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Introduction to WIFI. Co n te n ts. Introduction Wi-Fi Technology Wi-Fi Network Elements Wi-Fi Network Topologies Hotspots How a Wi-Fi Network Works Advantages Limitations Conclusion. WIFI Technology.
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Contents • Introduction • Wi-Fi Technology • Wi-Fi Network Elements • Wi-Fi NetworkTopologies • Hotspots • How a Wi-Fi NetworkWorks • Advantages • Limitations • Conclusion
WIFITechnology WIFI is an alternative network to wired network which is commonly used for connecting devices in wirelessmode.
WIFITechnology WIFI is stand for Wireless Fidelity is genericterm that refers to IEEE802.11 standard for Wireless LocalNetworksor WLANs.
Introduction WIFI connects computers to each other, tothe internet and to the wirednetwork.
The WIFITechnology • WIFI uses radio technology to transmitand receive data at highspeed. • IEEE802.11b • IEEE802.11a • IEEE802.11g
IEEE802.11b • Appear in Late1999 • 2.4Ghz radiospectrum • 11Mbps (theoretical speed) within 30mrange • 4-6Mbps (actualspeed) • 100-150 feetrange • Most popular and Lessexpansive • Interferencefrom mobile phones and Bluetooth devices which can reduce the transmissionspeed
IEEE802.11a • introduced in2001 • 5.0Ghz radiospectrum • 54Mbps (theoreticalspeed) • 15-20Mbps (actualspeed) • 50-75 feetrange • moreexpansive • not compatible with IEEE802.11b
IEEE802.11g • introduced in2003 • combine the feature of both standards(a,b) • 100-150 feetrange • 54Mbpsspeed • 2.4Ghz radiospectrum • compatible withb
Elements of WIFInetwork • AccessPoint (AP)-TheAPisa wirelessLAN transceiver or “base station” that can connect oneor manywirelessdevices Internet. simultaneously tothe • Wi-Ficards-Theyacceptthewirelesssignaland relay information. They can be internal andexternal.
Elements of WIFInetwork • Safeguards - Firewalls and anti-virus softwareprotect networks from uninvited users and keep information secure.
WIFITopologies • Peer-to-peer topology (Ad-hocMode) • AP-based topology (Infrastructure Mode)
Peer-to-peerTopology • AP is notrequired. • Client devices within a cell can communicate with each otherdirectly. • It isuseful forsettingupawirelessnetwork quickly andeasily.
Infrastructurenetwork • The client communicate through AccessPoint. • Any communication has to go throughAP. • If a Mobile Station (MS), like a computer, a PDA, or a phone, wants to communicate with another MS, it needs to send the information to AP first, then AP sends it to the destinationMS.
Hotspots • A Hotspot is a geographical area that has a readily accessible wirelessnetwork • Hotspots are equipped with Broad band Internet connection and one or more Access points that allow users to access the internetwirelessly
Hotspots • Hotspots can be setup in any public location that can support an Internet connection. All the locations discussed previously are examplesof Hotspots.
Hotspots can be setup in any public location that can support an Internet connection. All the locations discussed previously are examplesof Hotspots.
How a Wi-Fi NetworkWorks • A Wi-Fi hotspot is created by installing an access point to an internetconnection. • An access point acts as a basestation. • When Wi-Fi enabled device encounters a hotspot the device can then connect to that network wirelessly.
How a Wi-Fi NetworkWorks • A single access point can support up to 30 users and can function within a range of 100 – 150 feet indoors and up to 300 feetoutdoors. • Many accesspoints can be connected to each other via Ethernet cables to create a single large network.
Advantages • Mobility • Ease ofInstallation • Flexibility • Cost • Reliability • Security • Use unlicensed part of the radiospectrum • Roaming • Speed
Limitations • Interference • Degradation inperformance • High powerconsumption • Limitedrange
Wi-Fi is a simple and cost effective way to connect to internet without the need of wires. • It is growing in popularity because of decreasing costs and the freedom it gives tousers.