wireless fidelity NEW

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WIRELESS FIDELITY Wi-Fi AJEESH M BSc IT NIIT

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CONTENTS Wi-Fi Security

INTRODUCTION : 

INTRODUCTION Expansion of Wi-Fi Uses radio frequency to transmit data through the air Connect computers to each other to the internet and to the wired network

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THE WI-FI TECHNOLOGIES Wi-Fi networks use radio technologies to transmit and receive data at high speed. IEEE 802.11b IEEE 802.11a IEEE 802.11g In 2001 Operates at 5 GHz 15-20 Mbps (Actual speed) 50-75 feet range More expensive Not compatible with 802.11b In late 1999 Operates at 2.4GHz 4-6 Mbps (Actual speed) 100 -150 feet range Most popular, Least Expensive Interference from mobile phones and Bluetooth devices which can reduce the transmission speed In 2003 Combine the feature of both standards (a,b) 100-150 feet range 54 Mbps Speed 2.4 GHz radio frequencies Compatible with ‘b’

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Elements of a WI-FI Network Access Point (AP) - A wireless LAN transceiver or base station. Wi-Fi cards – Accept the wireless signal and relay information. They can be internal and external. Safeguards - Firewalls and anti-virus software protect networks.

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Wi-Fi Network Topologies AP-based topology (Infrastructure Mode) Peer-to-peer topology (Ad-hoc Mode) Point-to-multipoint bridge topology

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AP-based topology Communicate through AP. BSA-RF coverage provided by an AP. ESA-It consists of 2 or more BSA. ESA cell includes 10-15% overlap to allow roaming.

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Peer-to-peer topology AP is not required. Client devices within a cell can communicate directly with each other. It is useful for setting up of a wireless network quickly and easily.

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Point-to-multipoint bridge topology Use Line -of-Sight (LoS)strategy. Used to connect a LAN between buildings which are miles apart.

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How a Wi-Fi Network Works Basic concept is same as Walkie talkies. A Wi-Fi hotspot is created by installing an access point to an internet connection. Wi-Fi enabled device encounters a hotspot the device can then connect to that network wirelessly. Each AP can support up to 30 users within a range of 100 – 150 ft indoors and 300 ft outdoors.

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Data Integrity Encryption Authentication Wi-Fi security

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Future of Wi-Fi security The future of Wi-Fi security will be very bright if we overcome the security problems in the present technologies. And if we protect Wi-Fi from these security problems we have long way to produce great technologies under Wi-Fi networking in future.

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Modulation Spectrum Technique Change Default Passwords Wireless Equivalent Privacy (WEP) Crackers Service Set Identifier (SSID) Wi-Fi Security Problems

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Wi-Fi Applications Home Small Businesses or SOHO Large Corporations & Campuses Health Care Wireless ISP (WISP) Travellers

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Advantages Mobility Ease of Installation Flexibility Cost Reliability Security Use unlicensed part of the radio spectrum Roaming Speed

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Limitations Interference Degradation in performance High power consumption Limited range

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CONCLUSION Wireless Fidelity is common now. We are expecting more on this technology in future. Let’s hope for that ….