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F ACULTY OF C OMPUTER S CIENCE & E NGINEERING Chapter 01. Introduction to Wireless LANs
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O BJECTIVES The Wireless LAN Market History of Wireless LANs Today’s Wireless LAN Standards Define the roles of the organizations -FCC (The Federal Communications Commission) - IEEE - Wi-Fi Alliance Identify some of the uses for spread spectrum technologies - Wireless LANs, PANs, MANs, and WANs
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O BJECTIVES Applications of Wireless LANs Access Role Network Extension Building-to-Building Connectivityxtension Last Mile Data Delivery Mobility Small Office-Home Office Advantages and Disadvantages of WLAN
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T HE W IRELESS LAN M ARKET The market for wireless LANs seems to be evolving in a similar fashion to the networking industry The big difference between LAN and WLAN Wireless LANs allow so many flexibilities in their implementation
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History of Wireless LANs The military needed a simple, easily implemented, and secure method of exchanging data in a combat environment.
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Today’s Wireless LAN Standards Wireless LANs transmit using radio frequencies The Federal Communications Commission (FCC) regulates the use of wireless LAN devices. Wireless LAN Standards are created and maintained by the Institute of Electrical andElectronic Engineers (IEEE). Following wireless LAN standards: 802.11, 802.11a, 802.11b, 802.11b+ 802.11g, 802.11h
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T ODAY ’ S W IRELESS LAN S TANDARDS IEEE 802.11 was born 1997 Standard beginning of WLAN Use in both Spread Spectrum Technology FHSS and DSSS Bandwith max is 2 Mbps Frequency band 2,4 Ghz ISM
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T ODAY ’ S W IRELESS LAN S TANDARDS IEEE 802.11 a Open of 802.11 standard Provides data rates up to 54 Mbps Frequency band 5 Ghz UNII Use tecnology Orthogonal Frequency Division Multiplexing ( OFDM ). Non-overlapping 8 channel
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T ODAY ’ S W IRELESS LAN S TANDARDS IEEE 802.11 b Open of 802.11 standard Uses high-rate direct-sequence spread spectrum (HR/DSSS) instead of the original DSSS. Provides data rates up to 11 Mbps Frequency band 2,4 Ghz ISM Non-overlapping 3 channel IEEE 802.11 b+ Provides data rates up to 22 Mbps
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T ODAY ’ S W IRELESS LAN S TANDARDS IEEE 802.11 g Open of 802.11b standard Use tecnology Orthogonal Frequency Division Multiplexing ( OFDM ). & DSSS Provides data rates up to 11 Mbps 54 Mbps Frequency band 2,4 Ghz ISM
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T ODAY ’ S W IRELESS LAN S TANDARDS
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R OLES O RGANIZATIONS P LAY W ITHIN THE WLAN I NDUSTRY There are three primary categories of organizations that guide the wireless industry. These categories include regulation, standardization, and compatibility The Federal Communications Commission (FCC) is an example of regulatory bodies. The Institute of Electrical and Electronics Engineers (IEEE) is an example of a standards development organization The Wi-Fi Alliance is a compatibility testing and certification group
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FCC (T HE F EDERAL C OMMUNICATIONS C OMMISSION WLAN devices use radio wave communications, they fall under the regulatory control of the FCC. The factors regulated by the FCC include: ■ Radio frequencies available ■ Output power levels ■ Indoor and outdoor usage
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FCC (T HE F EDERAL C OMMUNICATIONS C OMMISSION The FCC regulates which frequencies may be used within the regulatory domain it manages The FCC provides two types of license-free bands for radio communications: the Industrial Scientific Medical (ISM) bands and the Unlicensed National Information Infrastructure (U-NII) bands. 2.4 GHz ISM, U-NII bands exist in the 5 GHz frequency range. They are all used by IEEE 802.11
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IEEE The Institute of Electrical and Electronics Engineers The IEEE developed standards that impact and benefit wireless networking. These standards include wireless specific standards as well as standards that have been implemented in the wired networking domain, which are now being utilized in the wireless networking domain.
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IEEE
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W I -F I A LLIANCE The Wi-Fi Alliance is a certification organization that provides testing and interoperability analysis for the wireless industry. While the FCC makes the rules and the IEEE determines how to live within those rules, the Wi-Fi Alliance ensures that devices are compatible with the IEEE’s way of implementing WLAN technology. Only products of Alliance members that have been tested successfully by the Wi-Fi Alliance are actually allowed to claim that they are Wi-Fi Certified.
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S PREAD S PECTRUM T ECHNOLOGY U SES Spread spectrum technology is used in multiple ways that can be organized within four primary categories: wireless LANs, wireless PANs (WPANs), wireless MANs (WMANs) and wireless WANs.
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W IRELESS LAN S Activities in Circle 200 m There are three primary roles that wireless LANs play in today’s enterprise organizations: Access role Distribution role Core role
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W IRELESS PAN S A wireless PAN (personal area network) provides hands-free connectivity and communications within a confined range and limited throughput capacity. Bluetooth is a perfect example of a wireless PAN technology that is both beneficial and in widespread use. Operating in the 2.4 GHz ISM band, Bluetooth technologies can cause interference with wireless LAN technologies like DSSS, HR/DSSS, and ERP.
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W IRELESS MAN S WiMAX is the most commonly referenced wireless MAN technology WiMAX is based on the IEEE 802.16 standard and provides expected throughput of approximately 40 Mbps for fixed, line of sight connections and approximately 15 Mbps for mobile, non–line of sight connections
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W IRELESS MAN S Was born in October, 2001 Operating in the 2- 66 GHz band Operating in the 2-11 Ghz at Europe Operating in the 3.5 Ghz for Mobie Operating in the 10-66 for Fixed points
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W IRELESS WAN S What is the WAN ?
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W IRELESS WAN S
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WAN services ?
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W IRELESS WAN S Integrated Services Digital Network Packet-Switched Frame Relay Cell –Switched Switch ATM
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WLAN,WPAN,WMAN,WWAN
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A PPLICATIONS OF W IRELESS LAN S Access Role Network Extension Building-to-Building Connectivityxtension Last Mile Data Delivery Mobility Small Office-Home Office
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Applications of Wireless LANs Corporate Data Access and End-User Mobility
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A PPLICATIONS OF W IRELESS LAN S Network Extension
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A PPLICATIONS OF W IRELESS LAN S Building-to-Building Connectivity: Bridging
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A PPLICATIONS OF W IRELESS LAN S Last-Mile Data Delivery: Wireless ISP
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A PPLICATIONS OF W IRELESS LAN S Small Office/Home Office (SOHO) Use
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A PPLICATIONS OF W IRELESS LAN S Mobile Office Networking Educational/Classroom Use
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A DVANTAGES OF WLAN Mobility is primary advantage of wireless technology Easier and Less Expensive Installation: Installing network cabling in older buildings difficult and costly Increased Reliability
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D ISADVANTAGES OF WLAN Security: Wireless signals broadcast in open air Security for wireless LANs is the prime concern Unauthorized users might access network Attackers might view transmitted data Employees could install rogue access points Attackers could easily crack existing wireless security Radio Signal Interference: Signals from other devices can disrupt wireless transmissions Health Risks: Wireless devices emit RF energy
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S UMMARY Review OSI, Protocol, IP Private, IP Public Dynamic IP, Static IP Enthenet 802.3 Today’s Wireless LAN Standards 802.11, 802.11a, 802.11b+, 802.11g, 802.11h Infracstructure WLAN, WPAN, WMAN, WWAN
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S UMMARY Roles Organizations Play Within the WLAN Industry The Federal Communications Commission (FCC) is an example of regulatory bodies The Institute of Electrical and Electronics Engineers (IEEE) is an example of a standards development organization The Wi-Fi Alliance is a compatibility testing and certification group
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