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King Fahd University of Petroleum and Minerals Electrical Engineering Department. Presenters: Faisal Shar Al-Shehri ID# 223036 Fahd Abdullah Al-Shehri ID# 235851 Project: Wireless Local Area Network (WiFi). Date: 31 / 5 / 2008. Outline . Introduction Network Access Layer
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King Fahd University of Petroleum and Minerals Electrical Engineering Department Presenters: Faisal Shar Al-Shehri ID# 223036 Fahd Abdullah Al-Shehri ID# 235851 Project: Wireless Local Area Network (WiFi) Date: 31 / 5 / 2008
Outline • Introduction • Network Access Layer • Internet Layer • Transport Layer • How Wireless LAN works • Security Levels • Conclusion
Introduction • Wireless LAN TCP/IP suit • Brief Overview: • Practical and affordable. • Serve as wired LAN ( without cables) • Basic principle: computers each other central server. (corporate environment)
Introduction Some of the standards:
Network Access Layer • Network Access Layer ( physical & Data link) layers • Responsible physical specification e.g ( frequency, R) • Most important hardware component Access Point (AP) Transparent Bridge
Network Access Layer • Some of the protocols used: • RTS/CTS avoid collision • Frame Relay allow communication between LANs • ATM used in high speed core
Internet Layer • Internet Layer ( Network Layer) • Responsible determining network path computer data • The major device router • Some of its protocols: • IP facilitates the communication of info. transport layer • ICMP provide diagnostic & troubleshooting info manage IP network
Transport Layer • It has two main protocols: • UDP ( connectionless ) deals with time sensitive application. reduce overhead in the packet header & ACK • TCP ( connection oriented ) grantee delivery by its mechanism ( packet numbering, ACK, windowing)
How Wireless LAN works • Wireless LAN depend on radio wave in transmission • Transmitter (AP) wired to an internet connection by this it provides “Hotspot” transmits the connectivity over radio waves • “Hotspots” & SSID (Service Set Identifier) : • Identify Info • Allow computers to locate them
How Wireless LAN works • Modes of Wireless LAN: • Ad-Hoc mode: • The wireless-enabled devices communicate with other without the use of AP. • Share files & other resources by this the sharing devices have to be running all the time • Infrastructure mode: • This mode uses APs • Devices on the network available as long as they are directly connected to the wireless network • More secure the users have to verify their access through APs
Security Levels • The most two important levels: • Level (I): • Basic level • Based on Wired Equivalent Privacy (WEP) algorithm • Level (II): • Based on WiFi Protected Access (WPA) • Better security technologies • Enforces data integrity
Conclusion • Advantages: • easy to install and eliminate the need to pull cables through walls which results in lower costs • mobility where users can move in the coverage area without losing the connection • Disadvantages: • Wireless LAN can not be perfectly secured because the signal propagates everywhere • The medium is shared between the users which results in supporting a lower number of users.