Transcript
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A TECHNICAL SEMINAR
ON
(CO-5G)
MUBEEN MOMIN
By
DEVI MAHALAXMI POLYTECHNIC COLLEGE
Contents What is wi-fi? Introduction The wi-fi technology Naming secreat Brief history How a wifi network works Devices and components General applications set forth by the
Wi-Fi Alliance Advantages and Disadvantages Basic sequrity stratigies
WI-FI TECHNOLOGY
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What is Wi-Fi ?Short for wireless fidelity.
It is a wireless technology that uses radio frequency to transmit data through the air.
Wi-Fi is based on the 802.11 standard:802.11a802.11b802.11g
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IntroductionWireless Technology is an alternative to Wired Technology, which is commonly used, for connecting devices in wireless mode.Wi-Fi is a generic term that refers to the IEEE 802.11 communications standard for Wireless Local Area Networks (WLANs).
Wi-Fi Network connect computers to each other, to the internet and to the wired network.
Wi-Fi works on physical and data link layer.
WI-FI TECHNOLOGY
The Wi-Fi Technology The technology used in Wi-Fi is easiest to understand in terms of
radio. It is quite similar to walkie-talkies, the only difference being in the strength of signals.
An ordinary walkie-talkie can handle only limited data in the range of 1000 bps, and operate at 49 MHz. In the case of Wi-Fi radios, the signal strength is much more, so they can handle much higher data rates.
There are three versions of Wi-Fi radios currently available- the ones that work with,
802.11b 802.11a 802.11g 5
WI-FI TECHNOLOGY
NAMING SECRET The term Wi-Fi suggests Wireless Fidelity, resembling the
long-established audio-equipment classification term high fidelity (in use since the 1930s ) or Hi-Fi (used since 1950).
Phil Belanger who is the founding member of the Wi-Fi Alliance states that term Wi-Fi was never supposed to mean anything at all.
The “yin-yang” logo indicates the certification of a product for interoperability.
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Brief History• IEEE (Institute of Electrical and Electronics Engineers) established the 802.11 Group in 1990. Specifications for standard ratified in 1997.• Initial speeds were 1 and 2 Mbps.• IEEE modified the standard in 1999 to include:• 802.11b• 802.11a• 802.11g was added in 2003.
• IEEE Created standard, but Wi-Fi Alliance certifies products
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HOW A WI-FI NETWORK WORKS
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Devices & Components
9PCI adapter (inside)
USB adapter (outside)
PCMCIA Card (Portables)
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APPLICATIONS AND TARGET MARKETS
TRANSMISSION CHARACTERISTICS
Application Examples Type Rate Duration/volume
Audio/Video 1
HDTV and DV viewing for commercial & domestics use
Constant (low jitter)
27 Mbps Hours
Audio/Video 2
SDTV viewing for commercial and domestic use
Constant (low jitter)
6 Mbps Hours
Audio/Video 3
Video conferencing with VoIP
Constant (low jitter)
2 Mbps < 1 hr
Interactive 1 Interactive gaming, Internet Browsing, Email
Variable 2 Mbps 1 hr
Interactive 2 VoIP, Internet gaming Constant with intervals
.2 MB/s 1 min – 1 hr
Bulk transfer Flash downloads file transfer, media transfer
Variable 30 Mbps 10 MB – 10 GB
General applications set forth by the Wi-Fi Alliance
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ADVANTAGES AND DISADVANTAGES OF ‘Wi-Fi’
ADVANTAGES DISADVANTAGES1) Freedom – You can
work from any location that you can get a signal.
Speed – Slower than cable.
2) Setup Cost – No cabling required.
Range – Affected by various medium.
3) Flexibility – Quick and easy to setup in temp or permanent space.
Travels best through open space.Reduced by walls, glass, water, etc.
4) Scaleable – Can be expanded with growth.
Security – Greater exposure to risks.
5) Mobile Access – Can access the network on the move.
Unauthorized access.Compromising data.Denial of service.
BASIC SECURITY STRATEGIES• Block your Service Set Identifier (SSID) from being broadcast.• Wireless beacon so PCs can easily find the access
point.
• Change the default network name in the access point.• Change the default access point password.• Center the access point in the middle of the building/house.
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THIS PRESENTATION IS DONE BY = MUBEEN MOMIN13
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THANK YOU
WI-FI TECHNOLOGY
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