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C. Williamson Wireless 2003 Tutorial Wireless Internet:Protocols and Performance SDUST Information Science and Technology Institute Fang Sheng Tutorial Outline 1. Introduction/Motivation (10 min) 2. Networking Terminology (10 min) 3. IEEE 802.11b WLANs (10 min) 4. Ad hoc networks(10 min) 5. Summary, Questions, Discussion (5 min) 1. Wireless Internet:Introduction What Is Wireless Networking? The use of infra-red (IR) or radio frequency (RF) signals to share information and resources between devices A hot computer industry buzzword: Lots of advertising by companies and media Wireless Broadband, 3G wireless, 4G, WAP, iMode, Bluetooth, WiFi Mobile Internet, Pervasive Computing, Nomadic Computing, M-commerce Ubiquitous; Global; Revolutionary Two Popular 2.4 GHz Standards: IEEE 802.11 Fast (11b) High Power Long range Ethernet replacement Easily Available Apple Airport, iBook, G4 Cisco Aironet 350 Bluetooth Slow Low Power Short range Cable replacement “Vapourware” (?) IEEE 802.11 Organization Tree: Pros and Cons of 802.11: Pro: High bandwidth (up to 11 Mbps) Two modes of operation: infrastructure vs. ad hoc Con: Incompatibility between old and new cards Signal blocked by reinforced concrete or tinted glass High channel BER can degrade performance (lots!) No standard for hand-off between base stations Some channel numbers overlap spectrum High power consumption in laptops Bluetooth Think USB, not Ethernet Cable replacement technology Created by Ericsson PAN - Personal Area Network 1-2 Mbps connections 1600 hops per second FHSS Includes synchronous, asynchronous, voice connections Piconet routing Small, low-power, short-range, cheap, versatile radios Used as Internet connection, phone, or headset Master/slave configuration and scheduling Security Wireless sniffers, “war driving” IEEE 802.11: ESSID – Extended Services Set ID WEP – Wired Equivalent Privacy (useless) NAT - Network Address Translation (firewall) Bluetooth Security FHSS, with rapid hop sequence Short range
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