Fi standard and works with
all other manufacturer's Wi-Fi equipment on the market. The Wi-Fi Alliance (WELA)
also has a Wi-Fi certification program for Wi-Fi products that meet interoperability
standards. It is an international organisation devoted to certifying interoperability
of 802.11 products and to promoting 802.11as the global wireless LAN std across
all market segment. IEEE 802.11
ARCHITECTURES In IEEE's proposed standard
for wireless LANs (IEEE 802.11), there are two different ways to configure a network:
ad-hoc and infrastructure. In the ad-hoc network, computers are brought together
to form a network "on the fly." As shown in Figure 1, there is no structure
to the network; there are no fixed points; and usually every node is able to communicate
with every other node. A good example of this is the aforementioned meeting where
employees bring laptop computers together to communicate and share design or financial
information. Although it seems that order would be difficult to maintain in this
type of network, algorithms such as the spokesman election algorithm (SEA) [4]
have been designed to "elect" one machine as the base station (master)
of the network with the others being slaves. Another algorithm in ad-hoc network
architectures uses a broadcast and flooding method to all other nodes to establish
who's who.
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